Purpose: This study 1) describes RA approaches for chemical mixtures; 2) characterizes differences in RA frameworks; and 3) assesses regulatory acceptance of these frameworks with a focus on food mixtures.
Methods: Reviews were completed for mixture RA paradigms used by US federal agencies, nonprofit organizations (WHO, IPCS) and international agencies (EU). There are significant overlaps and differences between paradigms and there appears to be no single unified approach. Considering the current challenges in food mixtures, a hypothetical case study was conducted using a tiered screening approach and hazard index method to evaluate the effects of mixtures in foods. A hypothetical new bean product is being considered to replace pinto beans for a food program. Component levels of the following differ between old beans (OB) and new beans (NB) (assuming a 10% decrease): cadmium, deltamethrin, cyfluthrin; and bisphenol A levels are the same in OB and NB. Non-cancer health effects following chronic oral exposure were evaluated.
Results: First tier provided a crude filter using the most recent and conservative health reference values for mixture components. Some assumptions in the first tier were refined in the second tier. Components were grouped based on health effects and biomonitoring data was used to estimate exposure in the second tier.
Significance: Results indicate that tiered approach is a useful way of rapidly screening the effects of chemical mixtures.