Investigating microplastics bioaccumulation and biomagnification in seafood from the Persian Gulf: a threat to human health?

Abstract

High bioavailability of microplastics (MPs) in the marine environment has raised serious concern during the last few decades. Nevertheless, the trophic transfer of MPs within edible parts of the marine food webs remain unknown. In this study, bioaccumulation, biomagnification, and potential human intake of MPs in muscles and gills of five popular commercial species (3 fish, 1 crab, and 1 prawn) from the Persian Gulf were investigated. The surface structure characteristics of the material and elemental composition signatures were used to screen for likely MPs and rule out non-plastics. Among the studied species, Penaeus semisulcatus and Epinephelus coioides displayed the highest (mean 0.360 items/g muscle) and lowest (mean 0.158 items/g muscle) MPs level in their muscles, respectively. The number of extracted MPs from the gills was higher than the muscle of the analyzed species, especially when it comes to scavengers and filter feeders such as (Liza klunzingeri, Portunus armatus, and P. semisulcatus).The results of the trophic magnification factor (TMF) and biomagnification factor (BMF) calculation indicated that MPs were not biomagnified in edible parts of the marine food web of the Persian Gulf. Hence, contrary to previous belief, MPs trophic dilution occurs rather than magnification in edible parts of seafood. The assessment of human intake of MPs highlights the possible risks posed by seafood consumption to the the human population depending to a great extent on a seafood diet. Considering possible physical and chemical toxicity of MPs and their associated contaminants, routine consumption of high doses of the studied seafood should be controlled for vulnerable groups such as pregnant/lactating women and their children to ensure their safety.