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PUBLIC HEALTH ASSESSMENT ESCAMBIA WOOD - PENSACOLA
(A.K.A. ESCAMBIA TREATING COMPANY)
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 concentration and frequency of detection of the contaminants found in various media. The concentrations found are then compared to background levels and to standard comparison values. A comparison value is used as a means of selecting environmental contaminants for further evaluation to determine whether exposure to them has public health significance. The following comparison values are used in the data tables:

    1. CREG – Cancer Risk Evaluation Guide–calculated from EPA's cancer slope factors, is the contaminant concentration that is estimated to result in no more than one excess cancer in a million persons exposed over a lifetime.

    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. 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.

    4. 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.

We have reviewed the environmental data collected at this site and selected the following chemicals as contaminants of concern:

Arsenic
Pentachlorophenol (PCP)
Benzene Polycyclic Aromatic Hydrocarbons (PAHs)
Dioxins/Furans

We selected these contaminants based on the following factors:

  1. Concentrations of contaminants on and off the site.
  2. Field data quality, laboratory data quality, and sample design.
  3. Comparison of on-site and off-site concentrations with health assessment comparison values for (1) noncarcinogenic endpoints and (2) carcinogenic endpoints.
  4. Community health concerns.

The PAHs of concern at the EWP site are: benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)anthracene, chrysene, dibenzo(a,h)anthracene, indeno(1,2,3-c,d)pyrene, and naphthalene. Benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)anthracene, chrysene, dibenzo(a,h)anthracene, and indeno(1,2,3-c,d)pyrene are possible or probable human carcinogens. However, an ATSDR comparison value is available only for benzo(a)pyrene. Although all of these chemicals are listed in the tables in Appendix B, analysis of the potential carcinogenic health effects from exposure to them will be based on the levels of benzo(a)pyrene found in various media at this site.

Dioxins/Furans refers to a general class of chlorinated dibenzodioxins and dibenzofurans, the most toxic of which is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The toxicity of the other chlorinated dibenzodioxins and dibenzofurans can be related to TCDD by using EPA's Toxic Equivalency Factors (TEF) (EPA 1989) to calculate their Toxic Equivalents (TEQ). By adding the TEQ concentrations of all the forms of dioxins and furans in a sample, we can determine the total dioxin toxicity (dioxin-TEQ). In this report, we use the term dioxin-TEQ to refer to the combined toxicity of all forms of chlorinated dibenzodioxins and dibenzofurans found in samples of various media at this site. We use dioxin-TEQ to evaluate the possible health effects from exposure to these chemicals.

Fifty-four chemicals were detected in various media on the EWP site at a level below human health concern. In addition, 83 other chemicals were detected in various media at this site for which there is insufficient human health data available to determine their public health significance. The chemicals in both of these categories are listed in Appendix C.

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 Escambia Wood - Pensacola site, we searched the EPA Toxic Chemical Release Inventory (TRI) data base for 1987-1991. EPA developed TRI from the chemical release information (air, water, and soil) provided by certain industries. The TRI search revealed two industries, Florida Drum Company at 10 Spruce Street and Precision Machining, Inc. at 3820 Hopkins St., within a one mile radius of the site, that reported releases of toxic chemicals. Between 1987 and 1991, Florida Drum Company reported releasing to the air a total of 151,223 pounds of mixed xylenes and 202,564 pounds of methyl ethyl ketone (2-butanone). Estimated annual air releases for 1992 and 1993 total 35,300 pounds of mixed xylenes and 41,700 pounds of methyl ethyl ketone. Between 1988 and 1991, Precision Machining reported releasing to the air a total of 60 pounds of cyclohexane, 1,769 pounds of ethylbenzene, 140,857 pounds of mixed xylenes, 48,777 pounds of methyl ethyl ketone (2-butanone), 68,850 pounds of toluene, 103,048 pounds of n-butyl alcohol, 4,812 pounds of methyl isobutyl ketone, 71 pounds of 1,1,1-trichloroethane, 803 pounds of dichloromethane, 19,055 pounds of acetone, and 17,925 pounds of methanol.

Methyl ethyl ketone (2-butanone), n-butanol, methylene chloride, acetone, and 1,1,1-trichloroethane have been detected in groundwater on the site, xylenes have been detected in on-site soil, groundwater and air, ethylbenzene has been detected in on-site groundwater and air, and toluene has been detected in on-site groundwater, air and waste oil sludge. Methyl isobutyl ketone, methanol, and cyclohexane were analyzed for but not detected at the site. All are used as paint thinners, solvents and cleaning agents. They evaporate easily into the air and exposure to them can cause irritation of the nose, throat, eyes, and skin. Based on limited information, only methylene chloride is believed to cause cancer (ATSDR 1990b, ATSDR 1990e, ATSDR 1992c, ATSDR 1993d, ATSDR 1993e, ATSDR 1994a, ATSDR 1994b, Lewis 1993). None of these chemicals, however, are present on the site at levels that could cause adverse health effects or increase the risk of cancer.

