Asbestos Bodies in Normal Lung of Western Mediterranean Populations with No Occupational Exposure to Inorganic Dust

Abstract

The aim of this study was to determine the following: (a) asbestos body count in lung tissue of different western Mediterranean populations; (b) the association, if any, of urban industrial residence with higher lung tissue asbestos body counts in this geographical area; and (c) the risk factor that environmental asbestos exposure posed for lung cancer in our population. Lung-tissue samples were studied in three groups of subjects from the general population: (1) group A comprised 18 patients from Barcelona's urban industrial area (mean age = 62.2 y, standard deviation [SD] = 13.6); (2) group B comprised 16 patients who lived in a rural area of Albacete in the south of Spain (mean age = 62.2 y, SD = 13.7); and (3) group C comprised 8 patients who had been diagnosed with lung cancer, who lived in or near Barcelona, and who had never been exposed occupationally to asbestos (mean age = 62.1 y, SD = 7.4). A wet lung/dry lung weight ratio was determined. In group A, asbestos bodies were observed in 9 of 18 (50%) subjects, and asbestos bodies numbered 52.35 per g dry lung (SD = 101.72) (upper limit of normality [higher value] = 430.12 asbestos bodies per g dry lung). In group B, asbestos bodies were observed in 2 of 16 (12.5%) subjects, and asbestos bodies numbered 5.37 per g dry lung (SD = 8.79) (upper limit normality = 35.15 asbestos bodies per g dry lung). In group C, we observed asbestos bodies in 2 of 8 subjects (25.0%), and asbestos bodies numbered 20.59 per g dry weight (SD = 24.10). Comparison between groups A and B indicated small differences in the prevalence of asbestos bodies (i.e., Barcelona 50%, Albacete 12.5%; p = .057 [chi-square test]), as well as small differences in asbestos body counts (i.e., asbestos bodies per g dry lung; Mann-Whitney U-test, p < .001). The results of these comparisons evidenced a higher exposure to asbestos in the urban industrial environment. No statistically significant differences were found between groups A and C (chi-square test/Mann-Whitney U-test: p > .05). We concluded that, in western Mediterranean populations, normal lung asbestos body counts were higher in urban industrial inhabitants than in rural inhabitants; however, in both populations, there was a low prevalence of asbestos bodies. Our results did not suggest that environmental exposure to asbestos played a role in the pathogenesis of lung cancer in subjects who had never been exposed occupationally to asbestos and who had lived in western Mediterranean areas.