New approaches to risk assessment of chemical mixtures

Abstract

Assessing the risk of chemical mixtures is an intricate process that should integrate published laboratory data; comparisons with the composition, toxicity, and functionality of similar mixtures; complete analytical characterization of the mixture components; and in silico modeling. Various tiered assessment protocols have been proposed to address this need, and these protocols may be adapted on a case-by-case basis for both mixture-based and component-based evaluations. Emerging technologies have enabled rapid mixture testing in alternative animal models, such as human organotypic cultures and zebrafish. In addition, quantitative modeling that uses systems toxicology approaches can identify exposure-induced cellular and molecular alterations that would not be detected by standard toxicology assays. This review summarizes the approaches to risk assessment of complex chemical mixtures as presented at the Eighth International Congress of the Asian Society of Toxicology, June 2018.

Systems toxicology assessment of a representative e-liquid formulation using human primary bronchial epithelial cells

“…Still, NHBE cells do not fully capture the complexity of the highly differentiated bronchial epithelium, which is composed of specialized cell types such as goblet, ciliated, and basal cells. Thus, as a second step of assessment of flavoring substances, the impact of aerosolization on the chemical composition of flavored e-liquids has to be addressed by using organotypic tissue culture, which is a better model of the human airway epithelium [40], as explained in our previous publications [5,41,42].…”

Concentrations, profiles, emission inventory, and risk assessment of chlorinated benzenes in bottom ash and fly ash of municipal and medical waste incinerators in northern Vietnam

“…It should be noted that many PCDD/F, PCB, and PAH compounds are classified as human carcinogens and their toxicity contribution may be more relevant than those of CBzs. Therefore, more comprehensive risk assessments of toxicity induced by residual ash, which consider multiple classes of toxic substances and interaction between them, are necessarily needed (Hayes et al 2019;Drakvik et al 2020).…”

Potential genomic biomarkers of obesity and its comorbidities for phthalates and bisphenol A mixture: In silico toxicogenomic approach

“…Many toxicology studies have demonstrated the usefulness of the dose-addition concept in exploring the combined effects of chemicals. Joint effects occur even when all mixture components are present at levels below doses that cause observable effects (Hayes et al, 2019;Kortenkamp, 2007). Considering that most mixtures contain multiple components, quantifying these interactions in terms of risk assessment is not an easy task.…”

“…Considering that most mixtures contain multiple components, quantifying these interactions in terms of risk assessment is not an easy task. It not only includes mining published data and characterizing the mixture in the laboratory, but also in silico hazard analysis and modeling (Hayes et al, 2019).…”