Assessment of cancer risk of microplastics enriched with polycyclic aromatic hydrocarbons

Abstract

Abundance of microplastics in aquatic and marine ecosystems is contaminating the seafood and it is leading to transfer of toxic pollutants to human beings. In this article, we report the hazardous nature and cancer risk of microplastics which originate from e-waste. Capture of carcinogenic polycyclic aromatic hydrocarbons (PAHs) onto microplastics by adsorption phenomena and an assessment of probable cancer risk of ingested PAHs enriched microplastics by human beings have been investigated. The adsorption equilibrium was well fit for the Freundlich isotherm model. The adsorption capacity of carcinogenic PAHs on microplastics was ranged from 46 to 236 μg g^-1 and the maximum binding was achieved within 45 min in water. The leachate derived from microplastics of e-waste were highly hazardous in nature, for example, the sum of PAHs was 3.17 mg L^-1 which is about 1000 times higher than the standard for benzo[a]pyrene, a congener of PAHs. The calculated cancer risk in terms of lifetime of microplastic ingestion would be 1.13 × 10^-5 for children and 1.28 × 10^-5 for adults and these values are higher than the recommended value of 10⁶. The abundance of microplastics could transfer hazardous pollutants to seafood (e.g., fishes and prawns) leading to cancer risk in human beings.

Keywords: Adsorption; Cancer risk; Leaching; Microplastics; Polycyclic aromatic hydrocarbons; Vectoring effect.