Researchers at MIT World Peace University (MIT-WPU), Pune, have detected microplastics in commonly consumed freshwater fish entering the city’s market, raising concerns about how plastic pollution moves through freshwater ecosystems and into the food chain.
The ongoing study, led by PhD scholar Simran Singh under the guidance of Dr Soma Mishra of MIT-WPU’s Department of Environmental Studies, is examining Rohu and Tilapia. Funded through the university’s Seed Grant, the research is assessing the occurrence, characteristics and potential sources of microplastic contamination in commercially consumed fish.
The study began by mapping Pune’s freshwater fish supply chain rather than examining only retail markets. Researchers surveyed major wholesalers and distributors, which act as key entry points for fish into the city. Pune was divided into four geographical zones, and 26 wholesalers and distributors were interviewed.
Based on the survey, the researchers estimate that approximately 37-40 tonnes of freshwater fish enter Pune’s market every day. Rohu and Tilapia are among the commonly traded species. A significant share of the supply comes from aquaculture systems, while fish also arrive from Andhra Pradesh, Gujarat, Ratnagiri, Mumbai and Kolkata, underlining the interstate nature of Pune’s freshwater fish network.
Laboratory investigations detected microplastics in the fish samples examined. The particles included fibres, fragments and pellets, forms commonly reported in freshwater environments. The findings indicate that contamination cannot be assessed only at the point of sale because fish entering Pune are connected to production, transport and distribution systems spread across multiple regions.
Using the detected levels and local consumption patterns, the study estimates that a person consuming an average of 250 grams of freshwater fish twice a week over 50 years could potentially ingest between 93,600 and 124,800 microplastic particles. The researchers have cautioned that this particle count cannot be directly equated with the number of plastic bottles or other plastic items. The mass and potential health implications depend on factors such as particle size, polymer composition and associated contaminants.
Detailed quantitative analysis and polymer characterisation are still underway as part of the doctoral research. The supplied study findings therefore establish the presence of microplastics in the samples examined, but do not by themselves establish a quantified health risk for fish consumers.
The research aims to create baseline scientific data on freshwater microplastic pollution in Pune and trace the pathways through which particles may move from freshwater environments into the food chain. Its findings could inform discussions on plastic waste management, wastewater management, freshwater ecosystem conservation and food safety.
The study was also recognised at the National Scientist Round Table Conference, where Singh recently received the Third Prize for her poster presentation. “Plastic pollution is no longer just an environmental issue; it is becoming a food-chain issue,” Mishra said. She added that understanding where microplastics originate, how they move through freshwater ecosystems and how they reach fish is necessary for developing informed policies and sustainable solutions.
The researchers are continuing the quantitative analysis and polymer characterisation to determine the composition and characteristics of the particles detected in the fish samples.
