PUBLIC HEALTH ASSESSMENT
ATLAS TACK SITE
(a/k/a ATLAS TACK CORPORATION)
FAIRHAVEN, BRISTOL COUNTY, MASSACHUSETTS
The Atlas Tack site was listed by the U.S. Environmental Protection Agency (EPA) 
on the National
Priorities List (NPL) in 1990. When a site is proposed for listing, the Agency for Toxic Substances and
Disease Registry (ATSDR) is required by federal law to conduct a Public health assessment (PHA) for
the site. The Massachusetts Department of Public Health (MDPH) has a cooperative agreement with
ATSDR to conduct PHAs at NPL and other sites in Massachusetts. In this capacity, MDPH conducted
a preliminary PHA for the Atlas Tack site in June 1990. This PHA was conducted at the request of EPA
to review the environmental data that have been generated since 1990 and to update the previous
assessment.
Public health assessments and risk assessments both investigate the impact or potential impact of hazardous substances at a specific site on public health. However, the two types of assessment differ in their goals and focus. Quantitative risk assessments are geared largely toward arriving at numeric estimates of the risk posed to a population by the hazardous substances found on a site. These calculations use statistical and biological models based on dose-response data from animal toxicologic studies and (if available) human epidemiological studies. Risk assessments estimate the public health risk posed by a site, and their conclusions can be used to establish allowable contamination levels, or to establish clean-up levels and select remedial measures to be taken at the site.
Public health assessments are intended to determine the past, current or future public health implications of a specific site, but focus more than risk assessments do on the health concerns of the specific community. Public health assessments are based on environmental characterization information (including information on environmental contamination and exposure pathways), community health concerns associated with the site, and community-specific health outcome data. They make recommendations for actions needed to protect public health (which might include the development and issuing of health advisories), and they identify populations in need of further health actions or studies.
The 1990 preliminary PHA concluded that, based on the information available at that time, the site was considered to be of potential public health concern caused by the possibility of exposure to hazardous substances. The potential pathways cited were ingestion of shellfish harvested at or near the site and ingestion of contaminated soils. The lack of groundwater hydrogeological characteristics precluded MDPH's ability to assess the possibility of human exposure to site contaminants via ingestion of contaminated groundwater. The 1990 assessment also recommended that appropriate warnings be posted in the area until such time when proper soil containment or removal measures be implemented.
The Atlas Tack Company conducted various manufacturing processes on this site beginning in 1901 and ceasing in 1985. Tacks, nails, and an assortment of different metal products were produced in their plant. When the 1990 preliminary PHA was done, there was a welding company operating on the site. The welding company ceased their operations on the site in the early 1990s (Craffey 1999).
B. Site Description and History
The Atlas Tack site is located in Fairhaven, Massachusetts (see Figure 1). This site comprises a 24-acre area and includes former manufacturing areas (i.e., approximately 13 acres) owned by Atlas Tack Corporation, Boys Creek, the adjacent marsh both inland and outside of a hurricane barrier that was constructed in the mid-1960s, and the Commercial and Industrial Debris Area (see Figure 2). The main entrance to the site is located on Pleasant Street, which bounds the site to the west. The site is bounded to the south and east by a tidal marsh that drains into Buzzards Bay. The site is also bounded to the south by Church Street and to the north by an unpaved, private road and Railroad Avenue, which is now a paved bike path open to public use. North of the bike path are some commercial businesses and open space. There are a number of residences immediately adjacent to the southern edge of the site on Church Street, as well as a few residences on Pleasant Street. MDPH is not aware of any private wells in this area.
Manufacturing activities took place at the site between 1901 and 1985. These activities included forging, machining, annealing, blueing, pickling, electroplating, painting, enameling, and parts cleaning. Among the products produced at the site were lining nails, tufting buttons, paper and leather headed tacks, cast head coffin tacks, eyelets, glaziers points, bolts, screws, rivets, bottle crowns, and shoe findings (Weston 1995). A variety of materials were used in these processes, some of which include acids, solvents, and metals such as copper and zinc (EPA 1999). Currently, there are persons reclaiming bricks at the site. Also, since 1985, there have been either one or two persons maintaining the alarm and fire suppression system for the buildings at the site (Craffey 2001).
The site consists of four distinct areas: the manufacturing area, the former
lagoon ,
the Commercial and Industrial Debris Area, and the Boys Creek area. The manufacturing
area consists of a main manufacturing building complex, an oil-fired boiler
plant, a garage-like building east of the main building complex, and a used
machinery building (see Figure 2). The original manufacturing building and power
plant were built in 1901. The main manufacturing building has three distinct
sections: the west building which is a two-story brick-walled office area that
faces Pleasant Street, the east building which is a three-story brick-walled
area at the eastern edge of the building, and the former one-story area that
was located in between the other two sections and covered the majority of the
building space. The one-story area of the building was demolished in December
1998, leaving the concrete floor of the building exposed and the other two sections
standing (see Figure 3). A carpenter shop and a recreation building were previously
located on site. The carpenter shop, which was located to the northeast of the
main manufacturing building complex, burned down. The recreation building, which
was located southwest of the main manufacturing building complex, was removed
sometime during the 1980s (Craffey 1999). Since approximately 1985, periodic
removal of debris from the site has occurred. The debris from the former carpenter
shop was removed in July 1985. Also, in 1992, other materials (e.g., building
materials) in the main manufacturing building were removed (Craffey 2000). At
the time of this public health assessment, some debris from the demolition of
the one-story area of the main manufacturing building remains; however, most
of it has been removed (Craffey 2001).
The former lagoon is a 100 square foot collection basin approximately 200 feet east of the
manufacturing building (see Figure 2). The lagoon, constructed in the early 1940s, was used as a
reservoir for acid waste from electroplating operations. Sulfuric acid wastes were also reportedly
neutralized with alkaline substances from "other plant operations" and disposed of in the lagoon. In
January of 1947, an exposure incident took place at the lagoon. Two children fell through the ice
resulting in the death of one child and injury to the other. Rescuers experienced skin ailments that
were believed to be caused by the waste substances in the lagoon. The lagoon was remediated in
1985 by the MA DEP to eliminate the imminent hazards. This action did not completely remediate
the former lagoon. During these remedial activities, sludge from the lagoon was displaced into a
drying area and then disposed of in an off-site, secure hazardous waste landfill in New York (Weston
1995). Final remediation of the former lagoon area will occur as part of the overall site remediation
(EPA 2000).
There is an area to the immediate east of the former lagoon containing industrial fill from the facility. This area extends out from the eastern edge of the former lagoon for approximately 250 feet and is approximately 300 feet long from north to south. The fill material in this area was deposited on top of the marsh surface and averages about three feet in thickness (Weston 1995).
The Commercial and Industrial Debris Area is located to the southeast of the manufacturing area and is not part of the Atlas Tack Corporation property (see Figure 2). The Commercial and Industrial Debris Area is on property owned by Hathaway/Braley Wharf Company (EPA 2000). The Commercial and Debris Area is approximately 220 feet by 160 feet and contains industrial fill about two to three feet deep. Review of aerial photographs tentatively identified a transport road leading from the manufacturing area to the debris area. Thus, it is a possibility that solid waste from Atlas Tack was disposed of at the Commercial and Industrial Debris Area (Weston 1995).
The Boys Creek area consists of the creek itself and a marsh adjacent to the creek. Boys Creek begins north of the manufacturing area, south of Center Street. From there, the creek flows around the former lagoon and the adjacent fill area before flowing underneath the hurricane barrier, eventually discharging into Buzzards Bay. Nearly the entire extent of the creek, from its origin to the hurricane barrier, is located within the fenced area of the Atlas Tack site (see Figure 2). At the time of this heath assessment, there was a ban on shellfishing in the area of Boys Creek because of the potential for bacterial contamination (Craffey 2001).
For the purposes of this public health assessment, MDPH staff conducted two site visits: one on August 11, 1999 with a representative from the Atlas Tack Company and one on October 11, 2001. During both site visits, there were fences surrounding the Atlas Tack facility as well as the former lagoon area, and access was limited to authorized personnel only (see Figure 2). During the August 1999 site visit, it was noted that the fence was in disrepair in two specific sections and could have been circumvented in these areas. One section of fence in disrepair was located at the gate that separates the commercial area of the site from the fenced area that surrounds the former lagoon. The other section of fence in disrepair was located where the fence crosses Boy's Creek adjacent to the hurricane dike. During the October 2001 site visit, those areas were seen to have been repaired, but the fence along the marsh was observed to be down. Also, MDPH staff observed a part of the fence, near where Boy's Creek enters the site, which did not have barbed wire and thus, could be accessed by climbing an adjacent tree. Abutting the facility fences to the north of the site, there is a paved bike path on which MDPH staff observed a fair amount of traffic (see Figure 2).
During both site visits, there was some evidence of trespassing (e.g., graffiti, broken bottles) within the fenced portion of the site. On the hurricane dike just outside of the facility there was evidence of moderate recreational use in the form of beer and liquor bottles, and trash on top of the hurricane dike as well as within Boy's Creek. Presently, there might be less trespassing on the site because some trees and shrubs have been removed, thereby increasing visibility (Craffey 2001). There is also a semi-worn path that leads to the formerly downed section of the fence that encloses the former lagoon at Atlas Tack. No trespassing activities were witnessed during the site visits.
The Atlas Tack site is located within the town of Fairhaven, Massachusetts. The 2000 U.S. Census showed a population of 16,159. Within the town of Fairhaven, the Atlas Tack site is located in both Census Tract 6553 and Census Tract 6554. The 2000 U.S. Census shows that 3,533 individuals reside in Census Tract 6553 and 4,215 individuals reside in Census Tract 6554. The sex, race, and age breakdowns for Fairhaven are presented in Table 1.
