Occupational exposure to respirable crystalline silica and chronic non-malignant renal disease: systematic review and meta-analysis
OBJECTIVES To evaluate mortality due to lung cancer, silicosis, renal cancer, renal disease and other causes among German porcelain production workers potentially exposed to crystalline silica. METHODS Seventeen thousand six hundred forty-four medical surveillance participants (1985-1987) were followed through 2005 for mortality. Cause-specific Standardized Mortality Ratios (SMR) and 95% confidence intervals were estimated. RESULTS Women (SMR = 0.85; 95% CI = 0.78 to 0.93), but not men, demonstrated a healthy worker effect. Lung and renal cancers, and renal disease (non-malignant renal disease) were not associated with employment or exposure surrogates. Mortality was increased from silicosis (SMR = 7.20; 95% CI = 2.32 to 16.8) liver (SMR = 1.99; 95% CI = 1.29 to 2.93) and pancreatic (SMR = 1.71; 95% CI = 1.18 to 2.41) cancers among men, and diabetes among women (SMR = 1.74; 95% CI = 1.07 to 2.65). A sub-cohort of Bavarian workers generated similar but generally higher SMRs. CONCLUSIONS Silicosis mortality was increased in this, among the largest studies to date. However, associations previously observed between crystalline silica exposure and renal or lung cancers or non-malignant renal disease were not supported.