Toxic waste studies

The first step in any toxic waste study is to determine what toxic materials are present and in what amounts. Since most toxic waste situations involve the dumping of diverse materials, problems of expensive technical methodology can be formidable. However, without an adequate inventory of the... 

The limitations of these observations can be described in terms of the general problems associated with such toxic waste studies. The health outcome of concern (cancer, specifically childhood leukemia) is a relatively rare disease. The toxic chemical exposure of particular persons having these diseases could not be directly documented, since the organic chemicals found in well water were transient. Therefore, no means were available for linking particular leukemia cases to particular toxic substances. For the present, then, we are left with an apparent leukemia case cluster and no good evidence for associating cases with the striking environmental toxic waste problems clearly present in the town. 

U.S. EPA may list a waste as hazardous for any and all of the above reasons. The majority of listed wastes fall into the toxic waste category. To decide if a waste should be a toxic listed waste, U.S. EPA first determines whether it typically contains harmful chemical constituents. An appendix to RCRA contains a list of chemical compounds or elements that scientific studies have shown to have toxic, carcinogenic, mutagenic, or teratogenic effects on humans or other life forms. If a waste contains chemical constituents found on the appendix list, U.S. EPA then evaluates 11 other factors to determine if the wastestream is likely to pose a threat in the absence of special restrictions on its handling. These additional considerations include a risk assessment and study of past cases of damage caused by the waste. 

U.S. Geological Survey, 1984, Groundwater Contamination by Crude Oil at the Bemidje, Minnesota, Research Site, U.S.G.S. Toxic Waste-Groundwater Study Water Resources Investigation Report, No. 84-4188. 

Bove FJ, Fulcomer MC, Klotz JB, et al. 1992a. Population-based surveillance and etiological research of adverse reproductive outcomes and toxic wastes. Report on Phase IV-A Public drinking water contamination and birthweight, fetal deaths, and birth defects. A cross-sectional study. New Jersey Department of Health. 

Acute- and chronic-duration inhalation exposure MRLs for diazinon were not derived because of a lack of suitable studies in the literature. Since diazinon is not volatile, inhalation exposure near toxic waste sites is probably less likely than oral or dermal exposure. However, the potential risk of adverse health effects from inhalation exposure to diazinon cannot be assessed without information on the levels actually present in the air around the site. The MRL level of 0.009 mg diazinon/m3 should be protective for individuals living near waste sites. NIOSH has recommended a Permissible Exposure Level (PEL) of 0.1 mg diazinon/m3 to protect the health of individuals who regularly use diazinon in their work the MRL level of... 

Reproductive Toxicity. No studies were located on reproductive effects of radium in humans or animals via inhalation, oral, or dermal exposure. Animal studies using the oral route would be especially useful in evaluating the potential for these effects in human populations exposed to high levels of radium in drinking water (eg., more than 5 pCi/L). Studies using dermal and inhalation exposure would also be useful, since these are also probable routes of human exposure to radium in the vicinity of hazardous waste sites and other settings. 

Because of the extremely diverse situations in which hazardous materials are involved, each study presents unique problems. Table I illustrates the diversity, both in waste materials and exposure settings, of eight recent toxic waste situations. Differences, in fact, can be quite large, ranging from the common drum-filled dump site to the widespread dispersal of waste material. Some generalizations, however, can be made about these kinds of studies. 

To explore the possible cause of reported cancer excesses, and particularly to examine the possible relationship between the town s toxic waste situation and the childhood leukemia case concentration, MDPH and CDC, in 1980, conducted a joint study. Incidence patterns for selected types of cancer were studied by using data collected from local and regional hospital sources. Increased frequencies for childhood leukemia and for kidney cancer were confirmed, with the childhood leukemia excess being located in one particular census tract. 

Dianne Rahm, The Politics of Toxic Waste , Policy Studies Journal 26 (1998), pp. 679-681, at p. 679. 

However, before implementing potentially time-consuming and expensive toxicity reduction studies, it is important to understand their capabilities and limitations. Eor instance, past protocols have had the greatest success with effluent constituents that cause acute toxicity and have questionable usefulness for chronic toxicity. In addition, no method ensures success for very complex waste mixtures (e.g., polar organic compounds), which are exceedingly difficult to analyze. 

In 1991, the National Academy of Sciences studied the health effects attributable to toxic waste sites and concluded, [W]e find that the health of some members of the public is in danger, but We are currently unable to answer the question of the overall impact on public health of hazardous wastes. The Academy pointed out that Millions of tons of hazardous materials are slowly migrating into groundwater in areas where they could pose problems in the future, even though current risks could be negligible. The Academy concluded, ...the committee does find sufficient evidence that hazardous wastes have produced health effects in some populations. We are concerned that populations may be at risk that have not been adequately identified, because of the inadequate program of site identification and assessment. ... 

Numerous studies, including by Union Carbide itself, acknowledge the presence of contamination and toxic wastes on and off site. A 1999 Greenpeace study confirmed the presence of persistent organic pollutant chemicals, such as DDT... 

Superfund sites are sites that emit numerous neurotoxins into the air and water environments. Love Canal studies have shown nervous system effects that can be attributed to living near a toxic waste site. I36 Elevated neural tube defects in offspring were identified with mothers residing proximate to hazardous waste sites. I49 50 It has also been shown that people residing close to industrial facilities that emit solvents or metals have offspring with increased CNS defects J51l... 

A Texas study found significant additional risk for congenital heart disease in children whose mothers lived close to hazardous waste sites than in children whose mothers did not live near toxic waste sites J43l... 

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