PUBLIC HEALTH ASSESSMENT
AGRICO CHEMICAL CO.
PENSACOLA, ESCAMBIA, FLORIDA
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
In this section, we review the environmental data collected at this site. We evaluate the adequacy of the sampling that has been conducted, select contaminants of concern, and list the maximum concentration and frequency of detection of the contaminants found in various media. The maximum concentrations found are then compared to background levels and to standard comparison values. The following comparison values are used in the data tables:
2. EMEG--Environmental Media Evaluation Guide--derived from ATSDR's Minimal Risk Level (MRL), which provides a measure of the toxicity of a chemical, is the estimate of daily human exposure to a chemical that is likely to be without an appreciable risk of adverse effects, generally for a period of a year or longer.
3. LTHA--Lifetime Health Advisory for Drinking Water--is EPA's estimate of the concentration of a contaminant in drinking water at which adverse health effects would not be anticipated to occur over a lifetime of exposure. LTHAs provide a safety margin to protect sensitive members of the population.
4. MCL--Maximum Contaminant Level--is the contaminant concentration that EPA considers protective of public health over a 70 year lifetime at an exposure rate of 2 liters of water per day. MCLs are regulatory concentrations.
5. RMEG--Reference Dose Media Evaluation Guide--is calculated from the EPA Reference Dose (RfD)--EPA's estimate of the daily exposure to a contaminant that is unlikely to cause adverse health effects. Similar to EMEGs, RMEGs are estimated contaminant concentrations at which daily exposure would be unlikely to cause a noncarcinogenic health effect.
We have reviewed the environmental sampling data collected at this site and selected the following chemicals as contaminants of concern:
| Arsenic Chromium Fluoride |
Lead Manganese Polycyclic Aromatic Hydrocarbons (PAHs) |
Sulfate Vanadium |
We selected these contaminants based on the following factors:
The PAHs of concern at the Agrico site are: benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benz(a)anthracene, chrysene, dibenz(a,h)anthracene and indeno(1,2,3-c,d)pyrene. All of these chemicals are possible or probable human carcinogens. However, an ATSDR comparison value is available only for benzo(a)pyrene. Consequently, although all of these chemicals are listed in the tables in Appendix B, analysis of the potential health effects from exposure to them will be based primarily on the levels of benzo(a)pyrene found in the various media at this site.
Twenty-nine chemicals were found in various media on the Agrico site at a level below health concern. In addition, 22 other chemicals were detected for which there is insufficient human health data to determine their public health significance. The chemicals in both these categories are listed in Appendix C. Two possible human carcinogens, 1,1-dichloroethane and 4-methylphenol (p-cresol), were detected only in groundwater at this site. We eliminated them from further consideration because direct human exposure to groundwater is not likely. See the Pathways Analysis section for details.
Identification of a contaminant of concern in this section does not necessarily mean that exposure will cause adverse health effects. Identification serves to narrow the focus of the health assessment to those contaminants most important to public health. When selected as a contaminant of concern in one medium, we have also reported that contaminant in all other media. We will evaluate these contaminants in subsequent sections and determine whether exposure has public health significance.
To identify industrial facilities that could contribute to the contamination near the Agrico Chemical Co. site, we searched the EPA Toxic Chemical Release Inventory (TRI) database for 1987-1991. EPA developed TRI from the chemical release information (air, water, and soil) provided by certain industries. The TRI search revealed one industry, Florida Drum Company at 10 Spruce St., within a one mile radius of the site that reported releases of toxic chemicals. Between 1987 and 1991, Florida Drum Co. reported releasing to the air a total of 151,223 pounds of mixed xylenes and 202,564 pounds of methyl ethyl ketone (2-butanone). Florida Drum Co. estimated annual air releases for 1992 and 1993 of 35,300 pounds of mixed xylenes and 41,700 pounds of methyl ethyl ketone.
Both methyl ethyl ketone (2-butanone) and xylene are used as paint thinners, solvents, and cleaning agents. They easily evaporate into the air and can cause irritation of the nose, throat, eyes, and skin. Based on limited information, neither is thought to be carcinogenic (ATSDR 1990c and 1992a). Only xylene was detected at the Agrico site.
In this assessment, the contamination that exists on the site will be discussed first, separately from the contamination that occurs off the site.
For the purposes of this evaluation, "on-site" is defined as the Agrico Chemical Co. property within the fenced boundary as shown in Figure 4, Appendix A.
