A Review and Meta-Analysis of Occupational Titanium Dioxide Exposure and Lung Cancer Mortality.

Abstract

A review of studies of occupational titanium dioxide (TiO2) exposure was conducted, and results from the three industry-based cohort mortality studies were summarized using meta-analysis. Summary standardized mortality ratios (SSMR) and summary Cox regression coefficients from exposure-response models were derived using random effects models. Results from studies of 24,312 TiO2 production workers were combined. SSMRs for lung cancer, all causes, all cancer, and non-malignant respiratory disease were 1.10 (95% confidence interval [CI]: 0.91 to 1.32), 0.85 (95% CI: 0.81 to 0.89), 0.92 (95% CI: 0.82 to 1.03), and 0.85 (95% CI: 0.71 to 1.02), respectively. For lung cancer, the summary hazard ratio for a 1 mg/m year increase in cumulative exposure was 0.999 (0.997 to 1.002). Consistent with other published qualitative reviews, there is no clear evidence of an association between occupational exposure to TiO2 and lung cancer.