Lead and zinc exposure in the blood of workers in municipal waste management

Abstract

Improper treating, sorting, storing, transporting, or disposing of wastes poses a potential risk to the health of humans and the environment. The workers of waste management plants are at risk of exposure to heavy metals and their toxic and hazardous effects through respiratory or cutaneous routes. Accordingly, concentrations of two heavy metals in the biological samples of workers of a municipal waste management (MSW) plant in Iraqi Kurdistan were measured in 139 persons who worked for at least 6months. Blood and plasma samples were collected to measure lead and zinc concentrations, respectively. Their working units, occupational history, smoking habits, and the distance living from the landfill site were recorded in a predesigned questionnaire. A blood lead level (BLL) of less than 40μg/dL was considered a safe cutoff. The lower limit of normal fasting plasma zinc was set at 70-120μg/dL. The study showed that the mean age of the workers was 33.43, ranging from 16 to 67years old, and they worked for the last 4.93years. Further, 22.3% of the staff had previous experience in a job with suspected exposure to heavy metals. The mean BLL concentrations and the plasma zinc level were 31μg/dl and 5.77μg/dl, respectively. The study did not find a substantial difference in lead and zinc among workers with different characteristics. We did not find any predictor for lead and zinc concentrations in our sample. The study showed that the mean levels of lead and zinc were lower than the permitted ranges.