We compiled data in this subsection from the following sources: FDEP groundwater investigation reports (Watts et al 1988, Watts and Wiegand 1989) and EPA reports (EPA 1983, Geraghty & Miller 1992a, 1992b).
Surface Soil
EPA collected a total of 57 surface soil samples (depth 0-6 inches) from various locations on the site between 1983 and 1992 (EPA 1983, Geraghty & Miller 1992a, 1992b) (Figure 5, Appendix A). Fluoride was the only contaminant of concern which was analyzed for in background surface soil samples on-site; its concentration was at a level below the comparison value.
Arsenic, benzo(a)pyrene, chromium, and fluoride levels in on-site surface soil samples exceeded the corresponding comparison values (Table 1, Appendix B). Lead was detected in all 18 samples at a maximum concentration of 46,000 milligrams per kilogram (mg/kg) and sulfate was detected in 3 of 13 samples at a maximum concentration of 1,000 mg/kg. No ATSDR soil comparison values are available for these chemicals. For this assessment, these samples were adequate to characterize the on-site surface soil quality.
Subsurface Soil
EPA collected a total of 157 subsurface soil samples (depth greater than 6 inches) from various locations on the site during 1992 (Geraghty & Miller 1992a, 1992b) (Figure 6, Appendix A). Arsenic, chromium, lead and sulfate were the only contaminants of concern anlayzed for in background subsurface soil samples on-site. Arsenic was found at a level above the comparison value; sulfate was not detected.
Arsenic, benzo(a)pyrene, chromium, fluoride, manganese, and vanadium levels in on-site subsurface soil exceeded the corresponding comparison values (Table 2, Appendix B). Lead was detected in 76 of 80 samples at a maximum concentration of 3,800 mg/kg and sulfate was detected in 11 of 56 samples at a maximum concentration of 9,100 mg/kg. No ATSDR soil comparison values are available for these chemicals. For this assessment, these samples were adequate to characterize the on-site subsurface soil quality.
Surface Water
EPA collected a total of five surface water samples from the wastewater holding ponds on the site during 1983 (EPA 1983) (Figure 7, Appendix A). No background samples were collected.
Fluoride, manganese and vanadium levels in on-site surface water exceeded the corresponding comparison values (Table 3, Appendix B). Arsenic and lead were not detected in any samples. No samples were analyzed for PAHs or chromium. Sulfate was detected in all five samples at a maximum concentration of 2,600,000 micrograms per liter (µg/L). This exceeds the Florida Secondary Drinking Water Standard for sulfate of 250,000 µg/L. No ATSDR comparison value is available for sulfate. Because no recent samples from the wastewater holding ponds have been analyzed and this water may be impacting on the groundwater quality at the site, we do not consider these samples adequate to characterize the on-site surface water quality. However, because the ponds do not contain permanent standing water, sample collection may not always be possible.
Shallow Groundwater
FDEP and EPA collected a total of seven shallow groundwater samples (depth less than 150 ft.) from two locations on the site during 1988 and 1992 (Watts et al 1988, Geraghty & Miller 1992a, 1992b) (Figure 8, Appendix A). No background samples were collected.
Arsenic, fluoride and manganese levels in on-site shallow groundwater exceeded the corresponding comparison values (Table 4, Appendix B). PAHs, chromium and vanadium were not detected in any samples. Lead was detected in 4 of 7 samples at a maximum concentration of 6.6 µg/L. This level is below the Florida Maximum Contaminant Level (FLMCL) of 15.0 µg/L. Sulfate was detected in all 7 samples at a maximum concentration of 94,000 µg/L. This is below the Florida Secondary Drinking Water Standard for sulfate of 250,000 µg/L. No ATSDR comparison values are available for these chemicals. For this assessment, these samples were adequate to characterize the on-site shallow groundwater.
Deep Groundwater
FDEP and EPA collected a total of eight deep groundwater samples (depth greater than 150 ft.) from two locations on the site during 1988, 1989 and 1992 (Watts et al 1988, Watts and Wiegand 1989, Geraghty & Miller 1992a, 1992b) (Figure 9, Appendix A). No background samples were collected.
