An experimental model for risk assessment of combined exposure to radon and other airborne pollutants

The results demonstrate the potential co-carcinogenic action of various environmental or industrial airborne pollutants combined with radon exposure, showing either a multiplicative, an additive or nul effect. The strongest co-carcinogenic effect was shown by combined exposure first to radon and then to tobacco smoke and resulted in an increased incidence of lung carcinomas, mainly of the squamous cell type. These results also indicated the possible application of this 'radon model' to the investigation of possible interactions between exposure to two occupational and/or environmental pollutants. The importance of such an experimental model for risk assessment should be emphasized since human industrial occupational or environmental exposures are nearly always not single but multiple. (author)