In response to community health concerns, the MDPH has conducted numerous environmental health investigations in the town of Fairhaven during the past two decades. These include, but are not limited to the Greater New Bedford PCB Health Effects Study (MDPH 1987), Childhood Leukemia in Fairhaven (MDPH 1982) and more recently, the Health Consultation for Galary Property, Fairhaven, Massachusetts (MDPH 1997).
For purposes of this public health assessment, the most recent cancer incidence data for Fairhaven will be reviewed. In addition, because lead is a contaminant of concern at the site, childhood lead poisoning prevalence data will also be reviewed.
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
To evaluate whether a site poses an existing or potential hazard to an exposed or potentially exposed population, health assessors review all available on-site and off-site environmental contamination data for all media (e.g., soil, surface water, groundwater, air, biota). The quality of the environmental data is discussed in the Quality Assurance and Quality Control section. Physical conditions of the contaminant sources and physical hazards, if any, are discussed in the Physical and Other Hazards section.
Surface soil, subsurface soil, sediment, surface water, groundwater, and biota (i.e., hard shell clams, soft shell clams, mussels) data from environmental sampling conducted at the Atlas Tack site from 1991 through 1999 were reviewed (Weston 1995; USACE 1998; Rizzo 1999). Data for surface soil, sediment, surface water, groundwater, and biota samples were tabulated and screened for this site. Data for subsurface soil was qualitatively analyzed and found to have contaminant concentrations approximate to surface soil.
Health assessors use a variety of health-based screening values, called comparison values, to help decide whether compounds detected at a site might need further evaluation. These comparison values include environmental media evaluation guides (EMEG), reference dose media evaluation guides (RMEG), cancer risk evaluation guides (CREG), and maximum contaminant levels for drinking water (MCL). These comparison values have been scientifically peer reviewed or were derived from scientifically peer-reviewed values and published by ATSDR and/or EPA. The MA DEP has established Massachusetts's maximum contaminant levels (MMCL) for public drinking water supplies. EMEG, RMEG, MCL, and MMCL values are used to evaluate the potential for noncancer health effects. CREG values provide information on the potential for carcinogenic effects. For chemicals that do not have these comparison values available for the medium of concern, EPA risk-based concentrations (RBCs) developed by EPA regional offices, are used. For lead, EPA has developed a hazard standard for residential soil (EPA 2001a).
If the concentration of a compound exceeds its comparison value, adverse health effects are not necessarily expected. Rather, these comparison values help in selecting compounds for further consideration. For example, if the concentration of a chemical in a medium (e.g., soil) is greater than the EMEG for that medium, the potential for exposure to the compound should be further evaluated for the specific situation to determine whether noncancer health effects might be possible. Conversely, if the concentration is less than the EMEG, it is unlikely that exposure would result in noncancer health effects. EMEG values are derived for different durations of exposure according to ATSDR's guidelines. Acute EMEGs correspond to exposures lasting 14 days or less. Intermediate EMEGs correspond to exposures lasting longer than 14 days to less than one year. Chronic EMEGs correspond to exposures lasting one year or longer. CREG values are derived assuming a lifetime duration of exposure. RMEG values also assume chronic exposure. All the comparison values (i.e., CREGs, EMEGs, RMEGs, and RBCs) are derived assuming opportunities for exposure in a residential setting.
Table 2a shows the minimum, mean, and maximum values detected in soil compounds in the commercial area of the site that exceeded their respective health-based comparison values or for which comparison values are not available. The commercial area of the site includes the main manufacturing building and boiler plant. It is separated from the noncommercial area of the site by a fence that runs adjacent to the former lagoon (see Figure 4). For 0- through 2-ft soil, ten samples were taken and tested for volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs), between 23 and 27 samples were taken and tested for metals, and eight samples were taken and tested for pesticides and PCBs. Of the compounds that were detected in the commercial area of the site, the ones that exceeded health comparison values or typical background levels in soil or for which there are no comparison values were antimony, arsenic, cadmium, calcium, chromium, copper, cyanide, iron, lead, nickel, vanadium, zinc, two SVOCs (i.e., bis(2-ethylhexyl)phthalate, and 4-nitroaniline), polycyclic aromatic hydrocarbons (PAHs) (i.e., benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, benzo(a)pyrene, chrysene, dibenzo(a,h)anthracene, fluoranthene, indeno(1,2,3-cd)pyrene, phenanthrene, and pyrene), PCBs (Arochlor 1260), and one pesticide (i.e., beta-benzene hexachloride [beta-BHC]). For the soil samples collected from the commercial area of the site, contaminants are mostly concentrated in a few hot spots. The hot spots are all located in areas that were formerly found within the one-story section of the main manufacturing building. These hot spots are the plating pit, tumbling room, tack wash area, and manhole #2 (see Figure 5).
The highest lead level in soil at the site was found in the catch basin of a floor drain in the tack wash area, which has a small cover but is accessible, and had a concentration of 5,950 milligrams per kilogram (mg/kg) (Craffey 2001). The next highest lead levels in soil from the commercial area were found in the plating pit, and had concentrations of 3,160 mg/kg, 1,380 mg/kg, 1,030 mg/kg, and 879 mg/kg. Soil samples collected from the tumbling room, manhole #2, and the pickling trench had lead concentrations of 2,800 mg/kg, 1,370 mg/kg, and 1,150 mg/kg, respectively. Three other soil samples collected from the commercial area also had lead concentrations over a comparison value. Two samples collected adjacent to the southern wall of the main building had lead concentrations of 1,630 mg/kg and 1,300 mg/kg. The third sample had a lead concentration of 380 mg/kg and was collected from the woods adjacent to the boiler plant. The background soil concentrations of lead in the eastern United States average 17 mg/kg and generally range from less than 10 mg/kg to 300 mg/kg (Shacklette 1984).
For chromium, cyanide, and zinc, the only soil samples collected from the commercial area that had concentrations over comparison values were collected from the plating pit (see Figure 5). Chromium had a single sample over a comparison value, with a concentration of 2,430 mg/kg. This is the concentration for total chromium in the soil. Chromium is a naturally occurring element that is present in the environment in several different forms. The most common forms are chromium (0), chromium (III) (i.e., trivalent chromium), or chromium VI (i.e., hexavalent chromium). Trivalent chromium occurs naturally in the environment, whereas chromium (0) and hexavalent chromium are generally produced by industrial processes. It is important to identify which form of chromium is in the soils because trivalent chromium and hexavalent chromium have different toxicological properties. For instance, trivalent chromium is considered to be less toxic than hexavalent chromium. Chromium (0) is not currently believed to cause a serious health risk. Total chromium is the sum of the concentrations of trivalent and hexavalent chromium. Because total chromium can be the sum of chromium in different oxidation states with different toxicities, and the concentrations of each species can vary, there is no comparison value for it (ATSDR 2000b). However, there are comparison values for both trivalent and hexavalent chromium. The soil RMEGs for trivalent chromium for children and adults are 80,000 mg/kg and 1,000,000 mg/kg, respectively. The soil RMEGs for hexavalent chromium for children and adults are 200 mg/kg and 3,000 mg/kg respectively. To be conservative, the comparison value for hexavalent chromium, the more stringent of the two values, was used to screen these soil samples. The background soil concentrations of total chromium in the eastern United States average 52 mg/kg and generally range from 1 mg/kg to 1,000 mg/kg (Shacklette 1984).
For cyanide, three of 27 samples exceeded a comparison value, with concentrations of 16,900 mg/kg, 7,650 mg/kg, and 2,350 mg/kg. Three of 27 zinc samples exceeded a comparison value, with concentrations of 190,000 mg/kg, 171,000 mg/kg, and 151,000 mg/kg. The background soil concentrations of zinc in the eastern United States average 52 mg/kg and generally range from less than 5 mg/kg to 2,900 mg/kg (Shacklette 1984).
Concentrations of calcium in soil samples from the commercial area ranged from nondetectable to 325,000 mg/kg. The maximum level was found in the pickling trench of the building and exceeded typical background levels. Copper concentrations ranged from nondetectable to 54,000 mg/kg with the highest levels found in the plating pit area of the building. Iron concentrations varied throughout the commercial area, with levels exceeding the comparison value found throughout.
For both cadmium and nickel, the soil samples from the commercial area that exceeded comparison values were found solely in the plating pit and the tumbling room sections of the building. Cadmium was found at concentrations of 1,500 mg/kg, 129 mg/kg, and 51.7 mg/kg in the plating pit and 686 mg/kg in the tumbling room. The chronic EMEG for cadmium is 10 mg/kg for a child's exposure. Nickel exceeded the comparison value in two individual samples from the plating pit and tumbling room, with concentrations of 1,630 mg/kg and 1,700 mg/kg, respectively. The RMEG for nickel is 1,000 mg/kg for a child's exposure. The background soil concentrations of nickel in the eastern United States average 18 mg/kg and generally range from less than 5 mg/kg to 700 mg/kg (Shacklette 1984).
Antimony concentrations in soil samples from the commercial area ranged from nondetectable up to 118 mg/kg and had a mean concentration of 18.4 mg/kg. Background soil concentrations of antimony in the eastern United States average 0.76 mg/kg and generally range from less than 1 mg/kg to 8.8 mg/kg (Shacklette 1984). The RMEG for antimony is 20 mg/kg for a child's exposure. The highest antimony levels were found in the tack wash, plating pit, and the tumbling room, with concentrations of 118 mg/kg, 110 mg/kg, and 79.7 mg/kg, respectively. The only soil samples that exceeded the comparison value for antimony were from the tack wash, plating pit, and the tumbling room.
