[Animal experiment and in vitro studies with inhaled environmental pollutants]

Risk assessment of inhaled toxicants is a critical treatise in inhalation toxicology. In particular, the extent of extrapolation from animal experiments to the human situation is frequently influenced by such factors as the method of application (Implantation, instillation or inhalation) and species-specific differences. This difficulty becomes especially conspicuous when the carcinogenicity is to be determined after the inhalation of, for example, diesel engine exhaust, coal oven flue gas, or cadmium compounds. Nowadays, in-vitro techniques are also available for successfully investigating the metabolism of hazardous compounds and thereby-induced DNA damage in animal and human airway epithelial cells; results gained through the employment of these techniques will, at all events, bear increasing weight in terms of the valuation and assessment of risks to humans.