Chrysotile and tremolite asbestos fibres in the lungs and parietal pleura of Corsican goats

Background and Aims: Environmental exposures to chrysotile and tremolite from the soil cause pleural plaques and mesothelioma in the northeast Corsica. Goats grazing in the contaminated areas inhale asbestos fibres. We used this natural animal model to study whether these exposures actually result in increased fibre burdens in the lungs and parietal pleura. Methods: Ten goats from areas were slaughtered. Fibre content of lung and parietal pleural samples was determined by analytical transmission electron microscopy. Results: Both chrysotile and tremolite fibers were detected. In the exposed goats, the geometric mean concentrations of asbestos fibres longer than 1 mum were 0.27 x 10(6) fibres/g dry lung tissue and 1.8 x 10(6) fibres/g dry pleural tissue. Asbestos fibres were not detected in the lungs of the two control goats. Chrysolite fibres shorter than 5mum were predominant in the parietal pleura. Tremolite fibres accounted for 78% and 86% of the fibres longer than 5mum in lung and parietal pleural samples, respectively. Conclusions: Environmental exposure in northeast Corsica results in detectable chrysotile and tremolite fibre loads in the lung and parietal pleura of adult goats. Tremolite fibers of demensions with a high carcinogenic potency are detected in the parietal pleura.