Microplastic contamination in Indian mackerel: A study of prevalence and potential health risks for Malaysian consumers

Abstract

Microplastic pollution has grown significantly due to the rapid production of plastic, becoming a major environmental issue. This study examines the prevalence and characteristics of microplastics in Indian mackerel, a commercially significant fish species in Malaysia, marking the first comprehensive analysis of its kind in the country. We collected 180 fish from six locations in the South China Sea and Malacca Strait, digested them with a 10% KOH alkaline digestion and further characterized using micro-Fourier transform infrared spectroscopy. Microplastics were found in 93.3% of the fish, primarily as fibers, black in color, and smaller than 0. mm. The average number of microplastics per fish was significantly higher (p < 0.05) in the gastrointestinal tract (3.07 ± 1.70 particles) compared to gills (0.33 ± 0.15 particles) and edible tissue (0.34 ± 0.15 particles). Notably, 28.89% of the fish had microplastics in their edible tissue, with an average concentration of 0.043 ± 0.036 particles g⁻¹. Based on edible tissue concentration and Ministry of Health Malaysia fish intake recommendations, Malaysians may ingest 670.8 to 2016.7 microplastic particles annually per capita through fish consumption, with Indian mackerel contributing an estimated 233.49 to 478.16 particles per year per capita. The main polymer types identified were rayon and polyamide, pointing to textiles and fishing gear as likely sources. These findings highlight the pervasive presence of microplastics in Indian mackerel and potential human health risks, emphasizing the need for further research and stricter regulations to combat microplastic pollution and ensure food safety in Malaysia.