The level of arsenic in on-site deep groundwater exceeded its comparison value (Table 5, Appendix B). PAHs and chromium were not detected in any samples. No samples were analyzed for manganese or vanadium. Lead was detected in 1 of 6 samples at a concentration of 6.7 µg/L. This level is below the FLMCL of 15.0 µg/L. Sulfate was detected in all 8 samples at a maximum concentration of 34,000 µg/L. This is below the Florida Secondary Drinking Water Standard for sulfate of 250,000 µg/L. No ATSDR comparison values are available for these chemicals. For this assessment, these samples were adequate to characterize the on-site deep groundwater.
Waste Sludge
EPA collected a total of 41 waste sludge samples from various locations on the site during 1983 and 1992 (EPA 1983, Geraghty & Miller 1992a, 1992b) (Figure 10, Appendix A). Waste sludge at the Agrico site is the residue from evaporation of wastewater discharged to holding ponds on the site. It has been described as a white or gray, spongy, crystalline or gelatinous material that is very soft and fine-grained with little structural strength. It is readily distinguished from the native soil which is an orange to brown firm, dense sand (EPA 1983, Watts et al 1988, Geraghty & Miller 1992a).
Arsenic, benzo(a)pyrene, chromium, fluoride, manganese and vanadium levels in on-site waste sludge material exceeded the corresponding comparison values (Table 6, Appendix B). Lead was detected in all six samples at a maximum concentration of 6,900 mg/kg and sulfate was detected in 5 of 12 samples at a maximum concentration of 9,100 mg/kg. No ATSDR comparison values are available for these chemicals. For this assessment, these samples were adequate to characterize the on-site waste sludge material.
For the purposes of this evaluation, "off-site is defined as the area outside the boundary fence around the Agrico Chemical Co. property as shown in Figure 4, Appendix A.
We compiled data in this subsection from the following sources: FDEP groundwater investigation reports (Watts et al 1988, Watts and Wiegand 1989) and EPA reports (Geraghty & Miller 1992a, 1992b).
Surface Soil
EPA collected a total of 16 surface soil samples (depth 0-6 inches) from various locations off of the site during 1992. Sample locations were chosen based on aerial photographs indicating the presence of a possible wood treatment facility to the east of the site and a drainage ditch running south of Fairfield Drive along the now-present Gulf Power right-of-way. Apartment complexes and residences are now in both of these locations (Geraghty & Miller 1992b) (Figure 11, Appendix A). PAHs, fluoride and lead were not detected in off-site surface soil background samples.
Benzo(a)pyrene and fluoride levels in off-site surface soil samples exceeded the corresponding comparison values (Table 7, Appendix B). No samples were analyzed for arsenic, chromium, manganese, sulfate or vanadium. Lead was detected in the three samples for which it was analyzed at a maximum concentration of 110 mg/kg. No ATSDR soil comparison value is available for lead.
The EPA Remedial Project Manager for the Agrico site has indicated that off-site surface soil sample analysis was limited primarily to fluoride because it was always found in association with other contaminants on the site. Since this site is adjacent to other industrial facilities, it is possible that contaminants found in off-site soil may have originated from a source other than the Agrico site. Fluoride is a contaminant unique to the Agrico site and it was assumed that if fluoride was not present in off-site surface soil samples, no other site-related contaminants would be present (Goldberg pers comm 1994). However, no surface soil samples from the off-site baseball fields were analyzed and many contaminants of concern have not been analyzed for in off-site surface soil. Without this information, we cannot definitely conclude that no off-site surface soil contamination exists at a level of health concern. Consequently, we do not consider these samples adequate to characterize the off-site surface soil.
Subsurface Soil
EPA collected a total of 24 subsurface soil samples (depth greater than 6 inches) from various locations off of the site during 1992 (Geraghty & Miller 1992b) (Figure 12, Appendix A). PAHs, fluoride and lead were not detected in off-site subsurface soil background samples.
Benzo(a)pyrene and fluoride levels in off-site subsurface soil exceeded the corresponding comparison values (Table 8, Appendix B). No samples were analyzed for arsenic, chromium, manganese, sulfate or vanadium. Lead was detected in all three samples at a maximum concentration of 37 mg/kg. No ATSDR soil comparison value is available for lead. For this assessment, these samples are adequate to characterize the off-site subsurface soil.
Shallow Groundwater
FDEP and EPA collected a total of 26 shallow groundwater samples (depth less than 150 ft.) from various locations off of the site during 1988 and 1992 (Watts et al 1988, Geraghty & Miller 1992a, 1992b) (Figure 13, Appendix A). Arsenic, PAHs, chromium and vanadium were not detected in off-site shallow groundwater background samples.
