NEW DELHI: Air quality in the city deteriorated to “hazardous” levels with the US embassy’s pollution monitoring station advising people to “avoid all physical activity outdoors”. Even the Delhi Pollution Control Committee (DPCC)’s real-time air quality monitoring system showed the 24-hour average count to be over 315 micrograms per cubic metre on Mandir Marg alone, which is about five times the national safe standard. Besides, a layer of smog shrouded the city the entire day.

What is worse, there are more such bleak days ahead. According to System of Air Quality Weather Forecasting and Research (SAFAR) under the ministry of earth sciences, pollution will increase at an alarming level in the next few days with a daily average of over 200 micrograms per cubic metre. The low temperature and calm air are causing “inversion” that can lead to pollution such as smog being trapped close to the ground.

Such poor air quality may trigger respiratory problems among people with low immunity, the elderly and the very young. Doctors fear poor air quality may be doing more damage than just triggering a few wheezing episodes. Constant exposure to bad air is making Delhiites vulnerable to arrhythmias and ischaemic heart disease. Arrhythmia is a disorder characterized by irregular heart beat or abnormal heart rhythm while ischaemic heart disease is associated with reduced blood supply to the heart.

Dr S K Chhabra, head of cardiorespiratory physiology department of VB Patel Chest Institute, says continuous exposure to high air pollution levels is like being exposed to second-hand smoke. Recently, he made a detailed presentation on this before pollution control agency officials from Saarc countries.

Chhabra quoted an AIIMS study which found higher number of complaints and instances of hospitalization due to chronic obstructive pulmonary disorder (COPD) and coronary issues apart from asthma and other respiratory conditions during high pollution days. He also said exposure to diesel emissions causes allergic responses.

“Fine particulate matter and gaseous pollutants are significant risk factors for acute stroke death. Women and the elderly are most susceptible to the effects of particulate air pollutants,” his presentation said.

Dr Ashwani Mehta, senior consultant cardiologist at Sir Ganga Ram Hospital also believes the rise in incidence of strokes and arrhythmias are linked to high air pollution levels. “The respiratory problems from bad air can affect the heart. Besides, air pollution can cause myocardial infarction or heart attacks. Unfortunately we don’t have much data in India that can directly relate air pollution with the incidence of heart attacks. But increasingly we are seeing young people having heart attacks. Women who you don’t expect to usually suffer heart attacks are increasingly reporting heart attacks. It’s a combination of issues but I think particulate matter is also to blame.”

Oncologists are seeing a 1% to 2% rise in lung cancer incidence each year but again there is no documentation of how much of lung cancer incidence is linked to air pollution. Dr Vinod Raina, director and HOD, oncology and haematology at Fortis Hospital, said there was a “slight increase in incidence of cancer among non-smokers. Otherwise, we need documentation to understand how much air pollution contributes to lung cancer.”

The Delhi government hasn’t started alerting people on poor air quality days yet. Usually governments in the West as well as in China issue alerts so that the vulnerable population can take necessary health precautions. The National Green Tribunal has recently ordered a ban on more than 15 year old vehicles and asked the government to consider hiking parking fee, imposing a congestion charge on vehicles and increasing the registration fee for two and four-wheelers in Delhi.