Syllabus: Conservation, environmental pollution and degradation, environmental impact assessment.
Context and Emerging Concern
- Indian cities experience severe winter smog with AQI remaining ‘severe’ or ‘very poor’.
- Regulatory focus remains on PM2.5 and PM10, overlooking newer airborne contaminants.
- Recent research highlights inhalable microplastics as an under-recognised urban air toxin.
What Are Inhalable Microplastics
- Inhalable microplastics are plastic particles smaller than 10 micrometres.
- They are classified as respirable emerging contaminants in atmospheric pollution.
- Their proliferation is linked to global production of 400 million tonnes of plastics annually.
- Around 52.1 million tonnes of plastic waste enter the environment each year.
Key Findings: Concentration and Exposure
- Average inhalable microplastic concentration across cities was 8.8 μg/m³.
- This implies daily inhalation of about 132 micrograms per person.
- Particle size enables bypassing of natural respiratory defences.
- Chronic exposure poses serious long-term public health risks.
Co-Pollutants and Health Risks
- Microplastics act as Trojan carriers of toxic co-pollutants.
- Attached contaminants include heavy metals like lead and cadmium.
- Hormone-disrupting chemicals such as diethyl phthalates were detected.
- Atmospheric lead levels were highest in Kolkata, followed by Delhi.
- Microplastics also carried harmful microbes and antibiotic-resistant fungi.
- Health risks include cancer, hormone disorders, breast problems, and respiratory diseases.
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- Particle Characteristics and Sources
- Fragments were more common than filaments in airborne samples.
- Major sources included packaging, tyre wear, textiles, cosmetics, construction, and households.
- Smaller particles dominated due to weathering and secondary fragmentation.
Policy Gaps and Imperatives
- Current AQI does not adequately capture microplastic pollution.
- Traffic police and labourers face heightened exposure risks.
- The study calls for policy reform, plastic bans, and better waste management.
- It establishes a baseline for addressing an emerging environmental crisis.