Arsenic, chromium and fluoride levels in off-site shallow groundwater exceeded the corresponding comparison values (Table 9, Appendix B). Lead was detected in 5 of 26 samples at a maximum concentration of 11 µg/L. This level is below the FLMCL of 15.0 µg/L. Sulfate was detected in 22 of 26 samples at a maximum concentration of 290,000 µg/L. This exceeds the Florida Secondary Drinking Water Standard for sulfate of 250,000 µg/L. No ATSDR comparison values are available for these chemicals.
Fluoride, which indicates the presence of site-related contaminants in the shallow groundwater, extends about one mile southeast of the site. Contaminants of concern, such as arsenic, chromium and lead, are currently confined to within one-quarter mile southeast of the site. There are no public or private drinking water wells using shallow groundwater in this direction from the site. For this assessment, these samples are adequate to characterize the off-site shallow groundwater.
Deep Groundwater
FDEP and EPA collected a total of 73 deep groundwater samples (depth greater than 150 ft.) from various locations off of the site during 1988, 1989 and 1992 (Watts et al 1988, Watts and Wiegand 1989, Geraghty & Miller 1992a, 1992b) (Figure 14, Appendix A). Arsenic, PAHs, chromium, and lead were not detected in off-site deep groundwater background samples.
Arsenic, chromium, and fluoride levels in off-site deep groundwater exceeded the corresponding comparison values (Table 10, Appendix B). No samples were analyzed for manganese or vanadium. Lead was detected in 10 of 47 samples at a maximum concentration of 27.2 µg/L. This level exceeds the FLMCL of 15.0 µg/L. Sulfate was detected in 63 of 73 samples at a maximum concentration of 784,000 µg/L. This exceeds the Florida Secondary Drinking Water Standard for sulfate of 250,000 µg/L. No ATSDR comparison values are available for these chemicals.
Fluoride, which indicates the presence of site-related contaminants in the deep groundwater, is present in monitoring wells about one and one-quarter miles east southeast of the site and has recently reached Bayou Texar. Sulfate has also been found in pore water samples from the bayou. Other contaminants, such as arsenic, chromium and lead have not been detected in monitoring wells more than three-quarter miles from the site. There are no public or private drinking water wells in this direction from the site. Although fluoride is entering Bayou Texar from the groundwater plume, the maximum concentration is insufficient to exceed the Florida surface water standard for fluoride (Woodward-Clyde 1993). For this assessment, these samples are adequate to characterize the off-site deep groundwater.
C. Quality Assurance and Quality Control
An EPA data review summary is not available for the environmental samples collected at this site. We assume these data are valid, however, since the environmental samples were collected and analyzed by governmental agencies or their contractors. In preparing this public health assessment, we relied on the information provided by these agencies and assumed that the quality assurance and quality control measures described in their reports were followed with regard to chain-of-custody, laboratory procedures, and data reporting. The validity of the analysis and conclusions drawn for this public health assessment are determined by the completeness and reliability of the referenced information.
In each of the preceding On- and Off-Site Contamination subsections, we evaluated the adequacy of the data to estimate exposures. We assumed that estimated data (J) and presumptive data (N) were valid. This second assumption errs on the side of public health by assuming that a contaminant exists when actually it may not exist.
Several physical hazards exist on the site, including an abandoned building, concrete foundation rubble, and a wastewater pond. Persons trespassing on the site would be exposed to these hazards. However, to prevent trespassing, EPA has completely fenced the site. Therefore, we consider the actual risk to trespassers from these physical hazards to be negligible.
To determine whether nearby residents are exposed to contaminants migrating from the site, we evaluated the environmental and human components of exposure pathways. Exposure pathways consist of five elements: a source of contamination, transport through an environmental medium, a point of exposure, a route of human exposure, and an exposed population.
An exposure pathway can be eliminated if at least one of the five elements is missing and will never be present. We categorize exposure pathways that are not eliminated as either completed or potential. For completed pathways, all five elements exist and exposure to a contaminant has occurred, is occurring, or will occur. For potential pathways, at least one of the five elements is missing, but could exist. For potential pathways, exposure to a contaminant could have occurred, could be occurring, or could occur in the future.
A. Completed Exposure Pathways
For a summary of the completed exposure pathways at this site, refer to Table 11, Appendix B.
