ABSTRACT
Microplastics (MPs), minute plastic particles of synthetic origin, pose a potential threat to human health. According to multiple studies, the frequency of microplastic ingestion in fish is quite high, with research indicating that between 50% and 70% of fish examined have been found to contain microplastics in their digestive tracts; meaning a significant portion of fish populations are likely to have ingested microplastics.
This research investigated MP levels in Trachurus trachurus (Atlantic horse mackerel) purchased from selected markets in Benin City, Nigeria. Fourier Transform Infrared Spectroscopy (FTIR) was employed following the extraction of organic matter from fish muscle tissue. Mean MP accumulation levels in T. trachurus (mean total length 29.95 ± 2.76 cm, mean weight 295 ± 2.15 g) ranged from 0.04 particles/g (November, New Benin Market) to 2.38 particles/g (October, Oba Market). A statistically significant difference (p < 0.05) in T. trachurus MP levels was observed between markets (Oba, Ekiosa, and New Benin) and between months (October, November, and December). Mean plastic load ranged from 0.0057µg/g (November, Oba Market) to 0.75µg/g (October, Oba Market), with a statistically significant difference (p < 0.05) between months at Oba Market. No significant difference in plastic load was observed at Ekiosa and New Benin Markets. Polyethylene pellets were the dominant microplastic particle type, exhibiting the highest frequency of occurrence in all sampled fish across all markets. Estimated daily intake values (particles/person/day) ranged from 0.0002005 (Ekiosa Market) to 0.0005361 (Oba Market), with an overall value of 0.0007366. A three-pronged approach is recommended to mitigate MP contamination, encompassing routine monitoring, rigorous enforcement of plastic waste disposal regulations, and public awareness campaigns to protect ecosystem integrity and public health.
