What risks does arsenic pose to human health?
Arsenic is a known human carcinogen and is acutely toxic. When estimating the potential risks that a chemical may pose, one must consider two factors: toxicity and exposure. Toxicity is described as the harmful effects that the chemical may cause, which is often dependent on the amount or dose received. Exposure is the dose received, typically orally or through contact with the skin, or by inhaling, over a certain period of time. Thus, whether any risk of toxic effects exists is dependent on both toxicity and exposure. As part of our comprehensive reassessment, EPA is evaluating both the toxicity and the potential exposure to arsenic from CCA-treated wood in light of the most recent scientific studies, which will allow EPA to characterize the potential risks from CCA-treated wood. EPA expects to release its comprehensive risk assessment for public and scientific review in 2003.