Surface Soil Pathway
Workers and trespassers on-site, as well as persons using the on-site ballfield, may have been exposed in the past to contaminants in the surface soil. Remediation workers may be exposed to these contaminants in the future. Past, present and future exposure to contaminants off of the site is also possible. However, the available information about off-site contamination is insufficient to enable us to evaluate possible health effects from this exposure pathway.
Direct dermal contact and incidental ingestion of surface soil are the primary routes of exposure by this pathway. Exposure to air-borne dust is also possible. Workers on the site and persons using the on-site baseball field may have been exposed. The number of workers employed at the site is unknown, but estimated to be fewer than 100. About 300 adults and 100 children may have been exposed while playing baseball at the on-site ballfield. This ballfield has been moved to a new location in an area north of the site. Because the children who used the ballfield for organized games are not from the local neighborhood, they were under adult supervision and it is unlikely that they would have been exposed to contaminants on other parts of the site. There are indications that the site has been trespassed by children in the past, most likely from the local neighborhood. These children and other trespassers may have been exposed to contaminants in surface soil on-site. However, their number is unknown.
Since access to the entire site is now restricted by fencing, future exposure to on-site surface soil contamination is not likely. Exposure to off-site surface soil contamination is likely; however, we do not have enough information to determine if adverse health effects are possible.
Waste Sludge Pathway
Workers and trespassers on-site, as well as persons using the on-site ballfield, may have been exposed in the past to contaminants in waste sludge material. Remediation workers may be exposed to these contaminants in the future.
Direct dermal contact and incidental ingestion of waste sludge are the primary routes of exposure by this pathway. Workers on the site and persons using the on-site baseball field may have been exposed. The number of workers employed at the site is unknown, but estimated to be fewer than 100. About 300 adults and 100 children may have been exposed while playing baseball at the on-site ballfield. This ballfield has been moved to a new location in an area north of the site. Because the children who used the ballfield for organized games are not from the local neighborhood, they were under adult supervision and it is unlikely that they would have been exposed to contaminants on other parts of the site. There are indications that the site has been trespassed by children in the past, most likely from the local neighborhood. These children and other trespassers may have been exposed to contaminants in waste sludge on-site. However, their number is unknown.
Since access to the entire site is now restricted by fencing, future exposure to waste sludge material is not likely.
On-site Surface Water Pathway
Workers and trespassers on-site may have been exposed in the past to contaminants in the wastewater disposal ponds. Remediation workers may be exposed to these contaminants in the future. Direct dermal contact is the primary route of exposure by this pathway.
The number of workers employed at the site is unknown, but estimated to be fewer than 100. There are indications that children have trespassed the site in the past; however, their number is unknown. Since the children who used the on-site baseball field for organized games are not from the local neighborhood and used the ballfield only under adult supervision, it is unlikely that they would have an opportunity for exposure to contaminants in the wastewater disposal ponds.
The available environmental data for the on-site disposal ponds consists of a few samples taken more than 10 years ago. We do not consider this information sufficient to evaluate possible health effects from this exposure pathway. However, because these ponds do not contain permanent standing water, collection of additional samples may not be possible.
B. Potential Exposure Pathways
For a summary of the potential exposure pathways at this site, refer to Table 12, Appendix B.
Subsurface Soil Pathway
On-site subsurface soil is contaminated. This soil is currently inaccessible and exposure to these contaminants is unlikely. However, if this site is remediated or otherwise developed, workers on the site may be exposed to contaminants in the subsurface soil through direct dermal contact and incidental ingestion.
Off-site subsurface soil is also contaminated. However, it is also currently inaccessible and exposure to contaminants is unlikely.
Off-site Surface Water Pathway
The groundwater contamination plume has recently reached Bayou Texar, an environmentally sensitive saltwater aquatic breeding ground. The bayou connects to Escambia Bay and is flushed by tidal action twice per day. Measurements of sediment pore water indicate that contaminants reaching the bayou are currently too low to be of health concern (Entrix 1993). However, if the amount of contamination reaching the bayou from groundwater intrusion increases in the future, recreational use of the bayou and fish or shellfish caught for consumption may be affected.
Groundwater on-site and off of the site to the southeast is contaminated. There are no private or public drinking water supply wells in the area of contamination. Several irrigation wells, however, are present in this area. According to the Escambia County Public Health Unit, these wells have been tested and are not currently contaminated. In addition, new wells located in a contaminated area that are permitted by the Northwest Florida Water Management District must be tested. If contamination is found, the well may have to be abandoned (Geraghty & Miller 1992c). Therefore, groundwater is not a likely exposure pathway.
