Chandigarh: blame cars, buses for making the air worse

CHANDIGARH: Even while the debate breaks out in Haryana, Punjab and Delhi, whether the farmers or crackers are blamed for the air worsening Quality in these regions, a study has confirmed the role of transport in pollution.

The study, conducted by scientists of the Graduate Institute of Medical Education and Research (PGI), was published in an international journal, 'Total Environmental Science'. The study was conducted for Delhi, but scientists said the findings are valid for all regions of the country.


The scientists analyzed the prevailing conditions in Delhi and concluded that cars and buses City roads contribute greatly to particles (PM). The wear of the brakes and tires, as well as the turbulence induced by the vehicle resulting in the resuspension of the dust from the road surface, are established as the main reasons for the contamination.

It was discovered that the non-exhaust emission of the vehicles was six times greater than that of the exhaust emissions. It was discovered that gasoline cars are the main culprits of non-exhaust emissions. In addition, the relative contribution in the exhaust and non-exhaust does not change significantly with the age of the motor vehicle.

The study revealed that the total PM10 emissions in Delhi were 31.5 Gg/year - exhaust 4.5 Gg/year and non-exhaust 27 Gg/year. The non-exhaust emissions were found to be 86% and the exhaust emission 14%. The highest contribution to the vehicular PM emission comes from cars (34%) followed by buses (23%) and heavy commercial vehicles (HCV, 17%). And. as the emissions are directly related to the average daily traffic and length of the road, major roads having length five times more than that of the national highway show higher emissions.

Cars and buses contribute less towards exhaust emissions and more to non-exhaust emissions. "Major roads are the largest contributors in Delhi. The emissions from HCVs, diesel cars along with the other diesel vehicles contribute more than the petrol vehicles to both exhaust and non-exhaust emissions. The study aligns with the objectives of national clean air programme, which aims 20%-30% reduction of PM2.5 and PM10 concentration by 2024," said Dr Ravindra Khaiwal, School for Public Health, PGI and one of the coauthor of the study.