Volatile Organic Molecules – UPSC Prelims

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.

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.

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.

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.