PUBLIC HEALTH ASSESSMENT
FLORIDA PETROLEUM REPROCESSORS
DAVIE, BROWARD COUNTY, FLORIDA
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
In this section, we review the environmental data collected at the site, evaluate sampling adequacy, and identify contaminants with the greatest potential of harming health (contaminants of concern). We select contaminants of concern based on the following factors:
1. Concentrations of contaminants on and off the site.
We compare maximum concentrations at the site with published ATSDR standard
comparison values. ATSDR's published standard comparison values are media-specific
concentrations used to select contaminants for further evaluation. They are
not used to predict health effects or to select clean-up levels. Contaminants
with media concentrations above an ATSDR standard comparison value do not necessarily
represent a health threat, but are selected for further evaluation. Contaminants
with concentrations below an ATSDR standard comparison value are unlikely to
cause illness and are not evaluated further, unless the community has specific
concerns about the contaminant.
2. Field data quality, laboratory data quality, and sample design.
3. Community health concerns.
4. Completed and potential exposure pathways.
5. Toxicological Information.
We compare maximum concentrations with toxicological information including information
from ATSDR toxicological profiles. These profiles are chemical specific and
summarize toxicological information found it the scientific literature.
We used the following ATSDR standard comparison values (ATSDR 1998a), in order of priority, to select contaminants of concern.
Identifying a contaminant of concern does not necessarily mean that exposure to a contaminant will be associated with illnesses. Identification serves to narrow the focus of the public health assessment to those contaminants most important to public health. We evaluate the contaminants of concern in subsequent sections and decide whether exposure has public health significance.
Environmental sampling data for contaminants of concern is summarized in Tables 1 through 8 in the Appendix.
Because groundwater contamination has public health implications extending beyond the FPR property and includes most of the south Peele-Dixie Well field, we defined the site as the area bounded by Peters Road on the north, US Highway 441 on the east, the Florida Turnpike on the west, and Oakes Road on the south (Figure 3). We subdivided the site into northern and southern areas using the New River Canal as the dividing line (Figures 4 and 5). Three groundwater exposure sources were analyzed: groundwater directly under the FPR property; groundwater outside of the FPR property but south of the New River Canal; and, groundwater outside of FPR property, north of the New River Canal (Figure 4 and 5).For soil and sediment contamination, we refer to the area outside and inside the fenced FPR property. We defined all soil and sediment contamination as on site.
Groundwater directly under the FPR Property
The source of groundwater contamination is spilled waste oil and volatile organic compounds (VOCs). Some lighter VOCs float on the top of the aquifer (water table). Other heavier VOCs sank to the bottom of the aquifer, or deep groundwater (EPA 1997).
The EPA sampled 40 wells within the fenced FPR property. The highest number and highest concentrations of contaminants were detected under the FPR property. Groundwater is discolored and has a distinct sweet odor indicative of solvents. Contaminated soil and chemicals floating on top of the water are the source of contamination and continue to dissolve in the groundwater thereby increasing concentrations since 1989 (EPA 1997). See Table 1 in the Appendix for the maximum levels of chemicals of concern and their screening values.
Groundwater Contamination outside of FPR Property
The EPA sampled 72 wells outside of the fenced property and one production well north and south of the New River Canal. Natural attenuation (breakdown) and a change in groundwater flow has reduced contamination of the Biscayne aquifer since 1992, but a distinct area of groundwater contamination still exists. The area of groundwater contamination is 8,000 feet long (more than 1½ miles). It is about 2,800 feet (or more than ½ mile), wide under FPR property (south of New River Canal). It is 1,300 feet wide (about 1/4 mile) under the wellfield, north of New River Canal. EPA's 1997 Remedial Investigation revealed groundwater in the Biscayne aquifer is currently migrating southeast - identical to the regional groundwater flow path.
Contamination was detected from the 190-200 foot sample in the lower portion of the Biscayne Aquifer, indicating that contamination has spread to the entire vertical extent of the aquifer, including the drinking water aquifer. The deeper contamination under FPR property migrated north to the Peele-Dixie wellfield. See Table 2 and 3 in the Appendix for the maximum levels of chemicals of concern and their screening values.
Surface Soil in the fenced FPR property (0-2 feet)
The EPA sampled 19 surface soil locations within the fenced area. See Table 4 in the appendix for the maximum levels of chemicals of concern and their screening values.
