Drinking water containing arsenic

The US National Research Council (2001) recently estimated that chronic ingestion of drinking water containing arsenic at a concentration of 10 mcg/L could be associated with an excess lifetime cancer risk greater than 1 in 1000. The latency period for development of arsenic-induced cancer is probably a decade or longer. 

Hundreds of people in Japan suffered from a degenerative bone disease called itai-itai because they drank water containing cadmium.9 They lived downstream from a mine and smelter that produced zinc and cadmium. In West Bengal, India, where 800,000 people drink well water containing over 50 /a/L arsenic, 200,000 people developed skin lesions from drinking the water.10 In Bangladesh, 70 million people drink well water containing arsenic.11 The problem... 

In routine analysis, arsenic in urine is usually determined. Recently, Karagas etal. (2002) proposed the use of toenail arsenic concentrations as a reliable biomarker of total As exposure reflecting arsenic intake by drinking water containing > 1 pg L kThe authors mentioned that urinary As may not be detected consistently in a population for which drinking water contents are primarily < 50 pg so that toenails may better provide risk information... 

In the United States, drinking water cannot by law contain more than 5 X 10-8 g of arsenic per gram of water ... 

For maximum protection of human health from the potential carcinogenic effects of exposure to arsenic through drinking water or contaminated aquatic organisms, the ambient water concentration should be zero, based on the nonthreshold assumption for arsenic. But a zero level may not be attainable. Accordingly, the levels established are those that are estimated to increase cancer risk over a lifetime to only one additional case per 100,000 population. These values are estimated at 0.022 pg As/L for drinking water and 0.175 pg As/L for water containing edible aquatic resources (USEPA 1980 Table 28.7). 

One excess cancer per million population (10" ) is estimated during lifetime exposure to 0.0022 pg arsenic per liter of drinking water, or to lifetime consumption of aquatic organisms residing in waters containing 0.0175 pg As/L (USEPA1980). 

In Bangladesh, 15-25% of the population is exposed to unsafe levels of arsenic in drinking water from aquifers in contact with arsenic-containing minerals. The analytical problem is to reliably and cheaply identify wells in which arsenic is above 50 parts per billion (ppb). Arsenic at this level causes vascular and skin diseases and cancer. 

Spike recovery and detection limit. Species of arsenic found in drinking water include AsO (arsenite), AsO - (arsenate), (CH3)2As02 (dimethylarsinate), and (CH3)AsO (methylarsonate). Pure water containing no arsenic was spiked with 0.40 pg arsen-ate/L. Seven replicate determinations gave 0.39, 0.40, 0.38, 0.41, 0.36, 0.35, and 0.39 pg/L.12 Find the mean percent recovery of the spike and the concentration detection limit (pg/L). 

Gu, Z. and Deng, B. (2007) Use of iron-containing mesoporous carbon (IMC) for arsenic removal from drinking water. Environmental Engineering Science, 24(1), 113-21. 

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