need to be broadened  and  pursued  with greater intensity. The information obtained from these studies, unlike studies of sulfur mustard exposure, will have broad application in industry, farming, and medicine.

Despite the many years that the problem of acute sulfur mustard toxicity to human skin has been known and observed, its long-term effects after acute and chronic exposure remain obscure. Unfortunately, large volumes of pertinent literature on experimental studies of human exposure remain obscure or destroyed. Despite the flaws in the literature explored to date, it is possible to conclude that (1) the evidence indicates a causal relation between acute, severe exposure to mustard agents and increased pigmentation and depigmentation in human skin; (2) acute and severe exposure can lead to chronic skin ulceration, scar formation, and the development of cutaneous cancer; and (3) chronic exposure to minimally toxic and even subtoxic doses can lead to skin pigmentation abnormalities and cutaneous cancer. The evidence would nevertheless be strengthened by (a) intensive data review; (b) physical examination of identifiable victims of experimentation during and preceding former wars, and the comparison of these individuals with matched cohorts of nonexposed persons; and (c) continued prospective evaluation of individuals with recent battlefield and experimental exposure. It should also be emphasized that scarring of scrotal and penile tissue, quite likely in mustard agent exposure, can impair sexual performance.

There is insufficient information, however, to establish a causal relationship between Lewisite exposure and long-term adverse effects on skin.