Cutting cars by half can reduce direct exposure to highly toxic emissions by several times

• CSE analysis of the official daily air quality data for PM2.5 for 2014 and 2015 from Delhi Pollution Control Committee shows that pollution is worse in winter of 2015 as compared with winter of 2014.
• Last December at least 3 per cent of days in December were in ‘good’ category (for air quality) – this year there has been none
• CSE has identified 11 smog episodes this winter – three consecutive days with severe pollution levels. Some episodes have occurred for continuous ten days. This justifies fortnight-long emergency action like the odd and even system.  Other countries clamp down on vehicles, industry and power plants, issue warnings and shut schools. 
• If with public support half of the cars stay off the road, the total toxic load of particulate matter, and nitrogen oxides can also be halved from the car segment. Total toxins including benzene, PAH and other cancer-causing substances can also be cut. More reduction is possible from diesel cars and SUVs.

New Delhi December 31, 2015:Centre for Science and Environment has released the results of its analysis of the official air quality data from the continuous air quality monitoring by Delhi Pollution Control Committee to show how this winter pollution levels have worsened compared to last year. This justifies emergency action like the odd and even system that Delhi should pilot successfully to reduce toxic exposure during smog episodes. Vehicles emit some of the worst toxins and toxic gases within our breathing zone.

CSE’s analysis of winter pollution has highlighted the following:

• Both November and December 2015 show higher number of days in ‘severe’ category, the worst category according to the National Air Quality Index.

• November 2015 had 73 per cent of days in severe category against 53per cent in November2014.

• December 2015 has 67November of days in severe category as against 65 per cent in December 2014.

• December 2014 had at least 3 per cent of days in ‘good’ and ‘satisfactory’ category but December 2015 has none. There has not been a single ‘good’ air quality day this winter.

• If globally smog episode is defined as three consecutive days in the worst category of the Air Quality Index, then the 2015 winter has already witnessed 11 such smog episodes. Such levels have lasted for 10 consecutive days as well.

Such high level of pollution this winter is a compelling reason for Delhi to pilot emergency action like odd and even system, closure of Badarpur power plant, etc. 

How each one of us can contribute towards air pollution reduction by not taking the car out

CSE said in its analysis that if with public support half of the cars are off the road, the total toxic load of particulate matter, and nitrogen oxides can also be halved from the car segment. Total toxins, including benzene, PAH and other cancer causing substances can also be cut. More reduction is possible from diesel cars and SUVs.

A user of single occupancy petrol car meeting Bharat Stage IV standards can reduce per capita particulate emissions per kilometer by at least two times by using a CNG bus. Benefit will be higher if the shift is from cars meeting older emissions norms.

A user of single occupancy diesel car meeting Bharat Stage IV can reduce per capita particulate emissions per kilometer by at least 40 times by using a CNG bus. If the shift is from diesel SUV the reduction will double.

The car pool strategy will reduce the per capita emissions by four times from the same car.

Metro ride causes zero emissions in the city (this does not account for emissions from electricity generation)

The programme will also allow enormous fuel savings and mitigation of heat-trapping carbon dioxide emissions. Per capita CO2 emissions from a single occupancy petrol car can reduce by 15 times with shift to buses. Also, per capita CO2 emissions from a single occupancy diesel car can reduce by 13 times with shift to buses and SUVs – 22 times. This translates into substantial fuel savings.

Don’t underrate the impact of vehicular pollution on our health

From a public health perspective, it would be misleading to underestimate the impact of vehicular pollution that occurs very close to our breathing zone. The Kanpur IIT study has shown that in winter vehicles are the second largest emitters of PM2.5 after road dust, if both combustion sources and dust sources are considered; but it is the top emitters among the combustion sources in winter. Moreover, in different parts of Delhi, diesel four-wheelers are the source of at least 60-70 per cent of PM2.5 in winter. Several other studies in Delhi have shown how real-time exposure on roads and close to roadside are several times higher than the background ambient levels.

• More than 55% of Delhi’s population live within 500 meters from some roadside and, therefore, within the direct influence of toxic vehicular pollution. Another study by the scientists of University of California, Berkeley, has shown that in Delhi people’s exposure to vehicle exhaust is three to four times higher than the world average.This population-weighted exposure to vehicular fumes is determined by the grams of vehicle pollution inhaled per grams of vehicle pollution emitted.

• Vehicular emissions contain some of the deadliest toxins like polycyclic aromatic hydrocarbons and benzene. These are more in diesel emissions.

• Serious health impacts have been associated with emissions from traffic. A recentlyreleased mega study in the US by the Health Effect Institute has implicated PM2.5 from diesel and coal with increased incidence of deaths due to ischemic heart disease. This is serious given the fact that India’s global burden of disease estimates have found half of the premature deaths due to air pollution related diseases in India are due to heart ailments.

• Global studies have linked air pollution with cardiovascular diseases, respiratory disorders and various allergies. Pollution may also be associated with central nervous diseases like Parkinson’s disease, stroke and Alzheimer’s disease. Higher incidence of respiratory and cardiac symptoms, stroke and effect on the brains of children are found in areas close to vehicular pollution.

CSE has urged that the odd and even number system is enforced with stringency to help develop alternative commuting practices and systems that can be sustained on a longer-term basis.

Given the level of choking pollution in the city and its health impact, people need to support to reduce their pollution foot print. Despite the exemptions granted to two-wheelers and women, voluntary participation is critical to reduce public health risk in the city.

Delhi government should take this opportunity to improve the public transport services. Reduced congestion will be an opportunity to make the public transport perform more efficiently.

• Down to Earth puts together a special package on odd and even system and air pollution