Quantitative silica dust exposure and lung cancer incidence in hard rock miners: 1.6 million person-years of follow-up in the Mining Master File cohort study
该研究基于加拿大安大略省48772名硬岩矿工长达44年的随访数据，发现低水平累积硅尘暴露也与肺癌风险正相关，且结果对潜在偏倚稳健。
Objective Inhalation of crystalline silica dust causes lung cancer, although evidence assessing risk at low levels of exposure is needed. We sought to estimate the association between cumulative silica exposure and lung cancer risk in a cohort of miners in Ontario, Canada. Methods A cohort of 48 772 hard rock miners enumerated from a medical surveillance programme was followed for lung cancer diagnoses in the Ontario Cancer Registry from 1964 through 2022. Silica dust exposure was estimated using a linear prediction model based on 12 325 personal sampling measurements from Ontario mines. Exposure–response associations were estimated, with adjustments for uranium mining, arsenic dust and screening CXR. Probabilistic bias analysis was used to evaluate differential outcome misclassification due to loss to follow-up using a known bias parameter. Results 3218 lung cancer cases were diagnosed during a median of 44 years of follow-up. Positive associations between cumulative silica exposure and incident lung cancer rates were observed in all categories of exposure, with 0.5–2.0 mg/m 3 -years of exposure associated with 1.33 times (95% CI 1.06 to 1.66) the adjusted rate of lung cancer compared with<0.5 mg/m 3 -years. The positive exposure–response association remained after excluding known silicotics and increased in magnitude when excluding radon-exposed uranium miners. Bias adjustment for outcome misclassification increased the monotonicity and slope of the exposure–response relationship, but attenuated the IRR in the 0.5–2.0 mg/m 3 -year category to 1.08. Conclusion Silica exposure was positively associated with lung cancer risk at low levels of cumulative exposure in a universally exposed population of miners. Findings were robust to suspected sources of bias.