Inhalation Research with Different Cadmium Compounds on Wistar Rats, Syrian Hamsters and NMRI-Mice

Since CdCl2 has proven to be carcinogenic in rats after exposure to very low concentrations, there was an urgent need to investigate the more occupationally relevant compounds CdO, CdS04 and CdS for their carcinogenic potencies after inhalative exposure. This task was taken over jointly by two Fraunhofer Institutes. To exclude species specific effects beside rats, hamsters and mice were used in this ongoing long-term inhalation study using the above mentioned four Cd compounds in various exposure concentrations. The animals are exposed for 8 or 19–22 hrs/ day 5–7 days/week and for 6–18 months. Despite of its very low solubility also CdS induced severe toxic effects in the lung using exposure concentrations of up to 2.4 mg Cd/m3. For these CdS groups as for other groups, which showed cadmium related toxic effects, the exposure had to be finished prematurely. Lower Cd concentrations or shorter exposure times per day were used replacing these groups.