The World Health Organization (WHO) estimates one person dies of air pollution-related causes in India every two minutes. The headlines in newspapers and TV news have focussed mostly on the smog over New Delhi in the recent weeks.

But, it is not just the residents of the national capital who are succumbing to air quality or the lack thereof. You are no better off if you live in Ahmedabad, Bengaluru, Mumbai, Hyderabad, or Chennai. You and your dear ones are dying faster than you would in places with cleaner air.

The following analysis of air pollution data, easily available with the wide use of air quality monitoring technology, together with a health event I recently went through, tells us how we Indians court significantly impaired lives — or even death— each day we continue to live in our large, polluted cities.

Surfacing for air

I split my time between Delhi and Bengaluru. I have the best of both worlds — the greenery, parks, wide roads of the national capital and the weather, gentle people, young energy of India’s tech capital.

Or, so I thought.

About two weeks before Diwali, I was hit by a nasty bout of asthma in Delhi. I was asthmatic as a schoolboy and have had occasional episodes of breathlessness in my adult life, but this one was the worst I had been in some 10 years. I didn’t have to get into hospital, but for about 10 sleep-challenged days, I had to go through nebulisation, steroids, shots, and bronchodilators that made my lungs feel like a stretched rubberband.

Once recovered, I moved to Bengaluru temporarily with an intent to rest my lungs. My first reaction when I stepped off the plane at the Kempegowda International Airport was that the air smelt different. Delhi has the highest levels of fine dust — measured by what are called PM2.5 and PM10 dust particles — among Indian cities. Near where I live in central Delhi, you can actually feel your nasal hair and cilia trapping the dust. I kid you not.

The Bengaluru air was a relief compared to Delhi’s, but something still was not right. My short walk to the metro station in the morning would leave me breathless.

Dust to dust

I decided to look up the pollution numbers of the two cities. Air quality is normally measured by an index of five pollutants: particulate matter or fine dust, carbon monoxide, sulphur dioxide, nitrogen dioxide, and ground-level ozone.

But, what about fine dust — which my doctor says is the primary trigger for my asthma? And, how do Indian cities rate against peers globally on this metric? The only comparable data for this is from the WHO, which tracks fine dust in 3,000 cities across 103 countries. First, some good news even if it is so in a twisted way: 98% of cities in low and middle income countries do not meet WHO standards for air quality.

That is, if you live anywhere in the developing world, your lungs are pretty much done for and the chances are that you will see lives cut short around you. The WHO calls air pollution, caused by high concentrations of fine dust “the greatest environmental risk to health — causing more than 3 million premature deaths worldwide every year”.

I turned to How India Lives, one of the smartest public data crunchers in the country (descriptor at the end of this copy), to help me make sense of the WHO data. See the graphic below (mouse over the bars to see individual city PM2.5 numbers).

Source: WHO, 2016. Visualised by: How India Lives

Killing us softly

New Delhi has the highest levels of fine dust — measured by the annual mean of PM2.5 dust particles in microgram per cubic metre (cu.m) of air — among global cities of population more than 8.5 million. If the population cut-off is not used, there is only one city with more particulate matter in the air than Delhi: Riyadh, the capital of Saudi Arabia. (The annual mean was arrived at by extrapolating from the daily mean levels and the classifications were per WHO guidelines.)

Delhi’s PM2.5 levels qualify it for a “hazardous” tag from WHO. In other words, the capital’s air “may cause serious health impacts on people with lung/heart disease [and] the health impacts may be experienced even during light physical activity”. A good example: me.

Ahmedabad, Bengaluru, Mumbai, Hyderabad, and Chennai, too, have PM2.5 levels that range between “very unhealthy” and “unhealthy for sensitive groups”, as rated by WHO. The air in the cities may not be as bad Delhi’s but are bad enough to impair lives. For reference, anything more than 120 microgram per cu.m of PM2.5 particles is classified as hazardous, 80 to 120 is very unhealthy, 60 to 80 is unhealthy, 40 to 60 is unhealthy for sensitive groups, 20 to 40 is moderate, and less than 20 is good.

Before you dismiss “hazardous”, “very unhealthy”, and “unhealthy for sensitive groups” as inscrutable descriptors, here’s what research cited by WHO says: if the PM2.5 level can be brought down from 70 microgram per cu.m to less than 20 microgram a cu.m, the number of air pollution-related deaths can be brought down by 15%.

Imagine the number of lives clean air could save in Delhi, Ahmedabad, Bengaluru, and Mumbai.

(How India Lives is a Delhi-based startup that aims to organise massive amounts of public data, and make it available in a searchable, comparable and visual format, to aid decision-making.)