Comparison of Biological Specimens for Manganese Determination Among Highly Exposed Welders

This research aimed to determine if less invasive biological specimens (other than blood), such as feces and clipped toenails could be used to determine manganese concentrations among occupationally exposed human subjects. In addition to blood samples, which have routinely been used in determining manganese concentration, specimens were collected from welders working at the Electricity Generating Authority of Thailand, Mae Moh Thermal Power Plant, Lampang Province. Manganese concentrations in these three biological samples were determined by atomic absorption spectrophotometer. Correlations of manganese concentrations among these three biological samples were measured, and found to be rather poor (Pearson's r <+/-0.2, p > 0.1 for any pair-wise comparisons). Blood remains the recommended material for biomonitoring manganese concentrations in occupationally exposed subjects.