Heavy metals (such as lead) and perfluorinated substances (such as perfluorooctanoic acid (PFOA) are two common pollutants known to reduce the quality of drinking water. Corrosion in water plumbing systems, and the use of aqueous film-forming foams by firefighters, are prevalent sources of these pollutants. Human exposure to these emerging pollutants has been linked to gastrointestinal, liver, and renal damage; immune system dysfunction; and neurological disorders. Contaminant regulations are generally based on individual constituent exposure. However, the more relevant exposure scenario to these pollutants in the environment is co-exposure to more than one chemical simultaneously (e.g., copper ions, lead ions, PFOA, and/or perfluorobutanoic acid (PFBA). Because humans are exposed to both simple and complex mixtures, it is critical to understand how these mixtures interact chemically (at the molecular level) and toxicologically (at the cellular level). This study was carried out using a three-dimensional human gut cell model composed of colon endothelial cells (Caco-2) mixed with goblet cells (HT29-MTX) to evaluate the exposure of various mixtures of lead II acetate, copper II nitrate, PFOA (long-chain C8), and PFBA (short-chain C4). Chemical interactions were determined using UV/Vis/IR spectroscopy.  After exposure to cells, cytotoxicity (ROS-Glo™ H<sub>2</sub>O<sub>2</sub> assay) and genotoxicity (Comet assay) were assessed. ICP-MS and LC-MS/MS were further used to determine the internal cellular dose concentration of copper, lead, PFOA and PFBA. Our initial inference from these studies is that mixtures containing PFOA are more toxic than those containing PFBA. Furthermore, we observed that chemical interactions of lead with PFOA caused a synergistic toxic response, indicating increased toxicity in human gut cells. These data provide striking evidence that more data is needed to assess the potential toxicities of drinking water contaminants after co-exposure of multiple constituents simultaneously.

Chemical and toxicological assessment of heavy metals and perfluorinated substances in a human gut cell model

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.