Subsurface Soil in the fenced FPR property (greater than 2 feet deep)
Soil contamination under the fenced property increases with depth. Soils greater than 4 feet below the surface, near the water table, are the most highly contaminated. Contaminants pool in the soil just above the water table and contribute to the groundwater contamination. See Table 5 in the appendix for the maximum levels of chemicals of concern and their screening values.
Surface Soil outside of the fenced FPR property (0-2 feet deep)
The EPA sampled five locations outside of the FPR property. Three samples were south and southeast of the fenced property and two samples were north of FPR in the southern portion of the Peele-Dixie wellfield. See Table 6 in the appendix for the maximum levels of chemicals of concern and their screening values.
Subsurface Soil outside of the fenced FPR property(Greater than 2 feet deep)
The EPA sampled five locations outside of the FPR property. See Table 7 in the appendix for the maximum levels of chemicals of concern and their screening values.
Sediment
The EPA sampled sediment in five locations in the drainage ditch outside of the fence. All sediment sampling locations receive runoff from the Florida Turnpike. They detected polycyclic aromatic hydrocarbons (PAHs) which are components of asphalt pavement and automobile oil and fuel. The EPA found low levels of metals and pesticides probably due to past agricultural activities in the area. See Table 8 in the appendix for the maximum levels of chemicals of concern and their screening values.
Surface Water
Most of the property runoff flows into SW 50th Street and can flow into wetlands south of the property. The wetlands discharge into the Florida Turnpike drainage system (channels, culverts and a borrow pit lake northwest of the property). The EPA collected five surface water samples from the drainage ditch between FPR property and the Florida Turnpike and two from the North New River Canal. The EPA did not find any organic chemicals, elevated metals, pesticides or polychlorinated biphenyls (PCBs).
Air
There is no air monitoring data. Therefore, FDOH cannot assess the public health threat from breathing site-related contaminants. We do not expect significant air contamination from soil because contamination is concentrated below the surface. We do not expect significant air contamination from groundwater into ambient outdoor air.We assessed the release of chemicals from household use of contaminated water using levels of contaminants in groundwater and modeling levels of chemicals released into the air.
We did not define any areas as off-site. We defined the site as the area bounded by Peters Road on the north, US Highway 441 on the east, the Florida Turnpike on the west, and Oakes Road on the south (Figure 3).The EPA defined the on-site area as the FPR property and all other areas as off-site.
C. Quality Assurance and Quality Control
In preparing this public health assessment, FDOH relied on the existing environmental data. We assumed consultants who collected and analyzed these samples followed adequate quality assurance and quality control measures concerning chain-of-custody, laboratory procedures, and data reporting. The completeness and reliability of the referenced information determines the validity of the analyses and conclusions drawn for this public health assessment.
In each of the preceding subsections, we evaluated the adequacy of the data to estimate exposures. We assumed that estimated data was valid because chemicals were found in the samples, but the exact amount was unknown. We did not include presumptive data because the exact amount and the identity of the chemicals was unknown. We did not carry tentatively identified compounds through the quantitative assessment due to uncertainty surrounding their identification and concentration (EPA 1989).
Inside the FPR property are two trailers, a shed, old FPR tanks in the containment structure, heavy equipment, old cars, tires, furniture and pluming pipes from the containment structure. Potentially, a trespasser could fall on the debris; however, since the property is not near residential areas, this possibility seems remote.
To identify industrial facilities that could contribute to the contamination near this site, we searched the EPA Toxic Chemical Release Inventory (TRI) databases. The EPA developed TRI from the chemical release information (air, water, and soil) provided by certain industries. We found two nearby facilities, using ZIP codes, reporting releases from 1987-1993. These ZIP codes covers an area including FPR and the Peele-Dixie wellfield. However, these facilities did not report releases of the same chemicals found at FPR.
The amount of contact that people have with hazardous substances is essential to assessing the public health significance of a chemical. Chemical contaminants in the environment have the potential to harm human health, but only if people have contact with those contaminants.
An exposure pathway is the way an individual comes into contact with contaminants. To decide whether nearby residents have contacted contaminants at the site, we looked at the human exposure pathways. An exposure pathway consists of five elements: The first element is an original source of contamination, like an industrial site. The second element is an environmental media, like air or groundwater, that moves contamination from the source to a place where people can contact the contamination. The third element is a place where people could contact the contaminated soil or groundwater, like topsoil or a drinking water well. The fourth element is the route of exposure, like drinking contaminated water or touching contaminated soil. The fifth element is a group of people who can potentially come in contact the contamination, like people living or working near the contaminated site. A completed exposure pathway includes all of these elements.
