Microplastic contamination in different tissues of cultured giant freshwater prawns for human consumption

There have been a relatively small number of studies on microplastics (MPs) in commercial freshwater prawns, although MP contamination in aquatic habitats is a global issue. This study presents the shapes, sizes, colors, and concentrations of microplastics discovered in 90 Macrostemum rosenbergii specimens gathered from three cultivated ponds in central Thailand. Microplastics in each prawn's four anatomical compartments (intestinal tract, hepatopancreas, muscle, and exoskeleton) were examined independently. MPs were detected in all studied specimens, with an average of 79.3 ± 2.92 MPs/individual. The intestinal tract had an average of 26.82 ± 0.92 MPs/individual, followed by the hepatopancreas at 21.09 ± 1.11 MPs/individual, muscle at 16.70 ± 0.63 MPs/individual, and the exoskeleton at 14.69 ± 0.65 MPs/individual. Fibers were predominant over fragments and spheres, with an average of 58.84%, 41.0%, and 0.16%. The most commonly observed microplastics were between 100 and 250 µm and 250 and 500 µm. Blue (58.09%) was the most common color of microplastic, followed by white/transparent (33.30%), red (7.06%), violet (1.42%), green (0.10%), and yellow (0.03%), respectively. Polyethylene terephthalate, polyvinyl acetate, and polyacrylonitrile-co-butadiene were the most frequent polymers, accounting for nearly 61% of all MPs found. There was a significant correlation (r = 0.85, p = 0.000, and r = 0.054, p = 0.002) between the weights of male and female prawn organs and the number of microplastics found in each. Male and female prawns showed no difference in microplastics larger than 500 µm across all organs (p > 0.05). This finding suggests that prawns in central Thailand's cultivated ponds are not free of microplastic pollution. The information offered here allows us to better understand the potential problems connected with human consumption of various tissues from contaminated prawns.