IOWA MALLEABLE IRON COMPANY
FAIRFIELD, JEFFERSON COUNTY, IOWA
Iowa Department of Public Health (IDPH) has been asked by the U.S. Environmental Protection Agency (EPA) Region 7 to complete a health consultation regarding possible health effects from exposure to contaminated soils and physical hazards existing at the Iowa Malleable Iron Company site in Fairfield, Iowa. If additional information is forthcoming, IDPH reserves the right to amend the conclusions and recommendations provided in this document.
The site is an abandoned iron foundry located at 9th Street and Kirkwood Avenue in Fairfield, Jefferson County, Iowa. It is bounded on the north and east by residences, and on the south and west by industrial properties. There are 18 residences within 200 feet of the site; the nearest residence is approximately 75 feet to the east. Approximately 700 persons live within 1/4 mile of the Iowa Malleable Iron Company (1). The site is 8.5 acres in size, and is unfenced and readily accessible to the public.
The foundry ceased operations in 1993, and since that time the facility has been repeatedly vandalized. Acts of vandalism in December 1995 resulted in a fuel oil spill of approximately 3,000 gallons from an aboveground storage tank. This oil spill brought the site to the attention of EPA Region 7. During the emergency response to the spill, over 100 individual storage tanks, containers, drums, buckets, and bottles labeled as containing polychlorinated biphenyls (PCBs) were discovered on site. Soil and concrete samples from the areas of highest contamination contained up to 729,000 parts per million (ppm) PCBs. Concentrations of lead in soil ranged from 4.7-273 ppm (2). Friable asbestos insulation and asbestos tiles were also found throughout the foundry.
In 1997, EPA Region 7 initiated a removal action to remove asbestos insulation and PCB-contaminated soils, concrete flooring, storage containers, and fixtures from the foundry and adjacent grounds (1). The site was cleaned to meet industrial re-use standards, with a soil PCB concentration of 10 ppm used as a screening level for removal. During the removal action, all storage tanks and fuel pipes were drained and two large aboveground storage tanks were razed. Approximately 60,000 gallons of fuel oil and fuel oil sludge were disposed of at an off-site incineration facility. Also, more than 800 tons of PCB-contaminated soils and concrete flooring and over 1,600 linear feet of asbestos insulation and 400 square feet of asbestos-containing tiles were removed, and then disposed of off site. A total of 220 tons of petroleum-contaminated soil were excavated and then removed to an appropriate waste-handling facility (1).
The removal action was completed in June 1997; since then, no further remedial work has been done. Post-removal sampling revealed PCBs remaining in soil at concentrations as high as 8.7 ppm; the average concentration is 2.7 ppm. Soils with highest remaining PCB levels are found in the extreme interior of the foundry site and are not readily accessible. According to EPA Region 7, the site is suitable for industrial re-use only (3).
Soils at four nearby residences were sampled during a preliminary assessment conducted prior to the 1997 removal action. PCBs were detected in surface soils (0-2") at these locations in concentrations from 0.025-0.43 ppm; the average concentration was 0.11 ppm. Lead was present in these samples from 48.1-95.7 ppm. Background concentrations of lead and PCBs in soil were 28.8 ppm and 0.021 ppm, respectively. There are no known private wells in the area, as residents within a 4-mile radius of the site rely on the Fairfield municipal water supply. Analysis of municipal well water in 1997 found no detectable presence of PCBs or volatile organic compounds (VOCs) (2).
The present condition of the site is such that a definite physical hazard exists. Site visits by IDPH staff in Spring and Summer 2001 confirmed this. The oldest of the remaining foundry structures (circa 1920) appears to present the greatest degree of hazard. Most windows in the foundry and adjacent offices have been broken, and much of the remaining interior furnishings and foundry equipment have been destroyed. Water-filled pits in flooring and foundation make footing treacherous and uncertain; a person falling into one of these pits could easily sustain serious injury. Sharp objects, shards of glass, and rusted parts of machinery abound.
Contaminants of concern at the site are PCBs and lead. Physical hazards exist and will be discussed separately.
