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PUBLIC HEALTH ASSESSMENT

BAYOU BONFOUCA
SLIDELL, ST. TAMMANY PARISH, LOUISIANA


ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS

A. On-Site Contamination

Soil

Throughout the history of plant operations, there have been numerous spills or releases of creosote at the site. Extensive soil contamination by creosote exists. Eight previously identified waste piles and two additional waste areas (the dredge-spoil piles along the EDC and the area identified as WP-8) were sampled during RI and Design Investigation (DI) explorations (Figure 5). The waste pile samples are composed of four types of materials: dry crust-like asphalt, tar, oil/water sludge, and dry creosote-contaminated wood waste material (Table A7). Analytical data reveals that shallow soils from 4 to 12 inches deep, underlying all waste piles, are contaminated by PAH compounds at concentrations above 100 ppm total PAH's (1) (2).

Soils sampled underneath the dredge spoil areas along the EDC do not exceed 100 ppm total PAH. The major PAH components of the waste pile samples are phenanthrene, fluoranthene, acenaphthene, naphthalene, and pyrene. The April 1986 RI showed the presence of 11 PAH compounds along with dibenzofuran and 2-methylnaphthalene in waste pile samples. The RI also reported the presence of six volatile organic compounds: 2-butanone, styrene, benzene, toluene, ethylbenzene, and total xylenes.

Seven stratigraphic soil layers have been identified at this site. The soil layers contain varying mixtures of silty sands, silty clays, clayey sands, sandy silty clay, and sands (3). The minimum depth of exploration for the soil borings was 73 feet. The soil samples, obtained from groundwater monitoring wells, hand augured borings, and a test pit, were checked for contamination by visual observations and by using an HNU photoionization detector. Chemical analyses were performed on all samples for volatile and semi-volatile organic compounds (Tables A8 and A9, and Figure 5). The soils were not tested for metals (3).

Groundwater

Creosote compounds from surface spills have migrated vertically downward and contaminated two of the three groundwater aquifers at the site (1). Groundwater is contained in three aquifers, namely, 1) the surficial aquifer, 2) the shallow artesian aquifer, and 3) the deep artesian aquifer. Although creosote contamination is evident in the surficial and shallow artesian aquifers, no human ingestion of the water contained in all three aquifers is occurring. Twenty groundwater monitoring wells were installed during the Remedial Investigation (1) (Figure 2A); thirty-eight were drilled, sampled, and installed during Design Investigation activities (Figure 2B). The results of inorganic and organic groundwater analyses range from not detectable to saturated or free phase (Tables A1, A2, A3, and A4 in Appendix A).

Surficial Aquifer

The surficial aquifer, when present, occurs in the uppermost strata. This strata consists primarily of silt and fill material associated with past plant operation activities. The aquifer ranges in thickness from 2 to 9 feet and averages in depth approximately 5 feet below the ground surface (+4 mean sea level). It is perched, unconfined and temporarily fills during precipitation events. It does not constitute an extensive, continuously saturated zone from which groundwater can be extracted economically and used as a public water supply.

The PAH contamination in this aquifer is present mainly in the bulkhead and process area near Well Nests A, B, and G (Figure 2A). The largest contaminated area was located in the plant's former operations area where free-phase creosote pools were observed at the surface. Two additional areas of free-phase creosote were located in the northwest corner of the site near the "D" well group and the Western Creek (Figure 3). Near the entrance to the site, free-phase creosote was found in borings T-18 and HA-C. The extent of the creosote was determined by borings and wells to the north, east, and south of the area. No western boundary has been established because of a utility trench to the west that prohibited additional borings. The western edge of the free-phase creosote plume was estimated to extend to the Western Creek. Along the Western Creek, boring NS-22 encountered creosote contamination at the 11 foot depth at a minimum concentration of 517 ppm (Figure 3). Well nests C, E, F, and H did not indicate any creosote contamination (Figure 2A).

Shallow Artesian Aquifer

Beneath the surficial aquifer, the shallow artesian aquifer consists of sands, silty sands, silts, and clays and ranges in thickness between 9 and 16 feet. The shallow artesian aquifer averages in depth approximately -11 to -18 feet below sea level. This confined zone is overlain by a 10 to 20 foot thick clay unit. The overlying clay strata is uniformly horizontal near the site but is absent in the bayou, presumably because of channel erosion or dredging.

