Objective: This study examined the correlation between manganese exposure and manganese concentrations in different biomarkers.
Methods: Air measurement data and work histories were used to determine manganese exposure over a work shift and cumulative exposure. Toenail samples (n = 49), as well as blood and urine before (n = 27) and after (urine, n = 26; blood, n = 24) a work shift were collected.
Results: Toenail manganese, adjusted for age and dietary manganese, was significantly correlated with cumulative exposure in 7 to 9, 10 to 12, and 7 to 12 months before toenail clipping date, but not 1 to 6 months. Manganese exposure over a work shift was not correlated with changes in blood nor urine manganese.
Conclusions: Toenails appeared to be a valid measure of cumulative manganese exposure 7 to 12 months earlier. Neither change in blood nor urine manganese appeared to be suitable indicators of exposure over a typical work shift.
From the Department of Environmental Health (Drs Laohaudomchok, Herrick, Fang, Cavallari, Christiani, and Weisskopf) and Department of Biostatistics (Dr Lin), Harvard School of Public Health, Boston, Mass.
Address correspondence to: Wisanti Laohaudomchok, ScD, Department of Environmental Health, Harvard School of Public Health, Landmark Center, 3rd Floor–E, 401 Park Dr, Boston, MA 02215 (firstname.lastname@example.org).
There is no competing interest for this research.