Arsenic concentrations in soil samples from the area ranged from 0.55 mg/kg up to 96 mg/kg, with a mean concentration of 12.4 mg/kg. Background soil concentrations of arsenic in the eastern United States average 7.4 mg/kg and generally range from less than 0.1 mg/kg to 73 mg/kg (Shacklette 1984). The highest levels of arsenic in soil from the commercial area were in the plating pit (96 mg/kg, 25.5 mg/kg), the tack wash (42.6 mg/kg), and the tumbling room (20.8 mg/kg). All of the samples collected from this area were at higher concentrations than ATSDR's CREG value of 0.5 mg/kg. However, this CREG is also below the background soil concentration. The samples collected from within the building were the only ones with concentrations higher than the chronic EMEG, intermediate EMEG, and RMEG for arsenic, which is 20 mg/kg. All of the arsenic levels in soil samples from the commercial area were within or close to the typical background concentrations.
Vanadium concentrations in soil samples collected from the commercial area of the site ranged from 5.8 mg/kg to 635 mg/kg, with a mean concentration of 38.1 mg/kg. The background soil concentrations of vanadium in the eastern United States average 66 mg/kg and generally range from less than 7 mg/kg to 300 mg/kg (Shacklette 1984). Three individual samples from this area exceeded the intermediate EMEG for a child's exposure, which is 200 mg/kg. These samples were collected from an area southeast of the main building and had concentrations of 635 mg/kg, 236 mg/kg, and 228 mg/kg. One sample (i.e., the sample with the maximum concentration) exceeded background levels for vanadium in the eastern United States.
PAHs were found in excess of comparison values in soil samples from the commercial area of the site. These PAHs were benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, benzo(a)pyrene, chrysene, dibenzo(a,h)anthracene, fluoranthene, indeno(1,2,3-cd)pyrene, phenanthrene, and pyrene. All PAHs with reported typical background levels (i.e., benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, benzo(a)pyrene, chrysene, and indeno(1,2,3-cd)pyrene) had detections that exceeded the range of their typical background levels. The PAHs were sampled for only in the plating pit, tumbling room, pickling trench, tack wash, manhole #1, and manhole #2. There were exceedences of comparison values in each of these areas. The PAHs found at the site were for the most part concentrated in manhole #2 (see Figure 5). The PAHs were two orders of magnitude higher in manhole #2 than anywhere else in this area of the site.
One SVOC (i.e., bis(2-ethylhexyl)phthalate) was detected once in the commercial area at a level slightly exceeding its comparison value.
Polychlorinated biphenyl (PCB) Arochlor 1260 was detected in six of the eight soil samples from the commercial area and had concentrations ranging from nondetectable to 36 mg/kg, with a mean concentration of 10.3 mg/kg. The highest levels were found in the building samples from the tumbling room (36 mg/kg), the tack wash (21 mg/kg), and the pickling trench (13 mg/kg, 8.4 mg/kg).
Other compounds that were detected that did not have comparison values were 4-nitroaniline and beta-BHC.
Table 2b shows the minimum, mean, and maximum values of soil compounds in the noncommercial area of the site that exceeded their respective health-based comparison values or for which comparison values are not available. For 0- through 2-ft soil, 19 samples were taken and tested for VOCs, SVOCs, pesticides, and PCBs, and between 10 and 18 samples were taken and tested for metals. Of the compounds that were detected in the noncommercial area of the site, the ones that exceeded health comparison values or typical background levels in soil or for which there are no comparison values were antimony, arsenic, cadmium, chromium, copper, cyanide, iron, lead, nickel, zinc, PAHs (i.e., anthracene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, benzo(a)pyrene, chrysene, dibenzo(a,h)anthracene, fluoranthene, indeno(1,2,3-cd)pyrene, and pyrene), PCBs (Arochlor 1260), and pesticides (i.e., aldrin, 4,4'-DDT, dieldrin, endosulfan sulfate, and endrin ketone). The fill area to the east of the former lagoon and the Commercial and Industrial Debris Area are the areas of greatest concern in the noncommercial area of the site (see Figure 4). The contaminant concentrations are highest in these two areas. In addition there was evidence of trespassing in the former lagoon area.
Background soil concentrations of lead in the eastern United States generally range from less than 10 mg/kg to 300 mg/kg, with a mean concentration of 17 mg/kg (Shacklette 1984). The highest lead levels in soil samples collected from the noncommercial area of the site were found in the Commercial and Industrial Debris Area and had concentrations of 2,450 mg/kg, 2,680 mg/kg, 2,750 mg/kg, and 2,790 mg/kg. The next highest levels of lead in soils from the noncommercial area were found in the fill area to the east of the former lagoon (see Figure 4). The 12 surface soil samples collected from the fill area had lead concentrations that ranged from 410 mg/kg to 1510 mg/kg, with an average concentration of 612 mg/kg. Every sample collected from the fill area was above the range of background soil lead concentrations (see Figure 4).
The surface soil samples collected from the noncommercial area with cadmium and nickel concentrations in excess of comparison values were found solely in the fill area. The four samples with cadmium concentrations that exceeded a comparison value had levels of 19.7 mg/kg, 27.9 mg/kg, 32.6 mg/kg, and 3,000 mg/kg. The two surface soil samples with nickel concentrations in excess of a comparison value had levels of 2,960 mg/kg and 17,900 mg/kg.
Antimony concentrations in surface soil samples from the noncommercial area ranged from nondetectable to 162 mg/kg, with a mean concentration of 41.5 mg/kg. Each of the four soil samples that had detectable concentrations of antimony was found at levels in excess of the comparison value. The samples were found in the Commercial and Industrial Debris Area at concentrations of 53.6 mg/kg, 55.8 mg/kg, 104 mg/kg, and 162 mg/kg.
Arsenic concentrations in surface soil samples from the noncommercial area ranged from 2.4 mg/kg to 72.5 mg/kg, with an average of 23.8 mg/kg. The highest arsenic concentrations in soil samples collected from the noncommercial area were found in the fill area, with concentrations of 36 mg/kg, 38.4 mg/kg, 52.6 mg/kg, and 72.5 mg/kg, and in the Commercial and Industrial Debris Area, with concentrations of 35.6 mg/kg and 48.3 mg/kg. Although the arsenic concentrations in all 18 surface soil samples collected from the noncommercial area were in excess of the CREG value and several of the samples had arsenic levels in excess of the chronic EMEG for a child's exposure, all of the concentrations detected in the noncommercial area were within the range of typical background levels. Background soil concentrations of arsenic in the eastern United States average 7.4 mg/kg and generally range from less than 0.1 mg/kg to 73 mg/kg (Shacklette 1984).
Chromium concentrations in soil samples from the noncommercial area ranged from 8.3 mg/kg to 768 mg/kg, with an average of 145 mg/kg. The chromium concentration in one sample collected from the Commercial and Industrial Debris Area exceeded the comparison value for hexavalent chromium (see discussion on chromium above) and had a concentration of 768 mg/kg. Chromium is a naturally occurring element that is present in the environment in several different forms (e.g., chromium (0), trivalent chromium, and hexavalent chromium). The soil RMEGs for trivalent chromium for children and adults are 80,000 mg/kg and 1,000,000 mg/kg, respectively. The soil RMEGs for hexavalent chromium for children and adults are 200 mg/kg and 3,000 mg/kg respectively.
Copper concentrations in soil samples that exceeded comparison values were found only in the fill area and in the Commercial and Industrial Debris Area. Cyanide concentrations in soil samples that exceeded comparison values were found only in the fill area. Iron concentrations in soil samples that exceeded the comparison value were found throughout the site, but the highest concentrations were found in the fill area and in the Commercial and Industrial Debris Area. Zinc concentrations that exceeded the typical background levels were found throughout the site and two concentrations that exceeded the Chronic EMEG for children were found in the fill area.
Several PAHs were found in excess of comparison values in soil samples collected from the noncommercial area of the site. These PAHs were anthracene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, benzo(a)pyrene, chrysene, dibenzo(a,h)anthracene, fluoranthene, indeno(1,2,3-cd)pyrene, and pyrene. Benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, and chrysene had detections that exceeded the range of their typical background levels. The PAHs in soil from the noncommercial area that exceeded comparison values were all found at the highest concentration in the fill area.
PCBs and five pesticide compounds (i.e., aldrin, dieldrin, 4,4'-DDT, endosulfan sulfate, and endrin ketone) were detected in soil samples collected from the noncommercial area. PCB Arochlor 1260 concentrations in soil samples from the noncommercial area ranged from nondetectable to 260 mg/kg, with a mean concentration of 14.9 mg/kg. The three highest concentrations of PCBs (i.e., 260 mg/kg, 6.1 mg/kg, and 6.0 mg/kg) were found in the Commercial and Industrial Debris Area. Aldrin was detected in two samples, both in the fill area and at concentrations of 0.22 mg/kg. Dieldrin was detected in a single sample in the Commercial and Industrial Debris Area at a concentration of 0.059 mg/kg. The 4,4'-DDT concentrations at the site ranged from nondetectable to 46 mg/kg, with an average concentration of 2.9 mg/kg. The two highest concentrations of 4,4'-DDT (i.e., 46 mg/kg and 2.2 mg/kg) were found in the Commercial and Industrial Debris Area (see Figure 4). Endosulfan sulfate and endrin ketone do not have comparison values.
Sediment
Table 3 shows the minimum, mean, and maximum values of sediment compounds in Boys Creek that exceeded their respective health-based comparison values or for which comparison values are not available. Eleven sediment samples were collected from the creek and analyzed for VOCs, SVOCs, metals, pesticides, and PCBs. Of the compounds that were detected in sediment samples, the ones that exceeded health-based comparison values or background levels or for which there are no comparison values were arsenic, cadmium, calcium, iron, magnesium, potassium, sodium, one SVOC (i.e., carbazole), PAHs (i.e., benzo(a)anthracene, benzo(a)pyrene, and dibenzo(a,h)anthracene), and one pesticide (i.e., endosulfan II). It should be noted that the comparison values used for evaluating the sediment data are based on soil exposure because EPA and ATSDR have not developed health-based comparison values based on exposure to sediment. It would expected that opportunities for exposure to soil would be greater than sediment. Hence, this is a conservative approach.