PCBs On-Site and Residential
The chronic minimal risk level (MRL) for ingestion of PCBs at the Agency for Toxic Substances and Disease Registry (ATSDR) has been set at 0.02 µg/kg/day (micrograms per kilogram of body weight per day). The MRL is an estimate of daily exposure to a hazardous substance that is likely to be without adverse health effects (4). In this case, chronic exposure is defined as lasting longer than 364 days. If an 8-year-old child trespassing on site ingested 200 milligrams (mg) of the most highly contaminated soil (8.7 ppm PCB), 3 days a week for 5 years, the dose received would be 0.015 µg/kg/day, lower than the established MRL. Three days per week for 5 years is an estimated amount of time a child could be on-site, and 200 mg is a representative amount established by previous research studies for childhood soil ingestion (5).
These assumptions are conservative, i.e., protective, in that it is unlikely a child will be on-site for 5 years ingesting soil, particularly the most highly contaminated soil. However, even with these protective assumptions, this estimated dose is more than 45 times lower than the lowest observed adverse effects level (LOAEL) of 5 µg/kg/day for immunological effects in adult monkeys evaluated after 23 and 55 months of exposure to PCBs (6). Therefore, it is reasonable to assume that no adverse health effects will result from exposure to PCBs in concentrations found at the Iowa Malleable site.
The U.S. Department of Health and Human Services (DHHS) has concluded that PCBs are reasonably anticipated to be carcinogenic in humans on the basis of sufficient evidence of carcinogenicity in animals (6). Both the highest (8.7 ppm) and average PCB (2.7 ppm) concentrations in on-site soil are above the ATSDR cancer risk evaluation guide (CREG) of 0.4 ppm. CREGs and MRLs are screening values and are considered to be protective of public health. It should be noted that exceeding a screening value does not necessarily imply that a health threat exists; screening values provide a means of selecting those contaminants that need further evaluation for their potential impact on public health (4). Laboratory studies on animals have established a cancer effect level for PCBs of between 1000-10,000 µg/kg/day (6). This is for chronic, long-term exposure, and is at least 10,000 times higher than the calculated PCB ingestion dose for on-site soil. No increased risk for cancer from PCB exposure through soil ingestion at the Iowa Malleable site should be expected.
Soils at nearby residences contain PCBs in concentrations above background levels but lower than on-site soil; the highest residential soil PCB concentration was 0.43 ppm. If an adult (70 kg body weight) were to consume an average of 100 mg/day of residential soil containing 0.43 ppm PCBs over a 30-year period, the resulting exposure dose would be 0.0003 µg/kg/day, more than 60 times lower than the minimal risk level. For a child of 1-6 years of age and 16 kg body weight, consuming 200 mg/day of this soil every day would give an exposure dose of 0.005 µg/kg/day, four times lower than the MRL. This dose was estimated using similar protective assumptions as for on-site soil ingestion. No adverse health effects should be expected from PCB exposure at these levels.
Lead in On-Site and Residential Soil
Although no health-based screening or comparison values for lead in soil are currently available from either the ATSDR or EPA, the U.S. Housing and Urban Development Agency (HUD) has set a screening level of 400 ppm lead in residential soil (6). This level is considered safe by HUD, and is over four times greater than the highest reported residential soil lead level of 95.7 ppm in the neighborhood surrounding the Iowa Malleable Iron Company site. On-site soil lead concentrations were also below the HUD screening level.
EPA has determined that only 1% of a child's total lead exposure is derived from soil, and that by far the greatest source of childhood lead exposure is lead paint dust and paint chips (7). At the residential lead level of 95.7 ppm, a child consuming 200 mg of soil in a manner similar to that previously evaluated for PCBs would receive a lead dose of 0.001 mg/kg/day. This is 20 times lower than the lowest reported nonlethal toxic dose in humans of 0.02 mg/kg/day. If the highest lead concentration in on-site soil is used in this same calculation, then the dose received by a child is approximately six times lower than the lowest toxic dose. The conservative assumptions applied here regarding amount of soil ingested are the same as those used for PCB exposure. As with PCBs, exposure to lead at concentrations found in both on-site and off-site soil should not cause any adverse health effects.
