The haze of smog over northern India is insidiously eating into our health. It can lead to not only respiratory diseases but increase the risk of heart attacks and strokes, cause spikes in blood pressure and developmental delays in children. At least 1.67 million deaths in 2019 — making up nearly 17.8 per cent of all deaths in the country that year — were attributable to air pollution, according to a study published in Lancet Planetary Health in 2021.
In fact, between 1990 and 2019, deaths attributable to indoor pollution (caused mainly when cooking with solid fuels like cow dung) went down 64.2 per cent but deaths attributable to outdoor air pollution went up by 115.3 per cent. Air pollution is now affecting every organ of the human body.
An anti-smog gun in action in Delhi. (Express photo by Praveen Khanna)
Respiratory diseases: When pollution levels rise, not only do doctors see a spike in their patients with respiratory diseases coming in with worsening symptoms, they also see healthy people coming in with cough, wheezing, and breathlessness.
A 2019-study found that the number of people seeking emergency care with respiratory symptoms went up by 40 per cent at the All India Institute of Medical Sciences (AIIMS), Delhi whenever pollution levels peaked in the city. Another study from AIIMS found that exposure to nitrogen dioxide (NO2), even for a short duration, between zero and seven days, increased the emergency room visits by 53 per cent.
In the long run, this can lead to respiratory conditions like Chronic Obstructive Pulmonary Disease (COPD), with a 2018 Lancet study saying that more than half the COPD in India is attributable to air pollution. Smoking is the most common cause of COPD in developed countries. Long-term exposure to high levels of air pollutants has been linked to lung cancers, even among non-smokers.
Even though there is limited evidence on the effectiveness of air purifiers, with pollution levels shooting off the chart, doctors recommend that it be used, especially for those over the age of 80, who are already likely to have other comorbid conditions such as heart disease. It may also be used by those who have existing respiratory illnesses.
Heart attacks and strokes: Exposure to high levels of pollution is known to increase the risk of heart attacks, strokes and abnormal heart rhythms. As Dr Rakesh Yadav, cardiology professor at AIIMS, says, “Heart attacks go up during colder months with blood vessels getting constricted. Living in polluted cities like Delhi, the risk of heart attacks and strokes goes up over the years.”
Dr Yadav had conducted an analysis of the impact of pollution on heart health in 2021. Every 10 µg/m3 (there are 10 micrograms of a chemical in every cubic meter of air) increase in the levels of PM2.5 was associated with a 2.5 per cent increase in the risk of heart attacks the very same day. And an annual increase of 10 µg/m3 of PM10 and 5 µg/m3 of PM2.5 was associated with an increased risk of 12 per cent and 13 per cent respectively. “Chronic air pollution was linked to plaque formation in the heart, which increases the risk of heart attacks. It was linked to high blood pressure, which could impact heart health,” says Dr Yadav. Smoking in these conditions is known to increase the risk of heart attack by at least 1.8 fold.
Autoimmune diseases: Pollutants flare up existing autoimmune conditions as well as increase the risk of developing autoimmune conditions. “The particulate matter is known to irritate respiratory cells, leading to inflammation first in the respiratory tract but then elsewhere in the body. This produces auto-antibodies that lead to a flare-up of existing autoimmune conditions,” says Dr Uma Kumar, head of the department of rheumatology at AIIMS.
Chronic exposure to air pollution, however, can lead to constant low-grade inflammation even in healthy people, thereby increasing their risk of developing an autoimmune condition. “A study we did found that 18 per cent of apparently healthy people, who have been living in Delhi for over 10 years, had elevated inflammation markers. A very high proportion also had oxidative stress (too many free radicals and few antioxidants to counter them),” she says.
Data from the Delhi transport department shows around 1,800 vehicles are added to the Capital’s roads in a day.
Other effects in the body: There is a palpable impact on brain health. Over the short-term, you may experience headaches, anxiety bouts and mood changes. Over the long-term, there could be an increased risk of stroke and possible lower IQ in children.
The eyes bear the brunt of pollution. In the short term, you may complain of irritation, watering, dry eyes, even conjunctivitis. Long term, it can increase the risk of glaucoma.
Pregnancy: Pollution increases the risk of still-birth, pre-term birth or low birth weight. It has been linked to development delays in children, including higher stunting and wasting.
How can you protect yourself?
1) Stay indoors as much as possible
2) Avoid early morning or late evening walks and exercise
2) Avoid lighting open fires and angeethis, not burn waste, not blast fire crackers, not use incense sticks, mosquito coils or tobacco products.
3) Use wet mops to clean the house.
4) Gargle with warm water and wash eyes with water if irritated.
5) Use properly fitted N-95 or N-99 masks and air purifiers. Air conditioners in buildings and vehicles should be set to the recirculate mode to minimise outside air from entering.
