Association Between Metal Mixture Exposure and Risk of Anthracosilicosis: A Case-control Study Based in Xinjiang,...

Anthracosilicosis is a legally recognized occupational disease that imposes a significant public health and economic burden on developing countries. Environmental exposure to mixed metals may influence the onset and progression of the disease, but relevant evidence among Chinese coal miners remains inconclusive. To evaluate the association between exposure to individual metal elements and their mixtures and the risk of anthracosilicosis using a case-control design. This case-control study included 154 coal miners (84 anthracosilicosis cases and 70 controls) who applied for occupational disease diagnosis at the Third People's Hospital of Xinjiang Uygur Autonomous Region between 2020 and 2024. Controls were frequency-matched to cases by age and work tenure. Plasma levels of seven metal elements (Al, Cd, Co, Cu, Ga, Mn, Sr) were measured by inductively coupled plasma mass spectrometry (ICP-MS). Single-metal exposure was analyzed using binary logistic regression and restricted cubic splines (RCS). Mixture effects were evaluated using quantile g-computation (QGC), weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR). The case group had higher concentrations of Cd, Co, Cu, and Mn than the control group (P < 0.05). Serum levels of Cd, Cu, Mn, and Sr were positively correlated with the risk of anthracosilicosis (P < 0.05), whereas an inverse association was observed for Ga (P < 0.05). Both QGC and WQS analyzes indicated that the mixture of seven metals (Al, Cd, Co, Cu, Mn, Sr, and Ga) was positively associated with anthracosilicosis risk (P < 0.05). The BKMR model indicated that when the overall mixture exposure level exceeded the 50th percentile, the joint exposure to metals was positively associated with an increased risk of anthracosilicosis (P < 0.05). Mn may be the largest contributor to the cumulative effect of mixed metal exposure on risk, and Ga was negatively associated with the risk of anthracosilicosis. The combined exposure to 7 metals (Al, Cd, Co, Cu, Mn, Sr, and Ga) was positively associated with the risk of anthracosilicosis.