In this public health assessment, the contamination that exists on the site will be discussed first, separately from the contamination that occurs off the site.

A. On-site Contamination

For the purposes of this evaluation, "on-site" is defined as the Escambia Wood - Pensacola property within the fenced boundary as shown in Figure 4, Appendix A.

We compiled data in this subsection from the following sources: the 1988 FDER groundwater investigation report (Hicks, Martin and Stodghill 1988) and EPA reports (Bruner 1982, Ferguson 1992, Roy F. Weston, Inc. 1991, 1992a, 1992b, 1992c, 1993a, 1993b).

On-site Surface Soil

EPA collected a total of 168 surface soil samples (depth 0-6 inches) from various locations on the site between 1991 and 1993 (Ferguson 1992, Weston 1991, 1992c, 1993a) (Figure 5, Appendix A). Dioxin-TEQ was the only contaminant of concern that was detected in background surface soil samples on-site; its concentration was at a level below the comparison value.

Arsenic, benzo(a)pyrene, dioxin-TEQ, and pentachlorophenol (PCP) levels in on-site surface soil samples exceeded the corresponding comparison values (Table 1, Appendix B). Dibenzo(a,h)anthracene and indeno(1,2,3-c,d)pyrene were not detected in any samples. No samples were analyzed for benzene. Naphthalene was detected in 24 of 168 samples at a maximum concentration of 250,000 milligrams per kilogram (mg/kg). No ATSDR soil comparison value is available for naphthalene. For this assessment, these samples were adequate to characterize the on-site surface soil quality.

On-site Subsurface Soil

EPA collected a total of 262 subsurface soil samples (depth 1-47 feet) from various locations on the site between 1982 and 1993 (Bruner 1982, Weston 1991, 1992c, 1993a) (Figure 6, Appendix A). No contaminants of concern were found in any background samples.

Arsenic, benzo(a)pyrene, dioxin-TEQ, and PCP levels in on-site subsurface soil exceeded the corresponding comparison values (Table 2, Appendix B). Benzene was not detected in the subsurface soil on-site. Naphthalene was detected in 47 of 262 samples at a maximum concentration of 5,200 mg/kg. No ATSDR soil comparison value is available for naphthalene. For this assessment, these samples were adequate to characterize the on-site subsurface soil quality.

On-site Groundwater

FDEP and EPA collected a total of 39 groundwater samples (depth 50-69 feet) from monitoring wells on the site between 1982 and 1992 (Bruner 1982, Hicks 1988, Weston 1991, 1992a) (Figure 7, Appendix A). No contaminants of concern were found in any background samples.

Arsenic, benzene, benzo(a)pyrene, naphthalene, and PCP levels in on-site groundwater exceeded the corresponding comparison values (Table 3, Appendix B). Dibenzo(a,h)anthracene and indeno(1,2,3-c,d)pyrene were not detected in any samples. No on-site groundwater samples were analyzed for dioxin-TEQ. For this assessment, these samples were adequate to characterize the on-site groundwater quality.

On-site Air

EPA collected a total of 66 air samples from various locations on the site between 1991 and 1993 (Weston 1991, 1992b, 1993b). Several samples were collected at each location shown in Figure 8, Appendix A. Dioxin-TEQ and PCP air samples were collected using high-volume samplers with polyurethane foam plugs and glass fiber filters. Samples for PAHs were collected using medium-volume samplers with XAD-2 tubes and filters. Volatile organic compounds were sampled using low-volume samplers with carbon tubes and carbon molecular sieve tubes. Samples were collected in the breathing zone (4-5 feet above the ground). Several sample stations were located along the northern property boundary of the site. No contaminants of concern were found in any background samples.

Benzene and dioxin-TEQ levels in on-site air exceeded the corresponding comparison values (Table 4, Appendix B). Benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)anthracene, chrysene, dibenzo(a,h)anthracene, and indeno(1,2,3-c,d)pyrene were not detected in any samples. No on-site air samples were analyzed for arsenic.

Naphthalene was detected in 38 of 66 samples, and PCP in 48 of 53 samples. No ATSDR air comparison values are available for these contaminants. For this assessment, these samples were adequate to characterize the on-site air quality.

On-site Liquid Waste

EPA collected two liquid waste samples from the site in 1982 (Bruner 1982) (Figure 9, Appendix A). Liquid waste at the EWP site consisted of wastewater from the cooling water tanks and the runoff holding pond.

