ANNISTON, AL—A federal study found that people living near the Solutia plant are likely breathing in PCBs, while plant employees and workers who dig up soil in the area also could be exposed to the chemical.
"We don't know what their exposure is, but there is some exposure," said Lynn Wilder, environmental health scientist for the Agency for Toxic Substances and Disease Registry (ATSDR).
The federal environmental health agency released its report last week. The agency studied the area near the plant to determine the public health threat from polychlorinated biphenyls, or PCBs, which were manufactured from the 1930s to the 1970s at an Anniston plant owned at the time by Monsanto.
PCBs later were banned after being linked to a range of health problems, and massive litigation has been brought against Solutia Inc. and its corporate relatives.
"We wouldn't disagree with the conclusion that people who live adjacent to the fence line could be exposed to PCBs in air," Craig Branchfield, remedial projects manager for Solutia, told The Anniston Star. "I think the main question is, are those PCBs in air an unusually high risk? And I think the answer to that question is no. They are consistent with normal urban background levels."
Wilder said there is no way for people who live near the plant to reduce their exposure.
The Environmental Protection Agency is overseeing a study and cleanup of PCBs in the Anniston area, but hasn't made much effort to learn how PCBs are getting into the air.
"We just haven't gotten to that point in the project," said Pam Scully, site manager for the Anniston PCBs cleanup. "Hopefully this year we'll come up with work plans."
The PCBs could be vaporizing from contaminated soil in the area, Scully said. Solutia contractors are replacing soil in some of the most contaminated yards in the area.
"Any kind of source control we can do should improve the air quality, and that's why we want to move on the properties," Scully said.
The air levels have been going down over the past five years, Branchfield said. He said the levels detected to date are well below federal occupational standards.
source: http://story.news.yahoo.com/news?tmpl=story&u=/ap/20031229/ap_on_sc/pcbs_health_report_1 29dec03
PCBs are a group of manufactured organic chemicals that contain 209 individual chlorinated chemicals (known as congeners). The acronym PCB is used in this document to refer to any commercial or environmental mixture of PCBs. PCBs are either oily liquids or solids and are colorless to light yellow in color. They have no known smell or taste. There are no known natural sources of PCBs. Most commercial PCB mixtures produced in the United States are known by their industrial trade name, Aroclor [9].
PCBs were widely used in the past as coolants and lubricants in transformers, capacitors, and other electrical equipment. PCBs were released into the air, water and soil during the manufacturing process and during the use of the electrical equipment. Although banned from production and distribution in the late 1970's, PCBs remain in the environment. The highly chlorinated PCBs were prevalent in the 1996 Consent Order sampling. These PCBs are poorly metabolized and tend to accumulate in tissues and organs rich in fat (lipids) [9]. PCB residues have been found in soil, air, water, aquatic and marine sediments, fish, wildlife, and humans.
The information currently available on the human health effects of exposures to PCBs is inconclusive, so the evaluation of health effects is complicated by a number of factors. Some of these factors include small numbers of individuals in any single study, poorly defined individual exposure status, the presence of other risk factors and other possible exposures, and lag (latency) period from the time of the PCB exposure to the time of that the health effect can be detected. An additional potential complication is variation in specific congener composition of the PCB exposure. Individual congeners may vary in toxic potency and may be influenced by the presence of other congeners and impurities. Thus, the toxicity of the mixture may depend on the toxicity of the individual congeners and their interactions. Most of the available toxicity data does not deal with effects from specific individual congeners. Therefore, current studies of health effects may overestimate or underestimate the actual health hazard of the various PCB mixtures [9]. More research is needed to better define the human health effects from both exposures to PCBs and from body burdens of PCBs.
The toxic effects of PCBs have been studied extensively both in laboratory animals and wildlife. Reported toxic effects include damage to the liver, skin, brain, stomach, and thyroid gland [9]. There have also been reports of developmental (problems in learning and memory), reproductive (difficulty in becoming pregnant, small offspring), and immune (increased numbers of infections) problems [9]. The PCB-induced changes were dependent upon a number of factors including the age, sex, and species of the animal, the route of exposure, the duration of exposure, and the chlorine content of the PCB-mixture [10].
Animal studies are useful in determining possible adverse health effects from exposure to contaminants; however, in some cases the relevance of animal data to human health is unclear or inconclusive. Occupational data, in conjunction with animal data, have suggested that there is a potential for certain effects on the thyroid gland, the liver, the skin, the eyes, the blood, and the immune system. There are also reports of neurodevelopmental and reproductive effects in humans exposed to PCBs [9].
PCBs have been reported to cause certain cancers in animals, including liver cancer, leukemia/lymphoma, and stomach cancer [11]. While PCBs are suspected of being carcinogenic to humans, current available data is still somewhat controversial. Studies of workers exposed to PCBs have reported an increased number of deaths due to cancers of the gastrointestinal tract, the rectum, the liver, the brain, the blood (leukemia and lymphoma) and skin (malignant melanoma) [12]. However, these cancers have not been observed consistently across studies. In a recent study of individuals with non-work-related (environmental) exposures, PCBs were linked to an increased risk of non-Hodgkin's lymphoma (NHL) [13].
Based on the cancer in animals, the Department of Health and Human Services (DHHS) has stated that PCBs may reasonably be anticipated to be carcinogens. The International Agency for Research on Cancer has determined that PCBs are probably carcinogenic to humans. The EPA has proposed that PCBs are probable human carcinogens. A detailed review of the carcinogenic potential of PCBs by EPA demonstrates that some PCBs mixtures in the environment (e.g., those typically found in fish or in soil) are likely to be more carcinogenic than others (e.g., those typically found in water or air) [14].
References
[9] Agency for Toxic Substances and Disease Registry. Toxicological profile for polchlorinated biphenyls. Atlanta: U.S. Department of Health and Human Services, Public Health Service, September 1997.
[10] Safe S. Toxicology, structure-function relationship, and human and environmental health impacts of polychlorinated biphenyls: progress and problems. Environmental Health Perspectives 100:259-268, 1993.
[11] Bertazzi PA, Riboldi L, Pesatori A, Radice L, Zocchetti. Cancer mortality of capacitor manufacturing workers. American Journal of Industrial Medicine 11:165-176, 1987.
[12] Kimbrough RD, Doemland ML, LeVois ME. Mortality in male and female capacitor workers exposed to polychlorinated biphenyls. Journal of Environmental Medicine 41:161-171, 1999.
[13] Rothman N, Cantor KP, Blair A, Bush D, Brock JW, Helzlsouer K, Zham SH, Needham LL, Pearson GR, Hoover RN, Comstock GW, Strickland PT. A nested case-control study of non-Hodgkin lymphoma and serum organochlorine residues. Lancet 350:240-244, 1997.
[14] Cogliano VJ. Assessing the cancer risk from environmental PCBs. Environmental Health Perspectives 106:317-23, 1998.
source: http://www.atsdr.cdc.gov/HAC/PHA/solutia/mcs_p1.html 29dec03
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