Saurabh Das/Associated PressCyclists and vehicles ride through New Delhi’s morning smog on January 3.Dr. Arunachalam Gunasekar is a 30-year veteran of the Indian armed forces, where he was a public health professional and director of medical research. He joined the World Health Organization in 2008, where he currently specializes in environmental health issues including air pollution and associated health problems.
He tracked air pollution levels in Delhi over several weeks this winter, and found them “phenomenally high,” sometimes five times the W.H.O.’s guidelines. India Ink, which has also been tracking Delhi’s air quality, spoke to Dr. Gunasekar about the causes and effects of Delhi’s air pollution and how to protect your health.
What are the best ways to protect yourself from wintertime’s increased air pollution?
If you’re inside a car, it is better to close your windows and run the air conditioner. Outdoor exercise is dangerous, because your intake of air increases exponentially and thus the amount of pollutants breathed in also increases.
It doesn’t matter if you are in a building; the pollution levels can be high, unless you seal yourself in by air conditioning. Air purifiers and filters should help, but only the very rich can afford to do that.
If you want to take a walk, the best time is the late afternoon, because it is the warmest time and the number of pollutants close to earth’s surface will be lower. One of the best ways to counter pollution is planting trees, which provide a surface for the pollutants to settle on; so walk in a park.
Who should be most careful of health risks from Delhi’s high pollution levels?
People with low immune systems, those suffering from other diseases, children, the very old, and people with lung diseases – these are the people who will suffer more and have an increased number of deaths.
There is no dependable database to track these disease and death rates in Delhi, so it is difficult to produce scientific evidence.
How does air pollution actually affect your health?
When diesel fuels burn, for example, they release nitrogen oxides and sulfur dioxides which accumulate as nitrates and sulphates on other suspended particles in the air, and are inhaled or ingested and cause irritation and damage different parts of the body. Carcinogenic substances like benzenes and benzpyrenes can get absorbed into the system and cause cancer. You’ll see increased deaths due to heart attacks because the increased clotting of blood.
Then, you have asthma with wheezing, and bronchitis which are somewhat less serious than cancers and heart attacks.
What are the main reasons for Delhi’s pollution?
The industries in Delhi are not the main culprits. The density of vehicles in the city is much higher than in other cities – the number of vehicles here is almost equal to the other top three metros combined. Also, a large number of people transit through Delhi from other states in cars and trucks.
Then, there is remarkable seasonal variation in northern India, because of phenomena known as “inversion” in winter months. Air pollution stays closest to the earth in winter months. It is similar to the London fog of 1948, where there were a few thousand deaths over a few days because of pollution.
What would be the most effective way to improve the quality of Delhi’s air?
Improve mass transit, so much so that people prefer to use it over their own vehicles. Today the Metro is very crowded, and bus service is not frequent enough.
Multi-sectoral action is required, but that is one of the most difficult things to do in many countries, including India.
Various ministries are supposed to play a role in tackling this problem, making it very difficult.
The Ministry of Environment and Forests is responsible for tracking and monitoring pollution; the Ministry of Health is supposed to give evidence of mortality; and based on that evidence the Ministry of Transport and Industry are responsible for taking action.
What should individuals do to try to reduce pollution?
Use public transport. Use L.P.G. (liquefied petroleum gas) in your home, rather than open fires. Plant more trees. Try carpooling.