The background levels of arsenic in sediment would be expected to be approximately the same as the background concentrations of arsenic in soil (see discussion above, regarding Table 2a results). Although the arsenic concentrations in all 11 sediment samples collected from Boys Creek were in excess of the CREG value and some of the samples had arsenic levels in excess of the chronic EMEG for a child's exposure, all of the concentrations detected in the noncommercial area were slightly higher than average, but within the range of typical background levels. Cadmium was detected once at a level exceeding the chronic EMEG for children. Some detections of iron were above the background sediment levels found at nearby West Island and above typical background soil levels (Shacklette 1984).
Three PAHs (i.e., benzo(a)anthracene, benzo(a)pyrene, and dibenzo(a,h,)anthracene) were detected in sediment samples at levels exceeding their comparison values.
Other compounds that were detected that did not have comparison values were calcium, magnesium, potassium, sodium, carbazole, and endosulfan II.
Surface Water
Table 4 shows the minimum, mean, and maximum values of surface water compounds that exceeded their respective health-based comparison values or for which comparison values are not available. The surface water samples were collected from locations within Boys Creek during low and high tides. For surface water, five samples were taken and tested for VOCs and SVOCs, eleven samples were taken and tested for pesticides and PCBs, and between 10 and 24 samples were taken and tested for metals. Of the compounds that were detected, the ones that exceeded health-based comparison values in surface water or for which there are no comparison values were metals (i.e., antimony, arsenic, barium, cadmium, calcium, iron, lead, magnesium, manganese, mercury, potassium, silver, thallium) and two pesticides [i.e., aldrin, and alpha-benzene hexachloride (alpha-BHC)]. It should be noted that the comparison values used for evaluating this surface water data are based on drinking water exposure (i.e., consumption of two liters per day). The surface water at the site is brackish and not fit for consumption. Therefore, the use of drinking water comparison values is a more conservative method of screening these data than other methods (e.g., assuming a dermal exposure).
Several metals (i.e., antimony, arsenic, barium, cadmium, iron, lead, manganese, mercury, silver, and thallium) and one pesticide (i.e., aldrin) were detected at least in once in surface water at levels exceeding their comparison values. Other compounds that were detected that did not have comparison values were calcium, magnesium, potassium, and alpha-BHC.
Groundwater
Table 5 shows the minimum, mean, and maximum values of groundwater compounds that exceeded their respective health-based comparison values or lacked comparison values. Groundwater sampling was conducted at 27 wells across the site during July 1991 and April 1992. For groundwater, 23 samples were taken and tested for VOCs, between 21 and 23 samples were taken and tested for SVOCs, 22 samples were taken and tested for pesticides and PCBs, and between 13 and 30 samples were taken and tested for metals. Of the compounds that were detected, the ones that exceeded health-based comparison values in groundwater at the site or for which there are no comparison values were aluminum, arsenic, barium, beryllium, cadmium, calcium, chromium, copper, cyanide, iron, lead, magnesium, manganese, nickel, potassium, sodium, vanadium, zinc, VOCs (i.e., benzene, ethylbenzene, methylene chloride, 1,1,2,2-tetrachloroethane, and toluene), SVOCs (i.e., benzyl acid, carbazole, 4-chlorophenyl-phenylether, 4-methylphenol, and 3-nitroaniline), one PAH (i.e., phenanthrene), and one pesticide (i.e., endrin ketone).
Elevated levels of the VOCs ethylbenzene [i.e., 160 micrograms per liter (µg/l)], methylene chloride (i.e., 820 µg/L), and toluene (i.e., 52,000 µg/L) were found in groundwater from a monitoring well in the area of the former carpenter shop (see Figure 4). Compounds that were detected once in the former carpenter shop at an elevated level included 4-methylphenol and 1,1,2,2-tetrachloroethane. The former carpenter shop has been listed as a potential waste dumping location for solvent contaminated sawdust and toluene (Weston 1995). A monitoring well immediately downgradient of the well in the area of the former carpenter shop, was also sampled and had no detections of toluene.
The highest concentration of toluene in a groundwater sample at the site, 220,000 µg/l, was collected from a monitoring well in the area of the former lagoon (see Figure 4). However, the monitoring well immediately downgradient from the monitoring well in the former lagoon did not have any detections of toluene. Analysis of groundwater data from 1987 through 1992 showed no trends in VOC concentrations of samples collected from the carpenter shop area, the former lagoon, or the well on the eastern edge of the site (Weston 1995).
The concentrations of several inorganic compounds in groundwater were highest near the former carpenter shop, where VOC compounds were also detected in groundwater samples (see Figure 4). Beryllium, cadmium, chromium, and nickel were all found at concentrations over their respective EPA maximum contaminant levels (MCLs) in the area of the former carpenter shop. Zinc was also found at a concentration over a comparison value in a well adjacent to the former carpenter shop. Similarly, chromium and cyanide were found at concentrations in excess of their MCLs in wells downgradient from, or within, the former lagoon, which is also an area where VOC compounds were detected in groundwater samples. The highest concentrations of copper, lead, manganese, and vanadium in groundwater samples were all found in wells within the Commercial and Industrial Debris Area. Aluminum and iron were detected in several samples across the site at levels exceeding their comparison values. Arsenic was detected at its highest level in the fill area, though all the detection limits exceeded the CREG value for arsenic. Barium was detected once in the fill area and once in the former lagoon at levels exceeding the RMEG for children. Overall, while there was substantial contamination detected in groundwater beneath the site, no plumes have been explicitly delineated. Groundwater beneath the site flows in the general direction of the former lagoon.
Other compounds that were detected that did not have comparison values were calcium, magnesium, potassium, sodium, benzyl acid, carbazole, 4-chlorophenyl-phenylether, 3-nitroaniline, phenanthrene, and endrin ketone.
Shellfish and Fish
Tables 6 and 7 show the minimum, mean, and maximum values of contaminants of concern in hard shell and soft shell clams collected near the mouth of Boys Creek that either exceeded their respective health-based comparison values or typical background levels or lacked comparison values.(1) Table 8 shows the minimum, mean, and maximum values of contaminants of concern in ribbed mussels that were deployed at three stations in Boys Creek in order to evaluate the bioaccumulation of selected metals, PCBs, and pesticides. Tissue samples from four hard shell clams and three soft shell clams were analyzed for metals, VOCs, SVOCs, PCBs, and pesticides. Hard shell and soft shell clams were chosen for analysis because they are the dominant species of biota on this site.
Hard shell clam tissue samples showed elevated levels of arsenic and mercury in each of the four samples. These levels were less than the background concentrations derived by collecting and analyzing samples from nearby West Island, though the background levels exceeded the comparison values. Arsenic concentrations ranged from 8.2 mg/kg to 14.3 mg/kg, with an average of 11.7 mg/kg. Mercury concentrations ranged from 0.66 mg/kg to 0.85 mg/kg, with a mean concentration of 0.76 mg/kg. There were also low-level detections of several SVOCs, pentachlorophenol, and 4,4'-DDT in hard shell clam samples. It should be noted that the detection limits for several PAH compounds in these samples were higher than their respective comparison values.
The arsenic and mercury levels in soft shell clam samples were very similar to those in the hard shell clam samples. Arsenic and mercury concentrations exceeded their respective comparison values in each of the three soft shell clam samples analyzed. Arsenic concentrations in soft shell clams ranged from 10.4 mg/kg to 15.1 mg/kg, with a mean concentration of 12 mg/kg. The specific form of arsenic is not identified (i.e., organic or inorganic). Inorganic arsenic is recognized as a human toxin. In contrast, studies have shown organic arsenic to be much less toxic. The arsenic found in shellfish tends to exist in an organic form that is essentially non-toxic (ATSDR 2000a). Mercury concentrations ranged from 0.79 mg/kg to 0.89 mg/kg, with an average of 0.82 mg/kg. Antimony, iron, and bis(2-ethylhexyl)phthalate were detected at levels in soft shell clams that exceeded comparison values. One compound (i.e., lead) was detected which had no comparison value.
Ribbed mussel samples were deployed and then analyzed as part of the site investigation (see Table 8) but will not be discussed in this assessment because they are not used for human consumption. They were collected to help determine seasonal habitat utilization and for use in ecological characterizations of the site (Weston 1995).
Mummichogs are the dominant fish species within Boys Creek. Mummichogs are not valued as commercial or sport fishes but are an important part of the ecological food chain (USACE 1985). They will not be discussed in this assessment because they are not expected to be used for human consumption. The hurricane barrier prevents any larger size fish from entering into the upper section of Boys Creek. No additional shellfish, finfish, or lobster data were gathered during site investigation activities.
Table 9 shows the minimum, mean, and maximum values of soil compounds that exceeded their respective health-based comparison values in the residential area adjacent to the Atlas Tack site. One sample was taken near the Rogers Elementary School, one was taken at a residence on Pleasant Street across from the Atlas Tack site, and one sample was taken from a residence located where Pleasant Street intersects Church Street (see Figure 6). The three soil samples were tested for VOCs, SVOCs, metals, pesticides, and PCBs. Of the compounds that were detected, the one that exceeded health-based comparison values in soil from the residential area was arsenic (i.e., maximum concentrations of 2.5 mg/kg for arsenic). The detections of arsenic were within background concentrations for the eastern United States (i.e., observed ranges from less than 0.1 mg/kg to 73 mg/kg with a mean of 7.4 mg/kg for arsenic).
C. Quality Assurance/Quality Control (QA/QC)
The site investigations that have taken place at the Atlas Tack site since the MDPH Preliminary Public health assessment were also associated with a Quality Assurance Project Plan that included information on QA/QC. EPA performed extensive QA/QC on the environmental sampling data collected in the remedial investigation. The validity of the conclusions made in this public health assessment depends on the accuracy and reliability of the data provided in the cited reports.
