Arsenic-induced inflammation in workers

Occupational and environmental exposures to metal and metalloids can result in neurotoxicity and immunotoxicity. Selenium (Se) is essential for the proper functioning of neutrophils, macrophages, natural killer (NK) cells, T-lymphocytes and other immune mechanisms, while zinc (Zn) is a trace element essential for basic cell activities, including cell growth and differentiation. Arsenic (As) may lead to different types of immunosuppressive effects. This study consisted of 62 male workers, who had been exposed to arsenic for different durations and 73 non-exposed male workers (control group) with no history of occupational toxic metal exposure. Whole blood and serum samples were taken from each participant for immunological, toxicological and routine analysis during their annual periodical examination. Arsenic, selenium and zinc levels were determined by the ICP-MS and cytokines, IL-6, IL-10, TNF-α, sE-selectin and VCAM-1, were measured by ELISA. There were statistically significant differences (p < 0.001) between control and As-exposed group in As (1.37 ± 0.42 vs. 4.27 ± 1.54 µg/L) and Se levels (106.37 ± 48.04 vs. 74.70 ± 30.45 µg/L). The changing levels of As, Zn and Se seems to affect the severity of inflammatory reactions based on IL-6, IL-10 and TNF-α levels (r = 0.755, r = 0.679 and r = 0.617, respectively, for all p < 0.01). Selenium was found to have a suppressive effect on cytokines, as evidenced by Pearson correlations and regression analysis. These findings support the need to closely monitor Se levels in individuals exposed to arsenic and benefits for Se supplementation in the case of arsenic exposure, occupationally or environmentally.