Arsenic water contamination level

The evaluation of risk has underlined the possible adverse effects both on human health after the exposure to drinking water contaminated by landfill leachate and on small rodents and aquatic species at the hypothesized condition for humans, the estimated toxic effects of the raw leachate are mainly due to the levels of ammonia and cadmium and carcinogenic effects are induced by arsenic first and then by PCBs and PCDD/Fs while ecological potential risk is mainly attributable to the concentration of inorganic compounds, in particular ammonia for small rodents, cadmium, ammonia, and heavy metals for fishes. 

In other areas of the world, such as Bangladesh, elevated arsenic levels in the drinking water are more acutely life threatening. People were encouraged to establish local wells to reduce exposure to drinking water contaminated with bacteria. 

Maximum contaminant levels (MCLs) Drinking water standards for various contaminants that are enforced by the United States Environmental Protection Agency (US EPA) that take into account the risks of human health effects and the costs of cleaning the water (Appendix E). The current MCL for arsenic is 10 pg E 1 (40 Code of Federal Regulations 141.62). 

Arsenic contents measured in sediments are between 0.1 and 490 mg/kg while levels up to 1.5 g/kg were found in coals (average 13 mg/kg). The concentration of arsenic in seawater varies between 0.09 and 24 pg/L (average 1.5 pg/L), and in Ireshwater between 0.15 and 0.45 pg/L (maximum 1 mg/L). In mineral and thermal waters, arsenic was found in concentrations up to a factor of 300 higher than its mean concentration in groundwater [100]. The WHO recommends a maximum contaminant level for arsenic in drinking water 10 pg/L. 

Spurred by increasing concern about the adverse health effects from exposure to low levels of arsenic in drinking water (1), the U.S. Environmental Protection Agency (USEPA) has proposed lowering the Maximum Contaminant Level (MCL) for arsenic from 50 J,g/L down to 5 j,g/L (2). Total compliance costs for a regulation of 5 J,g/L have been estimated at 1.47 billion per year (3). 

Urine levels depend mainly on the kind of contamination. Well water caused levels of 300-550 p,g As/liter [29,31,89] mean levels of air contamination are 74.1 (low exposure) and 378.1 p,g/liter (high exposure) [78]. Increased concentrations (mean 304-322 p.g As/g creatinine, range 10-941) were measured after mouth contact of hands contaminated with arsenic compounds during plant handling [47]. 

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