An exposure pathway is eliminated if at least one of five elements is missing and will never be present. For completed pathways, all five elements exist and exposure to a contaminant has occurred, is occurring, or will occur. For potential pathways, exposure to a contaminant could have occurred, could be occurring, or could occur in the future.
The public health findings for communities surrounding the FPR site are based on a review of past and present environmental data to identify past, present, and future exposure pathways. We identified exposure pathways that we determined are of public health significance in this assessment (See Table 9 in the Appendix).
A. Completed Exposure Pathways
Groundwater north of the New River Canal
Groundwater north of the New River Canal was a completed exposure pathway in the past.
The Peele-Dixie wellfield is contaminated and there are seven private wells remaining in the
area. Currently these homes are supplied with municipal water, but it is possible that they
may still be using their private wells. Routes of exposure would include ingestion, dermal contact and inhalation of volatilized contaminants.
B. Potential Exposure Pathways
Groundwater north of the New River Canal
A future potential exposure pathway may result from contaminated groundwater north of the
New River Canal. We do not expect people using municipal water to become exposed
because it is unlikely the city will pump from the wells in the future if the aquifer is still
contaminated. However, people may potentially become exposed to contaminated
groundwater from drinking or washing with private well water in this area.
Groundwater south of the New River Canal
A future potential exposure pathway may result from contaminated groundwater south of the
New River Canal from drinking or washing with private well water. Residences are over the
contaminated aquifer and no restrictions exist to prevent property owners from drilling a well
into the contaminated aquifer. Current and past potential exposure pathways do not exist
because no private wells have been identified in this area.
Groundwater under the fenced FPR property
The aquifer under the property is contaminated but there are currently no drinking water
wells on the property. However, there are no deed or other restrictions preventing new
drinking water wells on the FPR property. If land use at the site changes in the future, the exposure pathway may also change.
Surface soil and sediment outside of the fenced FPR property
Future exposure pathways may result from contaminated surface soil outside of the FPR
fenced property and contaminated sediment in the drainage ditch between the FPR
property and the Florida Turnpike. There are no controls to limit human exposure to
surface soil outside of the fenced area. If more people start living in the area, they may
come in contact with the contaminated surface soil or sediment through ingestion or dermal
contact
C. Eliminated Exposure Pathways
Subsurface soils (inside and outside of the fenced FPR property)
Subsurface soil is contaminated but currently there is no access to this soil. If, in the
future, remediation activities or building activities disturb the subsurface soil, the exposure pathway may be completed.
Surface soil inside the fenced FPR property
The FPR property is fenced and there are not many people living close to the property that would trespass.
Surface Water
There is currently no contamination in the surface water.
We estimated exposures that people might be exposed to by calculating a dose based on levels of contaminants in the various media (See Attachment 1).
Health Guidelines
To evaluate each contaminant of concern, we compared our estimate of exposure with EPA health guidelines. These health guidelines provide perspective on the relative significance of human exposure to contaminants at the site. These values alone, however, cannot determine the potential health threat of a particular chemical. If exposure estimates were less than the health guideline, the contaminant was not evaluated further. If exposure estimates exceeded the health guideline or if there was no health guideline, exposure estimates were compared with doses in human or animal studies.
For non-cancerous contaminants of concern, the estimated exposure doses were compared to health guidelines such as ATSDR's Minimal Risk Level (MRL's) and EPA's Reference Doses (RfD's; see Table 10). RfD's and MRL's are an estimate of daily exposure of a human being to a chemical that should not cause illness over a specified length of exposure (EPA 1989). When multiple MRLs were available for a specific chemical, we used long-term MRLs as the first preference followed by intermediate and acute MRLs.
We eliminated chemicals if they were below MRLs or well below levels reported it the toxicological literature. These chemicals included methyl butyl ketone (2-hexanone), dibutylphthalate, naphthalene, methylene chloride, aluminum, lead, copper, endrin aldehyde, chloromethane, 1,1,2,2-tetrachloroethane, bromodichloromethane, polycyclic aromatic hydrocarbons, 2-methylphenol (o-cresol), 1,1-dichloroethane, cobalt, tetrachloroethene (PCE), benzene and chloroethane (ATSDR 1992a,1999a, 1995a, 1993a, 1997a, 1997b, 1990a, 1996a, 1997f, 1996b, 1989, 1995b, 1992b, 1990b, 1992c, 1997d, 1995c, 1997e). We discussed the chemical further if it was above the MRL. We do not have enough information to assess the health effects of 2-methylnaphthalene, carbazole or dibenzofuran.
