Assessment of saliva, hair and toenails as biomarkers of low level exposure to manganese from drinking water in children

•Measured Mn in drinking water, children’s saliva, hair and toenails.•Mn concentrations in drinking water are very low.•Mn in hair and toenail reflect reasonably well Mn exposure from drinking water.•Mn in saliva correlates less strongly to Mn in drinking water. We evaluated hair, toenails, and saliva (whole and supernatant) as biomarkers of exposure to manganese (Mn) in 274 school age children (6–13 years) consuming well water in southeastern New Brunswick, Canada. Mn concentrations in tap water ranged from