In this study, the author examined the spatial and temporal distribution of tetrachloroethylene, trichloroethylene, nitrate, and several other organic and inorganic chemicals in large community wells in the Fresno-Clovis Metropolitan Area and estimated the lifetime cancer risk associated with exposure to tetrachloroethylene and trichloroethylene.
By 1992-1993, investigators found the industrial solvent tetrachloroethylene in 34 wells and found trichloroethylene in 16 wells.
All wells had detectable levels of nitrate.
In addition, investigators found radon, arsenic, cadmium, iron, manganese, trihalomethanes, and several other volatile organic chemicals in the wells, but only radon and arsenic posed a significant health risk.
In 1995,16 wells were closed because chemicals were found in them.
Twenty-six of 248 (10.5%) active wells and 24 of 43 (55.8%) closed wells contained multiple contaminants, excluding nitrate.
Between 1988 and 1993, concentrations of trichloroethylene, tetrachloroethylene, and nitrates increased in selected wells.
Daily, monthly, and bimonthly variations in the concentrations of tetrachloroethylene, trichloroethylene, and nitrate were often considerable.
Granulated activated carbon filtration reduced trichloroethylene levels in well water by 91% - 95%, and the author examined its usefulness as a remedial measure.
Estimated lifetime cancer risks for tetrachloroethylene and trichloroethylene were 1 excess cancer death per 9. (...)
Mots-clés Pascal : Ethylène(trichloro), Ethylène(tétrachloro), Nitrate, Contamination, Eau souterraine, Eau potable, Toxicité, Homme, Facteur risque, Tumeur maligne, Carcinogène, Analyse quantitative, Analyse chimique, Composé chimique
Mots-clés Pascal anglais : Ethylene(trichloro), Ethylene(tetrachloro), Nitrates, Contamination, Ground water, Drinking water, Toxicity, Human, Risk factor, Malignant tumor, Carcinogen, Quantitative analysis, Chemical analysis, Chemical compound
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0215239
Code Inist : 002B03H. Création : 11/09/1998.