New Delhi and Bangkok. What have the capital cities of India and Thailand got in common ? For starters, both cities are rapidly developing megapolises in Asia. New Delhi alone has 21.75 million people, which is – you guessed it – equivalent to Sri Lanka’s entire population. Bangkok, on the other hand, has around 9 million people.
Last month, I had the opportunity of making back to back one week visits to both cities. While I had been to both cities earlier, I still found them fascinating places, with a rich blend of the past and the present at every corner. Both cities are still coming up literally and figuratively – one can see glimpses of both prosperity and poverty amid the construction cranes.
But now, both cities have earned a not-so-enviable reputation for something else altogether – bad air quality. The day after I arrived in New Delhi, I opened my hotel room’s curtains, to be greeted by what appeared to be thick fog. I could not see more than a metre ahead. I was elated for a while, but then it dawned on me that this was not the ‘fog’ as seen on the John Carpenter movie of the same name (which I saw on Blu-Ray recently).
It was the haze brought about by high levels of pollution - especially Fine Particulate Matter (PM2.5) - tiny pollutant particles in the air that reduce visibility and cause the air to appear hazy when levels are elevated. And last week, when I was in Bangkok, the Thai Prime Minister ordered schools in the city to be shut and urged private car owners to keep their cars at home and travel by public transport, because PM 2.5 levels were extremely high. The city, which had not experienced any rain since January 8, used water-spraying drones to disperse the fine dust and adopted many other drastic measures.
The maximum recommended level of PM 2.5 is 10 micrograms per cubic metre of air, but this is exceeded several times over in the most polluted cities in the world. Zabol in Iran tops the list at 217 micrograms, while 10 Indian cities including New Delhi are in the top 20. Even in Colombo, Sri Lanka, the mean PM 2.5 level is 36 micrograms, which is much higher than the WHO recommended level.
Particles in the PM2.5 size range are able to travel deeply into the respiratory tract, reaching the lungs. Exposure to fine particles can cause short-term health effects such as, eye, nose, throat and lung irritation, coughing, sneezing, runny nose and shortness of breath. Exposure to fine particles can also affect lung function and worsen medical conditions such as asthma and heart disease.
Scientific studies have linked increases in daily PM2.5 exposure with increased respiratory and cardiovascular hospital admissions, emergency department visits and deaths. Studies also suggest that long term exposure to fine particulate matter may be associated with increased rates of chronic bronchitis, reduced lung function and increased mortality from lung cancer and heart disease. People with breathing and heart problems, children and the elderly may be particularly sensitive to PM 2.5.
There are outdoor and indoor sources of fine particles. Outside, fine particles primarily come from car, truck, bus and off-road vehicles (e.g., construction equipment, locomotive) exhausts, other operations that involve the burning of fuels such as wood, heating oil or coal and natural sources such as forest and grass fires. Fine particles also form from the reaction of gases or droplets in the atmosphere from sources such as power plants. Because fine particles can be carried long distances from their source, events such as wildfires or volcanic eruptions can raise fine particle concentrations hundreds of miles from the event. PM 2.5 is also produced by common indoor activities. Some indoor sources of fine particles are tobacco smoke, cooking, burning candles or oil lamps, and operating fireplaces and fuel-burning space heaters. Outdoor air levels of fine particles increase during periods of stagnant air (very little wind and air mixing), when the particles are not carried away by wind. One should try to minimize exposure to PM 2.5 to ward off any potential health effects.
This, then, is a very serious threat to public health. Unfortunately, there is very little awareness about this issue in many countries. Just pause for a moment to think whether anyone living in Colombo even bothers about PM 2.5. Most people I saw in Bangkok were wearing masks, but there was hardly anyone in New Delhi with a mask. It is thus vital to educate the public on the dangers of air pollution. A cheap mask that can stop PM 2.5 from reaching your lungs may literally be a matter of life and death in a few years.
We also have to consider the economic and medical cost of air pollution. Witsanu Attavanich, an associate professor of economics at Kasetsart University in Thailand was quoted in the Thai media as saying that every microgram of PM2.5 beyond the safe limit costs an estimated US$ 580 million in medical bills.
In Bangkok, many experts were expressing the opinion that diesel vehicles, some of which are three-decades old, were the main cause of the pollution, apart from factories. They had not switched over to better quality fuel, leave alone replacing the belching vehicles. In general, vehicles cause around 60 percent of the PM2.5 concentration.
The other bugbear seems to be the over-reliance on private cars in many Asian cities. Only Singapore, where it is extremely difficult to buy a private car due to the exorbitantly priced Certificate of Entitlement (COE), has succeeded to some extent in controlling private car usage. The private car is as popular as ever in Bangkok despite having many mass transit systems – MRT, Skytrain, buses and taxis. It is really hard to lure the private car user away from his or her vehicle. This is a lesson for our transport planners designing the upcoming Light Rail Transit (LRT) systems radiating outwards from Colombo. The biggest challenge is convincing the private car user to ditch the car and get on board the LRT or even the bus.
A dynamic solution involving the promotion of cleaner fuel sources in the transport sector, increased investment in reliable public transit solutions, and the allocation of more urban land for green spaces and parks must be on the agenda of city planners the world over. Improved monitoring and tighter government regulations surrounding industrial and vehicle emissions must also come into effect. City fathers must get serious about tackling pollution, acknowledge the threat to public health and the local economy that pollution represents, and mobilize every arm of Local Government to implement strategies to improve air quality. There are many lessons we have to learn from New Delhi and Bangkok to keep our air within safe limits.