ABSTRACT

The widespread switch from microbiologically unsafe surface water to microbiologically safe groundwater has led to the unanticipated poisoning of large numbers of people in the developing world who have consumed various toxic trace elements. In particular, elevated concentrations of arsenic in groundwater have been reported in Taiwan (Tseng 1977, Tseng et al. 1968), West Bengal (India), and Bangladesh (Das et al. 1994, Mandal et al. 1998, Nickson et al. 1998), resulting in a major public health issue. In Bangladesh and West Bengal (India), it is estimated that approximately 40 million people are suffering from drinking naturally occurring arsenic-rich shallow groundwater (Gault et al. 2008). Despite these concerns, groundwater is still a major source of drinking water in the developing world, especially in Southeast Asia. Recently, unsafe levels of arsenic have also been revealed in

CONTENTS

Introduction ...........................................................................................................63 Materials and Methods.........................................................................................65