Associations of welding-related metals and hypertension in male welders: Roles of cytokinesis-block micronucleus cytome assay parameters.

The effects of welding-related metals on hypertension remain unclear. In this study, we aimed to assess the associations between welding-related metals and hypertension risk in occupational settings, and to evaluate the mediating roles of micronucleus parameters in these associations. We conducted a study on 434 male welders from a vehicle manufacturing plant in Wuhan, China, in 2023. We measured 17 metals in welding workshops and office air, specifically copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), chromium (Cr), iron (Fe), barium (Ba), aluminium (Al), zinc (Zn), tin (Sn), indium (In), cesium (Cs), arsenic (As), tellurium (Te), cadmium (Cd), cobalt (Co), and selenium (Se). We also examined blood levels of welding-related metals and micronucleus parameters, including micronuclei (MN), nucleoplasmic bridges, and nuclear buds. Generalized linear models were used to assess metal-hypertension associations, with mediation analyses exploring the roles of micronucleus parameters in these associations. The median concentrations of Cu, Mn, Ni, Pb, Cr, and Fe in welding workshop air were five times higher than in offices and correlated significantly with welding fume, hence designated as welding-related metals. The mean age of the participants was 42.96 years and 108 (24.88 %) were hypertension patients. Significant positive associations were found between blood Mn (OR = 1.120, 95 %CI = 1.044-1.200, P = 0.002) and Pb (OR = 1.047, 95 %CI = 1.018-1.077, P = 0.001) and hypertension. These associations persisted even after adjustment for all other metals. Additionally, positive associations were found of MN with hypertension risk (OR = 2.684, 95 %CI = 1.431-5.037, P = 0.002) and Pb with MN (β = 0.007, 95 %CI = 0.002-0.011, P = 0.002). Furthermore, we observed a significant mediation role of MN in the Pb-hypertension association, with a mediating proportion of 16.10 %. Specifically, the ORs(95 %CIs) for the direct and indirect effects of Pb on hypertension risk were 0.0031(0.0004-0.0042) and 0.0006(0.0001-0.0012), respectively. Our findings indicated that Pb and Mn were associated with higher hypertension risk, with elevated MN frequency potentially mediating the Pb-hypertension association.