Health Effects of Arsenic

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Arsenic is a naturally occurring element with exposures in various work settings. Arsenic exposure can occur environmentally, particularly through drinking contaminated water and ingestion of some foods. The most toxic forms are inorganic arsenic, iAs (trivalent, pentavalent), and its metabolites, as well as the highly toxic arsine gas, the latter causing hemolysis. There are also organic arsenicals in food, particularly seafood, of little or no known toxicity. Inorganic arsenic is well absorbed through ingestion and respiration and is quickly cleared from the blood, distributed throughout the body (including across the placenta), metabolized in the liver, and excreted in the urine with metabolites monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). Most of it is excreted with a half-life of days. Inorganic arsenic disrupts numerous enzyme systems, causes oxidative stress and induces alterations in gene expression. Acute severe poisoning, rarely seen in occupational settings, is life-threatening, usually presenting with gastrointestinal symptoms and severe diarrhea that can progress to cardio-pulmonary collapse, requiring treatment in intensive care, with chelating medication. Chronic iAs exposure can lead to characteristic skin lesions, increased cancer risks (particularly skin, lung, bladder), and other cardiovascular, neurological, endocrine and reproductive adverse health effects. Assessment involves history, physical exam and urine arsenic (can be a spot sample corrected for creatinine), speciating the sample for inorganic species. This urine arsenic biomarker assesses current exposures. Treatment and prevention focus on identifying and eliminating or decreasing exposure, both in the workplace and environment. nbsp;