oa Trace metals in urine of farm workers in Qatar: Health implications

Human biomonitoring (HBM) is an emerging risk assessment tool that can be used to decipher the exposure and possible health effects of environmental chemicals. This report presents the results of a pilot HBM study involving 239 farmers in Qatar exposed to chemical fertilizers and pesticides as well as other environmental contaminants associated with the rapidly growing energy industry in the country. This cross-sectional study is based on urine as a biomarker and the objectives are to a) introduce HBM as a research tool in Qatar, b) quantify levels of trace elements and organic contaminants in urine from farmers and c) determine risks associated with the exposure to these contaminants using a detailed exposure questionnaire and biomarker results. This presentation focuses on results of 14 elements (V, Cr, Mn, Fe, Co, Ni, Cu, As, Se, Mo, Cd, Ba, Pb and U) in urine samples; results of the organic contaminants are being presented separately. The data set associated with this study is the first of its kind in Qatar. All results were within normal global ranges for farmers with the exception of Mo (elevated) and Fe, Cu and Co (depressed levels). The mean and range of these four elements are: Mo (108 µg/L, 9.59 - 737 µg/L), Fe (54.1 µg/L, 2.68 - 4071 µg/L), Cu (14.6 µg/L, 2.82 - 111 µg/L) and Co (0.505, <0.016 - 3.95 µg/L). Mo is a common constituent of oil and gas processes and this study suggests that it can be used as a biomarker of the energy industry in Qatar. The significance of the low levels of Cu, Co and Fe in terms of potential metabolic or dietary deficiencies is being investigated. This pilot study can serve as a model for future population scale human biomonitoring within the country and region.