what's the meaning of arsenic arsenic arsenic arsenic arsenic arsenic is a chemical element with the symbol as an atomic number 33. it is a poisonous metalloid that exists in various allotropes with highly toxic forms being found in minerals and ores exposure to arsenic can cause serious health effects including skin lesions cancer and death arsenic contamination in drinking water is a major Global Health concern particularly in developing countries additionally arsenic is used in a variety of industrial applications including the production of pesticides wood preservatives and electronics which can contribute to environmental pollution and human exposure