A new study has sounded the alarm on what scientists are calling a “new air pollutant” — inhalable microplastics. These are microscopic plastic fragments, less than 10 micrometres wide, small enough to slip deep into human lungs. While attention has long focused on fine dust such as PM2.5, researchers say its plastic equivalent — polymer dust — is now floating freely in the air we breathe.
Published in Environment International, the study is the first systematic investigation of airborne microplastics (iMPs) across Indian cities. It was conducted by researchers from the Indian Institute of Science Education and Research (IISER) Kolkata, AIIMS Kalyani, and the Institute of Mathematical Sciences (IMSc), Chennai.
Air samples were collected from bustling marketplaces in Kolkata, Delhi, Mumbai, and Chennai. In Chennai, the team sampled five high-footfall locations — T Nagar, Ritchie Street, Phoenix Marketcity, Parry’s Corner, and Zam Bazaar Market — to capture real-world exposure levels.
Using advanced pyrolysis–gas chromatography–mass spectrometry (Py-GC-MS), the scientists detected an average of 8.8 micrograms of plastic per cubic metre of air across all cities. In Chennai, the concentration was about 4 µg/m³, lower than Kolkata (14 µg/m³) and Delhi (13 µg/m³) but still significant. Researchers say the city’s coastal winds help disperse pollutants faster than in landlocked regions, but that does not make the air safe.
“Although coastal ventilation helps, the presence of synthetic fibres from clothes, plastic dust from waste sorting, and debris from packaging means the exposure is continuous,” the study notes.
Chemical fingerprinting showed polyester — mostly shed from clothing — was the most dominant polymer, followed by polyethylene (from packaging) and styrene-butadiene rubber (from tyres and footwear). “Textiles, packaging waste, and vehicular wear are key contributors,” said Gopala Krishna Darbha, senior scientist at IISER Kolkata and lead author of the study. “Our findings show we are not just surrounded by plastics — we are breathing them.”
The most unsettling finding is that these tiny particles are not inert dust — they can carry toxic chemicals and microbes. The researchers found phthalates and heavy metals like lead, arsenic, and chromium on microplastic surfaces. Under a microscope, the team also identified fungal spores and bacteria, including potential pathogens such as Aspergillus fumigatus. “Airborne microplastics can act as Trojan horses carrying microbes and hazardous contaminants. Their rough surfaces provide ideal habitats for microbes, and once inhaled, these could reach the deepest parts of the lungs,” Darbha told TNIE.
According to the study, a person breathing in a busy market for eight hours a day could inhale around 190 plastic particles daily in Chennai, compared with 370 in Kolkata and 300 in Delhi. Post-monsoon and winter evenings, when synthetic clothing use rises and air circulation drops, showed the highest levels of airborne microplastics. For Chennai, the findings reveal a hidden layer in its air pollution story. The city’s plastic recycling hubs in Perungudi and Kodungaiyur, textile units, and widespread indoor use of plastics all contribute to steady emissions. Experts warn that waste pickers, market vendors, and children face higher risks due to prolonged outdoor exposure.
“Chennai’s numbers may seem lower, but chronic exposure is what matters,” Abhishek Biswas, Phd student at IISER said. “These particles don’t just vanish; they accumulate in our environment — and possibly our bodies.”
Nikhil Chivukula, senior research fellow at IMSc, who worked under Prof Areejit Samal on the study, added that their computational analysis uncovered worrying links between plastic-associated chemicals and disease. “This research finds inhalation of iMPs laden with respirable emerging contaminants (RECs) represents an unexplored but critical layer of the urban atmospheric exposome. We identified 28 such chemicals — including carcinogens, endocrine disruptors, neurotoxicants, and respiratory irritants — many originating from everyday consumer products like vehicles, cleaning agents, and personal-care items,” Chivukula said.
By mapping these chemicals against known disease databases, the IMSc team found associations with 72 diseases, with cancer being the most reported, followed by endocrine, gastrointestinal, breast, and respiratory disorders. “This suggests airborne microplastics are not just passive carriers — they may transport active chemical mixtures capable of triggering a wide range of health effects,” Chivukula said.