According to the World Health Organization, the arsenic water crisis, affecting over 200 million people across 70 countries, is the largest mass poisoning in human history. Arsenic occurs in groundwater from natural geological formations, and can also be the result of agricultural/industrial activities.

Inorganic arsenic is present in two forms in water – As(V) and As(III) – which pose a risk to human health. Both are naturally occurring at high levels in the groundwater of a number of countries, including Argentina, Bangladesh, Chile, China, India, Mexico, and the United States of America. Drinking water, crops irrigated with contaminated water and food prepared with contaminated water are the sources of exposure.

Arsenic is one of the ten chemicals of major public health concern established by the World Health Organization (WHO). The current recommendended limit for arsenic in drinking water is 10 ppb (parts per billion), although this guideline value is as provisional because measurement difficulties and practical difficulties in removing arsenic from drinking water. The ingestion of this chemical, even in small doses, can produce different types of cancer, diabetes and developmental delays in children.

Bangladesh is the biggest calamity where 20% of deaths in a 10-year period were caused by arsenic related diseases. In United States, the arsenic concentrations don’t reach the levels of Bangladesh, where the levels are 100 times over the safety standard. In the US the concentration can reach levels of 5 to 20 times above the standard. However, there are 4,100 public water systems that have to take corrective action to lower the current levels of arsenic in their drinking water to comply with the standard. Additionally, 15% of the population in United States uses private wells as a source of drinking water, and it is estimated that 13 million people are exposed to the arsenic contamination through their wells.