Bioaccessibility of microplastic-associated heavy metals using an in vitro digestion model and its implications for human health risk assessment

Abstract

Microplastics can act as carriers of heavy metals and may enter humans through ingestion and threaten human health. However, the bioaccessibility of heavy metals associated with microplastics and its implications for human health risk assessments are poorly understood. Therefore, in this study, four typical heavy metals (As(V), Cr(VI), Cd(II), and Pb(II)) and one typical microplastic (polyvinyl chloride, PVC) were chosen to estimate the human health risk of microplastic-associated heavy metals by incorporating bioaccessibility. Significant adsorption of heavy metals was observed with the following order for adsorption capacity: Pb(II) > Cr(VI) > Cd(II) > As(V); the efficiencies for desorption of these four heavy metals from PVC microplastics were all below 10%. The Fourier transform infrared spectroscopy results indicated that the functional groups on the surface of the virgin PVC microplastics did not play an important role in the capture process. Heavy metals in both gastric and small intestinal phases were prone to release from PVC microplastics when bioaccessibility was evaluated with the in vitro SBRC (Soluble Bioavailability Research Consortium) digestion model. In addition, Pb(II) bioaccessibility in the gastric phase was significantly higher than those in the other phases, while As(V), Cr(VI), and Cd(II) bioaccessibilities showed the opposite trend. After incorporating bioaccessibility adjustments, the noncarcinogenic hazards and carcinogenic risks determined were lower than those based on total metal contents. The individual hazard quotients (HQ) and carcinogenic risks (CR) for ingestion of these four heavy metals from PVC microplastics were all lower than the threshold values for adults and children. In summary, this study will provide a new view of the human health risks of heavy metals associated with microplastics. Supplementary Information The online version contains supplementary material available at 10.1007/s11356-022-20983-8.

The simultaneous administration of microplastics and cadmium alters rat testicular activity and changes the expression of PTMA, DAAM1 and PREP

“…This antagonistic effect has been previously demonstrated in many experimental models and conditions, as MP reduced Cd toxicity in plants ( Lian et al, 2020 ; Wang et al, 2022b ; Zhang et al, 2022 ), fish ( Wang S. et al, 2022 ; Yang et al, 2022 ), and mice ( Wang et al, 2022d ). Considering that the two substances were administered separately (oral gavage for MP and drinking water for Cd) and that the rates of adsorption/release of heavy metals by MP depend on pH values ( Hildebrandt et al, 2021 ; Chen et al, 2022 ), we hypothesized that MP, by exploiting a sort of “positive-Trojan horse effect”, may reduce the bioavailability of Cd, explaining the minor consequences observed by concomitant treatment with MP-Cd as compared with Cd alone. Therefore, current studies focus on the use of “pre-adsorbed” MP with Cd to evaluate an effective “Trojan horse” effect on the rat testis.…”

Investigations on the co-occurrence of microplastics and other pollutants in the River Yamuna, Delhi

“…For instance, Rubin & Zucker (2022) have shown that the adsorption of triclosan (trace organic compound) on MPs surface increased the magnitude of toxicity in human epithelial cells Caco-2 in comparison to the exposure given for these pollutants individually. Chen et al (2022) have also affirmed the negative consequences of heavy metals' contaminated MPs on human health in simulated conditions. In their study, it has been revealed that the acidic condition of the gastrointestinal tract is unfavorable for metal binding due to which metals like Cr, Cu, Pb, Ni, Zn, As, and Mn leach from the surface of MPs and are suspected to cause severe health hazards.…”

A preliminary assessment of microplastic occurrence and their potential risk as pollutant transport vectors: A case study in Phu Ly, Ha Nam, Vietnam

“…To evaluate the human health hazard of the eight heavy metals on microplastics, were assessed with the modi ed human health risk assessment (HHRA) model based on bioaccessibility (Chen et al, 2022;Zhou et al, 2020). For the risk assessment, the average daily intake (EDI, mg•kg − 1 •day − 1 ) of heavy metals on microplastics was rst calculated:…”

“…They are also recycled and enriched in the aqueous environment. In addition, trace metals and MPs also are offered as persistent and hazardous pollutants to the environment (Chen et al, 2022;Gao et al, 2019). MPs can adsorb hazardous contaminants like pollutant transport vehicles and concentrate them to a very high level because of their enormous surface area (Hildebrandt et al, 2021;Selvam et al, 2021;Zhou et al, 2020).…”