Scientists have discovered a new type of air pollution: tiny plastic particles that we can breathe in. These are called inhalable microplastics (iMPs). They are so small, less than 10 micrometres across, that they can go deep into our lungs. We usually hear about fine dust like PM2.5, but now we have ‘polymer dust’ in the air too.
A recent study looked at airborne microplastics in four major Indian cities: Kolkata, Delhi, Mumbai, and Chennai. Researchers from IISER Kolkata, AIIMS Kalyani, and IMSc Chennai collected air samples from busy markets. In Chennai, they took samples from busy places like T Nagar and Parry’s Corner.
Using special equipment, they found an average of 8.8 micrograms of plastic in every cubic metre of air across the cities. Chennai had about 4 micrograms per cubic metre. This is less than Kolkata (14) and Delhi (13), but it’s still a concerning amount. Experts believe the sea winds in Chennai help to spread out pollutants, but this doesn’t make the air perfectly clean.
The study found that synthetic clothes, plastic waste from packaging, and wear and tear from car tyres and shoes are major sources of these tiny plastic particles. “Our findings show we are not just surrounded by plastics – we are breathing them,” said Gopala Krishna Darbha, a lead scientist on the study.
What’s more worrying is that these plastic particles are not just plain dust. They can carry harmful chemicals and even tiny living things like bacteria and fungi. The researchers found chemicals like phthalates and heavy metals such as lead and arsenic on the plastic pieces. They also found mould spores and bacteria, some of which could make us sick.
“Airborne microplastics can act like Trojan horses, carrying germs and dangerous chemicals,” explained Darbha. “Their rough surfaces are a good place for microbes to live. Once we breathe them in, they can go to the deepest parts of our lungs.”
The study estimates that someone spending eight hours in a busy market could breathe in about 190 plastic particles a day in Chennai. In Kolkata, it could be 370 particles, and in Delhi, 300 particles.
Levels of these tiny plastics were highest in the evenings during post-monsoon and winter. This is when people wear more synthetic clothes and the air doesn’t move around as much.
In Chennai, areas with plastic recycling, textile factories, and lots of plastic used indoors all add to the problem. People who work outdoors a lot, like waste pickers and market vendors, and children might be at greater risk. “Chronic exposure is what matters,” said Abhishek Biswas, a PhD student. “These particles don’t disappear; they build up in our environment and possibly in our bodies.”
Further analysis showed that chemicals found on these microplastics are linked to many diseases. Researchers identified 28 chemicals that could cause cancer, affect hormones, damage nerves, or cause breathing problems. Many of these chemicals come from everyday items like cars, cleaning products, and personal care goods.
By looking at health records, the research team found links between these plastic-associated chemicals and 72 different diseases. Cancer was the most common, followed by problems with hormones, digestion, breasts, and breathing.
“This suggests airborne microplastics are not just carrying things – they might be transporting mixtures of active chemicals that can cause a wide range of health issues,” added Nikhil Chivukula, a researcher involved in the study.