HEALTH CONSULTATION
H.O. FORGY SITE
JACKSON, TENNESSEE
BACKGROUND AND STATEMENT OF ISSUES
The Region IV U.S. Environmental Protection Agency (EPA) has requested that the Agency for Toxic Substances and Disease Registry (ATSDR) review environmental sampling data from the H.O. Forgy site in Jackson, Tennessee and determine (1) the potential public health impact from contaminated soil to area residents who may access the site, and (2) the potential threat to off-site populations through surface soil and groundwater migration of site contaminants [1]. This health consultation will address the data provided in a site investigation completed by the Tennessee Division of Superfund (TDSF) in May 1998 [2].
The H.O. Forgy site is now abandoned, but once housed an aluminum smelting operation that operated from 1951-77. Scrap cars were melted down in an incinerator and the aluminum was recovered. Metal dross, a by-product of the process, is present throughout the site. In 1997, five buildings on site, including the main smelting building, were demolished [2].
The site is triangular shaped occupying approximately 1.6 acres. Railroad tracks border the site on all three sides, and residential properties are situated just across the tracks North, South, and West of the site [2]. Access to the site is unrestricted from all directions. "Little children" from the neighborhood use the property as a playground. Homeless people and transients are also known to frequent the site [2]. The TDSF has recommended health screening for children in the immediate vicinity of the site [2].
The population within a four mile radius of the site receive their drinking water from the Jackson Utility Division (JUD) Wellfield. There are three wells from the JUD South Wellfield located within 1/4 mile of the site that serve an estimated population of 18,300 [2]. Volatile organic compounds (VOCs) have been detected in several wells of the South Well Field. The locations and concentrations of the VOCs were not available [2]. Organic solvents are suspected at the site, however, the groundwater pathway was not evaluated as part of the site investigation [2].
The Anderson Branch Creek, a tributary of the South Fork Deer River, is located 15 feet west of the site, and flows in a southernly direction. There are no known surface water intakes within the 15 mile surface water pathway of the creek and river [2]. Fishing has been observed at the mouth of the creek, and the river is used for recreation, irrigation, livestock watering, and fishing.
In January 1998, the TDSF conducted surface soil and sediment sampling at the site. A total of 9 surface soil samples (1-background) and 5 sediment samples were collected. The samples were analyzed for VOCs, extractable organics, and metals. Sampling locations were biased because they were collected from stained soil or suspected areas of contamination.
VOCs such as methylene chloride and toluene were detected in the surface soil in the low parts per billion (ppb) range. One surface soil sample detected polychlorinated bipheynls (PCBs) at 37.2 parts per million (ppm). The remaining surface PCB levels were less than 7 ppm. Lead, arsenic, aluminum and zinc concentrations were also elevated in the surface soil. Lead ranged from 202 to 4,710 ppm, arsenic was detected at 13.8 to 62.6 ppm, zinc was measured from 343 to 22,300 ppm, and aluminum ranged from 7,940 to 286,000 ppm [2].
Lead was detected at maximum concentration of 813 ppm in sediment near the site. Much lower lead levels were measured in the stream sediment.
Past activities at the site have resulted in elevated concentrations of metals and PCBs in the surface soil and sediments. Sampling data for the site is limited. Only nine surface soil samples were collected from stained soil and other areas of suspected contamination. These samples may not reflect the average concentration, and in turn, may overestimate average exposure to the soil.
Exposure to contamination at this site may occur through incidental ingestion and/or inhalation of soil or dust. The high levels of zinc in the surface soil will enhance exposure by preventing the growth of a protective grass cover, and may contribute to fugitive dust emissions potentially impacting nearby populations.
Exposure to contaminated sediments may also occur, but to a lesser extent. Since access to the site is unrestricted, those coming in contact with the soil are likely to be trespassers, particularly neighborhood children attracted to the abandoned site. Given the current status of the site, it can be assumed that exposure to the soil would be on an intermittent basis.
Lead
The nine surface soil samples collected from the site average 2,148 ppm for lead. The Centers for Disease Control and Prevention (CDC) has reported that blood lead levels in young children have been raised, on average, about 5 ug/dL for every 1,000 ppm of lead in soil or dust, and may increase 3 to 5 times higher than the mean response depending on play habits and mouthing behavior [3]. Blood lead levels of 10 ug/dL and above have been associated with adverse health effects such as developmental and hearing impairment, and reductions in intelligence quotient (IQ) in children [3,4].