In this section we discuss the health effects on persons exposed to specific contaminants, evaluate state and local health databases, and address specific community health concerns.
Introduction
To evaluate health effects, ATSDR has developed Minimal Risk Levels (MRLs) 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. ATSDR
developed MRLs for each route of exposure, such as ingestion, inhalation, and dermal contact,
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.
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 the following chemicals:
| Arsenic Benzo(a)pyrene Chromium |
Fluoride Lead Manganese |
PAHs Vanadium |
There is no Toxicological Profile available for sulfate.
In this section, we used standard assumptions to estimate human exposure from direct dermal exposure and incidental ingestion of contaminated soil.
To estimate exposure to children from incidental ingestion of contaminated soil, we made the following assumptions: 1) children between the ages of 1 and 6 ingest an average of 200 milligrams (mg) of soil per day, 2) these children weigh about 10 kilograms (kg), and 3) they ingested soil at the maximum concentration measured for each contaminant. For children exposed at the on-site baseball field, we assumed that they used the field about two days per week throughout the year.
To estimate exposure to adults from incidental ingestion of contaminated soil, we made the following assumptions: 1) adults ingest an average of 100 mg of soil per day, 2) adults weigh about 70 kg, and 3) they ingested soil at the maximum concentration measured for each contaminant. For adults exposed at the on-site baseball field, we assumed that they used the field about two days per week throughout the year.
Arsenic
Workers and trespassers on the site may have been exposed to arsenic in surface soil and waste sludge by incidental ingestion and dermal contact. The estimated daily dose of arsenic from incidental ingestion exceeds ATSDR's chronic MRL. Incidental ingestion of arsenic-contaminated soil on the site may lead to darkening of the skin and the appearance of "corns" or "warts". Although skin absorption is minor, contact with arsenic-contaminated soil on the site may cause irritation, swelling and redness of the skin (ATSDR 1993b).
Children who used the on-site baseball field may have also been exposed to arsenic in surface soil. However, the estimated daily dose from incidental ingestion is less than ATSDR's chronic oral MRL. Therefore, adverse health effects are unlikely from this exposure.
Arsenic is a known human carcinogen. Long term ingestion of arsenic may increase the risk of skin, bladder, liver, lung and kidney cancer. Incidental ingestion of arsenic-contaminated soil by workers and trespassers on the site could result in a "low" increased risk of cancer. About 25% of all Floridians will develop some form of cancer during their lifetime. This means that 25% of the people who worked at the EWP site will likely develop cancer for reasons unrelated to exposure to chemicals from this site. A "low" increase in the risk of cancer means that out of a population of 10,000 persons, of whom 2,500 are expected to develop cancer for reasons unrelated to exposure at this site, an additional one or two cases of skin cancer may occur. This would increase the number of expected cancers of these 10,000 persons from 2,500 to 2,502.
For persons using the on-site baseball field, lifetime incidental ingestion of surface soil would result in no apparent increase in the risk of cancer.
EPA did not analyze off-site surface soil samples for arsenic. Therefore, we do not know if exposure to arsenic is possible and cannot estimate the likely health effects.
Chromium
Workers and trespassers on-site and children who used the on-site ballfield may have been exposed to chromium in surface soil by incidental ingestion and dermal contact. The estimated daily dose of chromium from incidental ingestion is less than EPA's chronic oral RfD. No ATSDR chronic oral MRL is available. Exposure to chromium at the concentrations found in on-site surface soil is unlikely to cause adverse non-carcinogenic health effects. Dermal contact may cause allergic skin reactions in sensitive individuals, but skin absorption is insignificant (ATSDR 1993c).
Since some of the analytical laboratory reports did not specify which form of chromium was detected, we have assumed the presence of chromium(VI), the most toxic form. Chromium(VI) is a known human carcinogen by inhalation, but not by ingestion or dermal contact. Therefore, we do not expect any cancer risk through exposure by ingestion or dermal contact. Since EPA did not analyze any air samples, we cannot estimate the health effects from inhalation of chromium. However, because this site is in a low-lying area where the soil tends to remain damp and the ground is heavily vegetated by grasses, small bushes, and trees, we do not expect enough dust generation on the site or the now-abandoned ballfield to produce an adverse health effect by inhalation.
