Volatile Organic Molecules – UPSC Prelims

Volatile Organic Molecules:
  • VOCs are carbon-containing chemicals released by petrol and diesel vehicles. They impact air quality and human health.
  • VOCs can have a natural origin, too.
  • Plants emit these chemicals to attract pollinators, defend themselves from pests and predators and adapt to environmental stress.
Effect of VOCs on Health:
  • VOCs can irritate the eyes, nose and throat, damage body organs and cause cancer.
  • Long-term exposure to VOCs is not good because the majority of the VOCs are carcinogenic (cancer-causing).
  • It is also linked to medical conditions such as asthma and heart disease.
  • Black carbon is linked to health problems such as respiratory and cardiovascular disease, cancer and congenital disabilities. It also contributes to climate change.
Positive Feedback Loop:
  • VOCs can drive the formation of other dangerous pollutants.
  • For instance, they react with sunlight and nitrogen dioxide to form ground-level ozone.
  • VOCs also trigger the formation of Particulate Matter (PM2.5), a pollutant that reaches deep into the lungs, affecting their normal functioning.
  • They react in the air to produce secondary organic aerosols, minute particles suspended in the air.
Issues Related to VOCs:
  • Human-made VOCs are a cause for concern, yet they don’t draw enough attention.
  • Benzene, a chemical that induces cancer, is the only VOC included in the National ambient air-quality standards.
  • The other pollutants under ambient air-quality standards considered are PM10, PM2.5, nitrogen dioxide, sulphur dioxide, carbon monoxide, ozone, ammonia, lead, nickel and benzo(a)pyrene.
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