For cancerous contaminants of concern, FDOH compared estimates of exposure to EPA's cancer potency factors. We used a potency factor to estimate an upper-bound probability of an individual developing cancer from a lifetime of exposure to a particular level of a potential carcinogen (ATSDR 1992). The basis for estimating carcinogenic risk for humans based on animal studies is that there is no threshold exposure; the risk of cancer has some possibility at any and all exposures. Each exposure carries with it some degree of risk, regardless of how small. Therefore, 'safe exposure' is defined in terms of a reasonable or acceptable degree of risk (for example, one in one million) rather than zero (Williams 1985). We defined the degree of risk for a low increased risk as one in ten-thousand; the degree of risk for a moderate increased risk as one in one-thousand and the degree of risk for a high increased risk as one in one-hundred. When examining cancer risks, it is important to recognize the background cancer rate in United States is about 25% or 250 in one-thousand (ATSDR 1993b).
Trichloroethene (TCE)
Some residents in the area could be potentially exposed to TCE in the future through
groundwater under the FPR property.
Groundwater under FPR property
Drinking and Breathing
A child's future potential exposure from drinking TCE contaminated groundwater
from under the FPR property is 16 times higher than ATSDR's oral MRL.
There is evidence that TCE causes birth defects (increased fetal heart abnormalities)
in rats (ATSDR 1997 f). There is limited evidence that oral exposure to TCE
in drinking water may cause birth defects in humans; those studies have mixed
results. Therefore, we estimate that some children would be at an increased
risk of developmental effects such as heart abnormalities if their mother's
drink the contaminated groundwater under the FPR property. Since no one is using
the groundwater under the FPR property, currently there is little risk of illnesses
from groundwater.
A child's future potential exposure from breathing TCE released into indoor air from household use of groundwater under the FPR property is 360 times higher than ATSDR's inhalation MRL (ATSDR 1997 f). The MRL is based on neurological effects (decreased wakefullness during exposure and decreased heart rate) in rats. Our estimate is 5 times lower than the lowest exposure (dose) causing eye irritation, and neurological effects (headaches, fatigue and drowsiness) in people. Since TCE was used as an anesthetic in the past, it can depress the nervous system in people (ATSDR 1997 f). Therefore, we estimate that some residentsmay be at an increased risk of neurological effects if they use contaminated groundwater under the FPR property. Since no one is using the groundwater under the FPR property for household use, currently there is little risk of illnesses from groundwater.
Cancer Risk
The EPA classified TCE as a probable-possible human carcinogen based on animal
studies. However, the American Conference of Governmental Industrial Hygienists
(ACGIH) classified TCE as "not suspected as a human carcinogen". The available studies
are inconclusive. The EPA has not developed a potency factor to compare an adult's oral
or inhalation exposure (ATSDR 1997 f). We are unable to determine the increased risk of
cancer, if any, from TCE at FPR.
1,1,1-Trichloroethane
Some residents in the area could be potentially exposed to 1,1,1-trichloroethane in the
future through groundwater under the FPR property.
Groundwater under the FPR property
Drinking Breathing
ATSDR does not have an oral MRL and EPA does not have an oral reference dose to compare drinking 1,1,1-trichloroethane contaminated groundwater. A child's exposure from potentially drinking contaminated groundwater under the site is more than 270 times lower than the lowest exposure (dose) causing adverse effects in humans (ATSDR 1995a). We do not expect illnesses from exposure to 1,1,1-trichloroethane by drinking groundwater under the FPR property.
ATSDR does not have an oral MRL and EPA does not have an oral reference dose to compare drinking 1,1,1-trichloroethane contaminated groundwater. A child's future exposure from potentially breathing 1,1,1-trichloroethane released into indoor air from household use of groundwater under the FPR property is more than 36 times higher than ATSDR's inhalation MRL (ATSDR 1995 d). The MRL is based on the lowest exposure dose causing adverse neurological effects (decreased psychomotor performance) in people. Since the MRL is based on adverse effects in people, we estimate some residents would be at an increased risk of neurological effects if they use 1,1,1-trichloroethane contaminated groundwater under the FPR property for household use. Since no one is using the groundwater under the FPR property, currently there is little risk of illnesses from 1,1,1-trichloroethane in groundwater under the FPR property.
