A study by researchers from the Department of Zoology at Maharaja Sayajirao University of Baroda has detected microplastics and heavy metals in shrimp and crab species collected from the Narmada River and sold in seafood markets, raising concerns about river pollution and possible health risks.
The research was conducted by MSc student Riya Joshi under the guidance of Dr Niketa Mehta.
As part of the study, researchers collected around 50 samples of shrimp and crabs from 10 locations along the Narmada River stretch between Garudeshwar and Hansot.
The study found that microplastics were present in different body parts of the aquatic species, with the highest concentration detected in the digestive tract, especially the intestines.
Researchers explained that intestines become the main accumulation point for microplastics entering the organisms through contaminated water and food.
Smaller quantities of plastic particles were also found in muscle tissues, which are commonly consumed by humans.
According to the study, most samples contained between nine and 15 black and blue-coloured microplastic particles on average.
Researchers said possible pollution sources include synthetic fabric fibres, fishing nets, untreated sewage, and plastic waste entering the river system.
The analysis detected polyethylene in 95% to 100% of the shrimp and crab samples, while polypropylene was found in 75% to 85% of the samples examined.
The species studied included tiger shrimp, white shrimp, Kutchi shrimp, giant river prawn, mud crab, and freshwater crab.
Researchers warned that the presence of microplastics in edible tissues suggests ultrafine plastic particles could enter the human body through seafood consumption.
The study also highlighted increasing industrial and plastic pollution in the Narmada River.
For the analysis, researchers used Fourier Transform Infrared (FTIR) spectroscopy, a scientific method used to identify chemical compositions and plastic types through infrared absorption patterns.
Using this method, the team identified plastics such as nylon, polyethylene, polypropylene, and polyethylene terephthalate.
Apart from microplastics, the study also found heavy metals including chromium, nickel, copper, zinc, iron, cadmium, and lead in the aquatic species.
Researchers said further testing is underway to determine the exact concentration of these toxic substances.
According to the study, the combined presence of microplastics and heavy metals could pose long-term risks to aquatic ecosystems as well as human health.