Only PCP exceeded the corresponding comparison value (Table 5, Appendix B). No on-site liquid waste samples were analyzed for dioxin-TEQ. Because only a few of the contaminants of concern have been analyzed for in on-site liquid waste, we cannot fully evaluate the likely health effects from exposure to this medium. Consequently, we do not consider these samples adequate to characterize the on-site liquid waste. However, both the cooling water tanks and the runoff holding pond have been removed from the site, and the wastewater they contained has been treated and disposed of. There is currently no liquid processing waste on the site.

On-site Waste Sludge

EPA collected six waste sludge samples from the site in 1982 and 1991 (Bruner 1982, Weston 1991) (Figure 10, Appendix A). Waste sludge is the solid residue that settled out of wastewater in the cooling water tanks and runoff holding pond. This material was also present in soil near these structures.

Arsenic, benzo(a)pyrene, dioxin-TEQ, and PCP levels in on-site waste sludge exceeded their corresponding comparison values (Table 6, Appendix B). Benzene, dibenzo(a,h)anthracene and indeno(1,2,3-c,d)pyrene were not detected in any samples. Naphthalene was detected in 3 of 6 samples at a maximum concentration of 220 mg/kg. No ATSDR comparison value is available for naphthalene. For this assessment, these samples were adequate to characterize the on-site solid waste. The cooling water tanks and runoff holding pond have been removed from the site. All sludge material remaining in the soil on-site was excavated and stockpiled on the site during the EPA excavation activities in 1991-93.

B. Off-site Contamination

For the purposes of this evaluation, "off-site" is defined as the area outside the boundary fence around the Escambia Wood - Pensacola property as shown in Figure 4, Appendix A.

We compiled data in this subsection from EPA reports (Ferguson 1992, Roy F. Weston, Inc. 1993b).

Off-site Surface Soil

In 1992, EPA collected 7 surface soil samples (depth 0-6 inches) from residential yards in the neighborhood adjacent to the northern border of the site (Ferguson 1992) (Figure 11, Appendix A). No background samples were collected.

Dioxin-TEQ levels in six of the seven off-site surface soil samples exceeded the corresponding comparison value (Table 7, Appendix B). No samples were analyzed for arsenic or benzene. Samples were collected mostly from the yards adjacent to the site. Residents have indicated that stormwater runoff from the site flooded the entire neighborhood several times in the past. Because off-site contamination may extend further than is now known, we do not consider these samples adequate to characterize the extent and nature of off-site surface soil contamination.

Off-site Air

EPA collected a total of 36 air samples from various locations off of the site in 1992 (Weston 1993b). Several samples were collected at each location shown in Figure 12, Appendix A. Dioxin-TEQ and PCP air samples were collected using high-volume samplers with polyurethane foam plugs and glass fiber filters. Samples for PAHs were collected using medium-volume samplers with XAD-2 tubes and filters. Volatile organic compounds were sampled using low-volume samplers with carbon tubes and carbon molecular sieve tubes. Samples were collected in the breathing zone (4-5 feet above the ground). No background samples were collected.

Only benzene and dioxin-TEQ levels in off-site air samples exceeded the corresponding comparison values (Table 8, Appendix B). Benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)anthracene, chrysene, dibenzo(a,h)anthracene, and indeno(1,2,3-c,d)pyrene were not detected in the air off-site. No off-site air samples were analyzed for arsenic.

Naphthalene was detected in 24 of 36 samples, and PCP was detected in all 22 samples. No ATSDR air comparison values are available for these contaminants. Benzene and dioxin-TEQ found in off-site air samples may have been produced by the excavation activities. Additional off-site air samples are needed to assess the long-term health risk from exposure to these contaminants.

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.

D. Physical and Other Hazards

Numerous physical hazards exist on the site, including the vacant office building, piles of concrete rubble, some machinery, the contaminated soil pile, and two excavation pits, both of which are about 40 feet deep and contain standing water. Persons trespassing on the site would be exposed to these hazards. However, to prevent trespassing, the site is securely fenced and periodically patrolled. Therefore, we consider the actual risk from these physical hazards to be negligible.

PATHWAYS ANALYSES

To determine whether nearby residents have been 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 9, Appendix B.

Surface Soil Pathway

Former workers at the plant may have been exposed to contaminants in on-site surface soil. Vagrants and other trespassers on the site in the past may have also been exposed. Future remediation workers may be exposed to contaminants in on-site surface soil.

Direct dermal contact and incidental ingestion of soil are the primary routes of exposure by this pathway. About 35 former workers may have been exposed to contaminants in on-site surface soil while the plant was in operation. EPA has excavated contaminated surface soil and placed it in a securely covered pile. Future remediation workers on the site may be exposed to contaminants in this soil. Although the site is now secured to prevent trespassing, vagrants and other individuals trespassing on the site in the past may have been exposed to contaminated surface soil by dermal contact and incidental ingestion. However, we have no information to estimate the number of vagrants and other trespassers who may have been on the site.