Cancer Potential
At this time, it does not appear 1,1,1-trichloroethane exposure poses a clear cancer risk in
animals. Studies available do not allow a definitive assessment of the risk of cancer in
humans. The EPA classified 1,1,1- trichloroethane as "not classifiable" for carcinogenicity
to humans. The EPA has not developed a potency factor to compare an adult's oral or
inhalation exposure (ATSDR 1995 d). We are unable to determine the increased risk of
cancer, if any, from 1,1,1-trichloroethane at FPR.
1,1-Dichloroethene
Some residents in the area could have been exposed to 1,1-dichloroethene in the past
through groundwater north of the New River Canal. They could potentially be exposed to
1,1-dichloroethene in the future through groundwater south of the New River Canal and
groundwater under the FPR property.
Groundwater south of the New River Canal
Drinking and Breathing
A child's potential exposure from drinking 1,1-dichloroethene-contaminated water south of the New River Canal is lower than ATSDR's oral MRL and EPA's reference dose. Therefore, we do not expect any adverse heath effects from children or residents drinking groundwater south of the New River Canal for household purposes.
A child's potential exposure from breathing 1,1-dichloroethene released into indoor air from household use of groundwater south of the New River Canal is slightly higher than ATSDR's inhalation MRL (ATSDR 1994a). The MRL is based on the lowest exposure dose that did not cause adverse effects in mice. Although our estimate of a child's exposure to 1,1-dichloroethene from breathing contaminated indoor air from household use of groundwater south of the New River Canal is above the ATSDR MRL, we do not expect any health effects. Our estimate of a child's exposure is 500 times less than the lowest exposure (dose) causing adverse effects (kidney damage) in mice. There is no data on kidney damage in people. Animal studies show prolonged exposure does not cause adverse kidney effects and short-term exposure effects are reversible. Although the effects of 1,1-dichloroethene in people are not known, they are probably minimal at concentrations generally experienced at hazardous waste sites (ATSDR 1994a). Therefore, we do not expect any adverse heath effects from children or residents using groundwater south of the New River Canal for household purposes.
Groundwater under the FPR property
Drinking and Breathing
A child's future potential exposure from drinking 1,1-dichloroethene-contaminated
groundwater under the FPR property is 17 times higher than ATSDR's oral
MRL (ATSDR 1994a). The MRL is based on the lowest exposure (dose) causing adverse
effects (liver cell changes) in rats. We estimate that residents would be at
an increased risk of liver damage if they use 1,1-dichloroethene contaminated
groundwater under the FPR property. However, no one is drinking the groundwater
under the FPR property. Currently there is little risk of illnesses from 1,1-dichloroethene
in groundwater.
A child's future potential exposure from breathing 1,1-dichloroethene released into indoor air from household use of groundwater under the FPR property is about 122 times higher than ATSDR's inhalation MRL. The MRL is based on an exposure dose that did not cause adverse effects in animals. Our estimate of a child's exposure is only 4 times lower than the lowest exposure (dose) causing adverse effects (kidney damage) in mice (ATSDR 1994a). There is no data on kidney damage in people. Animal studies show prolonged exposure to low levels does not cause adverse kidney effects and short term exposure effects are reversible. Although the effects of 1,1-dichloroethene in people are not known, they are probably minimal at concentrations generally experienced at hazardous waste sites (ATSDR 1994a). Therefore, we do not expect any adverse heath effects from household use of groundwater under the FPR property.
Cancer Potential
The EPA classified 1,1-dichloroethene as a possible human carcinogen. 1,1-Dichloroethene has caused kidney cancer in mice (ATSDR 1994a).
Groundwater north
of the New River Canal
FDOH estimates that some adults would be at a low increased risk of kidney cancer
if they drank this 1,1-dichloroethene contaminated groundwater over a lifetime.
We estimate that some adults would be at a low increased risk of kidney cancer
if they breathe 1,1-dichloroethene released into the air from household use
of this groundwater over a lifetime.
Groundwater south
of the New River Canal
We estimate that some adults would potentially be at a low increased risk of
kidney cancer if they drank this 1,1-dichloroethene contaminated groundwater
over a lifetime. We estimate that some adults would be at a moderate increased
risk of kidney cancer if they use this 1,1-dichloroethene contaminated groundwater
for household use over a lifetime.
Groundwater under
the FPR Property
We estimate that some adults would potentially be at a high increased risk of
kidney cancer if they drink this 1,1-dichloroethene contaminated groundwater
over a lifetime. We estimate that some adults would be at a very high increased
risk of kidney cancer if they use this 1,1-dichloroethene contaminated groundwater
for household use over a lifetime.
