Estimating long-term aggregated exposure to titanium dioxide in the Belgian population

Abstract Background In our daily lives, we are often exposed to a particular chemical from multiple sources. Yet, chemical exposure assessments usually consider them separately, ignoring their aggregated effect. One example is titanium dioxide - a chemical found in a variety of consumer products. It was banned in 2022 as a food additive in the European Union due to human toxicity concerns and extensions of this decision to other industries are expected. Methods An exposure assessment of titanium dioxide from ingestion of food, dietary supplements, medicines, and personal care products in the Belgian population was performed. This involved the linkage of multiple datasets, including consumption surveys, demographics, chemical measurements, and market presence data. These components were modelled distinctively using Bayesian inference and then integrated through a simulation-based approach reflecting all possible individual exposure profiles. Results Before the ban, the median long-term aggregated exposure to titanium dioxide was estimated at 0.12 (0.09-0.17) mg/kg/day. Children under the age of 10 were found to be the most exposed demographic group due to their relatively higher consumption of food containing titanium dioxide (e.g., confectionery), which was the main contributing source before the ban. After it, the median was reduced to 0.012 (0.011-0.012) mg/kg/day, with medicines as the main contributing source and adults over the age of 64 as the most vulnerable. Conclusions By taking into account multiple sources, a more comprehensive understanding was obtained of the extent to which the Belgian population was exposed to titanium dioxide before and after the ban - identifying vulnerable subgroups and important contributors in the process. The proposed methodological approach can further be adapted to other contexts for more evidence-based public health decision-making. Key messages • Despite a ban of titanium dioxide in food, the general Belgian population is still exposed to it from other sources, with children and elderly among the most vulnerable demographic groups. • More informed public health policies related to chemicals can be obtained by considering multiple exposure sources simultaneously.