The estimated extent of free-phase creosote contamination in the shallow artesian aquifer is evident in two main contaminated areas on-site (Figure 4). The largest area is located in the plant's former operations area. The extent of contamination lies beneath the bulkhead and process area. The second area is located along the Eastern Drainage Channel, and extends from the bulkhead and process area to includes wells OW-1B and B-2 and boring NS-18. Both wells contain distinct water and creosote phases.

The extent of the dissolved creosote plume on-site in the shallow artesian aquifer surrounds the areas containing free-phase creosote (Figure 4). Groundwater flow directions are radial on the site proper, and toward the bayou on both the east and west banks (except when the bayou stage is high and/or groundwater levels are low at which point the directions of flow reverse). When the water levels are high in the bayou proper, water flow is toward the site. When the water levels are low or during droughts, the water may flow from the site to the bayou. Results of groundwater chemical analyses indicate the dissolved plume areas have concentrations of total PAHs below 1 ppm. Elevated levels of iron and manganese in the shallow aquifer exceed drinking water standards but are believed to be background levels and not site-related contaminants.

Deep Artesian Aquifer

Beneath the shallow artesian aquifer lies the deep artesian aquifer at roughly -40 feet below sea level. It is the second confined aquifer encountered with depth. This zone consists of very clean, fine-to-medium grained quartz sand. The total thickness has not been confirmed with drilling but is believed to be a minimum of 10 feet thick.

The water table of the deep artesian aquifer is higher than the water table of the shallow artesian aquifer. Because of this elevation and pressure differential between the shallow and deep aquifers, no leakage from the shallow artesian aquifer into the deeper artesian aquifer is expected. During drilling or sampling of the wells in the deep artesian aquifer, no contamination was detected. The results of the chemical analyses, well observations, and field screening with an HNU photoionization meter all indicated that the deep artesian aquifer is not contaminated.

Air

During the first RI (1), a limited air quality survey was performed on-site in an area of major creosote contamination. Emissions of volatile organic vapors were monitored using an HNU photoionization detector while the soil was being disturbed. Weather conditions were deemed representative of the area. Readings were taken at regular 1 foot intervals beginning 3 inches to 25 feet downwind from the disturbed area; organic vapor concentrations above the minimum detection limit of the HNU were detected only at the station closest (3" station) to the disturbed area. The other readings did not record any volatile vapors (1).

Additional air monitoring was reported in a "Pilot Study Report" (July 16, 1990) as part of the Source Control OU. The ambient air monitoring characterized air quality conditions on-site prior to remediation efforts. The air monitoring detected naphthalene in concentrations of 5 to 11 ppb in two of the five sample stations (3).

B. Off-Site Contamination

Groundwater

Before remediation, water flow in the shallow artesian aquifer transported contamination off-site. An area of free-phase creosote contamination in this aquifer was encountered off-site in five wells. These wells contained high levels of creosote contamination which ranged from visible sheen to saturated subsurface conditions.

Two plumes with different creosote phases exist in the shallow artesian aquifer. The dissolved plume occurs off-site along the east bank of the bayou near the water's edge. The free-phase creosote plume occurs along the west bank of the bayou in the shallow artesian aquifer. This contamination is believed to be the result of the presence of free creosote in both the shallow artesian aquifer and the bayou to the east (3).

Sediment

Two phases of off-site sediment sampling were conducted in Bayou Bonfouca, the Western Creek, and the Eastern Drainage Channel. Sediment sampling consisted of a total of 63 boreholes. The stream bed of Bayou Bonfouca was cored in 55 locations ranging from approximately 300 feet upstream of the confluence of Western Creek and the Bayou, to approximately 4,000 ft. downstream of the confluence of the Eastern Drainage Channel and the Bayou. Eight additional cores were drilled, four in the Western Creek and four in the Eastern Drainage channel (Figures 5 and 6).

