ABSTRACT

The basis for regulation of environmental chemicals is generally ascribed to the protection of public health. Specific regulations are typically based upon risk characterization combined with criteria to establish regulatory values from the risk characterization. Risk characterization stages adopted by regulatory agencies typically include evaluating hazards, exposure routes and doseresponse relationships. There is a general consensus on the utility of this approach although there is often a clear need for further and more accurate data. More variable are the criteria used to establish regulatory values from risk characterization studies. Such criteria include (Greim 2000): NOAEL-no observed adverse effect level; ALARA-as low as reasonably achievable; negligible risk; no risk above background; acceptable risk. Application is complicated by (i) uncertainties in dose-response relationships, particularly at low dosages and as

1 INTRODUCTION

Hundreds of millions of people across the globe are exposed to geogenic arsenic (As) hazards (Ravenscroft et al. 2009). In Bangladesh alone, such exposure may be resulting in 1,000s (Yu et al. 2003) or 10,000s of excess deaths annually (Argos et al. 2010). Governments and international organisations have introduced regulations/guidelines for arsenic in drinking water and, to a lesser extent, in food as one measure to address this problem. However, concerns have been expressed over the weakness of regulation (Smith et al. 2000; EFSA 2009; Meharg & Raab 2010; Polya et al. 2010a) and of inter-country variation (Smith & Smith, 2004). We explore reasons for this and discuss possible ways to (i) establish principles to determine what constitutes “better” regulation; and (ii) what practical steps the scientific & economic communities could take, in conjunction with others, to facilitate more rapid improvement of regulation of arsenic in drinking water and food.