Objective To prove the evidence for a causal relationship between exposure to silica dust and chronic renal disease, in particular Glomerulonephritis (GN)

Methods The review is based on a search of the Medline database for relevant epidemiological studies published between 1987 and 2012. The quality of selected papers was evaluated based on the Newcastle-Ottawa Scale and the CASP checklist. Meta-analyses were performed separately for cohorts of workers compensated for silicosis and for industry-based cohorts. In addition, synopses were undertaken for studies based on quantitative exposure estimates and for studies using end-stage renal disease (ESRD) as the outcome.

Results The review includes 10 cohorts of silicotics, 12 industry-based cohort studies, 5 case-control-studies and one pooled analysis. The pooling of the cohorts of silicotics did not show any excess risk for renal diseases (ICD-9: 580–589; SMR = 1,00 [0.84–1.18]_95%). By contrast, the meta-analysis of the industry-based cohort studies showed an elevated risk (SMR = 1,42 [1.15–1.75]_95%) when applying a random effects model to account for the strong heterogeneity of these studies. Five of those studies investigated the incidence of ESRD as the outcome. The corresponding relative risk estimators were in the range of 0.77 to 1.97, two of them were significantly elevated (p < 0.05). Three studies went further and investigated GN as the outcome. They resulted in markedly higher risk estimators (SIR in the range of 3.85 to 4.27) then for ESRD. Results could have been affected by a possible diagnostic bias and confounding by other occupational risk factors.

Conclusion The review does not provide sufficient evidence for establishing a causal link between exposure to silica dust and chronic renal disease. To clarify this relationship, further longitudinal studies are needed, which should make use of clinical or even pre-clinical data, including data of health surveillance programs for workers with high exposure to silica dust.