The acute toxicity of arsenic at high concentrations has been known about for centuries. It was only relatively recently that a strong adverse effect on health was discovered to be associated with long-term exposure to even very low arsenic concentrations. Drinking water is now recognised as the major source of human intake of arsenic in its most toxic (inorganic) forms.
PETRUSEVSKI, B. SHARMA, S. SCHIPPERS, J.C. SHORDT, K. (2007): Arsenic in Drinking Water. Delft: IRC International Water and Sanitation Centre URL [Accessed: 24.05.2019]