Residents in the community adjacent to the site may have been exposed to contaminants in off-site surface soil. Direct dermal contact and incidental ingestion of soil are the primary routes of exposure by this pathway. About 20 residents of homes immediately adjacent to the northern border of the site may be exposed to contaminants in surface soil in their yards. This contamination, which does not exceed ATSDR comparison values or soil action levels, may have been carried off-site by stormwater runoff. Residents have indicated that stormwater runoff from the site flooded the entire neighborhood several times in the past. We do not know how many other residential yards in the Rosewood Terrace neighborhood may have contaminated surface soil or how many of the other 75 residents may be exposed to this contamination.

Air Pathway

Former workers may have been exposed to air-borne contaminants while the plant was in operation. In the future, remediation workers on-site may also be exposed to contaminants in air-borne dust and volatile chemicals released from disturbed soil.

Inhalation of contaminated dust and volatile chemicals is the route of exposure by this pathway. About 35 former workers may have been exposed while the plant was in operation. Vagrants and other trespassers on the site between about 1982 and 1991 may have been exposed to contaminated dust; however, we have no information to estimate their numbers or the likely health effects from this exposure.

Individuals within one-quarter mile of the site may have been exposed to air-borne contaminants from plant operations in the past and from the 1991-1993 soil excavation activity. In the future, individuals within one-quarter mile of the site may also be exposed to contaminants in air-borne dust and volatile chemicals released from disturbed soil. About 925 people within one-quarter mile of the site may have been exposed by inhalation of contaminated dust and volatile chemicals while the plant was in operation.

Since access to the site is now restricted and excavated soil has been secured under a high density polyethylene liner , exposure to contaminated dust and volatile chemicals is currently unlikely. However, future exposure by this pathway is possible during remediation activities that produce dust and release volatile chemicals from contaminated soil stockpiled on-site.

Liquid Waste Pathway

Former workers at the plant and trespassers on-site may have been exposed in the past to contaminants in liquid process waste. About 35 former workers may have been exposed to contaminants in the liquid waste. An unknown number of trespassers may have been exposed to these contaminants before the holding ponds were drained and dismantled some time between 1988 and 1991. Exposure resulted from direct dermal contact and incidental ingestion. Since all liquid wastes have been treated and removed from the site, no current or future exposure is possible.

Waste Sludge Pathway

Former workers at the plant and trespassers on-site may have been exposed in the past to contaminants in solid waste sludge. About 35 former workers may have been exposed to contaminants in the sludge material while the plant was in operation. Although much of the sludge was removed and containerized shortly after the facility closed down, some contaminated residue still remained. Therefore, an unknown number of trespassers may have been exposed to these contaminants before EPA soil excavation occurred beginning in 1991. Direct dermal contact and incidental ingestion are the primary routes of exposure by this pathway.

Since all waste sludge has been excavated and stockpiled on-site and the site has been secured, current exposure is unlikely. However, future remediation workers may be exposed to contaminants in this material.

B. Potential Exposure Pathways

For a summary of the potential exposure pathways at this site, refer to Table 10, Appendix B.

Subsurface Soil Pathway

EPA has excavated contaminated subsurface soil from the site and stockpiled it on-site under a secured high density polyethylene liner. Some contaminated soil remains in the excavation pits. Since site access is restricted, current exposure to these contaminated soils is unlikely. However, future remediation workers may be exposed to the contaminants in the soil through direct dermal contact and incidental ingestion.

Fruits and Vegetables Pathway

Dioxin-TEQ found in off-site surface soil can be absorbed by fruit and vegetable plants. Although the concentration of dioxin-TEQ in the below-ground parts of plants may be the same as the soil concentration, the above-ground parts usually contain less than half the soil concentration (ATSDR 1989). PAHs in off-site surface soil can accumulate in plants (ATSDR 1990d). However, there is insufficient toxicological information about the PAHs found in off-site surface soil for us to assess their public health significance.

Fruit trees and small backyard gardens used for household consumption are present in off-site soil that may be contaminated. However, we do not know the full extent and nature of this contamination. In addition, no fruits and vegetables from contaminated areas off-site have been analyzed for any of the contaminants of concern at the EWP site. Therefore, we do not know if fruits and vegetables are a source of contamination and if exposure is possible by this pathway.

Small Game Pathway

Small game such as squirrel, rabbit and quail were hunted near the site in the past. Dioxin-TEQ, PAHs and PCP can be accumulated in animal tissues (ATSDR 1989, ATSDR 1990c, 1992a). However, no animal tissue has been analyzed for site-related contaminants. Therefore, we do not know if small game were a source of contamination and if exposure occurred by this pathway.

C. Eliminated Pathways

Groundwater north of the site (hydraulically upgradient) is not contaminated and, in addition, all residences in this area are supplied by city water. Groundwater on the site and off of the site to the southeast, however, is contaminated. Although there are no private or public drinking water wells in the area of contamination, several irrigation wells are present (Geraghty & Miller 1992). According to the HRS Escambia CPHU, 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. Therefore, groundwater is not a likely exposure pathway.

