Occurrence and exposure risk to potentially toxic metals from oral hygiene products in Nigeria.

Daily use of oral hygiene products (OHPs) contaminated with potentially toxic elements (PTEs) can cause acute or long-term intoxication. This study investigated the occurrence and human health risks associated with potentially toxic metals, namely Fe, Pb, Mn, Ni, Co, Cu, Cr, Zn, and Cd, in 55 commonly used OHPs, including dental powders (DP), toothpastes, and mouthwashes (MW), in Nigeria. The types of toothpastes included herbal toothpaste (HT), smokers'/medicated toothpaste (SMT), children's toothpaste (CT), and regular toothpaste (RT). The metal concentrations in the OHPs varied from 4.94 to 81.8, <LOQ to 33.8, 0.31 to 10.8, 0.08 to 2.44, 0.06 to 3.05, 0.25 to 11.5, 0.83 to 11.9, 1.51 to 10.9, and 0.53 to 6.24 mg kg-1 for Fe, Pb, Mn, Ni, Co, Cu, Cr, Zn and Cd, respectively. The order of metal concentrations in the OHPs was Fe > Pb > Zn > Cu > Mn > Cr > Cd > Co > Ni. The hazard index (HI) values for total metals and the hazard quotients (HQs) of the individual metals resulting from the use of the OHPs by adults and children were below the risk threshold of 1, suggesting a negligible non-carcinogenic risk. The carcinogenic risk (TCR) for Pb was several orders of magnitude below 10-6, confirming a negligible cancer risk.