Microplastics-sorbed phenanthrene and its derivatives are highly bioaccessible and may induce human cancer risks

Xiaojie Hu; Qing Yu; Michael Gatheru Waigi; Wanting Ling; Chao Qin; Jian Wang; Yanzheng Gao

doi:10.1016/j.envint.2022.107459

Microplastics-sorbed phenanthrene and its derivatives are highly bioaccessible and may induce human cancer risks

Environ Int. 2022 Oct:168:107459. doi: 10.1016/j.envint.2022.107459. Epub 2022 Aug 8.

Authors

Xiaojie Hu¹, Qing Yu¹, Michael Gatheru Waigi¹, Wanting Ling¹, Chao Qin¹, Jian Wang², Yanzheng Gao³

Affiliations

¹ Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
² Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: wj308119@njau.edu.cn.
³ Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: gaoyanzheng@njau.edu.cn.

PMID: 35964535
DOI: 10.1016/j.envint.2022.107459

Abstract

Microplastics (MPs) are ubiquitous in environmental media and human diets and can enrich organic contaminants, including polycyclic aromatic hydrocarbons (PAHs) and their derivatives. The bioaccessibilities and triggering cancer risks of MP-sorbed PAHs and PAH derivatives are closely linked with human health, which, however, were rarely focused on. This study explored the sorption behaviors of phenanthrene (PHE) and PHE derivatives on polyethylene (PE), polypropylene (PP), and polystyrene (PS) MPs, and assessed their bioaccessibilities in gastrointestinal fluids as well as their inducing human cancer risks. PE MPs harbored the highest sorption capacity, secondly the PP MPs, then the PS ones. Sorption of PHE and PHE derivatives on MPs was positively correlated with their hydrophobicities. The bioaccessibilities of sorbed PHE and PHE derivatives could reach 53.59 %±0.46 %-90.28 %±0.92 % in gastrointestinal fluids and 81.34 %±0.77 %-98.72 %±1.44 % in gastrointestinal fluids with the addition of Tenax (more close to the bioavailability). The hydrophobicities also controlled the bioaccessibilities of PHE and PHE derivatives in gastric fluids, and those in intestinal fluids with Tenax for PS MPs. The incremental lifetime cancer risk (ILCR) values for PHE, PHE-Cl, and PHE-NO₂ on MPs at tested concentrations were all higher than the USEPA-suggested safety limit (10^-6), and most of them were even higher than 10^-4, which thus indicates serious cancer risks. This study promoted our understanding of the potential health threats posed by organic pollutant-bearing MPs in the environment.

Keywords: Bioaccessibility; Human cancer risks; Microplastics; PAH-derivatives; Sorption behavior.