A recent study by The Real Urban Emissions (TRUE) Initiative has exposed a shocking truth:
actual vehicle emissions in Delhi far exceed laboratory test results, casting doubt on the effectiveness of current emission control measures. The study, conducted at 20 sites across Delhi, revealed that real-world emissions of particulate matter (PM), nitrogen oxides (NOx), and carbon monoxide (CO) exceed laboratory test results by a staggering 2-5 times. This disparity highlights the need for more accurate testing methods and stricter emission norms.

What is the Air Quality Index (AQI), and how is it measured?
The Air Quality Index (AQI) is a number that measures air quality by converting complex data into a single number, colour, and terminology. The AQI scale ranges from 0–500, with higher numbers indicating greater pollutant density in the air:

0–50: Good, with little or no risk from air pollution
51–100: Satisfactory, with little or no risk from air pollution
101–200: Moderate, with acceptable air quality but a potential health concern for some people who are sensitive to air pollution
201–300: Poor, especially for sensitive groups
301–400: Very poor
401–500: Severe

Laboratory tests are conducted under controlled conditions, which don’t accurately reflect real-world driving scenarios. In Delhi and Gurugram, vehicles are often stuck in traffic, subjected to extreme temperatures, and driven on poor road conditions, increasing emissions.  According to a study by the International Council on Clean Transportation (ICCT), these factors can cause real-world emissions to be up to 50% higher than laboratory test results. Furthermore, India’s emission norms are less stringent than those in developed countries, allowing vehicles to emit more pollutants. Impact of Air Quality and Public Health The impact of these excessive emissions on air quality and public health is devastating. As per a study by the Indian Institute of Technology (IIT), Kanpur, air pollution in Delhi causes approximately 10,000 premature deaths annually. This is due to an increased reliance on private vehicles and Delhi’s unique position as a seamless city. With the inflow of traffic from rapidly growing towns in neighbouring states, the NCT of Delhi has become progressively congested in the past few years.

Kaushik Deb, Executive Director of the Energy Policy Institute at the University of Chicago (EPIC India), shares, “The additional time spent in traffic by an average Delhi citizen has had adverse consequences regarding reduced productivity and loss of time. So when pollution or congestion is very high, each additional vehicle not only faces personal health risks and congestion delays but also imposes these costs on others.” Exposure to poor air quality increases the risk of respiratory diseases, cardiovascular diseases, and lung cancer. The World Health Organization (WHO) estimates that 9 out of 10 people worldwide breathe polluted air, resulting in 7 million premature deaths annually.

Explaining the health implications of excessive emissions in densely populated cities like Delhi, Tanushree Ganguly, Director of Air Quality Life Index, highlights, “Air pollution not only affects “sensitive” groups and causes temporary discomfort or illness but carries lasting and potentially latent consequences for the general population.” In India – particulate pollution takes 3.6 years off the life of the average Indian resident, which is greater than child and maternal malnutrition or unsafe water, sanitation, and handwashing. She adds, “In dense cities like Delhi – average life expectancy could go up by 4+ years if particulate levels were brought down to meet India’s annual PM2.5 standard of 40 ug/m3.”