Estimating human exposure to titanium dioxide from personal care products through a social survey approach

Titanium dioxide (TiO₂ ) has been widely applied in personal care products (PCPs), with up to 36% of TiO₂ in PCPs is present at the nanoscale. Due to the large quantity produced and the wide application of TiO₂ , there is a great potential for human exposure through various routes and therefore a great potential to elicit adverse impacts. This work utilizes a social survey to generate information and estimate TiO₂ (bulk and nanoparticle [NP]) exposure to individuals through the daily use of PCPs. Households in the Madison, Wisconsin, USA metropolitan area were surveyed about their PCP usage. Survey results were then combined with usage patterns and TiO₂ content in each PCP category to estimate human exposures. Results indicate sunscreen and toothpaste are major contributors to TiO₂ dermal exposure. The estimated daily dermal route of exposure ranges from 2.8 to 21.4 mg TiO₂ per person per day. Toothpaste has the potential to be ingested though the oral route; 0.15 to 3.9 mg TiO₂ per day were estimated to be ingested when 10% toothpaste ingestion was assumed. The results generated in the present case study are generalizable in predicting individual TiO₂ exposure from PCPs when the usage pattern is available. In addition, this study can be further used for risk assessment and to refine the use of TiO₂ in PCPs. Integr Environ Assess Manag 2019;00:1-7. © 2019 SETAC.