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1986
Conference Paper
Titel
Experimental induction of tumors in hamsters, mice and rats after long-term inhalation of filtered and unfiltered diesel engine exhaust
Abstract
Hamsters, mice and rats were used for long-term inhalation exposures to approximately maximum tolerated concentrations of Diesel engine exhaust applied with and without stationary particle filtration in order to study potential carcinogenic or syncarcinogenic effects over the life time of the animals. All Diesel exhaust levels in the exposure chambers corresponded to a concentration of 4 milligrams per cubic meter for the unfiltered Diesel engine exhaust. Straightforward animal exposures to filtered and unfiltered Diesel exhaust were accompanied by exposures of satellite groups of animals which were additionally treated with BaP, DBahA or nitrosamines in an attempt to ascertain syncarcinogenic effects. In spite of the high exposure concentration (approximately 250 times above curb side levels), alveolar lung clearance and mechanical lung function tests as well as biochemical and cytological measurements in lung lavage fluids as carried out on hamsters and rats revealed significant chan ges only after continued exposures to unfiltered Diesel exhaust and, in some cases, only in rats. Straightforward inhalation exposures produced no lung tumors in hamsters. In the same way, the spontaneous tumor rates of mice were increased by both types of Diesel exhaust exposure and enhanced the incidence of adenocarcinomas in the lungs. In rats, however, only the unfiltered Diesel exhaust caused an occurrence of lung tumors. The rate was 16% compared to no tumors in the controls.