Determination of lead and antimony in urine by atomic-absorption spectroscopy with electrothermal atomisation

Antimony exposure and speciation in human biomarkers near an active mining area in Hunan, China

Antimony (Sb) exposure threatens human health. To identify human biomarkers for Sb exposure, we analyzed 480 environmental samples from an active Sb mining area in Hunan, China. Elevated Sb concentrations exceeding the reference level were detected in drinking water (70% of n = 83 total samples), foods (80%, n = 188), urine (95%, n = 63), saliva (44%, n = 48), hair (80%, n = 51) and nails (83%, n = 47). Drinking water contributed 85%-100% of the average daily dose (ADD) of Sb, and the total ADD (11.7 μg/kg bodyweight/day) was up to thirty times higher than the oral reference dose (0.4 μg/kg bodyweight/day) as recommended by USEPA. A positive correlation was found between ADD and Sb content in hair (p = 0.02), but not in urine (p = 0.051), saliva (p = 0.52) or nails (p = 0.85), suggesting that hair is the best non-invasive biomarker. Micro X-ray fluorescence analysis indicated that Sb is distributed in discrete spots in hair and nails, and Sb distribution is correlated with other metals. Methylated Sb species were predominant in urine (46%-100%) and saliva (74%-100%) in collected samples, implying that the human metabolic system adopts methylation as an effective pathway to detoxify and excrete Sb.

Urinary lead levels among farmers in non-polluted areas in Japan

Urine samples, 1163 in total, were collected in the winters of 1982 and 1983 from 132 male farmers and 1031 female farmers in 6 non-polluted areas in various parts of Japan. The urine samples were analyzed for lead concentration by means of flameless atomic absorption spectrophotometry after wet digestion followed by solvent extraction in the presence of sodium diethyldithiocarbamate. The lead concentration in urine (Pb-U; adjusted for a specific gravity of 1.016) distributed log-normally with a geometric mean (GM) of 1.81 micrograms/l (GSD = 1.99) for men (n = 132) and 2.08 micrograms/l (1.95) for women (n = 1031). No age-related changes in Pb-U were observed in either sex in the 30-79 year age range, and there was no sex-related difference in Pb-U. Analyses of female smokers together with area- and age-matched non-smokers suggested that the smoking habit would cause a significant increase in Pb-U. Comparison of the present findings with Pb-U levels published in the literature disclosed that the current Pb-levels among the Japanese population appear to be lower than the levels in Western Europe and the U.S.A.