In a shocking revelation, the air you breathe in Kolkata might be filled with more than just oxygen and dust. You could be inhaling microplastics equivalent to a plastic bottle's worth over your lifetime! But how is this possible? A collaborative study by Indian researchers from IISER Kolkata, AIIMS Kalyani, and IMSc Chennai has uncovered a hidden danger in the air we breathe.
The study, published in Environment International, measured microplastics at human breathing height in bustling markets across four major Indian cities. And the results are concerning. Kolkata's air contains a staggering 14.23 micrograms of inhalable microplastics per cubic meter, closely followed by Delhi at 14.18 µg/m³. Even coastal cities like Chennai (4 µg/m³) and Mumbai (2.65 µg/m³) aren't spared.
But here's where it gets controversial: these microplastics are not just floating around harmlessly. They are smaller than 10 micrometres, and the study suggests they contribute significantly to PM10 and PM2.5 levels. These tiny particles, often from dust, smoke, and fuel, are already known to cause air pollution. But now, microplastics are adding to the problem, accounting for up to 5% of PM10 and PM2.5 in these cities.
The sources of these microplastics are everyday items like textiles (polyester), packaging, vehicle wear, and footwear. The researchers highlight a grave concern: microplastics can act as carriers for infectious agents, potentially increasing disease transmission risks in crowded urban areas. These airborne particles can be 'Trojan horses', carrying pathogens and contaminants deep into our lungs.
And this is the part most people miss: these particles don't just contain harmful substances; they can also harbour living microbes, some of which are pathogenic or antibiotic-resistant. The study identified bacteria and fungi like Aspergillus fumigatus, Candida (a respiratory pathogen), and various Bacillus species with antibiotic resistance genes.
Microplastics pose a unique threat due to their ability to remain suspended in the air for extended periods. Unlike dust, they don't settle or wash away easily. This allows them to travel long distances and, when inhaled, penetrate deep into the respiratory system, potentially entering the bloodstream and reaching vital organs.
Furthermore, the study revealed that Kolkata and Delhi's air had the highest lead contamination, surpassing national safety limits. Lead, often released from degrading plastics, vehicle emissions, and industrial waste, is linked to respiratory diseases, hormonal issues, and even cancers. It's a silent danger, as it's commonly used as a stabilizer and pigment in plastics, tyres, and coatings.
The researchers also detected other toxic additives, such as diethyl phthalate (DEP), a plasticizer and fragrance stabilizer found in cosmetics, plastics, and PVC products. Inhalation of DEP has been associated with endocrine disruption, reproductive toxicity, and respiratory problems. The air in Delhi, Kolkata, and Mumbai had the highest DEP concentrations.
This study raises important questions about the impact of microplastics and chemical additives on our health. Are we unknowingly exposing ourselves to a cocktail of harmful substances with every breath? What can be done to mitigate these risks? The answers may spark debate and require urgent action.