1,2-Dichloroethene
Some residents in the area could be potentially exposed to 1,2-dichloroethene (total) and
cis-1,2-dichloroethene in the future through groundwater from under the FPR property. We
discuss exposure to 1,2-dichloroethene (total) as a worst case scenario since it was
detected in higher levels in the groundwater.
Groundwater under the FPR Property
Drinking and Breathing
A child's future potential exposure from drinking 1,2-dichloroethene (total)
contaminated groundwater under the FPR property is 21 times higher than
ATSDR's oral MRL for chronic exposure to trans-1,2-dichloroethene (the most
conservative isomer screening value). The MRL is based on an exposure dose that
did not cause adverse effects in animals. There are no human studies available,
however, our estimate was 22 times lower than the lowest exposure (dose)
causing adverse effects (liver and circulatory system effects) in rats (ATSDR
1996c). Even though our exposure dose is lower than the dose causing adverse
effects in animals, people may be exposed to additional 1,2-dichloroethene from
other sources from the urban environment around FPR increasing the actual dose
they receive. At high levels, it is reasonable to expect liver and cardiovascular
effects among humans (ATSDR 1996c). Based on animal and human studies and the
potential for additional exposure, we estimate that some residents might be
at an increased risk of liver and circulatory system effects if they use 1,2-dichloroethene
(total)-contaminated groundwater from under the FPR property. Since no one is
using the groundwater under the FPR property, currently there is little risk
of illness from groundwater.
A child's future potential exposure from breathing 1,2-dichloroethene (total) released into indoor air from household use of groundwater under the FPR property is 337 times higher than ATSDR's MRL. The MRL is based on studies showing adverse effects such as immunological effects (fatty accumulation in Kupfeer cells, decreased leukocyte count), liver effects (slight fatty accumulation), and respiratory effects (slight capillary hyperemia and alveolar system distention) in rats (ATSDR 1996c). Adverse effects to the liver and respiratory system can be expected in people at higher doses, but the data on immunological effects is too limited to draw any conclusions. Even though our dose is slightly lower than the dose that caused adverse effects in animals, people may be exposed to additional 1,1-dichloroethene from other sources like the urban environment around FPR increasing the actual dose they receive. Based on animal and human studies and the potential for additional exposure, we estimate that some residents would be at an increased risk of adverse immunological, liver and respiratory effects if they use 1,2-dichloroethene (total) contaminated groundwater under the FPR property for household use. Since no one is using the groundwater under the FPR property, currently there is little risk of illness from groundwater.
Cancer Potential
Cancer effects of 1,2-dichloroethene have not been studied in humans or animals. The EPA has not developed a potency factor to compare an adult's oral or inhalation exposure (ATSDR 1996c). We are unable to determine the increased risk of cancer, if any,
from 1,2-dichloroethene (total) at FPR.
Vinyl Chloride
Some residents in the area could have been exposed to vinyl chloride in the past through
groundwater north of the New River Canal. Some residents in the area could be potentially
exposed to vinyl chloride in the future through groundwater north and south of the New
River Canal groundwater from under the FPR property.
Groundwater north of the New River Canal
Drinking and Breathing
A child's exposure from drinking vinyl chloride-contaminated water north of
the New River Canal is 70 times higher than ATSDR's oral MRL. The MRL
is based on the lowest exposure dose causing adverse liver effects (basophilic
foci of cellular alteration) in rats (ATSDR 1997 g). Changes in liver cellular
structure have been observed in people expose to vinyl chloride via inhalation.
Based on these human studies and animals studies supporting liver damage when
vinyl chloride is eaten, we estimate that residents would be at an increased
risk of liver damage if they drink vinyl chloride contaminated groundwater north
of the New River Canal.
A child's exposure from breathing vinyl chloride released into indoor air from using contaminated groundwater north of the New River Canal is slightly higher than ATSDR's inhalation MRL. Although our estimate of a child's exposure to vinyl chloride is above the ATSDR MRL, we do not expect any health effects. Our estimate was almost 118,000 times lower than the lowest exposure (dose) that did not cause adverse effects in people (ATSDR 1997 g).
Groundwater south of the New River Canal
Drinking and Breathing
A child's potential exposure from drinking vinyl chloride-contaminated water
south of the New River Canal is 260 times higher than ATSDR's oral MRL.
