Arsenic: Occurrence in Groundwater

Abstract

Groundwater arsenic contaminations from 35 countries all over the world are known. However, people suffering from arsenic toxicity with arsenical skin lesions and other arsenic-related health effects are known only from 11 countries. During 1917–71, arsenic groundwater contamination and suffering of people were reported from Argentina, Taiwan, and Mexico. This chronic arsenic exposure through drinking water in Chile is resultant of surface water contamination. South East Asian countries are mostly affected. The Asian countries where people are suffering from arsenic-related health effects are India, Bangladesh, Taiwan, China, Inner Mongolia, Nepal, Vietnam, and Cambodia. It is estimated that more than 130 million people from Asian countries have been potentially exposed to arsenic contamination above World Health Organization (WHO) guideline value of arsenic in drinking water (10 μg l −1 ). During past two decades, more epidemiological studies were carried out on chronic arsenic exposure and its carcinogenic and noncarcinogenic health effects. Mainly ecological studies and few case control and cohort studies are considered to explain cancer in relation to arsenic in drinking water. At present, international agencies dealing with health-related problems like International Agency for Research on Cancer (IARC), WHO, US Environmental Protection Agency (US-EPA), and few others consider arsenic in drinking water could cause skin, lung, liver, urinary bladder, and kidney cancer. Various other noncarcinogenic health effects like dermal, cardiovascular, neurological, respiratory, diabetes mellitus, gastrointestinal and reproductive and developmental effects are also due to chronic arsenic exposure through drinking water.