BRUNSWICK/GLYNN COUNTY COMMUNITY BASED ENVIRONMENTAL PROTECTION PROJECT (405A)
BRUNSWICK/GLYNN COUNTY, GEORGIA
The Region IV U.S. Environmental Protection Agency (EPA) has requested that the Agency for Toxic Substances and Disease Registry (ATSDR) review analytical data of soil samples collected from residential properties in the Brunswick/Glynn County Community Based Environmental Protection Project (BGCCBEPP), and determine if contaminants are present at levels of public health concern .
The City of Brunswick is located in southeastern Georgia in Glynn County on St. Simons Sound and the Atlantic Intracoastal Waterway. Historically, Brunswick has been a heavily industrialized area. Environmental problems include numerous Superfund sites and other waste sites identified by EPA and the Georgia Environmental Protection Division (EPD).
The BGCCBEPP is an area of approximately 200 square miles. The purpose of the project is to assess the project area by reaching across media-specific programs, while building partnerships with stakeholders. EPA is partnering extensively with the State of Georgia EPD in conducting assessment activities to characterize the environmental condition of the area.
The short-term goal is to assess the overall environmental conditions of the project area by identifying and cataloging existing environmental data, conducting short-term monitoring/sampling, assessing/inspecting regulated facilities, and developing a cross-media environmental database.
As part of this goal, EPA randomly sampled soil from 30 residential properties in the project area in December 1996. The collected samples were 5-point composites from each yard; soil samples were collected from 0 - 3 inches in depth. Samples were analyzed for purgeable organic compounds, extractable organic compounds, pesticides, polychlorinated biphenyls (PCBs), metals, and dioxin/furans. Analytical results are presented in Table 1 in the appendix. Purgeable organic compounds were not detected in samples at levels above detection limits.
The collection and analysis of composite surface soil samples from the 30 randomly selected residential yards in Brunswick was conducted for screening purposes; while the sampling may not be adequate to characterize the nature and extent of contamination in the sampled areas, the data are useful to identify areas that may require further investigation.
Exposure to contaminants in soil in residential yards is anticipated to be via oral incidental ingestion of soil. The measured levels of contaminants (Table 1) were evaluated under a residential oral exposure scenario; contaminants and contaminant levels were initially evaluated using ATSDR screening guidance, and contaminants that required further exposure evaluation were identified; toxaphene and polycyclic aromatic hydrocarbons (PAHs) were considered to be at levels that warrant further evaluation in this health consultation.
Toxaphene is a manufactured pesticide, and was heavily used in the United States until 1982 . Exposure to toxaphene at high enough levels can affect the lungs, nervous system, liver, and kidneys . Based on a study of the effect of toxaphene on the liver in rats, ATSDR has derived an intermediate oral Minimal Risk Level (MRL) for toxaphene of 0.001 milligrams per kilogram body weight per day (mg/kg/day) . An intermediate oral MRL is defined as an estimate of daily human oral exposure to a dose of a chemical that is likely to be without an appreciable risk of adverse noncancerous health effects over an exposure duration of two weeks to one year. A 16 kilogram child that ingests 200 milligrams of soil per day that contains toxaphene at 14 mg/kg (maximum measured concentration) will receive a dose of approximately 0.00018 mg/kg/day; this dose is approximately 1 order of magnitude less than the MRL. (Calculation - (14 milligrams/kilogram) x (1/16 kilograms) x (200 milligrams soil/day) x (1 kilogram/106 mg) = 0.00018 milligrams/kilograms/day)
Toxaphene is classified by the EPA as a probable human carcinogen. Evaluation of potential carcinogenic risk due to a lifetime (70 year) exposure to toxaphene using standard default values (50 milligrams of contaminated soil ingested per day, 70 kilogram body weight) indicates that toxaphene at 14 mg/kg does not present an unacceptable cancer risk. (Calculation - (14 milligrams/kilogram) x (1/70 kilograms) x (50 milligrams soil/day) x (1 kilogram/106 milligrams) = 0.00001 mg/kg/day; multiply by Cancer Slope Factor (1.1 (mg/kg/day)-1 = 1.1E-05 Estimated Cancer Risk)
Polycyclic aromatic hydrocarbons (PAHs) are a group of chemicals formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances .
Carcinogenic PAHs were measured at a maximum concentration of 2.6 mg/kg benzo(a)pyrene equivalents (B(a)P equivalents) . Noncarcinogenic PAHs were measured at a maximum concentration of 4.5 mg/kg. Because PAHs generally have a low degree of acute toxicity in humans, potential health effects due to chronic exposure to PAHs were evaluated .
EPA has derived an oral Reference Dose (RfD) for several non-carcinogenic PAHs; an oral RfD is defined an estimate of a daily oral exposure level for the human population, including sensitive subpopulations, that is likely to be without an appreciable risk of deleterious effects during a chronic exposure. The lowest RfD for a non-carcinogenic PAH is 0.03 mg/kg/day for pyrene. A 16 kilogram child that ingests 200 milligrams of soil per day that contains non-carcinogenic PAHs at 4.5 mg/kg will receive a dose of approximately 0.000056 mg/kg/day; this dose is approximately 3 orders of magnitude less than the pyrene RfD. (Calculation - (4.5 milligrams/kilogram) x (1/16 kilograms) x (200 milligrams soil/day) x (1 kilogram/ 106 milligrams) = 0.000056 mg/kg/day)
Benzo(a)pyrene is classified by EPA as a probable human carcinogen. Evaluation of potential carcinogenic risk due to a lifetime (70 year) exposure to B(a)P equivalents using standard default values (50 milligrams of contaminated soil ingested per day, 70 kilogram body weight) indicates that B(a)P equivalents at a soil concentration of 2.6 mg/kg does not present an unacceptable cancer risk. (Calculation - 2.6 milligrams/kilogram) x (1/70 kilograms) x (50 milligrams soil/day) x (1 kilogram/106 milligrams) = 0.000002 mg/kg/day; multiply by Cancer Slope Factor (7.3 (mg/kg/day)-1 = 1.4E-05 Estimated Cancer Risk)
Although the reviewed analytical data were the result of a screening sampling, ATSDR does not consider contaminants to be present in surface soil at levels of public health concern.
