Nanoparticle emissions from vehicles in Delhi may raise health risks: Study

New Delhi: Vehicular emissions that release toxic nanoparticles in Delhi may be hazardous to health, according to a study.

Nanoparticles or ultrafine particles are usually defined as a particle of matter that is between 1 and 100 nanometres (nm) in diameter and are invisible to the naked eye.

Due to rapid urbanisation, Delhi experiences frequent pollution events, and the particulate matter load exceeds the prescribed limit often.

The study, led by researchers from the Delhi Technological University (DTU), analyses nanoparticles (10 to 1090 nanometre) during different emission scenarios, seasonal and meteorological conditions in two phases: April to June 2021 (Period I) and October to November 2021 (Period II).

Period I experienced around 31 per cent less concentration of particles due to lockdown restrictions. On the other hand, particle concentration increased by 35 per cent compared to normal conditions due to the sudden rise in firework emissions due to Diwali in Period II.

“The study provides information regarding vehicle emission-based particle concentration under various emission scenarios in urban cities, which is crucial for estimation of emissions, health impact assessment, future policy formulation and strategy measures,” said the team in the study.

The team also found that the size of these particles varies depending on sources. In the second period, when emission sources were more complex, the size of the particles ranged from 20 nm to 200 nm, while it was 15 to 80 nm in the first period, when emission sources were restricted due to Covid restrictions.

Various previous studies have shown that inhaling nanoparticles are harmful as they can get deposited in the human body causing lung flammation, neurological problems and more.

“The particle number concentration estimates will be useful to determine deposition of particles in the human respiratory system based on various inhalation rates and associated physical activities,” the study said.

“The particles in the nano-size range, after deposition, can potentially be transported to other parts of the body, creating more chronic and acute illnesses,” it added.

The researchers called for “developing policies/standards, and initiating mitigation measures for pollution events with implications to climate change, and help move towards sustainability measures”.