Human health risk and food safety implications of microplastic consumption by fish from coastal waters of the eastern equatorial Atlantic Ocean

We examined the gastro-intestinal tracts (guts) of 160 fish species obtained from Nigerian coastal waters for microplastics and estimated annual microplastic intake by adult human population in the region from the fish species. A total of 5744 microplastics were recovered from the fish species analyzed with an average of 39.65 +/- 5.67 items/individual. Microbeads (43%) occurred in all guts assessed, followed by fragments (27%), burnt film (14%), thread (9%), fibers (4%), and pellets (3%). Most microplastics recovered were below 1000 mu m with the least size being 85 mu m. Based on the size classes estimated for this study, we argue based on literature that close to 15% (i.e., >100 mu m) of the microplastics in the guts studied have the potential to translocate gut barriers of the fish species into muscles, where they get ingested by humans, and thereon get translocated to other human organ tissues. The estimated annual intake of microplastics from the consumption of whole fish by the adult population followed the trend; M. cephalus (178,220) > I. Africana (131,670) > P. senegalensis (115,710) > P. jubelini (109,060) > S. maderensis (101,080) > G. decadactylus (101,346) > S. melanotheron (65,170). Estimated annual intakes were generally higher for fish species with broad habitat and feeding preferences.

Automated summary

This study examined microplastics in the gastro-intestinal tracts of 160 fish species from Nigerian coastal waters and estimated the annual microplastic intake by the adult human population. Microbeads and fragments were the most commonly found types of microplastics, with sizes mostly below 1000 μm. It was estimated that a significant portion of these microplastics could translocate from the fish guts to human muscles and other organ tissues. The annual intake of microplastics varied among different fish species, with higher intakes observed for those with broader habitat and feeding preferences.