Microplastic–toxic chemical interaction: a review study on quantified levels, mechanism and implication

Current problem facing researchers globally is microplastics as well as toxic chemical pollution of the ecosystem. Microplastics carry toxic chemicals in the ecosystem serving as a vector for transport. In this study, a review of the literature has been conducted with the following objectives: (1) to summarize the concentrations of toxic chemicals such heavy metals and hydrophobic organic contaminants sorped on microplastics; (2) to evaluate their spatial distribution regarding adsorbed contaminant; (3) to discuss plausible mechanism by which microplastics adsorp or desorp toxic chemicals in the environment; (4) to discuss implications of their occurrence in air, water and soil media; and (5) to discuss the impact of ingested microplastics to human health. Microplastics are ubiquitous environmental contaminant. Concentrations of sorped toxic chemical varied by location which represents a local problem; industrialized areas (especially areas experiencing crude oil-related activities or have history of crude oil pollution) have higher concentrations than less industrialized areas. Ingestion of microplastics has been demonstrated in a range of marine and soil organisms as well as edible plants, thus possibly contaminating the base of the food web. Potential health effect to human is by particle localization, chemical toxicity and microbial toxins. We conclude by highlighting the gap in knowledge and suggesting key future areas of research for scientists and policymakers.