Extensive creosote contamination exists in the bayou sediments. The horizontal extent of creosote contamination in bayou sediment appears to be defined by Borings BB-1 in the north and BB-56 and BB-57 in the south (Figure 6). Creosote contamination appears to extend beneath the east bank in Sections 12-14 near the water's edge. On the west side of these sections and in sections downstream from Section 14 (to approximately 4,000 ft. downstream of the turning basin), creosote contamination appears to be restricted to bayou sediment and has not migrated beneath the bayou banks (3). In 1981, pentachlorophenol (PCP) was detected in two sediment samples located downstream of the site at the boat landing. The low levels that were detected of PCP did not pose a health threat (9).

The depth of sediment contamination in the bayou extends down to the shallow artesian aquifer from the turning basin to approximately 500 ft. downstream of the turning basin. In this area, the contamination is not limited to the bayou sediment, but extends several feet below it. In Sections 12-14, contamination was only found in the bayou sediment, and extends into the shallow artesian aquifer on the east side of the bayou (Figure 6). Downstream of Section 14, contamination does not extend into the shallow artesian aquifer and often does not penetrate to the bottom of the sediment. PAH concentrations greater than 1,300 ppm, the EPA Action Level for total PAHs in soils, were not encountered in any of the borings. These borings from Bayou Bonfouca represent a sediment cross-section approximately 4000 ft. downstream from the turning basin (3).

The EPA Remedial Investigation states that contamination levels above Environmental Protection Agency's remedial action level of 1,300 ppm for total PAHs were found in all of the borings in the Eastern Drainage Channel. The depth of creosote contamination ranged from 2.6 to 6.1 feet below the bottom of the channel (1).

In the Western Creek (WC), WC-3 was the only boring with total PAH levels greater than 1,300 ppm. Because WC-1 and WC-2 were not highly contaminated, it is assumed that the creosote released near Boring WC-3 was not of sufficient volume to flow into the bayou. Contamination is limited to a depth of approximately 3 feet in a single isolated area at boring WC-3 (1).

Surface Water

Surface water samples from the bayou and the EDC were collected and analyzed during the second RI and DI explorations. Although oily sheens were visible during 1980 on the water in the bayou, only low levels of contamination (160-628 ppb) were detected in the bayou water (9). Minor concentrations of organic compounds were detected in the EDC samples. During a preliminary study on the effects of dredging bayou sediments for remediation, PAH compounds were shown to be released from the bayou sediments into the water column (2) (3). Visual inspection in April 1994 confirmed the presence of oily sheens on the water during the dredging operations. A boom in the bayou prevented the oily sheen from flowing downstream.

Biota

During 1981, the Center for Bio-Organic Studies at the University of New Orleans collected biota from Bayou Bonfouca. The biota were analyzed for metals and PAHs. The samples included plankton, blue crabs, and clams. The plankton and blue crabs were indigenous. The clams were suspended in the bayou at a location 1 mile downstream from the site and were not indigenous to the site. While analyses of the bayou waters did not detect PAH's, the biota sampled had total PAH concentrations of 210 parts per million (ug/g) in plankton; 170 ug/g in crabs; and up to 0.6 ug of benzo (a) pyrene per gram of wet tissue in the clams (8).

Three blue crabs were sampled in three different locations in Bayou Bonfouca: 1) 0.35 mile south of the turning basin, 2) 0.6 mile south of the turning basin, and 3) Bayou Bonfouca adjacent to Southern Shipyards (south of the site). The three blue crabs that were sampled had very low levels of PAH contamination which did not pose a health threat. However, the blue crabs did contain elevated levels of mercury and lead (9). Mercury concentrations in the crabs ranged from 20 - 250 ppb while lead concentrations ranged from 560 - 16,400 ppb. These metals have not been associated with the site. Since both crabs and fish are caught in the vicinity of the site, it is assumed that any fish or shellfish from the bayou may contain PAH's and/or heavy metals.

LDEQ posted an advisory against fish/shellfish consumption and swimming along a seven-mile length of Bayou Bonfouca on November 24, 1987; the advisory remains in effect during remediation and will be re-evaluated when new data becomes available.

Toxic Chemical Release Inventory (TRI)

A search of the Toxic Chemical Release Inventory was made by zip code for the Bayou Bonfouca area. No reportable discharges were indicated.

C. Quality Assurance and Quality Control

The analyses and conclusions presented in this Public Health Assessment are based on the data contained in the reports submitted to the EPA by CH2M Hill. The validity of the conclusions drawn are determined by the accuracy and reliability of the referenced information. The contractor at this site, CH2M Hill, upon review of the analyses, states that all the data are acceptable and reliable.

