PULMONARY TOXICITY OF INDIUM ARSENIDE AND ARSENIC SELENIDE FOLLOWING REPEATED INTRATRACHEAL INSTILLATIONS TO THE LUNGS OF HAMSTERS

Chronic toxicity of indium arsenide (InAs) and arsenic selenide (As2Se 3) was studied in male Syrian golden hamsters which received InAs or A s2Se3 particles, each containing a total dose of 7.5 mg of arsenic, by intratracheal instillations once a week for 15 weeks. As a control, h amsters were treated with the vehicle, phosphate buffer solution. Duri ng their total lifespan, the cumulative body weight gain of the hamste rs in the InAs group was suppressed significantly compared with that i n the control group, but not in the As2Se3 group when compared with th at in the control group. However, the survival rate for the InAs group was significantly higher compared with the control group, but not for the As2Se3 group when compared with the control group. During the ani mals' total lifespan, one lung adenoma was seen in the 27 hamsters in the InAs group and one lung adenoma in the 23 hamsters in the control group. No tumors of the lung were observed in the As2Se3 group. Malign ant tumors outside the lung appeared in four hamsters in the InAs grou p and in two in the As2Se3 group. No non-lung malignant tumours were s een in the control group. Total tumor incidence rates were 25.9% (7/27 ) in the InAs group, 10.3% (3/29) in the AsSe3 group and 8.7% (2/23) i n the control group. There were therefore no significant differences i n tumor incidence between the InAs or the As2Se3 group, and the contro l group. Regarding histopathological findings in the lung, incidence r ates of proteinosis-like lesions, pneumonia, metaplastic ossification and emphysema were seen only in the InAs group, and alveolar or bronch iolar cell hyperplasia observed in both the InAs and the As2Se3 groups were at significantly higher rates than those in the control group. F rom these results, it was concluded that InAs and As2Se3 particles cou ld induce pulmonary toxicity when instilled intratracheally into hamst ers. A great deal of attention should be paid to the toxicity of both InAs and As2Se3, even though in this study the adverse health effects of As2Se3 appeared to be less than those of InAs.