[Environmental and indoor air exposure to asbestos fiber dust as a risk and causal factor of diffuse malignant pleural mesothelioma].

In an interdisciplinary, multicentre case control study of the causal factors of the diffuse malignant mesothelioma (DMM) standardised histories where taken from n = 324 Patients suffering from DMM, n = 315 hospital control patients (KK) and n = 182 population controls (PK). For 66 DMM, 149 KK and 107 PK a risk from asbestos fibre dust at the workplace was not detectable. For latter persons indoor and outdoor asbestos exposure outside of the workplace were investigated. The following factors were examined: neighbourhood exposure from companies using asbestos, living in big cities and nearby main traffic roads, building materials containing asbestos, electric storage heaters and household contacts. For using electric storage heaters a statistically significant increased odds ratio (OR) was observed for DMM as well in comparison with KK (OR = 2.42; 95%-CI: 1.01-5.72) and in comparison for PK (OR = 2.91; 95%-CI: 1.08-7.80). Only outside of Hamburg an increased OR compared to KK was observed for people living in the neighbourhood of asbestos factories (OR = 16.3; 95%-CI: 1.35-196.8) and also, but only in Hamburg, compared to PK living nearby main traffic roads. There is only a trend for a mesothelioma-risk for household-contacts based on a few cases. In one DMM-patient without an occupational asbestos exposure the lung dust fibre analysis yielded 2.912 FB and 1.459 x 10(3) crocydolithe fibres per gram dried lung tissue. As a child he lived in the immediate vicinity of the blue asbestos mine in Wittenoom, Australia. Therefore in special cases a para-occupational asbestos or a neighbourhood asbestos exposure can be demonstrated as a risk factor of diffuse malignant mesothelioma.