Lewisite carcinogenicity

Lewisite is generally considered a suspect carcinogen because of its arsenic content. 

Chronic Exposure Lewisite can cause sensitization and chronic lung impairment. Also, by comparison to agent mustard and arsenical compounds, it can be considered as a suspected human carcinogen. 

The subcommittee believes the potential enviromnental and metabolic breakdown products of lewisite are not well identified. There is a possibihty that inorganic arsenic and perhaps even vinyl chloride, two known carcinogens, may be break down products. Accordingly, the subcommittee recommends that the environmental degradation and metabolic products of lewisite be determined, and, if those breakdown products are found to be produced, that the carcinogenic potential of those substances, as well as lewisite, be considered in future assessments. 

Data are inadequate to quantitatively assess the potential carcinogenicity of lewisite. There are inadequate human and inadequate animal data regarding the carcinogenic potential of lewisite. Genotoxicity data are equivocal or negative. 

It was recommended by the MCRA Working Group that for risk assessments, the carcinogenic potential of lewisite degradation products be considered. 

Lewisite does not cause damage to the bone marrow or immunosuppression (Sidell et al, 1997). Arrhythmias and renal dysfunction are due to hypovolemia from fluid loss. Lewisite was fetotoxic to rats and rabbits and is a suspected carcinogen (Goldman and Dacre, 1989 RTECS, 2008). 

There are no data on human exposure from which to predict the long-term effects from Lewisite. There is no substantial evidence to suggest that Lewisite is carcinogenic, teratogenic, or mutagenic (Goldman and Dacre, 1989). The committee appointed by the National Academy of Science reported a causal relationship between Lewisite exposure and chronic respiratory diseases, and also that acute, severe injuries to the eye from Lewisite will persist (Pechura and RaU, 1993). 

The Department of Health and Human Services (DHHS), the International Agency for Research on Cancer (lARC), and the EPA have not cla.ssified Lewisite as to its carcinogenicity. Both the... 

DHHS and lARC have classified the blister agent H/HD (the sulfur mustard used in the Mustard-Lewisite mixture) as a human carcinogen. It is not known whether the Mustard-Lewisite mixture might also be a human carcinogen. 

---