Cardiovascular Toxicity in Copper Production Workers Exposed to Heavy Metals

Abstract

Introduction. Cardiovascular diseases (CVD) are a leading cause of morbidity and mortality. The role of occupational hazards in the CVD prevalence remains to be clarified. Material and methods. Here we report the results of the study of risk factors and CVD prevalence in 590 workers at the largest copper production plants in the Sverdlovsk region, exposed to heavy metals in the workplace. The workers' health information was obtained during a regular medical examination in 2018. The lead concentration increase to 1.3-1.8 occupational exposure limits was registered in the working areas of the concentrating mill (for bunkerman) and copper smelting workshops (transporter, smelter, converter, non-ferrous metal spreader, repairman, electrician). Results. We studied the exposure indices (Pb level in blood), the response markers (reticulocyte count, erythrocytes basophilic stippling, coproporphyrin, and aminolevulinic acid in the urine), and their correlation to a working tenure. Based on this analysis, we attributed CVD risk factors and cardiovascular diseases to the occupation, in order to potentially modify some of those risk factors and ultimately inform the risk management. Hypertension occurred in 57% of the examined workers, which is higher than in the general population. We calculated relative risk, confidence intervals and attributable fraction. We developed a predictive mathematical model (stepwise logistic regression) to predict high-stage hypertension and identified the risk factors associated with its development. Conclusions. Correlation analysis revealed direct correlations between stages 2 and 3 hypertension and a working tenure over 20 years. We think it's reasonable to consider the documented CVDs as related to the toxic effects of heavy metals (lead and cadmium). © 2020 Izdatel'stvo Meditsina. All rights reserved.