PUBLIC HEALTH IMPLICATIONS

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.

A. Toxicological Evaluation

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
Pentachlorophenol (PCP)
Benzene Polycyclic Aromatic Hydrocarbons (PAHs)
Dioxin-TEQ

We use EPA's cancer slope factors to evaluate the increased risk of cancer from lifetime exposure to site-related contaminants. A slope factor is a plausible upper-bound estimate of the probability of a response per unit intake of a chemical. We adjust for less than lifetime exposure and make a qualitative estimate of the increased cancer risk.

In this section, we used the following assumptions to estimate human exposure from incidental ingestion of contaminated soil and waste materials, and inhalation of contaminated air.

To adjust for less than lifetime exposure in estimating increased cancer risks, we assumed that adult workers on the site worked 5 days per week, 50 weeks per year for the entire 40 year period the plant was in operation. For trespassers on the site, we assumed they were on the site 1 day per week, 52 weeks per year for the 8 year period between the time the plant closed and soil excavation activities began. For off-site residents, we assumed they were exposed to off-site contamination 7 days per week, 50 weeks per year for the estimated 40 year period they could have resided near the site.

To estimate exposure to children from incidental ingestion of contaminated soil and solid waste materials, 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.

To estimate exposure to adults from incidental ingestion of contaminated soil and solid waste materials, we made the following assumptions: 1) adults ingest an average of 100 mg of soil per day, 2) they weigh about 70 kg, and 3) they ingested soil at the maximum concentration measured for each contaminant.

To estimate exposure to adults from incidental ingestion of contaminated liquid waste material, we made the following assumptions: 1) adults ingest an average of 0.05 milliliters (ml) of liquid waste per day, 2) they weigh about 70 kg, and 3) they ingested liquid waste at the maximum concentration measured for each contaminant.

To estimate exposure to children from inhalation of airborne contaminants, we made the following assumptions: 1) children between the ages of 1 and 6 breathe 15 cubic meters (m3) of air per day, 2) these children weigh about 10 kg, and 3) they breathe contaminants at the maximum measured concentration.

To estimate exposure to adults from inhalation of airborne contaminants, we made the following assumptions: 1) adults breathe 23 m3 of air per day, 2) they weigh about 70 kg, and 3) they breathe contaminants at the maximum measured concentration.

Arsenic

Former workers at the plant 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 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 1993a).

Arsenic is a known human carcinogen. Incidental ingestion of surface soil by workers at this site may result in a "low" increase in the risk of skin 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 five cases of skin cancer may occur. This would increase the number of expected cancers of these 10,000 persons from 2,500 to 2,505. Incidental ingestion of surface soil by trespassers on the site would result in no apparent increase in the risk of cancer.

EPA did not detect arsenic in on-site liquid waste and did not analyze on-site and off-site air or off-site surface soil for arsenic. Therefore, we do not know if exposure to arsenic off of the site is possible and cannot estimate the likely health effects.

Benzene

Former workers at the plant, site trespassers, and nearby residents may have been exposed to benzene by inhalation. The estimated daily dose of benzene from inhalation exceeds ATSDR's acute inhalation MRL. No chronic inhalation MRL is available (ATSDR 1993b). Although the levels of benzene found on and off of the site are much lower than those at which adverse health effects have been observed, we do not have enough information to determine what levels may be safe for people.

Benzene is a known human carcinogen. Long-term inhalation of benzene at the levels found off of the site may increase the risk of leukemia. However, there is no known site-related source of benzene. Benzene detected in the air may have been produced by machinery and electrical generating equipment operated during the EPA soil excavation activities or from other, unknown, local sources. Since no air samples were taken prior to EPA's work at the site and none were taken after the work was completed, we do not have enough information to determine if exposure to benzene represents a long-term health threat to nearby residents.

Benzene was also detected in air samples on the site. However, inhalation of benzene at the levels found on the site would result in no apparent increase in the risk of leukemia.

Benzene was not detected in on-site subsurface soil, liquid waste or solid waste. EPA did not analyze on-site or off-site surface soil for benzene.

Dioxin-TEQ

Former workers at the plant and trespassers on the site may have been exposed to dioxin-TEQ in surface soil and waste sludge by incidental ingestion, and to dioxin-TEQ in the air by inhalation. The estimated daily dose of dioxin-TEQ from incidental ingestion exceeds ATSDR's chronic oral MRL. This MRL is extrapolated from the ATSDR intermediate oral MRL (ATSDR 1989). Incidental ingestion of dioxin-TEQ-contaminated on-site soil and waste sludge, and inhalation of contaminated air on-site may have affected the immune system, produced chloracne, and caused liver damage in former workers at the plant. These effects may also have occurred in trespassers on the site. However, there is insufficient information about the exposure of trespassers to dioxin-TEQ for us to estimate the likely health effects.

