A Study On Exposure Characteristics Of Welding Fumes And Genetic Damage In Exposed Workers

Background: Welding fume is a possibly carcinogen to humans, and occupationalexposure to welding fumes can lead to pneumoconiosis. Exposure characteristics play an importantrole in the potential health effects induced by particles. Genetic damage is an important indicator toevaluate the potential carcinogenic effects of chemicals. Welding fumes contain a certainproportion of ultrafine particles and fine particles. So far, few of studies have investigated exposurecharacteristics of welding fumes and their genetic damage to exposed workers, so it is necessary toinvestigate the exposure characteristics of welding fumes and influence factors, and study thegenetic damage in workers exposed to welding fumes. The aims of this study are to provide ascientific basis for criteria formulation on ultrafine particle sampling, detection and evaluation inworkplaces, and for health protection of welders.Methods:(1) Field investigation on exposure characteristics: exposure characteristics ofwelding fumes of different weldings in different factrories were investigated using the portable,real-time equipments, under different time, distances, wind speed, background particles, weatherconditions, etc. The indicators included number concentrations, mass concentrations and theirdistributions and so on.The purposes were to explore the sampling strategy of ultrafine and fineparticles in workplaces.(2) Study on genetic damage in workers: various types of welding workersand controls were selected as research subjects. The level of oxidative stress (SOD, MDA andGSH-Px) and genetic damage (comet assay and urinary8-hydroxy-deoxyguanosine) in subjectswere determined. Oxidative stress testing was conducetd using the biotech companies kits. Urinary8-OHdG test was carried out using ELISA kit.Results: particle concentrations of ultrafine and fine particles were closely related to thewelders activities and the number of on-site welding points;The particle number concentrations andmass concentrations declined with increasing distances. Ultrafine and fine particle numberconcentrations were negatively correlated to the wind speed (r=-0.241, P <0.05). ultrafine and fineparticle mass concentration were negatively correlated to the workplace environment humidity (r=-0.372, P <0.05).In terms of the results of genetic damage, welders showed significant increase inthe indicators of MDA levels, tail moment, Olive tail, and8-OHdG levels comparing with controls(P <0.05),and the GSH-Px in welders was significantly lower than that in the control group (P <0.01); the tail moment and Olive tail in gas shielded arc tail group were significantly higher thanthose of manual welding group (P <0.05).Conclusions:The mass concentration and number concentrations of ultrafine particles andfine particle in welding fumes were influenced by time, space, wind speed and other factors. Thetwo concentrations were associated with the number of welding points, production activities andthe type of welding. Occupational exposure to welding fumes could induce genetic damage inwelders. The genetic damage was associated with oxidative stress and number concentrations ofultrafine and fine particles in welding fumes.