Emissions, dust reasons for rise in air toxicity'

New Delhi: Dust may be the most visible marker of Delhi’s air pollution, but its sheer abundance may actually be masking the bigger killers — emissions from vehicles, thermal power plants and industries.

Studies and research reports have underlined chemical composition of ultrafine particulates PM2.5 or PM10, and not their volume, as more crucial in determining the toxicity of air.

The Environment Pollution (Prevention and Control) Authority (EPCA), a Supreme Court-appointed pollution watchdog, made a similar point in its report that coal and diesel particles are more harmful than wind-blown dust, as they can lead to a rise in heart disease-related deaths.

“Similarly, particles from diesel combustion are toxic and have been classified by the WHO as a class-I carcinogen for strong links with lung cancer, putting them in the same bracket as tobacco smoking and asbestos. This suggests that we must prioritise the more harmful particulates for action. Combustion sources such as vehicles, power plants and industry, need more stringent action,” the report said.

The EPCA mentioned it separately under a section — addressing quantum vs toxicity. An IIT-Kanpur report, which assessed the chemical composition of pollution from various sources in the city, also concluded that combustion, vehicular and industrial, was responsible for the formation of PM2.5 in greater quantity.