tamination. The pits themselves represent a threat to wildlife drawn to the water, especially in otherwise arid regions, and there is now a widespread legacy of saltwater contamination in the shallow aquifers in these regions. Health effects may also occur where wildlife and livestock consume saline water in surface pits. The health effects of chronic exposure to produced water for humans have not been directly studied, although the individual compounds found in the saline fluids have been investigated out of context with the oil and gas industry. Generally, the taste threshold for humans is sufficiently low that little saline water is consumed by accident, and salinization of drinking water is immediately apparent. However, some produced fluids contain naturally occurring radioactive material, and special disposal procedures are required for this fluid (Rajaretnam and Spitz, 2000).
Petroleum contamination of soil is common in oil-producing states in the United States, and many landowners have inherited old collection lines and both low- and high-pressure pipelines where small oil leaks were commonplace. Although the health impacts of benzene, toluene, ethylbenzene, and xzylene3 (BTEX) have been extensively studied and BTEX pollutant plumes are the subject of ongoing remediation in many parts of the country, the health consequences of contamination of soil and water by the full range of oil components are poorly understood. It is not clear whether health problems are associated with long-term exposure to low concentrations of petroleum in water or air, or if degraded oil poses adverse health effects. The individual components in petroleum in groundwater, particularly the aromatic compounds, are now recognized to rapidly degrade due to the metabolic activity of the native microbial consortium (NRC, 2000a). However, the end product of degradation is not solely carbon dioxide or methane but rather can be a variety of complex, partially degraded, carbon compounds that persist in the water and are transported much farther than the primary BTEX-type compounds. These compounds are generally unresolved by standard analytical techniques and remain largely unidentified, recognized only by the dissolved organic carbon (DOC) plume or after extraction and characterization by advanced analytical techniques (Eganhouse et al., 1993).
The crosscutting issues associated with perturbations of the earth’s environment, and the public health consequences of such perturbations,