US EPA

1173144 

Technical Report 

Is Arsenic a Mutagen? 

Simmon, VF 

1983 

NIOSH/00178596 

Industrial 

Industrial 

The question of whether arsenic (7440382) is a mutagen was discussed and the nature of mutagenicity was considered. A mutagen can be defined as any heritable change in genetic material. Some investigators have estimated that as much as 10 percent of human disease may be attributed to mutations. Studies of arsenic mutagenicity reported in the literature were reviewed. In-vitro studies in bacterial and mammalian cell systems have given conflicting results. Many of the studies yielding positive results were subject to known artifacts or the conclusions were based on extreme cytotoxicity. Studies directed at detecting chromosomal changes generally agree that arsenicals may cause damage to chromosomes. It was noted that the observed chromosomal damage may reflect cytotoxic effects. Studies in individuals exposed occupationally or therapeutically to arsenic have found an increase in chromosome aberrations or an increase in sister chromatid exchange rates but no increase in chromosome aberrations. Only two studies have been conducted in laboratory animals, both of which were dominant lethal studies in mice. Both found that arsenic by itself did not increase dominant lethality. The author concludes that the published studies of arsenic causing mutations are flawed. The clastogenic effect demonstrated in some studies should be viewed with caution as many agents not considered to be human mutagens have given positive results in in-vitro cytogenetic assays. The author concludes that evidence for arsenic being a mutagenic hazard is very poor, although it is a toxic chemical. 

DCN-166449; Mutagenesis; In vitro studies; Arsenic compounds; Metalloids; Microbial test systems; Chromosome damage; Risk analysis; Humans; Bioassays; Mammalian cells; In vivo studies; Laboratory animals