The MRL is based on the lowest exposure dose causing adverse liver effects (basophilic
foci of cellular alteration) in rats (ATSDR 1997 g). Changes in liver cellular
structure have been observed in people expose to vinyl chloride via inhalation.
Based on these human studies and animals studies supporting liver damage when
vinyl chloride is given orally, we estimate that residents would be at an increased
risk of liver damage if they drink vinyl chloride-contaminated groundwater south
of the New River Canal.
A child's potential exposure from breathing vinyl chloride released into indoor air from using groundwater south of the New River Canal is 4 times higher than ATSDR's inhalation MRL. Although our estimate of a child's exposure to vinyl chloride is above the ATSDR MRL, we do not expect any health effects. Our estimate was almost 32,000 times lower than the lowest exposure (dose) that did not cause adverse effects in people (ATSDR 1997 g).
Groundwater under the FPR Property
Drinking and Breathing
A child's future potential exposure from drinking vinyl chloride contaminated
groundwater under the FPR property is 14,000 times higher than ATSDR's
oral MRL. The MRL is based on the lowest exposure dose causing adverse liver
effects (basophilic foci of cellular alteration) in rats (ATSDR 1997 g). Changes
in liver cellular structure have been observed in people expose to vinyl chloride
via inhalation. Based on these human studies and animals studies supporting
liver damage when vinyl chloride is given orally, we estimate that residents
would be at an increased risk of liver damage if they use vinyl chloride contaminated
groundwater under the FPR property.
A child's potential exposure from breathing vinyl chloride released into indoor air from using groundwater under the FPR property is almost 230 times higher than ATSDR's inhalation MRL. The MRL is based on studies showing liver effects (increased liver weight) in rats. Our estimate was almost 600 timeslower than the lowest exposure (dose) that did not cause adverse effects in people. We do expect adverse effects from vinyl chloride released into the air from household use of groundwater under the FPR property.
Cancer Potential
The EPA classified vinyl chloride as a human carcinogen. A large number of studies have
reported a greater than expected incidence of a rare type of cancer, angiosarcoma of the
liver, among workers breathing air contaminated with vinyl chloride. In addition, these
workers have had increased cancer of the brain, central nervous system, lung and
respiratory tract, and the lymphatic/hematopoietic system. Although no human studies
examine cancer from ingesting vinyl chloride, animal studies support cancer from ingesting vinyl chloride (ATSDR 1997 g).
Groundwater north
of the New River Canal
We estimate that some adults would be at a moderate increased risk of cancer
if, in the past, they drank this vinyl chloride contaminated groundwater over
a lifetime. We estimate that some adults would be at a moderate increased risk
of cancer if, in the past, they used this vinyl chloride contaminated groundwater
for household use over a lifetime.
Groundwater south
of the New River Canal
We estimate that some adults would be at a moderate increased risk of cancer
in the future if they drink or use this vinyl chloride contaminated groundwater
over a lifetime.
Groundwater under
the FPR property
We estimate that some adults would be at a very high increased risk of cancer
in the future if they drink this vinyl chloride contaminated groundwater over
a lifetime. We estimate that some adults would be at a very high increased risk
of cancer in the future if they use this vinyl chloride contaminated groundwater
for household use over a lifetime.
Toluene
Some residents in the area could be potentially exposed to toluene in the future through
groundwater under the FPR property.
Groundwater under the FPR property
Drinking and Breathing
A child's future potential exposure from drinking toluene-contaminated water
under the FPR property is lower than EPA's reference dose (ATSDR 1994b).
Exposures below a reference dose are unlikely to cause adverse effects, therefore,
we do not expect any adverse effects from toluene by drinking groundwater under
the FPR property.
A child's future potential exposure from breathing toluene released into indoor air from household use of groundwater under the FPR property is 2 times higher than ATSDR's inhalation MRL. The MRL is based on the lowest exposure dose causing adverse effects (lower test scores for spacial tests) in humans (ATSDR 1994b). Since the is based on adverse effects observed in people, we estimate that some residents would be at an increased risk of adverse neurological effects if they use toluene-contaminated groundwater under the FPR property. Since no one is using the groundwater under the FPR property, currently there is little risk of illness from groundwater.
Cancer Potential
None of the available data suggest that toluene is carcinogenic (ATSDR 1994b). We are
unable to determine the increased risk of cancer, if any, from toluene at FPR.
3,4-Dimethylphenol
Some residents in the area could be potentially exposed to 3,4-dimethylphenol in the future through groundwater under the FPR property.