D. Physical and Other Hazards

The site visits in 1991 and 1994 included inspection of the site for hazards. The site itself is fenced and does not present an easy route for entrance either by land or water. The main hazards associated with this site appear to be swimming in the bayou, contact with the sediment and ingestion of contaminated biota. There are numerous warning signs and no one was observed in the water during the site visits. During the site visit on April 20, 1994, signs along the fences warned the public of the hazardous waste site and cautioned people to stay away. There was a guard on duty limiting access to the site and remediation workers were busy dredging the bayou and incinerating contaminated sediments.

 

PATHWAYS ANALYSES

To determine whether nearby residents are exposed to contaminants migrating from the site, ATSDR evaluates the environmental and human components that lead to human exposure. This pathways analysis consists of identifying five elements. These elements are: 1) a source of contamination, 2) transport through an environmental medium, 3) a point or location of exposure, 4) a route of human exposure, and 5) an exposed population.

ATSDR categorizes an exposure pathway as a completed or potential exposure pathway if the exposure pathway cannot be eliminated. Completed pathways require that the five elements exist and indicate that exposure to a contaminant has occurred in the past, is presently occurring, or will occur in the future. Potential pathways, however, require that at least one of the five elements is missing, but could exist. Potential pathways indicate that exposure to a contaminant could have occurred in the past, could occur now, or could occur in the future. An exposure pathway can be eliminated if at least one of the five pathways is missing and will never be present. Table 1 identifies the completed exposure pathways, and Table 2 identifies the potential exposure pathways. Some of the exposure pathways that have been eliminated are also discussed.

A. Environmental Pathways

Soils/Sediments

Completed past exposure pathways are possible from contact with site soils prior to the time the site was fenced; a potential future pathway could exist if the site's security is not maintained (See Human Pathways: Dermal and Ingestion). Contact with site soils and waste piles by remediation workers may constitute a present and future completed pathway if workers do not take protective measures. Remediation of the site is currently being conducted and is expected to conclude in 1996.

Completed past, present, and future pathways also exist through contaminants bound to soil particulates being transported off-site as fugitive dusts. Fugitive dusts may travel off-site during the remedial incineration process (See Human Pathways: Ingestion).

In addition, completed past, present and future exposure pathways are possible from human contact with contaminated bayou sediments during swimming. Presently, the bayou is posted with signs warning against swimming. Potential completed present and future pathways are possible if the signs warning against swimming are not heeded (See Human Pathways: Dermal).

Drinking Water

Exposure to site contaminants through area drinking water is not a completed exposure pathway. There are 11 known wells within a 1-mile radius of the site. These wells have been drilled through the shallow artesian aquifer to deeper aquifers. The water is primarily used for residential air conditioning and heat pump units. Spent water goes to the sewer lines or to surface drainage systems to the bayou. These wells are not used for human consumption and therefore are not considered a route for human exposure to contaminants.

The city of Slidell has a municipal water supply that draws from deeper aquifers (-2300 ft. level). Testing of the city wells and others in the vicinity of the site during RI and DI activities did not find any contamination in these wells.

Air

The air pathway constitutes completed present and future exposure pathways because of the possibility of air releases during incineration of the contaminated sediments and soils during remediation (See Human Pathways: Inhalation). Safety precautions such as air monitoring and the use of personal protection equipment have been adopted by LDEQ and USEPA to protect remedial workers and the public (See Recommendations).

Biota

Studies by the University of New Orleans demonstrated contamination of crabs and plankton from Bayou Bonfouca and clams suspended in the bayou within a mile of the site proper. Human ingestion of contaminated blue crabs and shellfish constitutes a completed past pathway and potential present and future pathways (See Human Pathways: Ingestion). No in situ fish (finfish) samples from the area were taken. However, there are signs warning against consumption of fish in the bayou. Fish consumption is considered a potential present and future exposure pathway if the warning signs are not heeded.

B. Human Exposure Pathways

Dermal Contact

Dermal contact with contaminated soils and bayou sediments constitute human exposure pathways (See Environmental Pathways: Soils/Sediments). Prior to the time the site was fenced, it was accessible to the general population. During remediation, on-site workers may engage in remedial activities which result in exposure unless they consistently use personal protective equipment or materials. Because the bayou is shallow, those who swim or wade in it are also at risk of dermal exposure to contaminants in sediments.