EPA did not analyze off-site surface soil samples for chromium. Therefore, we do not know if exposure to chromium is possible and cannot estimate the likely health effects.
Fluoride
Workers and trespassers on-site and children who used the on-site ballfield may have been exposed to fluoride in surface soil and waste sludge material by incidental ingestion and dermal contact. The estimated daily dose of fluoride from incidental ingestion exceeds the ATSDR chronic oral MRL. Exposure to fluoride at the concentrations found in surface soil and waste sludge on-site and at the on-site ballfield can cause fluorosis of teeth and bones. Fluorosis of the teeth is characterized by mottling, the appearance of white spots on the teeth. Skeletal fluorosis causes bones to become denser and more brittle, making them more easily broken. Fluoride salts are not absorbed through the skin (ATSDR 1993a).
Individuals off of the site may have also been exposed to fluoride in surface soil by incidental ingestion. However, the estimated daily dose of fluoride from incidental ingestion is less than ATSDR's chronic oral MRL. Therefore, adverse health effects from this exposure are not likely.
Lead
Workers and trespassers on-site may have been exposed to lead in surface soil and waste sludge material by incidental ingestion and dermal contact. Individuals off of the site may have also been exposed to lead in surface soil. No ATSDR MRL or EPA RfD is available for lead.
The estimated daily dose of lead from incidental ingestion of on-site surface soil and waste sludge exceeds the level at which behavioral impairment has been observed in monkeys (Laughlin et al 1983, Rice 1985, Rice and Karpinski 1988). Several studies have also reported that blood lead levels rise about 3-7 µg/dL for every 1,000 mg/kg increase in soil lead concentration (EPA 1986, Bornschein et al 1986, ATSDR 1988). The level of lead in surface soil at this site is high enough that adverse effects such as decreased intelligence scores, slow growth, and hearing impairment could occur in children exposed to it.
Children who used the on-site baseball field may have also been exposed to lead in surface soil and waste sludge. However, the estimated daily dose from incidental ingestion is less the level at which studies have reported behavioral or neurological impairment. Therefore, adverse health effects are unlikely from this exposure.
Lead is a probable human carcinogen based on animal studies. However, the estimated daily dose of lead is at least 100 times less than the level at which cancer effects have been shown to occur in animals (ATSDR 1993d). Therefore, carcinogenic effects from incidental ingestion are not likely.
Manganese
Workers and trespassers on-site may have been exposed to manganese in surface soil and waste sludge material by incidental ingestion and dermal contact. The estimated daily dose of manganese from incidental ingestion is less than EPA's chronic oral RfD. No ATSDR MRL is available. Exposure to manganese at the concentrations found in on-site surface soil is unlikely to cause adverse health effects. Manganese absorption through the skin is negligible (ATSDR 1992b). Therefore, adverse health effects from dermal exposure are not likely.
EPA did not analyze surface soil or waste sludge samples from the on-site baseball field for manganese and did not analyze off-site surface soil samples for manganese. Therefore, we do not know if exposure to manganese is possible for persons off-site or using the ballfield and cannot estimate the likely health effects.
Polycyclic Aromatic Hydrocarbons (PAHs)
Workers and trespassers on-site may have been exposed to PAHs in surface soil and waste sludge by incidental ingestion and dermal contact. Individuals off of the site may also have been exposed to PAHs in surface soil. The PAHs of concern include: benz(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, dibenz(a,h)anthracene, and indeno(1,2,3-c,d)pyrene. All of these chemicals are possible or probable human carcinogens (ATSDR 1990b). However, an ATSDR comparison value is available only for benzo(a)pyrene (ATSDR 1990a). We do not have enough human health information to determine the health risks from exposure to the other PAHs. Consequently, the evaluation of the health risks from exposure to PAHs will focus on benzo(a)pyrene.
The estimated daily dose of benzo(a)pyrene from incidental ingestion is less than ATSDR's intermediate oral MRL. No chronic oral MRL is available. Exposure to benzo(a)pyrene at the concentrations found in on-site waste sludge and surface soil on and off of the site is unlikely to cause adverse non-carcinogenic health effects. Benzo(a)pyrene may also be absorbed through the skin; however, it is normally metabolized and rapidly excreted (ATSDR 1990a, 1990b).
