FORMER RALLY'S RESTAURANT AND BRIARCLIFF STATION
ATLANTA, DEKALB COUNTY, GEORGIA
No physical hazards are present at these sites that would pose a threat to public health. The sites are located on public property with unlimited access. The area surrounding the sites is approximately 50% residential and 50% commercial/industrial (Figure 3). The closest residential property is within 300 feet from the sites. Three schools are within a mile radius of the sites, with the closest school approximately 2,000 feet southeast.
The Agency for Toxic Substances and Disease Registry (ATSDR) and GDHR evaluate chemical releases and assign categories of human exposure pathways to those releases. An exposure pathway is a description of the process by which a chemical containment moves from a source of contamination to a receptor population. A completed exposure pathway exists if all five of the following elements exist: 1) source of contamination, 2) a transport mechanism to the environmental medium; 3) a point of exposure; 4) a route of exposure to the body; and 5) a receptor population.
Though contaminant levels may be present above reportable quantities, a public health hazard only exists if there was an actual exposure to the chemical and at high enough doses to result in adverse health effects. A review of the scientific literature on possible health effects associated with the contaminants that were present at levels that exceeded comparison values was conducted and the results are included in this section of the health consultation.
Potential Exposure Pathways
No air sampling has been conducted at these sites. Therefore, we cannot evaluate whether volatile organic compounds released into the air posed a problem for people in the immediate area. Because someone would have to be very close to the small area where volatile organics were detected, the likelihood that anyone would be exposed to levels high enough to cause adverse health effects is very small.
No public or private groundwater wells are within a three mile radius of these sites; therefore, there is no point of exposure, no route of exposure, and no receptor population for groundwater contamination.
We found no indication of widespread contamination or lateral migration of contaminated surface soil. Contamination appears to be localized to the soil directly beneath the dry cleaner valve boxes.
Ingestion of contaminated soil and soil dust is the primary route of exposure to contaminants at the subject sites. The transport mechanisms for ingestion exposure at these sites are direct ingestion of soil (e.g. children with pica) and ingestion of soil and soil dust during work or recreational activity in the contaminated area.
Persons who may be exposed to contaminated soil at these sites include tenants, employees, patrons, contractors, and other individuals who may come into contact with the soil directly beneath the dry cleaner's valve boxes. The persons at greatest risk for exposure are the tenants who operate the dry cleaning establishment. No information is available about the operator(s) exposure history, safety procedures, use of protective equipment, or health status. Because of the limited amount and unfavorable location of contaminated soil, it is highly unlikely that people are exposed to the contaminated soil in any way that would result in a high enough dose to cause adverse health effects.
Although the level of tetrachloroethene did not exceed the comparison value for the contaminant in soil, people who work in the area, especially at the dry cleaning shop where exposures may be greater, may be interested in additional information about tetrachloroethene. Sampling data indicated the presence of tetrachloroethene in two soil samples taken from the Briarcliff Station site (Table 2). The highest level detected in soil was 6.0 ppm. There are no federal regulatory standards for tetrachloroethene in soil.
Tetrachloroethene is a manufactured chemical used primarily for dry cleaning. Irritation of the skin, eyes, and respiratory tract may result from repeated or extended contact, but these symptoms occur almost entirely from inhalation exposure in the indoor work environment. Ingestion of large quantities of tetrachloroethene (>4 grams) may result in acute neurological symptoms including reversible drowsiness, vertigo, mood and behavioral changes, impairment of coordination, and anesthetic affects . These effects were only observed in people who swallowed the chemical in liquid form. There are no documented cases of high or low level ingestion exposure over a long or short period of time. Insufficient data are available to determine whether tetrachloroethene affects reproductive and developmental outcomes in humans, nor has it been established if it causes cancer in humans .
The maximum concentrations of tetrachloroethene detected in soil are summarized in Table 5, along with the ATSDR comparison values. Comparison valuess provide informatin that can be used to estimate a dose for specific exposure scenarios at which health effects might be observed. Concentrations less than the comparison values are unlikely to pose a health threat, even if exposure occurs, and concentrations above the comparison values do not necessarily pose a health threat if the exposure is not long or frequent . In addition, cancer risk values are assigned to substances which may be classified as a carcinogen or reasonably anticipated to be a carcinogen. Comparison values and cancer risk estimates are discussed in Appendix A.
On the basis of these very conservative guidelines, GDHR derived exposure doses and an excess cancer risk value for potentially exposed individuals. Estimates for exposure to tetrachloroethene through ingestion of soil does not exceed health guidelines (minimal risk levels [MRL]) based on acute exposure (less than or equal to 14 days). In addition, the cancer risk estimate for potentially exposed individuals does not exceed the acceptable risk value based on chronic long-term exposure (365 days/year for 70 years).