Study about Inhalable Microplastics

Why in news?

A new study has revealed that inhalable microplastics are becoming a hidden toxin in the air of Indian cities, exacerbating already severe pollution levels.

• Inhalable microplastics – They are tiny airborne plastic particles, which are less than 10 micrometres (µm) that stay suspended in air and can be inhaled into the lungs, unlike larger microplastics.
• Common Sources – Synthetic clothes (polyester), tyre/brake dust, plastic packaging, paints, cosmetics, and waste burning.
• Indoor vs. Outdoor – Concentrations are often higher indoors (where people spend 90% of their time) due to poor ventilation and enclosed plastic materials.

Key Findings

• Atmospheric Pollution -
  • Traditional criteria pollutants – PM10, PM2.5, carbon monoxide, lead, sulphur oxides, nitrogen oxides, Ozone.
  • Emerging respirable contaminants – Inhalable microplastics (new pollutant category) driven by 400 million metric tonnes of plastics produced annually.
• 52.1 million tonnes of plastic waste are released into the environment each year, globally.
• Pollution in Metropolises - Researchers examined inhalable microplastics (<10 µm) in the air of 4 major Indian cities – Delhi, Kolkata, Mumbai, and Chennai.
• Average concentration – 8.8 µg/m³ of inhalable microplastics across the 4 cities, and confirms microplastics as a new component of urban particulate pollution.
• Daily exposure – Average city resident inhales approximately 132 µg of microplastics per day.
• Toxic co-pollutants – Heavy metals (Lead, cadmium), hormone-disrupting chemicals (eg, diethyl phthalates), and antibiotic-resistant microbes, including fungi (eg, Aspergillus fumigatus).
• Health risk – Linked to cancer, hormone‑related diseases, breast problems, respiratory illnesses and cardiovascular risks.
• Vulnerable groups – Children, pregnant women, the elderly, and those with chronic respiratory or heart conditions.
• Contribution to pollution – Microplastics now make up about 5% of total city air pollution.
• Seasonal variation – Levels spike during winter evenings, with concentrations rising by 74%, worsening smog conditions.
• Inter-city variation – Delhi (14.18 µg/m³) & Kolkata (14.23 µg/m³) worst hit (~14 µg/m³), whereas Mumbai (2.65 µg/m³) & Chennai (4 µg/m³) are safer.
• Factors Influencing Microplastic Pollution – Meteorological conditions, Urban population density, Waste mismanagement.

References

The Hindu | Inhalable microplastics worsening Indian cities' air