In the past, the former lagoon presented a physical hazard. In January 1947, two children fell into the lagoon. One child died, the other child sustained injuries, and the rescuers were treated for skin ailments believed to be caused by the contaminants in the lagoon (Weston 1995). The one-story (middle) building was removed in 1998. The deteriorating roof and floors of the three-story (east) building make it structurally unsound, and it could present serious physical hazards to individuals trespassing on the site or contract employees working on the premises. As noted during the site visit, the fence was in disrepair in two specific sections and could have been circumvented in these areas. One section of fence in disrepair was located at the gate that separates the commercial area of the site from the fenced area that surrounds the former lagoon. The other section of fence in disrepair was located where the fence crosses Boy's Creek adjacent to the hurricane dike. Although these sections have been repaired, there is at least one section that is in disrepair (i.e., the fence along the marsh is down) (Craffey 2001). The pickling trench area is covered only with plywood and the plating pit is covered with a blue tarp. The tack wash area is not covered (Craffey 2001). Though the two-story (west) building is currently sound, it will not remain so unless maintenance-work is performed (USACE 1996). In the past, the condition of the building made it a potential fire hazard. However, at the time of this public health assessment this has been somewhat improved by the addition of an operating fire extinguishing system. In August 1999, EPA filed a Unilateral Administrative Order for Atlas Tack to remove friable asbestos from the east building and the boiler plant. The majority of the windows had been broken and the building was open to the elements (EPA 1999). Between September 1999 and February 2000, EPA removed all of the asbestos-containing materials (EPA 2000). Hence, the opportunity for exposure to friable asbestos material is no longer present at the site. While it is difficult to quantify the risk from past opportunities for exposure to asbestos, it is quite possible that there could have been opportunities for exposure at levels of health concern, particularly for those who might have trespassed on the site.
To determine whether nearby residents and people on-site were, are, or could be exposed to contaminants, an evaluation was made of the environmental and human components that lead to human exposure. The pathway analysis consists of five elements: a source of contamination, transport through an environmental medium, a point of exposure, a route of human exposure, and a receptor.
Exposure to a chemical must first occur before any adverse health effects can result. Five conditions must be met for exposure to occur. First, there must be a source of that chemical. Second, a medium (e.g., water) must be contaminated by either the source or by chemicals transported away from the source. Third, there must be a location where a person can potentially contact the contaminated medium. Fourth, there must be a means by which the contaminated medium could enter a person's body (e.g., ingestion). Finally, the chemical must actually reach the target organ susceptible to the toxic effects from that particular substance at a sufficient dose for a sufficient time for an adverse health effect to occur (ATSDR 1993).
A completed exposure pathway exists when all of the above five elements are present. A potential exposure pathway exists when one or more of the five elements is missing and indicates that exposure to a contaminant could have occurred in the past, could be occurring in the present, or could occur in the future. An exposure pathway can be eliminated if at least one of the five elements is missing and will not likely be present. The discussion that follows incorporates only those pathways that are important and relevant to the site.
A. Completed Exposure Pathways
Surface Soil
Past and present opportunities for exposure to contaminants in soil (i.e., metals, cyanide, PAHs, PCBs) at this site likely occurred. Opportunities for exposure might be expected to have begun around 1901, when manufacturing operations began at the site. Populations that would have had exposure opportunities include past employees (i.e., plant workers, maintenance personnel, grounds keepers, etc.), present employees (i.e., grounds keepers, contractors, demolition workers, etc.), and persons (e.g., children) trespassing on the site. Past or present exposure opportunities might have occurred through incidental ingestion of contaminated soils or possibly skin absorption as a result of direct contact with contaminated soils in both the commercial and noncommercial areas of the site.
Sediment
Past and present opportunities for exposure to contaminants in sediment (i.e., metals, PAHs) at this site likely occurred. As in surface soil, opportunities for exposure might have begun in the early 1900s. Populations that might have had opportunities for exposure include past employees (i.e., plant workers, maintenance personnel, grounds keepers, etc.), present employees (i.e., grounds keepers, contractors, etc.), and persons trespassing on the site. Past or present exposure opportunities might have occurred through incidental ingestion of contaminated sediments or possibly skin absorption as a result of direct contact with contaminated sediments in both the area near the former lagoon and the marsh area in and around Boys Creek.
Surface Water
Past exposure to contaminants in surface water occurred in the former lagoon between its construction in the early 1940s and its remediation in 1985. At least one incident of exposure took place in the former lagoon (i.e., January of 1947). During this incident, two children fell through the ice covering the lagoon. One of the children died, the other sustained injuries and the rescuers were treated for skin ailments believed to be caused by contaminants in the lagoon (Weston 1995).
Other past and present opportunities for exposure to contaminants in surface water (i.e., metals, pesticides) at this site likely occurred. These exposures might have begun in the early 1900s. Potentially exposed populations include past employees (i.e., plant workers, maintenance personnel, grounds keepers, etc.), present employees (i.e., grounds keepers, etc.), persons trespassing on the site, and persons recreating in Boys Creek adjacent to the hurricane barrier outside of the Atlas Tack property fence. Past or present exposures might have occurred by skin absorption through direct contact with contaminated surface water in Boys Creek. The water in Boys Creek is brackish, and would not be used for human consumption. The shallow depth of Boys Creek makes it highly unlikely that people would swim in Boys Creek. MDPH staff did not observe any evidence of persons swimming in Boys Creek during the site visit. The Fairhaven Board of Health was not aware of any persons swimming in Boys Creek (Fowle 2001). Therefore, the main route of exposure to contaminants in surface water would be through skin absorption if someone were to wade in the water, which also is unlikely to occur to any great extent due to reported field observations and the brackish nature of the water. Given that metals do not tend to be readily absorbed through the skin, adverse health effects from current exposures to contaminants in surface water are not likely.
B. Potential Exposure Pathways
Ambient Air
Past opportunities for exposure to compounds (e.g., VOCs and metals) in ambient air (e.g., emissions from the power plant and manufacturing processes) at this site might have occurred for former Atlas Tack employees and residents living in neighborhoods adjacent to the site through daily inhalation. At the time of this public health assessment, there did not appear to be any opportunities for exposure through the ambient air pathway. In the future, opportunities for exposure to contaminants in ambient air (e.g., volatilization, fugitive dusts) could occur for residents living in adjacent neighborhoods and workers on the site should remedial or excavation activities take place.
Shellfish
There is currently a ban on shellfishing in the area of Boys Creek because of the potential for bacterial contamination (Craffey 2001). The local shellfishing warden has observed a single occurrence of an individual illegally shellfishing in the Boys Creek area. The area is actively patrolled by the shellfishing warden and the Environmental Police to enforce the ban (Costa 1999). Should the ban on shellfishing in this area be lifted, or should illegal harvesting and consumption of shellfish from Boys Creek take place, people could be exposed to contaminants (e.g., metals, PAHs, PCBs, and pesticides) in shellfish.
Subsurface Soil
Future exposures to contaminated soils might occur should excavation activities or pavement removal take place. Data for subsurface soil was qualitatively analyzed and found to have contaminant concentrations approximate to surface soil. At this time, MDPH is not aware of excavation activities taking place on the site.
C. Eliminated Exposure Pathways
Groundwater
In August of 1992, a residential well survey was conducted by EPA to determine the presence and usage of private wells within one-half mile of the Atlas Tack site. This survey was distributed to 981 residents with a one-third response rate. An additional effort was made to reach approximately 400 of the residents who either submitted incomplete surveys or did not reply to the mailing. No residences were identified as using the groundwater for human consumption in the survey area (Weston 1995). In addition, the Fairhaven Board of Health consulted the Fairhaven Water Department on December 16, 1999, and determined that there are 1,849 residences within half a mile of the site. Only one residence in this area has a potable well and it is located almost half a mile upgradient from the site.
MDPH staff have summarized the available environmental data and exposure pathways for the Atlas Tack site in this public health assessment. Completed exposure pathways included past and present contact with surface soil, sediment and surface water in the former lagoon. The main compounds of concern at the site are metals. In soil samples, the other compounds that exceeded either screening, typical background values or for which there are no comparison values were SVOCs (i.e., bis(2-ethylhexyl)phthalate and 4-nitroaniline), PAHs (i.e., anthracene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(g,h,i)perylene, benzo(a)pyrene, chrysene, dibenzo(a,h)anthracene, fluoranthene, indeno(1,2,3-cd)pyrene, phenanthrene, and pyrene), PCBs, and pesticides (i.e., aldrin, beta-BHC, dieldrin, 4,4'-DDT, endosulfan sulfate, and endrin ketone). In sediment samples, the other compounds that exceeded either screening, typical background values or for which there are no comparison values were PAHs (i.e., benzo(a)anthracene, benzo(a)pyrene, and dibenzo(a,h)anthracene), one SVOC (i.e., carbazole), and a pesticide (i.e., endosulfan II). Opportunities for exposure to these compounds are primarily via incidental ingestion of surface soil or sediments at the site.
Surface water in Boys Creek is contaminated with metals (i.e., antimony, arsenic, barium, cadmium, calcium, iron, lead, magnesium, manganese, mercury, potassium, silver, and thallium) and two pesticides (i.e., aldrin and alpha-BHC). The contaminants are assumed to be coming from the site. Opportunities for exposure to contaminants in the surface water are limited because the water in Boys Creek is brackish (i.e., unfit for consumption) and the Creeks depth is shallow (i.e., not suitable for swimming).
