Reference values for heavy metals in the urine and blood of Saudi women derived from two human biomonitoring studies

摘要

We previously assessed the exposure of Saudi women to mercury, cadmium and lead based on reference values (RVs) established for other populations experiencing differences in environmental exposure, diet and lifestyle as an indicator of background exposure to pollutants. The present study aimed to (1) calculate RV95 for mercury, cadmium and lead in blood and urine from Saudi women based on the 95th percentile of the metal and its corresponding 95% confidence interval (95%CI) as defined by the German Human Biomonitoring Commission, and (2) compare with RV(95)s established in other countries. RV(95)s were derived using data from two different human biomonitoring studies measured three metals in the blood (2005-2006), and both urine and blood (2011-2013) from healthy non-smokers and non-occupationally exposed women living in Al-Kharj and Riyadh. RV(95)s for mercury, cadmium and lead in Al-Kharj (Riyadh) blood were 5.9 (1.6) mu g/l, 1.4 (1.9) mu g/l and 4.3 (4.8) mu g/dl, respectively. RV95S for urinary mercury, cadmium and lead in Riyadh samples expressed in mu g/l (mu g/g creatinine) were 2.5 (1.9), 1.2 (0.96) and 14 (10.8), respectively. Values in both matrices remained high even when potential factors such as secondhand smoking, dental amalgam, and/or fish consumption excluded. RV(95)s for metals in blood were generally higher than in other countries, except for mercury in Riyadh samples, which was also 4-fold lower than in Al-Kharj. However, due to the time lag between the two studies, and since the Al-Kharj study was conducted 13 years ago, the most recent RV(95)s derived from the Riyadh study are recommended for Saudi women living in the Central region. The RV(95)s for urinary mercury and cadmium were comparable to other countries, but lead requires closer attention. To our knowledge, this study is the first to propose RV(95)s for mercury, cadmium, and lead in blood and urine of Saudi women of childbearing age, a population that is highly susceptible to the adverse health effects of these metals.