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Objectives-The high incidence of malignant mesothelioma in some villages of Cappadocia (Turkey) is due to environmental exposure to erionite fibres. The aim was to evaluate the fibre burden in bronchoalveolar lavage fluid (BALF) from inhabitants of an erionite village and compare it with Turkish subjects with or without environmental exposure to tremolite asbestos. Methods-Ferruginous bodies (FBs) and fibres were measured and analyzed by light and transmission electron microscopy (TEM) in the BALF of 16 subjects originating from Tuzköy. Results-FBs were detected in the BALF of 12 subjects, with concentrations above 1 FB/ml in seven of them. Erionite was the central fibre of 95.7% of FBs. Erionite fibres were found in the BALF of all subjects, by TEM, and these fibres were low in Mg, K, and Ca compared with erionite from Tuzköy soil. The mean concentration of erionite fibres in BALF was similar to that of tremolite fibres in Turks with environmental exposure to tremolite. The proportion of fibres longer than 8 µm in BALF represented 35.6% for erionite compared with 14.0% for tremolite. The asbestos fibre concentrations in erionite villagers was not diVerent from that in Turks without environmental exposure to tremolite. Conclusion-Analysis of BALF gives information about fibre retention in populations environmentally exposed to erionite for whom data on fibre burden from lung tissue samples are scarce. This may apply to exposed Turks having emigrated to other countries. (Occup Environ Med 2001;58:261-266)

Background and Aims:Environmental exposures to chrysotile and tremolite from the soil cause pleural plaques and mesothelioma in 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 with asbestos outcrops and two from other areas were slaughtered. Fibre content of lung and parietal pleural samples was determined by analytical transmission electron microscopy.Results:Both chrysotile and tremolite fibres were detected. In the exposed goats, the geometric mean concentrations of asbestos fibres longer than 1 μm were 0.27 × 106fibres/g dry lung tissue and 1.8 × 106fibres/g dry pleural tissue. Asbestos fibres were not detected in the lungs of the two control goats. Chrysotile fibres shorter than 5 μm were predominant in the parietal pleura. Tremolite fibres accounted for 78% and 86% of the fibres longer than 5 μm 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 fibres of dimensions with a high carcinogenic potency are detected in the parietal pleura.

Refractory ceramic fibers (RCF) are widely used to replace asbestos in applications requiring high heat resistance. Ferruginous bodies mimicking asbestos bodies (ABs) have been detected in the lungs of RCF production workers. This raises the question about their presence in other occupational groups and whether "typical ABs" still reflect past asbestos exposures in all settings. An AB counting by phase-contrast light microscopy and a screening test by analytical electron microscopy were systematically performed on all bronchoalveolar lavage fluids (BALF) submitted to our laboratory in 1992 through 1997 (n = 1,800). When RCF were detected in electron microscopy, the structures considered as "typical ABs" were marked under light microscopy and prepared for further chemical and structural analysis. Pseudo-ABs on RCF were detected in samples from nine subjects (0.5%). All of them had worked either as foundry workers, steel workers, or welders. In these subjects, alumino-silicate fibers compatible with RCF accounted for 42% of the core fibers analyzed, other nonasbestos fibers for 28%, and asbestos fibers for 30%. ABs thus remain a valid marker of asbestos retention but attention must be paid to a possible occurrence of pseudo-asbestos bodies on RCF and other nonasbestos fibers in end-users of refractory fibers.