The foundry buildings present a serious physical hazard due to neglect and vandalism. Physical hazards exist in and around the foundry itself and throughout the site. Presently, there is no perimeter fence at the site, and the public has unrestricted access to the foundry. A previous health consultation in 1997 recognized these same factors but made no recommendation concerning access because at that time removal action was scheduled to begin (8). Unrestricted access permits trespassers and neighborhood children to come in contact with soil contaminants and the physical hazards associated with the site.
Children differ from adults in their exposures, and might differ in their susceptibility to hazardous chemicals. Children's unique physiology and behavior can influence the extent of their exposure; for example, children breathe more air per kilogram of body weight than do adults. They also engage in substantial hand-to-mouth activity, and might ingest inappropriate things such as dirt. This fact is important regarding ingestion exposure at the Iowa Malleable site, where soils contain lead and PCBs. Lead is particularly toxic to children, and ingestion of lead in sufficient amount may cause developmental and neurologic problems (7).
Lead and PCBs in soil at the Iowa Malleable site have been evaluated in relation to children's health and the potential for adverse health effects caused by exposure to these compounds. Calculated exposures to lead and PCBs are below acceptable, established health guidelines for children.
The Iowa Malleable site poses a number of physical hazards, both to adults and children. Children are less able to judge physical hazards than adults, and therefore might be more susceptible to injury from the hazards that are present on-site.
- Chemical contamination of soils at the Iowa Malleable Iron Company site presents no apparent public health hazardunder current site conditions.
- Off-site soils present no apparent public health hazard. Lead and PCBs are present, but at levels well below health concern.
- The dilapidated condition of the site poses a physical hazard to trespassers.
- Implement measures to limit contact with physical hazards.
- Re-evaluate the need for further actions should site use change.
- Ecology and Environment, Inc. Removal assessment/removal for the Iowa Malleable Iron Company, Fairfield, Iowa. Prepared for United States Environmental Protection Agency Region 7 Site Assessment and Cost Recovery Program. 1998 Dec.
- Ecology and Environment, Inc. Preliminary assessment/site inspection report for the Iowa Malleable Iron Company Site, Fairfield, Iowa. Prepared for United States Environmental Protection Agency Region 7 Site Assessment and Cost Recovery Program. 1998 Dec.
- US Environmental Protection Agency Region 7. Letter to Denise Jordan-Izaquirre, ATSDR Region 7, from Bruce Morrison. Kansas City, Kansas. May 21, 2001.
- Agency for Toxic Substances and Disease Registry. Public health assessment guidance manual. Atlanta: US Department of Health and Human Services; 1993.
- Calabrese EJ, et al. 1989. How much soil do young children ingest: an epidemiologic study. Regul Toxicol Pharmacol. 10:123-137.
- Syracuse Research Corporation. Toxicological profile for polychlorinated biphenyls. Prepared for Agency for Toxic Substances and Disease Registry. Syracuse, New York: Syracuse Research Corporation. Contract No. 205-1999-00024. 2000 Nov.
- Research Triangle Institute. Toxicological profile for lead. Prepared for Agency for Toxic Substances and Disease Registry. Research Triangle Park, North Carolina: Research Triangle Institute. Contract No. 205-93-0606. 1999 Jul.
- Agency for Toxic Substances and Disease Registry. Health consultation for Iowa Malleable Iron Company, Fairfield, Iowa. Atlanta: US Department of Health and Human Services; 1997 May.
Hazardous Waste Site Health Assessment Program
Iowa Department of Public Health
ATSDR Regional Representative
Office of Regional Operations, Region VII
Office of the Assistant Administrator, ATSDR
ATSDR Technical Project Officer
Division of Health Assessment and Consultation
Superfund Site Assessment
The Iowa Department of Public Health, Hazardous Waste Site Health Assessment Program, prepared this health consultation for the Iowa Malleable Iron Company site under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). The health consultation is in accordance with approved methodology and procedures existing at the time work on it began.
Technical Project Officer, SPS, SSAB, DHAC, ATSDR
The Division of Health Assessment and Consultation, ATSDR, has reviewed this health consultation, and concurs with its findings.
Chief, SPS, SSAB, DHAC, ATSDR