Microplastics in two commercial marine fish species: A pilot study from the Arabian Sea

Humans are exposed to microplastics (MP) via ingesting contaminated fish, with a potential to cause adverse health effects such as oxidative stress, cytotoxicity, immunotoxicity, genotoxicity, and reproductive toxicity. To our knowledge, this is the first report of microplastics in edible muscles of commercially traded marine fish in Pakistan. Pampus argenteus and Otolithes ruber were purchased from the fish market, and the entire gastrointestinal tract (GIT) and a small portion of muscle of P. argenteus and O. ruber were digested, filtered, dried and observed under a stereomicroscope to detect MPs in the laboratory. Fourier Transform Infrared analysis was performed to determine chemical composition. All GIT samples and 50% of the muscle samples had MPs; a total of 46 MPs were isolated. The predominant shape of MPs detected was fibers (76%), the predominant color was black (48%), and polymer types included polyamide (33.4%), polyethylene (11.1%), and polyethylene terephthalate (22.2%), which can be sourced back to the textile and packaging industry. This pilot study reports the microplastic contamination in the GIT and muscles of P. argenteus and O. ruber, thereby raising a food safety concern. Future studies are needed to assess the risk associated with MP exposure via ingesting contaminated fish and associated adverse health effects, which will set the ground for risk communication and risk mitigation.