Hygienic evaluation of the impact of working conditions on the health of workers of the complex for production of phthalic anhydride and fumaric acid

In a priori assessment, the professional risk for workers in the production of phthalic anhydride is characterized by an average (class of labor conditions — 3.2), the main harmful chemical production factors: phthalic anhydride, fumaric acid, maleic aldehyde, dimethylbenzene (MPC for single dose (MPC_sd) — up to 5.9). These factors are identified as priority ones in the development of adverse effects from the side of the hepatobiliary system. The impact of chemicals is intermittent in character during the shift, which requires control of the content of chemicals in the air in the working area in the form of average shift concentrations. In workers of the complex for the production of phthalic anhydride and fumaric acid, there is an accumulation of o-xylene, phthalic and fumaric acid, whose concentrations are significantly higher (p = 0.0001–0.03) if compared with the reference parameters of the comparison group (the excess multiplicity up to 7 times). Among the workers of the phthalic anhydride and fumaric acid production complex, there were no established statistically significant differences in the blood content of o-xylene, phthalic acid and fumaric acids when performing work under conditions of thermal loading of the environment and under conditions with acceptable microclimate parameters. The development of disorders of the hepatobiliary system was shown to begin with the intensification of free radical damage to cell membranes (manifested by an increase in the MDA content of blood relative to the age physiological norm and relative to the index of workers in the comparison group). With a work experience of up to 5 years, the accumulation of secondary products of lipid peroxidation (LPO) in workers is hampered by the activation of antioxidant protection processes. At the experience of more than 5 years, the development of adverse effects from the side of the liver has been established: significantly higher levels of aspartate aminotransferase (AST) (p = 0.027), in cases with an experience of more than 10 years - the level of total and direct bilirubin in blood serum is elevated by 1.4–1.5 times, p = 0.0001–0.002). There was found the statistically significant cause-and-effect relationship of the elevated total blood bilirubin content with labor conditions (RR = 2.86, 95% CI = 1.03–7.98, etiological proportion 65.08%)