Residents in the neighborhood adjacent to the northern border of the site may have been exposed to dioxin-TEQ by incidental ingestion of off-site surface soil and by inhalation of contaminated air. The estimated daily dose of dioxin-TEQ from incidental ingestion of off-site surface soil exceeds ATSDR's chronic oral MRL for children, but not for adults. The estimated daily dose for children, however, is at least ten times less than the level at which no adverse health effects have been observed in animals (ATSDR 1989). Although incidental ingestion of dioxin-TEQ in soil can affect the immune system, produce chloracne, and cause liver damage, these effects do not appear to be likely at the levels present in off-site surface soil. The estimated daily dose of dioxin-TEQ from inhalation of air off-site is at least one hundred times less than the level at which no effects have been observed in animals. Therefore, we do not expect any non-carcinogenic adverse health effects from inhalation exposure in people living near the site.

Dioxin-TEQ in soil is poorly absorbed through the skin. Skin contact with dioxin-TEQ may cause chloracne. Based on extrapolation from studies on ingestion of dioxin-TEQ and information from research on animals (ATSDR 1989), we estimate that dermal exposure of former workers at the plant to dioxin-TEQ in surface soil and waste sludge on the site could cause chloracne. These effects may also have occurred in trespassers on the site. However, there is insufficient information about dermal exposure of trespassers to dioxin-TEQ for us to estimate the likely health effects.

Dioxin-TEQ levels in off-site surface soil are much lower than those on the site. Therefore, it is unlikely that exposure of the skin to dioxin-TEQ-contaminated soil in residential yards could cause chloracne.

Based on animal studies, EPA has classified dioxin-TEQ as a probable human carcinogen. Although there is some indication that exposure to dioxin-TEQ may increase the incidence of soft tissue sarcoma, which is a rare cancer of tissues such as ligaments and tendons (Bertazzi et al 1993), the association of dioxin-TEQ exposure with other cancers in humans has not been clearly demonstrated (Tollefson 1991, Fingerhut et al 1991, Bertazzi et al 1992).

The U.S. Public Health Service and EPA are reviewing the data on risks of dioxin-TEQ exposure for human health. Because of the uncertainty involved in estimating the cancer risks from exposure to dioxin-TEQ, we are currently unable to determine the cancer risks for former workers at the plant and trespassers on the EWP site, or for residents in the adjacent neighborhoods.

EPA did not analyze on-site liquid waste for dioxin-TEQ.

Pentachlorophenol

Former workers at the plant and trespassers on-site may have been exposed to pentachlorophenol (PCP) in surface soil, waste sludge, and liquid waste by incidental ingestion and dermal contact, and in air by inhalation. The estimated daily dose of PCP from incidental ingestion exceeds ATSDR's intermediate oral MRL. No chronic oral MRL is available (ATSDR 1992a). Incidental ingestion of PCP-contaminated soil and waste material on the site may have affected the liver, kidney, central nervous system, and immune system of former workers at the plant and trespassers on the site.

The estimated daily dose of PCP from inhalation of contaminated air on the site is at least ten times less than ATSDR's intermediate oral MRL. No inhalation MRL is available. Although information on the health effects of chronic low-level inhalation exposure to PCP is limited, we do not expect any adverse non-carcinogenic health effects from this exposure.

PCP is readily absorbed through the skin. However, there is no information available regarding the level of PCP in soil that would produce an adverse health effect from dermal exposure.

Although PCP has not been demonstrated to cause cancer in humans, ingestion of PCP in rats and mice has been shown to increase the incidence of liver, spleen and adrenal cancer. Based on extrapolations from these animal studies, EPA has classified PCP as a probable human carcinogen. Long-term ingestion of PCP may also increase the risk of these cancers in humans. Based on the assumption that PCP may cause cancer in humans in a manner similar to that demonstrated in animal models, we estimate that incidental ingestion of PCP-contaminated soil and waste material by former workers at the plant may have resulted in a "moderate" to "high" 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 "moderate" to "high" increase in the risk of cancer means that out of a population of 1,000 persons, of whom 250 are expected to develop cancer for reasons unrelated to exposure at this site, four to twenty additional cases of liver, spleen or adrenal cancer may occur. This would increase the number of expected cancers of these 1,000 persons from 250 to 270.

Incidental ingestion of PCP-contaminated soil and waste material by trespassers on the site may have resulted 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 trespassed on 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, two to nine additional cases of liver, spleen or adrenal cancer may occur. This would increase the number of expected cancers of these 10,000 persons from 2,500 to 2,509.

Former workers at the plant, trespassers on the site and residents in the neighborhood adjacent to the northern border of the site may have been exposed to PCP in the air. However, the increased risk of cancer from this exposure is negligible.

