Lung cell toxicity of co-exposure to airborne particulate matter and extremely low-frequency magnetic field

Human epithelial lung cell toxicity assessment of collected graphite particles from an iron casting industry (in vitro study)

Workers in the iron casting industries are exposed to various chemicals, especially graphite in furnace process. This study aims to investigate the toxic effects of graphite particles on human lung cells. Particle characteristics were confirmed by electron microscope and light scattering. Cell viability and oxidative stress markers were measured. The expression of oxidative repair genes, namely OGG1, MTH1, and ITPA, was evaluated. The average particle size was determined to be 172.1 ± 11.96 nm. The median inhibition concentration (IC50) of graphite particles was 46.75 µg/mL. Notably, 25 and 50 µg/mL concentrations resulted in significant GSH depletion and MDA production. The high concentration of graphite particles (200 µg/mL) led to OGG1 suppression and increased MTH1 expression. Based on these findings, graphite exposure may induce toxicity in human lung cells by increasing oxidative stress. Further research is necessary to fully understand the mechanisms underlying graphite toxicity.

DNA damage in workers exposed to mineral oils

Mineral oils, untreated or mildly treated, have been classified in group 1 as a potential source of cancer by the International Agency for Research on Cancer (IARC). Although numerous studies have implicated metalworking fluids (MWFs) as human carcinogens, toxicology data regarding the mechanism of carcinogenicity are limited. This study is intended to examine the systemic effects of machining workers' exposure to MWFs. The potential toxicity of mineral oils was investigated in 65 lathe workers compared to controls (66 men). The occupational exposure was measured by the National Institute for Occupational Safety and Health (NIOSH) 5026. The DNA damage has been examined by the comet assay method. According to the field assessments, the time-weighted average (TWA) exposure to mineral oil mist was 7.67 ± 3.21 mg/m3. A comet assay of peripheral blood cells showed that tail length (TL) and olive moment (OM) were significantly higher in the exposed group (p < 0.05). A multiple logistic regression analysis revealed that, within subjects with over 10 years of exposure, the odds ratio of worker with high TL, percent of DNA in tail, OM, and tail moment (TM) were 1.68, 1.41, 1.71, and 2.71, respectively. DNA strand break in exposed workers was associated with higher exposure time in years. Mineral oil toxicity could be altered in the presence of by-products and impurities. For a better understanding of genotoxicity, further studies are required.