Ingestion

Ingestion of contaminated soil particles could occur during remediation and excavation if workers fail to take precautionary measures or if dust control is not properly carried out (See Recommendations). Those close to the site could also be exposed to dusts transported from the site. Dust control should prevent this from occurring (See Recommendations). Ingestion of contaminated bayou sediments or water by swimmers is also a possibility.

Ingestion of contaminated seafood (fish and shellfish) has occurred in the past and may occur in the present and future. These organisms are known to bioaccumulate PAH compounds. Sampling done in connection with remedial activities indicated that the levels of PAH compounds in crabs were elevated and human consumption should be limited. An advisory was issued by the Department of Environmental Quality in November, 1987. The bayou is posted with warning signs and as long as the advisory is heeded, such exposure will not occur. However, ingestion of contaminated seafood prior to the establishment of the advisory occurred and future ingestion by those not heeding warning signs is possible.

Inhalation

During RI and DI activities, the potential for human inhalation of contaminated air was explored. Ambient air monitoring at the site did not indicate significant concentrations of site contaminants. However, inhalation of contaminants during remediation remains a potential exposure pathway (See Recommendations). Workers on-site will be at the greatest risk of exposure and will be required to take protective measures. There are also school children, industrial workers, and residential populations close to the site who may be exposed to creosote fumes from dredging operations at the site. LDEQ is currently conducting air monitoring to guard against unsafe releases.

Table 1. Completed Pathways for Bayou Bonfouca

Pathway Name Source Media Point of Exposure Route of Exposure Exposed Population Time
soil OAC* soil OAC dermal OAC workers, tresspassers, people using the bayou past
present
fugitive dusts OAC* soil particulates in air property line and off-site inhalation

ingestion

residents of Bayou Bonfouca past
present
future
bottom sediments OAC* sediment Bayou Bonfouca dermal swimmers

fishers

past
air OAC incineration air property line and off site inhalation residents of Bayou Bonfouca past
present
future
biota OAC/Slidell fish

shellfish

Bayou Bonfouca ingestion local fish eaters past
present

* Old American Creosote facility which comprises the Superfund site.

Table 2. Potential Exposure Pathways

Pathway Name Source Media Point of Exposure Route Exposed Population Time
Unremediated soil OAC* soil OAC, Bayou Bonfouca dermal people using the bayou future
Unremediated sediments OAC* bottom sediments Bayou Bonfouca dermal people not following the advisory present
future

* Old American Creosote facility which comprises the Superfund site.

 

 

PUBLIC HEALTH IMPLICATIONS

A. Toxicological Evaluation

In this section, we will discuss the health effects in persons exposed to specific contaminants, evaluate state and local health databases, and address specific community health concerns. To evaluate health effects, ATSDR has developed a Minimal Risk Level (MRL) for contaminants commonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to a contaminant below which non-cancer, adverse health effects are unlikely to occur. MRLs are developed for each route of exposure, such as ingestion, dermal contact and inhalation, and for the length of exposure, such as acute (less than 14 days), intermediate (15 to 364 days), and chronic (greater than 365 days). ATSDR presents these MRLs in Toxicological Profiles for many environmental contaminants. These chemical-specific profiles provide information on health effects, environmental transport, human exposure, and regulatory status. In the following discussion, we used ATSDR Toxicological Profiles for mercury, trichloroethene, and lead.

PAHs

PAH's may be absorbed through intact human skin. Dermal exposure to certain PAH's, such as anthracene and phenanthracene, followed by exposure to sunlight may result in phototoxic effects such as erythema (redness of the skin), urticaria (elevated patches of skin), burning and itching. Acute dermal contact with naphthalene results in skin irritation. Other PAH's, particularly benzo(a)pyrene and benzo(a)anthracene, and some mixtures of PAH's, have been shown to be carcinogenic in experimental animal studies by all routes of exposure for which humans may be exposed. Skin cancers have been induced in a variety of animals at very low levels of application. No length of exposure was specified in the animal studies. Epidemiological studies of workers occupationally exposed to PAH's have provided limited evidence that PAH exposure may contribute to increased incidence of skin, lung, and urinary tract cancers (11, 12, 13). EPA has classified benzo(a)pyrene as a probable human carcinogen, (ie. sufficient animal evidence and limited human evidence has been established).