Groundwater at the site is contaminated with metals, VOCs (i.e., benzene, ethylbenzene, methylene chloride, 1,1,2,2-tetrachloroethane, and toluene), SVOCs (i.e., benzyl acid, carbazole, 4-chlorophenyl-phneylether, 4-methylphenol, and 3-nitroaniline), one PAH (i.e., phenanthrene), and one pesticide (i.e., endrin ketone). The groundwater at the site generally flows in a northeasterly direction and away from the nearby residences along Church Street. A well survey performed in 1992 by EPA identified no residences using the groundwater for residential use within one-half mile of the site. According to the Fairhaven BOH, only one residence within one-half mile of the site has a potable well and it is located upgradient from the site. Should new private wells be dug and used for consumption, or should residents begin using their wells for residential use, people could be exposed to contaminants in groundwater. Although the opportunity for persons to be exposed to contaminants in surface water at the site is present, health effects are not expected to result from the kind of exposures likely at the site (i.e., dermal contact with surface water). At the time of this public health assessment, there do not appear to be any opportunities for exposure through the ambient air pathway. However, opportunities for exposure to contaminants in ambient air could have occurred in the past to residents living in adjacent neighborhoods and workers on the site and could occur in the future should remedial or excavation activities take place.
Hard shell clams were found to have elevated levels of metals (i.e., arsenic, calcium, magnesium, mercury, potassium, and sodium), SVOCs (i.e., bis(2-ethylhexyl)phthalate, 2-methylnaphthalene, 2-nitrophenol, and pentachlorophenol), PAHs (i.e., acenaphthylene, benzo(a)anthracene, benzo(b)fluoranthene, and benzo(g,h,i)perylene), and one pesticide (i.e., 4,4'-DDT). Soft shell clams were found to have elevated levels of metals (i.e., antimony, arsenic, iron, lead, and mercury) and one SVOC (i.e., bis(2-ethylhexyl)phthalate). Although the levels were elevated, at the time of this public health assessment, this area is closed to shellfishing. Therefore, there are no opportunities for exposure to these contaminants in clams.
A. Chemical-Specific Toxicity Information
As noted earlier in this public health assessment, metals, two SVOCs, PAHs, PCBs, and pesticides in surface soil at the site exceeded either comparison or typical background values or had no comparison values. Several metals, one SVOC, three PAHs, and one pesticide in sediment at the site exceeded comparison values or typical background values or had no comparison values.
The average concentration of arsenic in soil and sediment in different areas of the site was close to or within typical background levels for this metal. Because of the limited number of detections above comparison or background levels, and because it is unlikely that a person visiting or trespassing on the site would consistently come into contact with the few areas that show higher contamination levels, arsenic will not be considered further in this assessment.
The average concentration of zinc in soil in the commercial area of the site and the maximum concentration found in the noncommercial area of the site slightly exceeded the chronic EMEG for children. For the commercial area, this is due to a few large detected concentrations (i.e., 151,000 mg/kg, 171,000 mg/kg, and 190,000 mg/kg) in the plating pit area. The maximum concentration found in the noncommercial area was located in the fill area. Since it is unlikely that someone would be consistently exposed to the highest concentrations of zinc, it will not be considered further in this assessment.
Three detections of vanadium from the commercial area exceeded the intermediate EMEG for a child's exposure. These samples were collected from an area southeast of the main building and had concentrations of 635 mg/kg, 236 mg/kg, and 228 mg/kg. Since the average concentration found in the commercial area was 38.1 mg/kg, the average background level ranges from less than 7 mg/kg to 300 mg/kg, and it is unlikely that someone would be consistently exposed to the highest concentrations of vanadium, it will not be considered further in this assessment.
Calcium, magnesium, potassium, and sodium were detected at concentrations in soil and/or sediment that exceeded background levels but because they are naturally occurring minerals, they will not be considered further in this assessment.
Several SVOCs (i.e., bis(2-ethylhexyl)phthalate, carbazole, and 4-nitroaniline) and pesticides (i.e., aldrin, beta-BHC, dieldrin, endosulfan sulfate, endosulfan II, and endrin ketone) were detected in soil and sediment between one and three times. One detection of bis(2-ethylhexyl)phthalate, one detection of dieldrin, and two detections of aldrin slightly exceeded their comparison values while the other compounds did not have comparison values. Since these compounds were found infrequently on the site and when detected were found at low concentrations, they will not be considered further in this assessment.
One pesticide (i.e., 4,4'-DDT) was detected twice at levels exceeding a comparison value but since it is unlikely that someone would be consistently exposed to these two concentrations, it will not be considered further in this assessment.
Of the contaminants in soil that exceeded their respective health-based comparison values, cadmium, chromium, copper, cyanide, iron, lead, nickel, PCBs, and PAHs are of the most concern at this site.
In order to evaluate possible public health implications, estimates of opportunities for exposure to compounds (e.g., in soil) must be combined with what is known about the toxicity of the chemicals. ATSDR has developed minimal risk levels (MRLs) for many chemicals. An MRL is an estimate of daily human exposure to a substance that is likely to be without an appreciable risk of adverse noncancer health effects over a specified duration of exposure. MRLs are derived based on no-observed-adverse-effect levels (NOAELs) or lowest-observed-adverse-effect levels (LOAELs) from either human or animal studies. The LOAELs or NOAELs reflect the actual levels of exposure that are used in studies. ATSDR has also classified LOAELs into "less serious" or "serious" effects. "Less serious" effects are those that are not expected to cause significant dysfunction or whose significance to the organism is not entirely clear. "Serious" effects are those that evoke failure in a biological system and can lead to illness or death. When reliable and sufficient data exist, MRLs are derived from NOAELs or from less serious LOAELs, if no NOAEL is available for the study. To derive MRLs, ATSDR also accounts for uncertainties about the toxicity of a compound by applying various margins of safety, thereby establishing a level that is well below a level of health concern.
Asbestos
Asbestos is the name for a group of six naturally occurring fibrous minerals with heat and chemical resistant properties. Because of their heat resistant properties, they were frequently used in building materials such as insulation, ceiling and floor tiles, roof shingles, and cement. Inhalation of asbestos fibers suspended in air is the most common route of exposure. Asbestos does not readily, if at all, pass through the skin into the body.
EPA and the United States Department of Health and Human Services National Toxicology Program (DHHS/NTP) have classified asbestos as a known human carcinogen. Lung cancer and mesothelioma are the cancers associated with asbestos exposure.(2) Chronic, high-level exposure to asbestos can lead to a buildup of scar-like tissue in the lungs (ATSDR 1995a).
Cadmium
Cadmium is used in a variety of consumer products including metal coatings and some metal alloys. Although it is a naturally occurring element, most of the cadmium enters the environment as a result of human activities. On average, about 25% of the cadmium inhaled by humans is absorbed by the body, and about 5% of the cadmium consumed (in food, soil, water, etc.) is absorbed by the body. Very little cadmium enters the body through the skin. Ingestion of low levels of cadmium over an extended period of time can cause cadmium to build-up in the kidneys, which in turn can result in kidney damage and weakened bones. DHHS/NTP has determined that cadmium and cadmium compounds might reasonably be anticipated to be carcinogens (ATSDR 1999a). EPA has classified cadmium as a "probable human carcinogen" based on limited evidence from occupational epidemiological studies. One study is considered to supply limited evidence of an increase in lung cancer due to exposure to cadmium via inhalation (EPA 1998).
Chromium
Chromium is a naturally occurring element that is present in the environment in several different forms. The most common forms are chromium (0), chromium (III) (i.e., trivalent chromium), or chromium VI (i.e., hexavalent chromium). Trivalent chromium occurs naturally in the environment, whereas chromium (0) and hexavalent chromium are generally produced by industrial processes. It is important to identify which form of chromium is in the soils because trivalent chromium and hexavalent chromium have different toxicological properties. For instance, trivalent chromium is considered to be less toxic than hexavalent chromium. Chromium (0) is not currently believed to cause a serious health risk. Total chromium is the sum of the concentrations of trivalent and hexavalent chromium. Because total chromium can be the sum of chromium in different oxidation states with different toxicities, and the concentrations of each species can vary, there is no comparison value for it (ATSDR 2000b). The soil RMEGs for trivalent chromium for children and adults are 80,000 mg/kg and 1,000,000 mg/kg, respectively. The soil RMEGs for hexavalent chromium for children and adults are 200 mg/kg and 3,000 mg/kg respectively.
EPA has determined that hexavalent chromium in air is a human carcinogen and that there is insufficient information to determine whether hexavalent chromium in water or food and trivalent chromium are human carcinogens (ATSDR 2000b).
Copper
Copper is a metal that occurs naturally in the environment. It is an essential element for all known living organisms. Most copper compounds found in the environment are strongly attached to dust and dirt or imbedded in minerals so that they cannot easily affect human health. Copper is not known to cause cancer but long term exposure to copper dust can be a nose, mouth, and eye irritant and can cause headaches, dizziness, nausea, and diarrhea (ATSDR 1991).
Cyanide
Cyanide and some cyanide compounds are used in electroplating and metallurgy as well as other industrial uses. Smoking cigarettes and breathing smoke-filled air during a fire are the major sources of cyanide exposure for people not employed in cyanide-related industries. Certain kinds of food (e.g., cassava roots, lima beans, almonds) contain cyanide compounds. Low-level exposures can cause blood changes, difficulties in breathing, headaches, heart pains, vomiting, and enlargement of the thyroid gland (ATSDR 1997a).
Iron
Iron is an essential element that is vital to oxygen transport and metabolism. The Recommended Dietary Allowance (i.e., the daily dietary intake level that is sufficient to meet the requirements of almost all healthy individuals in each age and gender group) of iron is 10 mg for children age four to eight years old, 8 mg for males age 19-50 years old, and 18 mg for women age 19-50 years old. Iron is found in different forms in meat and plants and the forms have different uses in the body. Adult men and post-menopausal women lose very little iron, except through bleeding [National Institute of Health (NIH) 2001].
Some studies have suggested an association between high iron stores in the body and coronary heart disease. Available data do not provide convincing support for this connection. Individuals with hereditary hemochromatosis (a hereditary disease where iron can build up to dangerous levels in the body) have an increased risk of liver cancer. Evidence is inconclusive about an association between iron levels in humans and incidence of cancer, though several studies have reported a high rate of lung cancer mortality in workers who were exposed to iron oxide and other potentially carcinogenic substances in mines and smelters (EPA 2001b, NIH 2001).
