Arsenic reduction to <1 µg/L in Dutch drinking water.

Arsenic (As) is a highly toxic element which naturally occurs in drinking water. In spite of substantial evidence on the association between many illnesses and chronic consumption of As, there is still a considerable uncertainty about the health risks due to low As concentrations in drinking water. In the Netherlands, drinking water companies aim to supply water with As concentration of <1 μg/L - a water quality goal which is tenfold more stringent than the current WHO guideline. This paper provides (i) an account on the assessed lung cancer risk for the Dutch population due to pertinent low-level As in drinking water and cost-comparison between health care provision and As removal from water, (ii) an overview of As occurrence and mobility in drinking water sources and water treatment systems in the Netherlands and (iii) insights into As removal methods that have been employed or under investigation to achieve As reduction to <1 µg/L at Dutch water treatment plants. Lowering of the average As concentration to <1μg/L in the Netherlands is shown to result in an annual benefit of 7.2-14 M€. This study has a global significance for setting drinking water As limits and provision of safe drinking water.