Dermal exposure to the maximum concentrations of PAH's found at the site may have caused skin irritation for anyone who came in contact with contaminated soils and sediments. Inhalation of particulates or vapors has not been shown to be occurring at levels where health would be impacted, but remains a potential exposure for unprotected remediation workers and populations residing or attending school in proximity to the site during remediation (See Recommendations). Ingestion of shallow groundwater is not of concern because it is not used for drinking purposes.

Ingestion of contaminated fish and shellfish prior to the establishment of the advisory against consumption in 1987 has increased the cancer risk of these consumers above the level of 1E-4 used as a risk index by the Louisiana Office of Public Health. Sampling of crabs during remedial activities indicated concentrations of mercury and lead at levels at which consumption should be limited. Further characterization of the potential health risks due to human consumption of local fish and shellfish is necessary (See Recommendations).

While attempts have been made to eliminate present exposure to site contaminants, populations potentially exposed in the past include on-site workers and visitors during the period that the site was operating (1892-1970), those swimming or eating fish and shellfish from Bayou Bonfouca, and those who came in contact with contaminated site soils prior to the site being fenced.

B. Health Outcome Data Evaluation

The health outcome data that were evaluated addressed health concerns by the local community. The only data systematically collected over time is data that addresses chronic, long-term health consequences. Chronic health consequences associated with PAHs are malignant melanoma and cancers of the lung and urinary system. To assess these health outcomes, diagnosed cases of cancers by age, sex, and anatomic site in the Slidell area and South Louisiana were obtained from the Louisiana Tumor Registry for the years 1983 to 1987 for Slidell and for the years 1983 to 1986 for South Louisiana (10) (See Appendix B). Cancer incidence data for Slidell is not available before 1983. Based on occupational exposure levels to PAH's, the following acute health problems may occur: eye irritation, headaches, confusion, excitement, profuse sweating, nausea, and vomiting. These acute outcomes are difficult to analyze due to a lack of data.

The creosote facility operated from 1892 to 1970. Based on the data available, one can not rule out that human exposure occurred during any period of operation of the site. In 1986, a Preliminary Health Assessment concluded that the site posed a public health threat for persons using Bayou Bonfouca for swimming and fishing. Therefore, if cancer outcomes are associated with past exposures to site-related contaminants, the time period during which cancers might be expected to appear would be from 1907 to 2001 or later. This assumes a 15-year minimum period between exposure and onset of disease.

Cancer data from the Tumor Registry were evaluated for all cancers based on toxicological implications. These include cancers of the urinary system: bladder, kidney, renal pelvis, ureter, and other urinary organs (International Classification of Disease-Oncology, code 188.0 - 189.9); the combined cancers of the trachea, bronchus, and lung (code 162.0, 162.2 - 162.9) and malignant melanoma (173.0 - 173.9). Malignant melanoma is the only cancer of the skin reported in the Registry. In addition to these three histological cancer sites, all-sites cancer was also examined.

To calculate incidence rates, population figures for 1980 were obtained for Census Tracts 408 - 411 and 412.03 (1980 census figures are the most current population figures available for the Slidell area). These Census Tracts incorporate the zip code delivery zones 70458, 70459, 70460, and 70461 which make up the Greater Slidell Area. This area includes the incorporated city of Slidell with a total population of 26,718. Because cancer cases are coded to zip code, it is not possible to desegregate the available data (on number of cases and population size) to a division smaller than the Greater Slidell Area. Consequently, there is a large degree of incongruence between the residential area within 1 mile proximity of the site and the operationally defined site population which is used in the analysis (See Appendix B and Figures B1, B2 & Table B1).

The descriptive information analyzed allows one to determine if an excess of disease has occurred in the Greater Slidell Area relative to South Louisiana. Statistically significant excesses were reported for the lung cancer rate and the rate of all-sites combined. When cases of lung cancer are removed from the all-sites combined category, the significant excess remains. While these elevated rates warrant further interpretation, there is no plausibility for a completed exposure pathway explaining them.

