Arsenic toxicity in humans: Research problems and prospects.

The disposition and toxicity of the metalloid, arsenic, is affected by its oxidation state and on the extent to which it is converted to methylated species. Given that these chemical modifications influence the fate and action of arsenic, new research efforts should be directed both towards elucidating the molecular processes involved in the metabolism of arsenic and in characterising interindividual variation in capacity for processes such as the methylation of arsenic. This information will contribute to a better understanding of the mechanisms of arsenic toxicity and carcinogenicity and to a better assessment of the hazards associated with chronic exposure to this agent.