EPA did not detect PCP in off-site surface soil.

Polycyclic Aromatic Hydrocarbons (PAHs)

Former workers at the plant 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 have also been exposed to PAHs in surface soil. The PAHs of concern include: benzo(a)anthracene, benzo(a)pyrene, benzo(b)-fluoranthene, benzo(k)fluoranthene, chrysene, dibenz(a,h)-anthracene, indeno(1,2,3-c,d)pyrene, and naphthalene.

Former workers at the plant and trespassers on the site may have been exposed to naphthalene by incidental ingestion of soil and solid waste material, and by inhalation. No ATSDR MRL is available for naphthalene (ATSDR 1990c). Therefore, we do not know if exposure to naphthalene is likely to have any adverse health effects. The estimated daily dose from incidental ingestion of the other PAHs is less than EPA's chronic oral RfD. No ATSDR chronic oral MRL is available (ATSDR 1990d). Therefore, it is unlikely that this exposure will produce any adverse non-carcinogenic health effects.

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 surface soil and waste sludge 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).

Benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)anthracene, chrysene, dibenzo(a,h)-anthracene, and indeno(1,2,3-c,d)pyrene are possible or probable human carcinogens (ATSDR 1990d). Of these carcinogenic PAHs, only benzo(a)pyrene has an ATSDR comparison value (ATSDR 1990a). We do not have enough human health information to determine the health risks from exposure to the other carcinogenic PAHs. Consequently, our evaluation of the cancer risks from exposure to PAHs will focus on benzo(a)pyrene.

Benzo(a)pyrene is a probable human carcinogen based on animal studies, where it has been shown to induce leukemia and tumors of the stomach and lung. Although no information is available directly correlating human exposure to benzo(a)pyrene with cancer formation, reports of skin tumors among individuals exposed to mixtures of PAHs containing benzo(a)pyrene lend some qualitative support to its potential for human carcinogenicity (ATSDR 1990a). Based on information from animal studies, incidental ingestion of surface soil by former workers at the plant could result in a "low" increase in the risk of leukemia or lung 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, two additional cases of leukemia or lung cancer may occur. This would increase the number of expected cancers of these 10,000 persons from 2,500 to 2,502. Incidental ingestion of surface soil by trespassers on the site would result in no apparent increase in the risk of cancer.

Incidental ingestion of subsurface soils, which are now stockpiled on the site, could result in a "moderate" increase in the risk of leukemia or lung cancer to persons coming in contact with them in the future. There is insufficient information to estimate the risk of skin cancer from past dermal contact with on-site surface soil and from future dermal contact with subsurface soil stockpiled on the site.

EPA did not detect dibenzo(a,h)anthracene or indeno(1,2,3-c,d)pyrene in on-site surface soil or solid waste. They did not detect benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)-fluoranthene, benzo(a)anthracene, chrysene, dibenzo(a,h)-anthracene, or indeno(1,2,3-c,d)pyrene in on-site air. No PAHs were detected in on-site liquid waste. EPA also did not detect benzo(a)pyrene, dibenzo(a,h)anthracene, or naphthalene in off-site surface soil and did not detect benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)-fluoranthene, benzo(a)anthracene, chrysene, dibenzo(a,h)-anthracene, or indeno(1,2,3-c,d)pyrene in off-site air.

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 EWP 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. None of the contaminants of concern at this site is present at a level that would increase the risk of kidney cancer. Pentachlorophenol is present in on-site surface soil and waste sludge at a level that could increase the risk of liver cancer. Benzo(a)pyrene is present in on-site surface soil at a level that could increase the risk of lung cancer. However, we do not have any information about the incidence of liver or lung cancer among people who worked at or trespassed on the site, or among residents of the neighborhood north of the site.

C. Community Health Concerns Evaluation

We have addressed each community health concern as follows:

1. Can any of the contaminants at the site cause non-cancerous health effects such as respiratory problems (i.e., asthma), itching and burning eyes, skin rashes, sinus problems, thyroid problems, heart murmurs, bladder stones or tuberculosis?

A number of the contaminants at the site, including arsenic, pentachlorophenol and PAHs, can irritate the skin, eyes and respiratory system. Contact with arsenic-contaminated soil at the maximum concentration found on the site may cause irritation, swelling and redness of the skin. The levels of pentachlorophenol present on the site are not likely to cause skin or lung irritation. The odor of some of the PAHs, such as naphthalene, may be irritating to sensitive individuals. None of the contaminants of concern at this site are known to cause thyroid problems, heart murmurs, bladder stones, or tuberculosis.

