Inhalable Microplastics Threat: Why This Matters for India?

A first-of-its-kind Indian study published in Environment International has identified inhalable microplastics (IMPs) as a hidden but serious component of urban air pollution.
IMPs are plastic particles smaller than 10 micrometres (µm) that can penetrate deeply into the human respiratory system.
The study covered Delhi, Mumbai, Kolkata and Chennai, sampling air at human breathing height.

About Microplastics

Microplastics are defined as plastics less than 5mm in diameter.
There are two categories of microplastics.
- Primary Microplastics: Tiny particles designed for commercial use, like in cosmetics or textiles.
- Secondary Microplastics: Tiny particles that are a product of the breakdown of larger plastic items due to exposure to environmental factors such as the sun’s radiation or ocean waves.

High Daily Rxposure: Average concentration across cities was estimated at 8.8 µg/m³, implying that an urban resident inhales about 132 micrograms of microplastics daily.
City-Wise Variation: Exposure was significantly higher in Delhi and Kolkata (around 14 µg/m³) than in Mumbai and Chennai.
Seasonal Spike: Winter evenings showed a 74% rise in inhalable microplastics compared to non-winter periods, mirroring trends seen in PM2.5 pollution.
Most particles were fragments rather than fibres, mainly originating from packaging waste, tyre wear, construction activities, cosmetics, synthetic textiles and informal industries.
Trojan-Horse Effect: Microplastics were found to carry heavy metals (lead, cadmium) and endocrine-disrupting chemicals such as phthalates, amplifying toxicity.
Biological Risks: Microplastics were found to carry pathogenic fungi (e.g., Aspergillus fumigatus) with antibiotic-resistant genes, raising concerns about difficult-to-treat respiratory infections.
Regulatory Blind Spot: Existing Air Quality Index (AQI) frameworks do not explicitly account for microplastics or nanoplastics, limiting policy responsiveness.

In the first half of 2025, Delhi recorded an annual average PM2.5 level of about 87 µg/m³, far exceeding the WHO guideline of 5 µg/m³, placing it among the most polluted Indian cities.
Recent studies indicate that inhalable microplastics now account for nearly 5% of particulate pollution in Indian cities.
Over a lifetime, an urban resident may inhale nearly 2.9 grams of microplastics, roughly comparable to the weight of a small plastic bottle.
The combined burden of particulate matter and microplastics disproportionately affects traffic police and sanitation staff, who are exposed to toxic particles containing heavy metals.

Single-Use Plastic Ban (2022): Ban on identified single-use plastic items (straws, cutlery, thin bags, thermocol) to reduce fragmentation of plastics into microplastics.
Plastic Waste Management (PWM) Rules: Extended Producer Responsibility in PWM mandates producers to collect, recycle, and safely dispose of plastic waste, limiting environmental leakage.
Microbead Prohibition: PWM Rules prohibit plastic microbeads in cosmetics and personal care products, directly eliminating a primary microplastic source.
National Action Plan for Marine Litter: Targets plastic inflow into rivers and seas through better waste management, coastal clean-ups, and monitoring to curb secondary microplastics.

Integrate microplastics into air monitoring systems, expand CPCB and State Pollution Control Board monitoring to include microplastic load at breathing height, especially in high-footfall urban zones.
Target tyre and textile emissions, introduce abrasion standards for tyres and mandatory labelling for synthetic textiles based on microplastic shedding potential.
Treat open dumping, poor segregation and waste burning as air pollution offences, recognising their role in generating airborne microplastics.
Move beyond single-use bans to material substitution strategies, incentivising cotton, biodegradable polymers, and low-shedding recycled textiles through GST and procurement policies.