Induction of systemic inflammation by welding fume exposure in office workers as well as welders in welding factories.

Welding fumes are metal particles of 1 µm or less generated during welding. Welding fumes generated in welding factories spread throughout the workplace. However, the effects of exposure have been measured primarily in welding workers, and no research has been conducted on the effects of fumes on workplace office workers. In this study, we recruited welding and office workers who worked in the same factories at ten workplaces in Japan, mainly in the Kyushu and Kanto regions, and separated their serum after blood sampling. We also obtained serum from the general subjects of Minami-Kagoshima City, which is located far from the welding factory. Cytokines and chemokines were quantified in the serum samples, and the concentration of interleukin (IL)-1β was significantly increased in office workers and welders compared with general subjects. Importantly, the serum concentrations of IL-12p70, IL-17A, IL-33, tumor necrosis factor α, and C-C motif chemokine ligand 3 in office workers were significantly higher than those in the general subjects, and there was no significant difference in the levels of these inflammatory molecules between welders and general subjects. This study suggests that office workers exposed to high fume concentrations exhibit increased systemic inflammation. Exposure assessments should be conducted not only for welders but also for office workers to reduce exposure risks.