Probabilistic Risk Assessment of Consumer Exposure to Reproductive and Developmental Toxicants

In 2009, the French Health Ministry requested the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) to assess the risks for consumers regarding exposure to suspected endocrine disruptors (EDs) and/or reproductive toxicants (R2s). For the purpose of the study consumer products containing the selected EDs were identified from a national sector survey among manufacturers and available bibliographic data. For each product, use patterns and exposure scenario were defined for workers and general populations including vulnerable population. A scientific review of the effects on reproduction (fertility/development) and endocrine-disrupting potential was conducted in order to select critical doses for these target populations. Toxicological reference doses (TRs) were calculated as the ratio between critical doses and uncertainty factors. Both direct consumer exposure to EDs in consumer products and indirect exposure by the intake of contaminated air and house dust were considered. For each scenario, uptake doses were modelled through a probabilistic approach based on a one-dimensional Monte Carlo simulation. Finally, the statistical distributions of doses through direct and indirect exposure were compared to TRs to assess the risk. Probabilistic exposure assessment was preferred to the deterministic approach because it includes uncertainty and variability in some parameters and therefore allows a more realistic description of consumer exposure. It also provides the opportunity to assess the final consumer exposure uncertainty by sensitivity analysis. The method described was applied tofiveR2s and/or EDs: n-hexane, toluene, cisCTAC, orthophenylphenol (OPP) and methyl-tert-butylether (MTBE). Results showed that exposure situations posing a potential risk for embryonic or foetal development may exist, due to occupational or non-occupational exposure of pregnant women to certain consumer products containing toluene, n-hexane or cisCTAC. Situations at risk for reproduction have also been brought to light, although ANSES emphasizes that strong uncertainties exist with regard to the risk situation identified for MTBE.