If further clarification is required or if additional information becomes available, please do not hesitate to contact this office at 404/639-0616.
Steven Kinsler, Ph.D.
Kenneth G. Orloff, Ph.D., DABT
- Letter and Attached Data Package, To: Mr. Robert Safay, ATSDR, From: Dorothy Rayfield, Brunswick CBEP Coordinator, Subject: Residential Soil Data, Brunswick/Glynn County, Georgia, Date: March 21, 1997.
- Toxicological Profile for Toxaphene, U.S. Department of Public Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry, August 1996.
- Toxicological Profile for Polycyclic Aromatic Hydrocarbons, U.S. Department of Public Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry, August 1995.
- U.S. Environmental Protection Agency, Comparative Potency Approach for Estimating the Cancer Risk Associated with Exposure to Mixtures of Polycyclic Aromatic Hydrocarbons, 1989.
- ATSDR Case Studies in Environmental Medicine, Polynuclear Aromatic Hydrocarbon (PAH) Toxicity, U.S. Department of Public Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry, June 1990.
(a) value is total of constituents or metabolites of technical chlordane
(b) Reference; Interim Procedures for Estimating Risks Associated with Exposures to Mixtures of Chlorinated Dibenzo-p-Dioxins and -Dibenzofurans (CDDs and CDFs) and 1989 Update, U.S. Environmental Protection Agency, Risk Assessment Forum, March 1989. The 2,3,7,8-TCDD isomer was not measured in any samples at levels above the detection limit.
Background and Statement of Issues
The Region 4 U.S. Environmental Protection Agency (EPA) has requested that the Agency for Toxic Substances and Disease Registry (ATSDR) review surface soil analytical data from school playgrounds and city and county parks in Brunswick, Georgia, and determine if contaminants are at levels of public health concern .
EPA initiated a Community Based Environmental Project in Burnswick, Glynn County, Georgia in response to community concerns about potential contamination in the community due to emissions from multiple sites in the area. In June 1996, the EPA conducted the first phase of the upland surface soil investigation, which involved the collection of surface soil (0-3 inches) samples from school playgrounds and city and county parks. These areas were selected due to the potential for children to be exposed. Locations selected at the schools and parks included pay areas, ball fields, dirt mounds, barren areas, open areas, and picnic areas .
Forty-seven surface soil samples and two split samples were collected and analyzed for metals on the Target Analyte List, pesticides/PCBs, extractable organic compounds (base/neutral and acid extractables) and purgeable organic compounds on the Target Compound List. Five samples were analyzed for dioxins/furans. Each soil sample was a composite of aliquots collected from several locations, except for samples analyzed for purgeable organics, which were individual grab samples. The EPA has requested that ATSDR evaluate the analytical data from the following samples301SL, 304SL, 308SL, 311SL, 317SL, 321SL, 323SL, 326SL, 344SL, 345SL, and 346SL.
Metals were detected at the maximum concentrations indicated in Table 1.
Pesticides/PCBs were detected at the maximum concentrations indicated in Table 2.
Extractable organic compounds were detected at the maximum concentrations indicated in Table 3 (table does not include analytical data qualified as "N", or "presumptive evidence of presence of material"; this qualifier indicates that the identity of the contaminant is uncertain ).
Purgeable organic compounds were not detected at levels about detection limits.
Dioxin/furan compounds were detected at a maximum concentration of 2.4 parts-per-trillion TCDD equivalents .
Limited soil sampling was conducted in areas where children are likely to be in direct contact with soil at schools and parks in Brunswick, Georgia. This screening sampling event did not indicate the presence of contaminants in surface soil that would result in exposures to contaminants at levels of public health concern.
Based on the limited data, ATSDR concludes that contaminants are not in surface soil at levels of public health concern.
Steven Kinsler, Ph.D.
Date: October 4, 1996
- Personal Communication, B. Safay/S. Kinsler, September 30, 1996.
- Memorandum and Attached Data Package, From: Jonathan Vail, Hazardous Waste Section,
- U.S. Environmental Protection Agency, Risk Assessment Guidance for Superfund, Human Health Evaluation Manual, Part A, Interim Final, Page 5-14, Exhibit 5-5, U.S. EPA, Solid Waste and Emergency Response, July 1989.
- Interim Procedures for Estimating Risks Associated with Exposures to Mixtures of Chlorinated Dibenzo-p-Dioxins and -Dibenzofurans (CDDs and CDFs) and 1989 Update, U.S. EPA, March 1989.
Ed Skowronski, Acting Chief, EICB
Steven Kinsler, Toxicologist, CS
Bob Safay, Region 4 ATSDR Senior Regional Representative
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