Lead
Most of the lead in urban soils comes from old automotive exhaust from when leaded gasoline was used and from leaded paint. Background soil concentrations of lead in the eastern United States average 17 mg/kg and range from less than 10 through 300 mg/kg (Shacklette 1984). However, lead concentrations in soil vary widely. The upper levels of soil beside busy roadways are typically 30 through 2000 mg/kg higher than natural levels. Soils adjacent to houses with exterior lead based paints might have lead levels of greater than 10,000 mg/kg. Exposure to lead, which could occur in unvegetated areas, is particularly a concern for young children even at low exposure levels. At low levels, lead can affect mental and physical growth in children. At higher levels, lead can affect blood and brain function (ATSDR 1999b). No ATSDR comparison values are available for lead in soils and sediments. EPA has developed a hazard standard for residential soil (EPA 2001a).
Nickel
Nickel is an element naturally found in abundance in the environment. It is often combined into alloy compounds with other metals and used in nickel plating and the production of various metal products and items. The most common adverse health effect associated with exposure to nickel is an allergic reaction. After a person becomes sensitized to nickel, subsequent exposures to it will produce reactions such as a rash (most common) or possibly an asthma attack (less common) (ATSDR 1997b).
PCBs
Polychlorinated biphenyls are considered a probable human carcinogen by EPA and the International Agency for Research on Cancer (IARC), based on sufficient evidence of carcinogenicity in animal studies and limited supporting evidence from human studies. PCBs are associated with liver cancer as well as other cancers such as skin, biliary tract, and intestinal, in human studies, and are clearly liver carcinogens in animals. Monkeys, which are more biologically similar to humans than most laboratory animals, appear to be the most sensitive species to the non-cancer health effects (e.g., immunological effects, developmental toxicity) of PCBs.
Currently, human and animal studies of the toxic effects of PCBs have indicated that PCBs are associated with a variety of systemic health effects in addition to cancer. Skin conditions, such as acne and rashes, have been observed in people exposed to high levels, but these effects are not considered likely to result from environmental exposures. Studies in workers suggest that exposure to PCBs can cause respiratory irritation, gastrointestinal discomfort, changes in blood chemistry, depression, and fatigue. Studies have shown that human poisoning with PCBs has resulted in immunological damage, thyroid hormone malfunction, skin damage and liver function alteration. In animal studies, ingestion of high levels of PCBs was associated with anemia, skin conditions, and systemic damage including altered function in the liver, immune system, and endocrine system. Studies of women who were exposed to PCBs during pregnancy have suggested that lower birth weight infants, and neurological and behavioral effects on infants, can result. Animal studies have shown similar reproductive and developmental damage.
PAH Compounds
PAHs are ubiquitous in soil. Combustion processes release PAHs into the environment. Therefore, the major sources of PAHs in soils, sediments, and surface water include fossil fuels, cigarette smoke, industrial processes, and exhaust emissions from gasoline engines, oil-fired heating, and coal burning. PAHs are also found in other environmental media and in foods, particularly charbroiled, broiled, or pickled food items, and refined fats and oils (ATSDR 1995b).
There are a variety of different types of PAHs. Benzo(a)pyrene is the most toxic. The primary health concern for these compounds is carcinogenicity, and EPA considers several (i.e., benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, dibenzo(a,h,)anthracene, and indeno(1,2,3-c,d)pyrene) to be "probable human carcinogens," based on sufficient evidence in animal studies and inadequate evidence for human studies (ATSDR 1995b).
B. Evaluation of Possible Health Effects
Populations that could have had opportunities for exposure to compounds in surface soil and sediments include past and present employees of Atlas Tack, workers associated with the demolition of a section of the manufacturing building in December 1998, and persons trespassing on the site. Although the site is fenced, there is at least one section that is in disrepair (i.e., the fence along the marsh is down) (Craffey 2001). The section of fence that crosses Boys Creek would allow relatively easy access to Boys Creek and the associated marsh. MDPH staff observed evidence of trespassing (e.g., graffiti, alcohol containers) occurring in both the commercial and noncommercial areas of the site.
Past and present employees of Atlas Tack are assumed to have spent approximately 250 days per year on the site. These employees would have had the greatest opportunity for exposure to contaminants in soil. Of the contaminants in soil that exceeded their respective health-based comparison values, cadmium, chromium, cyanide, lead, nickel, PCBs, and PAHs are of the most concern at this site. To further evaluate the public health impact of these contaminants, opportunities for exposure based on ingestion of contaminated soil were evaluated for children trespassing on the site and employees working on the site.
The estimated exposure for ingestion of cadmium at the maximum concentration found in soil (i.e., 3,000 mg/kg) at the site is 0.003 mg/kg/day for an employee on the site(3) and 0.02 mg/kg/day for a child trespassing on the site.(4) The estimated exposures are higher than ATSDR's chronic oral minimal risk level (MRL) for cadmium, which is 0.0002 mg/kg/day.
The oral MRL is based upon a lifetime accumulated threshold of 2,000 mg of cadmium from dietary sources. This threshold is associated with an increased incidence of proteinuria, which is a symptom of renal complications. The average dietary cadmium intake of adult Americans is approximately 0.0004 mg/kg/day, which suggests that Americans do not have a margin of safety with respect to cadmium intake (ATSDR 1999a). Although this estimated exposure is calculated using the maximum concentration found in the soils at the site, some conservative assumptions are made in estimating this exposure, and an uncertainty factor of 10 is calculated into the MRL, there is still a concern for potential for adverse health effects (e.g., renal effects) that might result from opportunities for exposure to cadmium in the soils of the site.
The estimated exposure for ingestion of copper at the maximum concentration found in soil (i.e., 70,000 mg/kg) at the site is 0.04 mg/kg/day for an employee on the site and 0.2 mg/kg/day for a child trespassing on the site. The estimated exposure for an employee at the site is equal to, and the estimated exposure for a child trespassing on the site is greater than EPA's chronic oral reference dose of 0.04 mg/kg/day. While the possible exposure from the maximum levels of copper on the site exceeds the EPA reference dose, it is unlikely that a person would have consistently been in contact with only the highest spot.
The estimated exposure for ingestion of total chromium at the maximum concentration found in soil (i.e., 2,430 mg/kg) at the site is 0.001 mg/kg/day for an employee on the site(5) and 0.006 mg/kg/day for a child trespassing on the site.(6) Under most conditions hexavalent chromium will be reduced to trivalent chromium in the environment (ATSDR 2000b). Thus, assuming that the chromium in soil is trivalent chromium, the chromium concentrations in the soils at the site are well below the comparison values, and thus below levels of health concern. In addition, the mean soil values for chromium are below levels of health concern for children and adults using screening values for hexavalent chromium. While the maximum levels of chromium on the site do considerably exceed the screening values for the hexavalent form, it is unlikely that a person would have consistently been in contact with only the highest spot (e.g., in plating pit).
The estimated exposure for ingestion of cyanide at the maximum concentration found in soil (i.e., 16,900 mg/kg) at the site is 0.009 mg/kg/day for an employee on the site(7) and 0.04 mg/kg/day for a child trespassing on the site.(8) The estimated exposure for a child trespassing is slightly higher than EPA's chronic oral reference dose for cyanide, which is 0.02 mg/kg/day. Given the conservative nature in which the estimated exposure dose was calculated (e.g., maximum rather than average soil concentrations selected), the uncertainty factor of 100 and the assumptions of daily exposure on a yearly basis for the chronic oral reference dose, adverse health effects are not likely from exposure to cyanide in the soils of the site.
The estimated exposure for ingestion of iron at the maximum concentration found in soil (i.e., 305,000 mg/kg) at the site is 0.2 mg/kg/day for an employee on the site and 0.7 mg/kg/day for a child trespassing on the site. The estimated exposure for a child trespassing is higher than the EPA's provisional chronic oral reference dose of 0.3 mg/kg/day. Given the conservative nature in which the estimated exposure dose was calculated (e.g., maximum rather than average soil concentrations selected), the uncertainty factor of 100 and the assumptions of daily exposure on a yearly basis for the chronic oral reference dose, adverse health effects are not likely from exposure to iron in the soils of the site.
The high levels of lead found in the soils of the site (i.e., greater than 2,000 ppm) could present health concerns for children playing on the site. The EPA soil standard for residential environments is 400 mg/kg. It is important to note that public health screening for lead in children indicates that lead paint in older housing stock continues to be the most important risk factor for lead exposure in children (ATSDR 1999b). Compared to lead paint, soil is generally believed to be a lessor contributor to elevated blood lead levels or lead poisoning in children. However, lead in soil at this site is high and could possibly contribute to a child's lead level. Hence, area children who might trespass onto this site might have opportunities for exposure of health concern.
The estimated exposure for ingestion of nickel at the maximum concentration found in soil (i.e., 17,900 mg/kg) at the site is 0.01 mg/kg/day for an employee on the site(9) and 0.04 mg/kg/day for a child trespassing on the site.(10) This estimated exposure for a child trespassing on the site is slightly higher than the EPA chronic oral reference dose for nickel, which is 0.02 mg/kg/day. Given the conservative nature in which the estimated exposure dose was calculated (e.g., maximum rather than average soil concentrations selected), the uncertainty factor of 300 and the assumptions of daily exposure on a yearly basis built into the chronic oral reference dose, adverse health effects are not likely from exposure to nickel in the soils of the site.
The estimated exposure for ingestion of PCBs at the maximum concentration found in soil (i.e., 260 mg/kg) at the site is 0.00014 mg/kg/day for an employee on the site(11) and 0.00064 mg/kg/day for a child trespassing on the site.(12) These estimated exposures are higher than the chronic oral MRL for PCBs, which is 0.00002 mg/kg/day. It is unlikely that persons exposed would have had contact with the maximum detected concentration of PCBs in soil every day they were at the site. With the exception of the sample with the maximum concentration, PCBs are not found in high concentrations at this site. Given the conservative nature in which the estimated exposure dose was calculated (e.g., maximum rather than average soil concentrations selected) and the assumptions of daily exposure on a yearly basis for the chronic oral Minimum Risk Level (MRL), adverse health effects are not likely from exposure to PCBs in the soils of the site.
