University of Delhi researchers found microplastics in all 12 freshwater fish species they examined from the Yamuna River, recovering 1,678 particles in total. Samples taken in Delhi were significantly more contaminated than those upstream in Haryana. The study recorded 751 particles in digestive tracts, 605 in gills and 322 in muscle tissue—the part typically eaten by people—and found nearly 45% of fragments were polyethylene or polypropylene. Researchers call for better sewage treatment, tougher industrial discharge rules and stronger waste management to curb the problem.
All Fish Sampled in the Yamuna Contain Microplastics — Delhi Stretch Worst Affected
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New study finds microplastics inside every freshwater fish species sampled from the Yamuna River, with contamination peaking in Delhi.
Researchers from the University of Delhi tested 220 freshwater fish collected at four sites—Yamuna Nagar and Karnal in Haryana, and Sur Ghat and Sonia Vihar in Delhi—and found microplastic particles in all 12 species examined. In total the team recovered 1,678 microplastic particles across the samples, with pollution levels rising markedly as the river flows into the national capital.
Study Findings and Tissue Distribution
The study documented 751 particles in digestive tracts, 605 in gills and 322 in muscle tissue—the portion most often consumed by people. Species-level results ranged from a high of 436 particles in omnivorous Nile tilapia sampled at Sonia Vihar to a low of 37 particles in freshwater needlefish from Karnal.
Types of Plastics and Sources
Nearly 45% of detected fragments were polyethylene and polypropylene, materials commonly used in carry bags, food packaging and many single-use household items. The researchers linked Delhi’s higher contamination to pressures on the river inside the capital: rapid urbanisation, untreated sewage, textile and industrial runoff, and heavy suspended solids that transport microplastic fragments downstream.
Health, Ecosystem, and Policy Implications
Finding particles in muscle tissue, not only in guts, indicates that microplastics can translocate into edible tissues—raising concerns about potential human exposure through local diets. The problem is not limited to the Yamuna: similar microplastic contamination has been reported in the Ganga, Brahmaputra, Mithi and Cooum rivers and in other items such as shellfish, drinking water, table salt and agricultural soils.
The UN Environment Programme estimates global plastic production at more than 474 million US tons (430 million tonnes) a year; as larger items degrade they fragment into particles smaller than five millimetres and spread widely through aquatic systems.
Researchers stress that surface cleanups that remove visible debris and foam do not eliminate microplastics. To address the problem at its source they recommend improved sewage treatment, stricter industrial discharge standards, better management of textile and urban runoff, and stronger municipal solid-waste systems. India has already restricted some single-use plastics, but gaps in waste collection, recycling and disposal remain.
Bottom line: The study shows microplastic pollution in the Yamuna is widespread and reaches the tissues people eat, underscoring the need for upstream infrastructure and policy reforms as well as continued monitoring.
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