Mortality from nephritis and nephrosis in the fibreglass manufacturing industry

Objectives-To investigate the question of whether there is an association between exposure to silica or respirable glass fibre and mortality from nephritis or nephrosis among workers in fibrous glass wool manufacturing facilities. Methods-A case-control study with cases and controls derived from the Owens Coming mortality surveillance system. Two case-control analyses were carried out, one where the cases are defined with nephritis or nephrosis as the underlying cause of death and one where cases are defined as those where nephritis or nephrosis is either the underlying or a contributing cause of death. Results-There is no consistent relation between respirable fibres or respirable silica and nephritis or nephrosis when the analysis is based either on underlying cause only or on underlying plus contributing cause of death. None of the sociodemographic variables considered suggests an increased risk when considering both underlying and contributing cause of death. Conclusions-These data would seem to support the contention that the most accurate picture of renal disease will be gained from the use of all information on the death certificate and not only the underlying cause. For these data, all odds ratios (ORs) for respirable fibres and silica based on both underlying and contributing cause of death are <1 with the exception of the highest exposure to silica which is slightly >1 (OR=1.04)). Although these results do not prove that there is no association between nephritis and nephrosis and exposure to fibreglass or silica in the fibreglass manufacturing environment, they do not support the assertion that such an association exists.