Health risk implications of heavy metals in toothpaste

Abstract

Sufficient intake of lead, cadmium, mercury, and arsenic has the potential to elicit adverse health effects. Recently publicized dentifrice testing commissioned by a business focused on lead poisoning prevention indicated that most of the 53 products tested had detectable lead. Additionally, cadmium, mercury, and/or arsenic were detected at lower product frequencies. In the present study, the level of concern for potential health effects associated with the presence of these metals in toothpaste was contextualized using the principles of screening level health risk assessment. Metal ingestion doses for children and adults were compared to precautionary health guidance values (HGVs). Hazard quotients (HQs) greater than 1.0 indicated that the potential for adverse effects could not been ruled out and that there is a need for a higher tier, or more refined, assessment. Average daily doses (ADDs) of cadmium and mercury in children and adults were markedly lower than the HGVs for the upper bound scenario, and the HQs were less than 1.0. The lead ADDs exceeded the HGV in 10 toothpastes for children and one for adults for the upper bound usage, and one children’s toothpaste for typical usage; however, these ADDs were markedly lower than the dietary lead intakes. For arsenic, the lifetime average daily doses (LADDs) exceeded the HGV for three toothpastes; however, these LADDs were several orders of magnitude lower than the dietary arsenic intakes. The presence of the four metals in toothpastes at concentrations similar to those reported recently are not anticipated to appreciably increase the likelihood of metal-related toxicity when the products are used as directed.