The principal limitation of the analysis is the geographic coverage of the data. The incongruence between the 1 mile area surrounding the site and the operationally defined site population prevents the direct analysis of cancer incidence in the site area. Another limitation inherent with this type of descriptive evaluation is the lack of adjustment for all established risk factors. Without more information on other known risk factors, it is not possible to explain why the rates for the Greater Slidell area are more elevated than South Louisiana's rates.

C. Community Health Concerns Evaluation

The LOPH determined community health concerns by attending LDEQ and EPA open houses. The LDEQ and EPA has held open houses in the community a few times a year since 1985. The most recent open house was in April, 1994 and focused mainly on remedial activities currently underway at the site and the recent accidental release of lime over a six block area adjacent to the site. Regional Representatives of ATSDR attended several of these meetings and during the past year representatives from LOPH have attended all of the open houses and made themselves available to address health related questions. Citizen participation has varied with attendance figures ranging from 20 to 100 people per meeting. However, during the Public Meeting to address the draft Public Health Assessment in December of 1993, no community members attended. During the various contact with the community, the following health concerns were voiced:

  1. Could exposure to site contaminants be related to cases of dermal irritation reported by local residents?

  2. Could exposure to site contaminants be related to cases of cancer reported by local residents?

  3. Are bayou shellfish contaminated with site chemicals?

  4. Will the smoke from the incinerator pose a hazard to my health?

  5. Is the Bayou safe to swim in near Palm Lake (2 1/2 miles south of the site)?

  6. The smell of Creosote is strong now that they are dredging the bayou. Is this smell going to effect my health?

We have addressed each of the community concerns about health as follows:

  1. Could exposure to site contaminants be related to cases of dermal irritation reported by local residents?

    Yes. It is possible that, prior to the time the site was fenced, dermal contact with the highest levels of PAH's on-site resulted in cases of dermal irritation. Such exposure is not expected as long as the site remains securely fenced and people do not trespass. Present contact with the highest levels of PAH's in bayou sediment could also result in dermal irritation. An advisory against swimming, fish/shellfish consumption, and sediment contact in the bayou was issued on November 24, 1987. It should be heeded.

  2. Could exposure to site contaminants be related to cases of cancer reported by local residents?

    PAH's are probable human carcinogens. Cancers associated with exposure to PAH's are lung, skin, and urinary tract. Long-term exposure with the contaminant detected at Bayou Bonfouca may increase a person's risk of developing these cancers. However, the contribution of risk from the contaminant is difficult to determine in the absences of knowledge about other known risk factors such as lifestyle, behavior, diet, and medical history.

  3. Are bayou shellfish contaminated with site chemicals?

    Three blue crabs were sampled from Bayou Bonfouca by the University of New Orleans in 1981. Elevated levels of the site contaminant (PAHs) were not detected in the crabs but clams suspended in the bayou did accumulate PAHs during a short time period. Metals analyses indicated elevated levels of mercury and lead (non-site contaminants) in the blue crabs. An advisory against consumption of fish/shellfish from the Bayou was issued on November 24, 1987. It should be heeded. Further characterization of area biota has yet to be performed (See Recommendations).

  4. Will the smoke from the incinerator pose a hazard to my health?

    Occupational Safety and Health Act (OSHA) safeguards against worker exposure are being implemented and the LDEQ conducts air monitoring to guard against unsafe releases. If releases from the site are detected at elevated levels that pose a health risk, remedial activities will stop (See Recommendations).

  5. Is the Bayou safe to swim in near Palm Lake (2 1/2 miles south of the site)?

    Releases of polyaromatic hydrocarbons into the bayou from the Bayou Bonfouca site and other industrial complexes as well as urban runoff into the bayou suggest that public health may be impacted if swimming occurs in the area. Sampling data of surface water and sediment from Palm Lake is needed to determine is swimming near Palm Lake poses any health threat.

  6. The smell of creosote is strong now that they are dredging the bayou. Is this smell going to effect my health?

    Continuous air monitoring during dredging is being performed to protect the remedial workers who are closest to the site contaminants. This air monitoring is designed to warn the workers if levels of PAHs in air exceed federal health guidelines. If they do, dredging will cease and no community residents will be exposed. Site workers must adhere to OSHA safeguards and wear face masks to protect their lungs from fumes from contaminants.

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