In India, when we discuss Air Pollution we think the only possible solution is to switch to electric vehicles, solar energy, and windmills.

Even if we replace all cars, buses, trucks, and two-wheelers with electric vehicles overnight, then air pollution might come down by 20% at best. Stay with me to understand why.

In India, even if we replace all combustion engine vehicles with electric vehicles overnight the Air pollution indices won’t come down significantly

All these solutions are from the West, which is perhaps right for their problems and unfortunately not suitable for a developing country like India. Our problems are different, which the developed countries solved decades ago.

Demystifying air pollution

There is a lot of difference between air pollution in developed as opposed to developing countries. Take a look at the global air pollution map below. You can find the developed world, i.e, U.S., Canada, EU, Australia are in the green and yellow zone (< 100 in pollution index), whereas one will not find a single green zone in the developing world, especially India and China. Why is it so different?

Pollution Index — World

Now take a look at the pollution map of North America. One will not find any place which has more than 100, in the pollution index, except a few.

Pollution Index — North America

Who are the major oil consumers?

The U.S. consumes 20% of the world’s oil whereas India uses only 4.7%.

Even though the U.S. alone consumes more than four times that of India, why is that there is no place in the U.S. in the RED zone?

We can find most of the U.S. cities fall in the green category which is less than 50, with numbers averaging around 30.

Look at the only RED on the map. Let’s zoom in and see what’s really going on there?

The place in RED is a small border town called Mexicali in Mexico. On the U.S. side, we can find the city of Calexico, California. The two monitoring stations are 4.8 km apart and one can find that the difference is nearly double. This triggers the question again. What is so different between a developed country and a developing country?

Developed vs developing country

Let’s also take a look at the Asia map. Here also we can clearly find the same pattern. Developed countries like Japan, Singapore, Malaysia, Taiwan, etc. are in green and yellow zone whereas developing countries like China, India, Philippines, etc. are having figures ranging from 100 to 999.

Pollution index — Asia

Take a look at Calexico vs Mexicali again. As you can see Mexicali has PM2.5 and PM10 in the RED zone and other pollutants such as SO2, NO2, CO, and O3 are in the green zone.

Now, take a look at Delhi’s condition as on 29-Oct-2018. We can find that the levels of SO2, NO2, CO, and O3 are in the safe zone, but PM2.5 and PM10 are in deep RED zone. In both cities, PM2.5 and PM10 are in the RED zone and rest all other emissions are in the GREEN zone.

New Delhi pollution index

What are PM2.5 and PM10?

Particulate Matter (PM) is a mixture of solid and liquid particles that are suspended in the air. These are categorized into coarse, fine and ultra fine. Coarse particles have a diameter of 2.5 micrometers to 10 micrometers, are relatively heavier and thus tend to settle. Dust, spores, and pollen are some examples. PM2.5 refers to particles that have a diameter less than 2.5 micrometers and remain suspended for longer.

Since they are so small and light, fine particles tend to stay longer in the air than heavier particles. This increases the chances of humans and animals inhaling them into their bodies. Owing to their minute size, particles smaller than 2.5 micrometers are able to bypass the nose and throat and penetrate deep into the lungs and some may even enter the circulatory system.

Studies have found a close link between exposure to fine particles and premature death from heart and lung disease. Fine particles are also known to trigger or worsen chronic diseases such as asthma, heart attack, bronchitis, and other respiratory problems.

India has 7 out 15 most polluted cities in the world, and surprisingly except Delhi, all other cities are non-metro cities. Why is it so?

Dust, Dust, Dust Everywhere

The real difference between the developing world and developed world’s pollution is dust. There are developed countries with more gas guzzling cars than a small Indian city like Gwalior or Raipur but has very less air pollution. We always consider air pollution as something entirely caused by vehicular and industrial emissions, which is wrong. While these are also contributing factors, the majority contributor is suspended dust PM2.5 and PM10 mainly from the dust kicked up by vehicles plying.

The difference in India is that this dust is not cleaned up regularly and sources of dust are not controlled whereas it is controlled in the developed world.

Humidity and PM are inversely proportionate — If you observe the pollution numbers during the year, then you’ll find the number vary according to different seasons. Vehicular emissions are not seasonal. It is mostly the same, except for holidays.

As humidity drops in winter pollution increase proportionately. But the pollution index values are seasonal. It shows that humidity and pollution are connected. Dust settles faster when humidity is high.

Take a look at the Delhi pollution numbers above and compare with figure 6. Both are taken in a week’s time. Look at the pollution levels and humidity levels. The connection between humidity can be established further by looking at the overall pollution index again. Coastal cities are not in the most polluted cities list even though cities like Mumbai have very high vehicle density but still doesn’t make it to the top.

Dusty Indian streets

To sum it up most Indian cities looks dusty and dirty. We can find soil/mud all over the streets. Vehicles keep sweeping the dust settled on the roads. Even if we replace it by an electric vehicle, the dust sweeping will go on. So, let’s treat the cause, not the symptom.

In India, dust contributes to nearly 80% of our Air pollution. Let’s treat the cause, and not the symptom

Read more about the solutions in the second part of this article here.

I have done some experiments using an air quality monitor to measure the pollution index under various conditions in Bangalore streets. I have validated most of my assumptions. I can share the measurements for anyone interested. I look forward to your thoughts below.