Cardiovascular Risk on Workers Exposed to Heavy Metals, Pb, and Cd

Abstract

PP-31-142 Background/Aims: Sudden cardiac death caused by malignant ventricular arrhythmias represents a major public health problem. We tried to determine the cardiovascular risk on workers exposed to Pb and Cd from a nonferrous metallurgical plant, based on the repolarization changes and the beat-by-beat variability of the RR and QT intervals that is known to be in relation with the SVT. Methods: We investigated 70 workers with mean age = 36.0 + 8.2 years and mean time of exposure = 12.1 + 7.6 years. We made clinical examinations, standard questionnaires regarding the effects of Pb and Cd on the human organism, biochemical and biotoxicological investigations: total cholesterol (TC), triglycerides (TG), HDL-chol (HDL-C), LDL-Chol (LDL-C), glycemia, seric ferrum, anemia degree, blood picture, Ca and Mg in blood, DALA, blood cadmium, blood lead, EKG registering. From this group, 30 workers, aged 30–50 years, with normal myocardium and representative length of service were hospitalized in the Clinic of Occupational Health, completely investigated and followed up by Holter high resolution EKG. Results: More than 80% of the investigated workers presented a small variability of RR interval with TSH fraction significant increased as during the mental stress, and in conclusion a great risk for sudden death due to the supranormal sympathetic drive that is arrhythmogenic and life-threatening. These workers had normal values of lead and cadmium in blood but great values of the lead storage in organism, emphasized by the provocation tests with EDTA that allow to classify great absorption of lead. Ten percent of workers had great levels of serum lipids (TC, TG, LDL-C) LDL-C being known as an aeterogenic factor. Conclusion: The obtained data suggest that heavy metals—in our case Pb—could generate an increase of the SVT with ventricular arrhythmias and sudden death, the risk being assessed by RR-QT variability from the Holter high resolution EKG.