Risk of Cancer for Workers Exposed to Antimony Compounds: A Systematic Review

Background: Antimony (Sb) trioxide and antimony trisulfide are “2B: Possibly carcinogenic to humans” and “3: Unclassifiable” according to the International Agency for Research on Cancer (IARC). The U.S. National Toxicology Program (NTP) concluded that antimony trioxide “is reasonably anticipated to be a human carcinogen based on studies in rats and mice”. We investigated the cancer hazard of antimony compounds for workers, a population with high exposure to antimony substances. Methods: Using the “Guidelines for performing systematic reviews in the development of toxicity factors” (Texas Commission on Environmental Quality (TCEQ) 2017) as a guidance, we established a human and an animal toxicology data stream in Medline and ToxLine. Data from this review were applied in a human health risk assessment. Results: A final pool of 10 occupational and 13 animal toxicology articles resulted after application of TCEQ guidelines. Conclusions: Antimony carcinogenicity evidence involving workers is inadequate, based on confounding, small sample sizes, incomparability across studies, and inadequate reference populations. An increased lung cancer risk cannot be excluded. Evidence for lung neoplasms caused by antimony trioxide inhalation in experimental animals is sufficient. Overall, carcinogenicity in workers is probable (International Agency for Research on Cancer (IARC) 2A). It remains unclear from what occupational exposure duration and dose this effect arises and whether exposure threshold values should be reconsidered.