Total Mercury (THg), Lead (Pb), Cadmium (Cd) and Arsenic (As) in Hair Samples: Method Validation and Quantification among Women at Reproductive Age in Selangor

Mercury (Hg), lead (Pb), cadmium (Cd) and arsenic (As) have been known to cause toxicity to pregnant women, fetus and children. Method to detect these elements in human hair samples using single acid-microwave digestion-atomic absorption spectroscopy combination was validated and applied to quantify levels among women (n=311) at reproductive age. The value of R 2 u003e 0.995 for all four elements indicates an excellent and precise linear relation. Recovery between 90% - 110% along with RSD less than 10%, LOD between 0.1 – 0.3 ug/L and LOQ of hair samples between 0.09 – 0.24 μg/g describes a reliable efficiency to extract maximum toxicant level and quantify at moderately small level. Application of the validated method shows that 10.9%, 11.3%, 35.0% and 89.4% women had hair THg, Pb, Cd and As below the respective LOD. A significantly higher level of Hg (p = 0.031) and Pb (p = 0.003) was found in hair of coastal rural women. Also, 44.4% (95% CI = 38.5, 49.5) exceeded the EPA RfD of 1ug/g for hair Hg and a major portion of women (85.2%, 95% CI=81.3, 89.2) exceeded the WHO Pb maximum venerable level, 0.2ug/g. None of the respondents exceeded the WHO maximum venerable level of Cd, 10ug/g and the levels of As found were much lower than the ASTDR maximum level for non-exposed group, 1ug/g, except for five women.