The guidelines of CDC are based on residential exposure scenarios where frequent contact with the contaminated soil and/or dust occurs. At this site, exposure to the soil would be intermittent, and would not likely include children in the most susceptible 0-to-6 year old age group. Children at this age are unlikely to be regularly left unsupervised at an abandoned site surrounded by railroad tracks. An occasional trespasser or visitor should not be exposed sufficiently to warrant concern. A more significant concern may be the transportation of lead contaminated soil into homes by tracking on shoes, clothing, and pets. In addition, exposed contaminated soil may be spread to adjoining properties through wind erosion exposing other more sensitive populations such as infants or pregnant women.
Lead was also present in the sediments near the site at levels up to 813 ppm. The same rationale used to rule out the lead as a contaminant of concern for oral exposure to the surface soil, applies to the sediments. In addition, exposure to sediments are less than that which would occur from soil, and the concentrations of lead in the sediments were an order of magnitude less than that detected in the surface soil.
Lead concentrations were low in the sediment down stream from the site, and would not present a concern to people using the South Fork Forked Deer River for recreation or fishing.
PCBs
PCBs are a group of 209 synthetic organic chemicals that have varying levels of toxicity. In humans, long-term exposure to PCBs can effect the skin, liver, reproductive and endocrine systems [5]. While human evidence of PCB carcinogenicity is limited, animal studies provide sufficient evidence. Based on these findings, EPA has characterized some commercial PCB mixtures as "probable human carcinogens" [5].
Humans are exposed to PCBs through multiple pathways. In addition to the ingestion of soil, water, and inhalation of contaminated air, food serves as a major source of PCB exposure [5]. The potential health threat from environmental PCBs is dependent on factors such as concentration in media, completed exposure pathways, frequency of exposure, and duration of exposure.
The average PCB concentration for this site is in the low ppm range. Concentrations of PCBs in this range do not pose a health threat, particularly on a site where frequent exposure to the soil does not occur. In addition, the sampling was biased, targeting stained areas, and would likely over-estimate the concentrations of PCBs in the soil.
Zinc
Although zinc is an essential nutrient in humans that is necessary for a large number of metalloenzymes, adverse health effects can occur from overexposure [6]. Several studies have suggested that ingestion of relatively high doses of zinc can result in gastrointestinal disturbances [6]. In one report, a female ingested approximately 2.6 milligrams of zinc per kilogram body-weight per day (mg/kg/day) for treatment of acne. After taking each capsule, she experienced epigastric discomfort, and later passed melanic stools indicative of gastrointestinal bleeding [6]. In another study, gastrointestinal upset (nausea, vomiting, abdominal cramps) occurred in 26 of 47 healthy volunteers following ingestion of 2 mg zinc/kg/kg/day tablets for six weeks [6].
If a 20 kg child (i.e.,4-6 year old) should access the site and ingest 200 mg of soil containing zinc at 286,000 ppm while playing, that child could receive a dose of 2.86 mg zinc/kg-body weight. This dose may be sufficient to cause gastrointestinal distress.
Groundwater Pathway
The sampling conducted to date has focused on the surface soil contamination. Description of the nature and extent of contamination, to include the soil and groundwater, has not been accomplished. There are groundwater wells in close proximity to the site that are potentially impacted. VOCs are of particular concern since they can readily move through the soil into the groundwater. The surface soil sampling did not detect high levels of VOCs. However, the site has been inactive for years, and surface VOCs may have dissipated through volatilization. Therefore, surface VOCs may not be indicative of contamination at depth.
ATSDR's Child Health Initiative recognizes that the unique vulnerabilities of infants and children demand special emphasis in communities faced with contamination of environmental media. As part of the ATSDR initiative, ATSDR health consultations must indicate whether any site-related exposures are of particular concern for children. At this site, initial sampling has identified high levels of lead and zinc in the surface soil, and there is evidence that children are accessing the site. Children are uniquely susceptible to the deleterious effects of lead. Blood lead levels of 10 ug/dL and above have been associated with adverse health effects such as developmental and hearing impairment, and reductions in IQ in children. Because children are also likely to engage in frequent contact with the soil, the zinc contamination also poses a health threat to children, although to a lesser degree. Additional sampling will be required to determine if the contamination is pervasive enough to pose a health threat.
Based on the information provided, and assuming the present site conditions and usage, ATSDR concludes the following:
Timothy Walker, MS
Environmental Health Specialist
Concurrence: Richard Canady, PhD, DABT
Senior Toxicologist
