Arsenic levels and drinking water quality in rural areas - Is the contamination level below 50 ppb considered safe

Original Query: Nupur Bose, Department of Environment and Water Management, A. N. College, Patna
Posted: 22 August 2005

I am working in an academic department that deals with water resource based issues. So far, our research work has involved wetland studies, industrial waste water treatment, and ground water contaminants like arsenic and fluoride. Currently, my research group has been doing some pioneering work in the assessment of arsenic contamination in ground water in a few districts in Bihar. Very high arsenic contamination has been recorded in densely populated rural areas, which demands immediate mitigation measures. Stakeholders are already looking into mitigation techniques. Bihar is a very poor state with negligible infrastructure and health services that are still inaccessible to most of the contaminated areas.

W.H.O. has set the 10 ppb. level as the permissible limit of arsenic content in drinking water, Australia has 7 ppb. mark with USA set to lower its acceptable limits from its current permissible limit. Arsenic is a bio-accumulative toxin, and epidemiological studies have revealed that that continuous intake of As. contaminated water show symptoms at a later stage, resulting in reduced life span and fatalities.

My query is -
Is it justified to declare Arsenic contaminated water sources of less than 50 ppb. as safe for mitigation purposes, particularly among the rural poor in India? What will be the implications of regarding below 50 ppb as "SAFE"?

Your response will be vital in shaping my stance and I look forward to receiving it.

Please see attachment below for the responses.