Arsenic (As) is a toxic natural element that is found in some rock and soil types, and also as a byproduct to human-made pesticides and wood preservatives. Humans most commonly come into contact with arsenic through contaminated groundwater. Information source: the World Health Organization.
Soluble inorganic arsenic is very toxic. Intake of this pollutant over time can lead to chronic arsenic poisoning (arsenicosis). Effects, which can take years to develop, include skin lesions, peripheral neuropathy, gastrointestinal illness, diabetes, renal system effects, cardiovascular disease, and cancer. Information source: the World Health Organization.