Delhi’s Toxic Air is Laced With Microplastics: What It Means for Your Health

A new study measured how much microplastic an average resident of the national capital breathes in.

A new study finds Delhi’s pollution crisis worsening, with microplastics detected in PM10, PM2.5, and PM1. (Image for representational purpose only.)

(Photo: Generated using AI/ altered by The Quint)

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Delhi’s already toxic air now has another invisible threat swirling through it: Microplastics.

A new study by the Indian Institute of Tropical Meteorology (IITM), Pune, in collaboration with Savitribai Phule Pune University, has, for the first time, quantified the amount of microplastic inhaled by an average resident of the national capital.

The researchers found microplastic particles are suspended in PM10, PM2.5, and PM1 pollutants present in Delhi’s air.

According to the study, people in the capital inhale about 10.7 microplastic particles per day in winter, and 21.1 particles per day in the summer.

Experts warn that these particles aren’t just floating debris. Microplastics can carry toxic chemicals and can cause a slew of health issues in the long run.

The Quint speaks to experts to decode the findings of the study, and what this means for you.

How Did Microplastics Enter Delhi’s Air?

Microplastics are extremely small plastic particles, often invisible to the naked eye.

"This breakdown (of microplastics) happens for many reasons," explains Satish Sinha, Associate Director of Toxics Link, an environmental NGO that engages on issues of chemical safety, who was not involved in the study. "It could be heat, natural weathering, or wind, which gradually fragment larger plastics into smaller pieces that eventually become airborne."

In this new study, researchers found that the average airborne microplastics detected by them ranged in size from 1-1000 micrometers, with most particles being smaller than 25 micrometres.

In this study, the first detailed look at microplastics in Delhi’s air, researchers collected samples from Lodhi Road, a busy central area, and found 2,087 microplastic particles in the air samples. On average, they detected about 1.87 particles per cubic meter of air in PM10, 0.51 in PM2.5, and 0.49 in PM1—with the highest levels in PM10 (the larger particle size category).

The study also found that most of the microplastics in Delhi’s air were made of polyethylene terephthalate (PET) (41 percent) and polyethylene (PE) (27 percent) — material commonly used in packaging (bags, films, bottles), construction (pipes, insulation), automotive parts, and household items like toys and containers.

Researchers noted that microplastics are also released from textile industries, garment processing, and even laundry at home.

“For example, clothes made of synthetic materials like polyester or nylon shed tiny fibres when washed or dried. These fine particles can be carried by wind and end up airborne,” says Sinha.

“What many people don’t realise is that everyday personal products like your face wash or body wash, or feminine hygiene products also contain some amount of microplastics."

Satish Sinha, Associate Director, Toxics Link

Adding to this, Dr Suneel Pandey, Senior Fellow and Director, Environment & Waste Management Division, TERI, tells The Quint:

“Few people realise that vehicle tyres release microplastics as they wear down on the road. With heavier traffic and more cars, this wear-and-tear adds significantly to the city’s pollution load, releasing tiny plastic particles that remain suspended in the air.”

Open burning of plastic waste is another major source, and researchers say the dominance of PET and PE in Delhi’s air is hardly surprising, given the city generates nearly 690 tonnes of plastic waste every day—much of it from single-use packaging.

How Much Microplastics Are You Breathing In?

Sampling for the study was carried out weekly during the winter (January-March) and summer (April-June) of 2024, and the researchers separated particulate matter into three size fractions: PM10, PM2.5, and PM1. This allowed them to track seasonal variations in the concentration of microplastics in Delhi’s air.

The study found significantly higher levels of microplastics observed during the summer season than in winter.

Experts told The Quint that this is because in summer, "the air is hot, which breaks down plastic faster, releasing more tiny plastic particles into the air."

This study, also for the first time, provides an age-based breakdown of how much microplastic an individual in Delhi is breathing in.

To put it simply, the study found that the average daily intake of airborne microplastics varied significantly across different age groups. Adults had the highest average daily intake (about 21.1 microplastics per person per day in summer).

However, experts warn that the health risks may be greater for infants and young children, since their lungs are still developing and they breathe more rapidly for their body size.

How Microplastics Threaten Your Health

Studies have detected microplastics throughout the human body from the gut, the lungs, the brain, to the bloodstream, sperm, and even breast milk. It’s becoming clear there’s hardly any escaping them.

"They have the same chemical composition and properties as your regular plastic. So you can imagine it’s not great to have them inside our bodies. Once they get into our lungs, bloodstream, or organs, they can start causing problems," says Sinha.

According to Sinha, while it's "clear that it is dangerous and harmful,", the full extent of the damage is still not well understood, as research on this issue is relatively new.

However, inhaling airborne microplastics is now recognised as a significant exposure route to keep a watch on.

"Studies in the past have found that if you ingest microplastics through food, etc, your kidneys generally flush them out. But if you breathe them in, they can enter your bloodstream through the lungs and cause harm like any other particle pollutant."

Dr Suneel Pandey, Senior Fellow and Director, Environment & Waste Management Division, TERI

A peer-reviewed study conducted in France and published in the medical journal PLOS One earlier this month found that inhaled microplastics can penetrate deep into the lungs and enter the bloodstream, carrying harmful chemicals like BPA and phthalates. The study linked this exposure to chronic respiratory issues, increased risk of infertility, and even potential cancer.

Another comprehensive review of nearly 3,000 studies conducted in Spain and published in 2024 found that microplastic inhalation exposure is “likely linked” to digestive, respiratory, and reproductive health problems, including colon cancer, fertility issues, and reduced lung function.

'No Safe Limit Yet'

Since research on microplastics in the human body is still at an early stage, unlike conventional air pollutants such as PM2.5, there are no standardised methods for measuring airborne microplastics, nor are there clear benchmarks for what constitutes a “safe” level of exposure.

Experts also note that microplastics vary widely in size, shape, and chemical makeup, which makes it challenging to predict their exact effects on the body.

Researchers agree that larger, long-term studies are essential to establish direct links between microplastic exposure and specific health outcomes. But, until then, the issue should be treated with caution, and not dismissed.

“The goal is to better understand, not just the health impacts of microplastics, but also how much exposure people actually face," says Dr Pandey. He adds,

"Some sources, like vehicle tyres, are unavoidable. Even if we switch to electric vehicles, tyre friction on roads will continue to release microplastics into the air. But there are other areas where plastic use can be reduced or avoided, and that’s where interventions can make a difference.”

"This can be done by improving the waste collection and management systems, for starters. Because the more plastic waste is there just lying around in the environment, they will slowly keep degrading and turning into microplastics," he adds.