Analysis on site: Heavy metals
Heavy metals such as arsenic and mercury find their way into the ground water in many regions of the world, either through natural processes or as the result of human activities. Limit values are exceeded many times over, particularly for arsenic in drinking water, in many areas. This calls for a rigorous monitoring of water quality. The present article focuses on the causes of heavy metal pollution in the environment and on field determinations of heavy metals - directly at the sampling site.
Heavy metals in drinking water - a global problem
The contamination of drinking water with heavy metals is a global problem. A particularly prominent case is the highly arsenic-contaminated well water in Bangladesh, although it is by far not the only one. According to an estimate by the WHO, more than 200 million people worldwide are exposed to drinking water containing more than 10 μg/L arsenic and thus exceeding the WHO guideline value.
Large regions in the US, for example, are affected by elevated levels of arsenic resulting from geological conditions, including among them states in the Southwest such as Nevada, but also New England and the Upper Midwest. In Switzerland as well, drinking water sources are used in scattered locations that have an arsenic content that exceeds the WHO guideline value.