2. Can any of the contaminants at the site cause emphysema, leukemia, bone cancer, colon cancer, or spinal cancer?

Five of the contaminants of concern at this site, arsenic, benzene, benzo(a)pyrene, dioxin-TEQ, and pentachlorophenol, are known or suspected carcinogens. Long-term incidental ingestion of benzo(a)pyrene at the levels found on the site may increase the risk of leukemia or lung cancer. Long-term exposure to benzene at the levels found off of the site may increase the risk of leukemia. However, the benzene detected in the air off-site may have been produced by the machinery and electrical generating equipment used during the EPA soil excavation activities or by other unknown local sources. Additional air sampling is needed to determine if benzene levels in the air off-site have remained elevated. None of the carcinogens found at this site are known or suspected to cause emphysema, bone cancer, colon cancer, or spinal cancer.

3. Dioxins/furans, pentachlorophenol and polycyclic aromatic hydrocarbons have been found on the site. What health effects could result from exposure to these contaminants?

The likely health effects from exposure to dioxins/furans (dioxin-TEQ) and pentachlorophenol (PCP) are detailed in the Toxicological Evaluation section above. Briefly, exposure to dioxin-TEQ may affect the immune system, produce chloracne, and cause liver damage. Incidental ingestion of PCP-contaminated soil and waste material on the site may affect the liver, kidney, central nervous system, and immune system. Exposure to PCP may also increase the incidence of liver, spleen and adrenal cancer. A number of polycyclic aromatic hydrocarbons (PAHs), including benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)anthracene, chrysene, dibenzo(a,h)anthracene, indeno(1,2,3-c,d)pyrene, and naphthalene, have been detected at the site. Exposure to one of these PAHs, benzo(a)pyrene, may increase the risk of leukemia, lung cancer, and skin cancer for former workers at the plant and trespassers on the site.

4. What contaminants cause the strong, burning odor coming from the site and what health effects could result from exposure to them?

Creosote, which is composed primarily of phenol and polycyclic aromatic hydrocarbons (PAHs), was used during the wood treatment process on the site and has a sharp, smokey odor and burning taste. Exposure to these chemicals may be irritating to the skin and eyes of sensitive individuals. The chemicals released into the air from the Florida Drum Company and Precision Machining are also irritating to the nose, throat, eyes, and skin. However, none of these chemicals have been detected on the site at levels that could cause adverse health effects.

5. What contaminants have migrated from the site to residential yards and what health effects may result from exposure to them?

Dioxin-TEQ and several PAHs have been detected in surface soil in residential yards adjacent to the site. None of the PAHs are at concentrations that are likely to cause adverse health effects. The levels of dioxin-TEQ in off-site surface soil are unlikely to cause non-carcinogenic health effects. Because the cancer risk in people from exposure to dioxin-TEQ is currently under scientific review, we do not know what carcinogenic health effects are likely.

6. Can any of the contaminants that may have migrated from the site to residential yards get into fruits and vegetables grown in that soil and what health effects could occur from eating them?

Dioxin-TEQ and PAHs found in off-site surface soil can be taken up by fruit and vegetable plants (ATSDR 1989, 1990c). Although the levels of dioxin-TEQ and PAHs are likely to be very low, no fruits and vegetables from contaminated areas off-site have been analyzed for any of the contaminants of concern at the EWP site. Therefore, we do not know if fruits and vegetables are a source of exposure.

7. Could small game (i.e., rabbit, quail, squirrel, etc.) hunted in the past near the site have been contaminated and what health effects are likely from having eaten them?

Some of the contaminants of concern at this site can accumulate in animals. However, no animal tissue has been analyzed for site-related contaminants. Therefore, we do not know if small game were contaminated or if adverse health effects were likely from eating them.

8. Can benzene from the site get into the public water supply system?

Benzene has been detected in groundwater on the site. However, groundwater flow in this area is to the southeast and not toward any public drinking water supply wells. In addition, all public water supplies are routinely tested for contamination. Therefore, it is not likely that benzene will be of concern in the public water supply in the future.

9. Can the stressful situation experienced by residents near the site cause mental health problems in these individuals?

Exposure to stress can cause a variety of adverse physical and mental health effects in some individuals. However, an evaluation of the likelihood of mental health problems occurring in residents near the site is outside the scope of this public health assessment.

10. If soil incineration is chosen as the method for cleaning up the site, what effect will this have on the air quality and what monitoring will be done to check for contamination coming from the site?

We do not know what method EPA will use to clean up the contamination at this site. Prior to implementing any clean up operation, EPA will likely hold meetings with the community to get suggestions and input about their concerns regarding the proposed clean up methods. Whenever EPA clean up actions have any possibility of producing air-borne contamination, monitoring stations are routinely set up to ensure that any contamination is detected immediately and corrective action taken.

In addition to the health concerns addressed above, residents near the site have raised the issue of environmental equity/justice. They feel that they have been treated unfairly by the agencies involved with the site since work began there because the members of the community are a racial minority. This issue is of importance to the community. However, it is currently outside the scope of the public health assessment process.

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