The concentrations of several PAH compounds in soil samples were in excess of their respective CREGs. Except for benzo(a)pyrene, no health-based comparison values have been derived by ATSDR or EPA for PAH compounds in soil. However, using the CREG for benzo(a)pyrene, CREGs for several other PAHs can be calculated using toxicity equivalency factors (TEFs). TEFs serve to compare the toxicity of several PAHs to benzo(a)pyrene. TEFs were used to calculate the benzo(a)pyrene equivalent concentration for PAHs in soil on the site. This showed that for workers and children trespassers on the site, being exposed on a continual basis to the maximum concentrations of the PAHs could result in cancer risks higher than what environmental regulatory agencies typically consider unacceptable in terms of cleanup actions. It is unlikely, however that a person would have consistently been in contact with only the highest spot. For workers and children trespassers on the site, being exposed on a continual basis to the mean concentrations of the PAHs would result in cancer risks within the range typically acceptable to environmental regulatory agencies.
None of the estimated exposures to compounds that exceeded comparison values in sediment exceeded available ATSDR MRLs or EPA reference doses.
There is no friable asbestos present in any of the buildings on the site (Craffey 2000). Hence, the opportunity for exposure to friable asbestos material is no longer present at the site. While it is difficult to quantify the risk from past opportunities for exposure to asbestos, it is quite possible that there could have been opportunities for exposure at levels of health concern, particularly for those who might have trespassed on the site.
Three on-site soil samples were taken from locations near the fence on the southern side of the property. Three of the samples were tested for metals, VOCs, SVOCs, PAHs, PCBs, and pesticides. Arsenic was the only compound detected at a level greater than its comparison value. Each of the three detections were within the background concentrations for the eastern United States (i.e., observed ranges from less than 0.1 mg/kg to 73 mg/kg with a mean of 7.4 mg/kg for arsenic). However, due to the location and small number of samples, additional sampling information from along the fence on the southern side of the property would be useful.
The three off-site soil samples were taken from locations west and northwest of the site.
If the use of the site changes (e.g., development), the physical characteristics of the site changes (e.g., wooded areas would be cleared, construction activities occur), then the opportunities for exposure could possibly increase.
C. Health Outcome Data Analysis
This public health assessment has indicated that exposure, particularly to lead, cadmium, or PAHs in site soils or within the buildings might pose a risk for workers or trespassers on the site. The most recent health outcome data available for review include cancer incidence data from the Massachusetts Cancer Registry from 1993 through 1997 (MDPH 200a) and childhood lead poisoning prevalence data from 1990 through 1998 (MDPH 2000b). Based on a review of the literature, the cancer types most likely associated with opportunities for exposure of most concern at the site (e.g., ingestion of soil containing PAHs) include stomach, skin, and lung cancers. Information on lead poisoning prevalence is of interest because lead in soil is also a contaminant of concern.
Cancer incidence data for the years 1993 through 1997 were obtained from the Massachusetts Cancer Registry. To determine whether elevated numbers of cancer cases have occurred in Fairhaven, standardized incidence ratios (SIRs) were calculated by the MDPH's Bureau of Health Statistics, Research and Evaluation for the time period 1993 through 1997 (MDPH 2000a).
Table 10 summarizes cancer incidence data for the town of Fairhaven during the years 1993 through 1997. Review of available town-wide cancer incidence data for Fairhaven indicated that leukemia (4.02 expected vs. 11 observed) and non-Hodgkin's lymphoma (9.00 expected vs. 16 observed) were statistically significantly elevated among females in Fairhaven. Uterine cancer was also statistically significantly elevated (14.44 expected vs. 24 observed). Cancers of the lung and stomach, as well as melanoma (skin) occurred more often than expected, but no elevation achieved statistical significance. For lung cancer, 83 cases were observed vs. about 71 expected. Sixteen cases of melanoma occurred among males and females combined vs. about 12 expected cases. Eleven cases of stomach cancer occurred vs. about nine expected.
Review of available town-wide cancer incidence data for Fairhaven indicated that leukemia, non-Hodgkin's lymphoma, and uterine cancer were statistically significantly elevated among females. Uterine cancer is most strongly associated with nonenvironmental risk factors (e.g., family and reproductive history). MDPH further evaluated leukemia and non-Hodgkin's lymphoma among Fairhaven females. Addresses at the time of diagnoses were mapped. The majority of leukemia cases resided in a census tract other than that in which the Atlas Tack site is located and cases appeared widely distributed throughout Fairhaven.
It is important to note that there are four major types of leukemia, which have their own risk factors and characteristics: acute lymphoid leukemia (ALL), acute myeloid leukemia (AML), chronic lymphoid leukemia (CLL), and chronic myeloid leukemia (CML). ALL occurs predominantly among children. Exposure to ionizing radiation is a known risk factor and other risk factors (e.g., genetics) are suspected but not well established. In Fairhaven, 2 of the 11 leukemia cases among females occurred in children, and both children had ALL. CLL is primarily an adult disease, where ninety percent of individuals diagnosed with CLL are over the age of 50 years. Genetics, viruses, and diseases of the immune system have been suggested as playing a role in the development of CLL. In Fairhaven, two individuals were diagnosed with CLL and both were over the age of 70. The incidence of AML increases slightly in childhood and levels off through middle age and then rapidly increases in incidence after about age 55. High dose radiation exposure, exposure to benzene, and exposure to alkylating agents have been associated with increased risk of developing AML. In Fairhaven, five cases of AML occurred among females, with the age at diagnosis ranging from the upper 60s to the lower 90s. Thus, the age distribution for the different leukemia types diagnosed among Fairhaven females does not appear to be unusual relative to information from the medical literature.
As with leukemia, NHL cases among females appeared to be widely distributed throughout Fairhaven, with the majority of cases in census tracts other than that in which the Atlas Tack site is located. NHL occurs among all ages but the incidence of NHL generally increases with age. In Fairhaven, all but two of the sixteen cases occurred in individuals over the age of 50 years. The median age of diagnosis among Fairhaven females was 68 years. Several viruses have been shown to play a role in the development of NHL. Some occupations have also been associated with NHL, such as farming, herbicide and pesticide applicators, and grain workers.
Based on a review of the information about cancer incidence in Fairhaven as a whole and a more detailed review of those cancer types statistically significantly elevated for the town as a whole, it does not appear that the patterns of cancer incidence observed for the town as a whole suggest that the presence of the Atlas Tack site contaminants played a primary role.
Review of childhood lead poisoning prevalence data indicates that the rate of lead poisoning (i.e., blood lead level greater than or equal to 25 micrograms per deciliter [mg/dL]) over the time period from 1990 through 1998 was 2.41 per 1,000 for Fairhaven children screened compared to 2.15 per 1,000 for MA children screened (MDPH 2000b). Additionally, from July 1, 1993 to July 1, 2001, no cases of lead poisoning (i.e., blood lead levels greater than 25 mg/dL) were reported for residences on streets located near the site (MDPH 2000b).
D. ATSDR Child Health Initiative
ATSDR and MDPH, through ATSDR's Child Health Initiative, recognize that the unique vulnerabilities of infants and children demand special emphasis in communities faced with contamination of their environment. Children are at a greater risk than adults from certain kinds of exposure to hazardous substances emitted from waste sites. They are more likely exposed because they play outdoors and because they often bring food into contaminated areas. Because of their smaller stature, they might breathe dust, soil, and heavy vapors close to the ground. Children are also smaller, resulting in higher doses of contaminant exposure per body weight. The developing body systems of children can sustain permanent damage if certain toxic exposures occur during critical growth stages. Most importantly, children depend completely on adults for risk identification and management decisions, housing decisions, and access to medical care.
MDPH evaluated the likelihood of exposures to children from compounds in surface soil at the Atlas Tack site and the adjacent residential neighborhood. See section B above ("Evaluation of Possible Health Effects") for a discussion of these exposure scenarios. Because lead is a contaminant of concern at this site, MDPH also reviewed available information for childhood lead poisoning for the streets located near the site, town of Fairhaven, and for MA as a whole (please see "Health Outcome Data" section). This public health assessment was released for public comment and additional discussion regarding community health concerns are included in Appendix A.
The equation used to derive a comparison value for contaminants without a cancer slope factor was:
Cancer Risk = 1 x 10-6; SF = Slope Factor (mg/kg)-1; BW = Body Weight (kg);
CR = Consumption Rate (kg/d); RfD = Reference Dose (mg/kg/d); Comparison (or screening)
value is in mg/kg.
2. Mesothelioma is cancer of the thin membrane that surrounds the lung and other internal organs. It is invariably fatal within a few months of diagnosis (ATSDR 1995a).
| Exposure Dose (employee) | = | (max. contaminant concentration) (ingestion
rate) (exposure factor x 10-6) Body Weight |
| Exposure Factor | = | (5 days/week) (50 weeks/year) (40 years) (70 years) (365 days/year) |
| Ingestion Rate | = | 100 mg/day |
| Body Weight (adult) | = | 70 kg |
| Exposure Dose (child trespassing) |
= | (max. contaminant concentration) (ingestion
rate) (exposure factor x 10-6) Body Weight |
| Exposure Factor | = | (4 days/week) (39 weeks/year) (18 years) (18 years) (365 days/year) |
5. See footnote 3 on page 24.
6. See footnote 4 on page 24.
7. See footnote 3 on page 24.
8. See footnote 4 on page 24.
9. See footnote 3 on page 24.
10. See footnote 4 on page 24.
11. See footnote 3 on page 24.
12. See footnote 4 on page 24.
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