Groundwater under the FPR property
Drinking and Breathing
A child's future potential exposure from drinking 3,4-dimethylphenol contaminated
groundwater under the FPR property is 2 times higher than EPA's reference
dose. The reference dose is an estimate of daily exposure to the human population,
including sensitive subgroups like children and the elderly, which will not
cause illness. The reference dose is based on the lowest exposure dose that
did not cause adverse effects in rats. Although our estimate of a child's exposure
to 3,4-dimethylphenol from FPR is above the reference dose, we do not expect
any illnesses. Our estimate was 7000 times lower than the lowest exposure dose
causing adverse effects (blood pressure changes and body weight and pathological
changes in liver kidney, liver and spleen) in rats (IRIS 1998).
We do not have enough information to assess potential exposures from breathing indoor air with 3,4-dimethylphenol contaminated groundwater (Risk Assistant 1994).
Cancer Potential
The EPA has not evaluated 3,4-dimethylphenol for evidence of human carcinogenic
potential. We are unable to determine the increased risk of cancer, if any, from 3,4-dimethylphenol at FPR (IRIS 1998).
Manganese
Some residents in the area could have been exposed to manganese in the future through
groundwater under the FPR property.
Groundwater under the FPR property
Drinking
A child's future potential exposure from drinking manganese contaminated groundwater
under the FPR property is slightly higher than EPA's reference dose for
manganese in water (ATSDR 1997h). Although our estimate of an adult's exposure
to manganese is above the MRL, we do not expect any illnesses. Our estimate
was about 10 times lower than the lowest exposure dose causing adverse effects
(mild neurological signs) in people (ATSDR 1997h).
Cancer Potential
The information on the carcinogenic potential of manganese is limited and the results are
difficult to interpret. The results of animal studies and human studies suggest the potential
for cancer in humans is probably low. The EPA classified manganese as not classifiable
as to its carcinogenicity to humans. They have not developed a potency factor to compare
an adult's oral or inhalation exposure (ATSDR 1997h). We are unable to determine the
increased risk of cancer, if any, from manganese at FPR.
There are about 1800 children under the age of nine living in the area bounded by Peters Road on the north, US Highway 441 on the east, the Florida Turnpike on the west, and Oakes Road on the south (Figure 3). We do not know how many children live in the homes on S.W. 77th Terrace with private wells. About 700 children under age nine live in the area south of the New River Canal. It is unlikely children could come into contact with contaminated surface soil both on FPR property and outside FPR property because the site is surrounded by large highways and the main property is fenced. Since children represent a sensitive subpopulation, we used children specific exposure scenarios to estimate the potential threat (See Toxicological Evaluation Section).
C. Community Health Concerns Evaluation
In this subsection, we address the community health concerns in terms of our findings presented in the Toxicological Evaluation subsection above.
Although we interpret the health concerns in terms of our toxicological findings, it is important to remember that many individual symptoms, conditions, and illnesses reported by the community have more than one cause. Similarly, any one suggested cause may be associated with many different illnesses. It is not the intention of this review to link a particular case of an illness with exposure to site chemicals. Our findings in this subsection suggest health problems that are possible, instead of health problems that are likely.
We address community health concerns as follows:
1. A few residents were concerned about poor water quality and carcinogens in municipal (Peele-Dixie wellfield) water.
The city is currently not using the southern Peele-Dixie wellfield to serve the area and it is reasonable to expect they will not use the wellfield in the future if the is aquifer still contaminated. Past exposures are unlikely because water from the south Peele-Dixie wellfield is combined with groundwater from many different wells before treatment and distribution. Therefore, the concentration of volatile organic compounds in contaminated wells were likely diluted before distribution.
2. One person was concerned about multiple chemical sensitivity.
There are no set, well defined symptom or diagnostic criteria in the medical community for "multiple chemical sensitivity." Multiple chemical sensitivity has been cited for over 100 common problems, ranging from headaches to dizziness to trouble sleeping. There are no verifiable, reliable, or valid measurements a person can undergo to determine whether or not a person suffers from this ailment. Until there is more research on multiple chemical sensitivity, we are unable to draw any conclusions about its association with the Florida Petroleum Reprocessors site.
3. One person was concerned about asthma.
Asthma primarily affects the bronchial tube system. Asthma is a very treatable disease either by eliminating the causes or with appropriate treatment. The substances producing asthma vary widely, as do some of the immunologic responses (Williams 1985). Without more definitive information on exposure, it is very difficult to draw any conclusions about its association with the Florida Petroleum Reprocessors site.
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