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

Abstract

Objective: 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.

Methods: Summary standardized mortality ratios (SSMR) and summary Cox regression coefficients from exposure-response models were derived using random effects models.

Results: 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).

Conclusions: Consistent with other published qualitative reviews, there is no clear evidence of an association between occupational exposure to TiO2 and lung cancer.