Benzo(a)pyrene is a probable human carcinogen based on animal studies. However, lifetime incidental ingestion of surface soil and waste sludge at this site would result in no apparent increase in the risk of cancer.
EPA did not analyze surface soil or waste sludge samples from the on-site baseball field for PAHs. Since the concentrations of contaminants found at the on-site ballfield are much lower than those found on the rest of the site, we do not expect the levels of PAHs to exceed those already found. However, we do not know what levels of PAHs actually occur on the ballfield and cannot currently estimate the possible health effects.
Sulfate
Workers and trespassers on-site and children who used the on-site ballfield may have been exposed to sulfate in surface soil and waste sludge material by incidental ingestion and dermal contact. No ATSDR MRL or EPA RfD is available for sulfate. The estimated daily dose of sulfate from incidental soil ingestion is at least 100 times less than the dose that would be received by drinking water at the Florida secondary drinking water standard. Therefore, we do not expect any adverse health effects from exposure to sulfate at this site.
EPA did not analyze off-site surface soil samples for sulfate. Therefore, we do not know if exposure to sulfate is possible and cannot estimate the likely health effects.
Vanadium
Workers and trespassers on-site may have been exposed to vanadium in on-site surface soil and waste sludge material by incidental ingestion and dermal contact. The estimated daily dose of vanadium from incidental ingestion is less than ATSDR's intermediate MRL. No chronic oral MRL is available. Exposure to vanadium at the concentrations found in on-site soil and waste sludge is unlikely to cause adverse health effects. Absorption of vanadium through the skin is negligible (ATSDR 1992c). Therefore, adverse health effects from dermal exposure are not likely.
EPA did not analyze surface soil or waste sludge samples from the on-site baseball field for vanadium and did not analyze off-site surface soil for vanadium. Therefore, we do not know if exposure to vanadium is possible for persons off-site or using the ballfield and cannot estimate the likely health effects.
B. Health Outcome Data Evaluation
Guided by community health concerns in the population living near the site, Florida HRS epidemiologists conducted an evaluation of cancer incidence in this area. Cancer information was available for the two zip code areas closest to the site. The incidence of cancer in these zip codes was compared with the incidence for the state of Florida. Since these zip code areas are much larger than the residential areas adjacent to the site, the majority of the people living in these zip codes have probably not been exposed to any contaminants from the Agrico site.
Based on a comparison of cancer rates corrected for the influence of age and race, three cancer types, liver, kidney and lung, appear to be elevated in the 32503 and 32505 zip code areas (Hammond 1994). A cancer rate in these zip codes was considered elevated if it was greater than the Florida rate at the 95% confidence level. Arsenic is present on the site at a level that could increase the risk of liver, lung and kidney cancer. However, we do not have any information about the incidence of liver, lung or kidney cancer among people who worked at or trespassed on the site, or among residents of the neighborhood west of the site.
C. Community Health Concerns Evaluation
We have addressed each community health concern as follows:
1. What contaminants are present at the ballfield on the Agrico site and what health effects may result from exposure to them, especially in children?
Children playing on the on-site baseball field may have been exposed to fluoride at a level that could result in mottling of the teeth; that is, the appearance of white spots could occur. This effect may be permanent. Since this ballfield has been abandoned and access is restricted by fencing, no future exposure is likely.
2. What contaminants may have migrated from the site to the residential yards west of the site and what health effects may result from exposure to them?
The Agrico site is in a low-lying area toward which stormwater runoff generally flows. The CSX railroad lines act as an additional barrier to the westward flow of any runoff that may come from the site. Although the site is now heavily vegetated, it may not have been in the past when the Agrico plant was in operation. Air-borne dust may have carried contaminants from the site to areas off-site. However, no air monitoring information is available for us to assess what contaminants may have migrated from the site in this way. Surface soil sampling on the west side of the site, although limited, does not indicate that any site-related contaminants have migrated off of the site.
3. What contaminants have entered Bayou Texar and what health effects may occur in people who eat fish and shellfish that may contain these contaminants?
The only contaminants of concern that has been detected entering Bayou Texar via surfacing groundwater are fluoride and sulfate. The amount entering the Bayou is currently too low to pose any health hazard either from direct exposure or by consumption of fish and shellfish from the bayou. Lead, arsenic and other site-related contaminants have not been detected in monitoring wells greater than about three-quarter miles from the site. However, these contaminants may reach the bayou in the future.
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