Tumorigenicity of inorganic arsenic compounds following intratracheal instillations to the lungs of hamsters.

The tumorigenicity of arsenic trioxide (As2O3), calcium arsenate (Ca3(AsO4)2) and arsenic trisulfide (As2S3) was studied in male Syrian golden hamsters which received arsenic compounds containing a total dose of 3.75 mg arsenic by means of intratracheal instillations once a week for 15 weeks. As controls, some hamsters were treated with only the vehicle, phosphate buffer solution. During the animals' total life span, one lung adenocarcinoma was seen in the 17 hamsters in the As2O3 group, one lung adenocarcinoma and 6 lung adenomas in the 25 hamsters in the Ca3(AsO4)2 group, one lung adenoma in the 22 hamsters in the As2S3 group and one lung adenosquamous carcinoma in the 21 hamsters in the control group. From these results, we conclude that calcium arsenate is tumorigenic to the lungs of Syrian golden hamsters. The results concerning the other 2 arsenic compounds were not conclusive.