Chandigarh: Doctors differ on drawing parallel between poor AQI, smoking

The Air Quality Index (AQI) of the City Beautiful, which touched 425 last Thursday, worst ever for the city and higher than New Delhi (423), moderated to “poor” (203) today. Fresh memes on AQI have flooded the social media with one of them suggesting “smoking in Bangalore is healthier than doing yoga in Delhi’.

Prof Ashutosh N Aggarwal, Head, Department of Pulmonary Medicine, PGI, said, “There is no simple formula to draw an equivalence between air quality and smoking tobacco. However, full day exposure to an AQI greater than 400 (categorised as ‘severe’) with PM2.5 (particulate matter) concentrations of >250 µg/m3 might roughly have the same health hazards as smoking >10 cigarettes that whole day.”

Dr Ravindra Khaiwal, Professor of Environmental Health, Department of Community Medicine and School of Public Health, PGI, termed equating AQI with smoking tobacco as misleading. He said, “Many online platforms and media outlets compare AQI to cigarette smoking. However, this comparison should be based on PM2.5 levels, not AQI. A PM2.5 concentration of 22.5 µg/m³ is roughly equivalent to smoking one cigarette. That said, it is incorrect to compare air pollutants with cigarette smoking because it can create a false perception that smoking is less harmful. Smoking a single cigarette exposes a person to over 70 known harmful chemicals/carcinogens at once. While raising awareness about the dangers of high levels of air pollution, using AQI and PM2.5 calculators is important, equating it with smoking risks normalising tobacco use can be counterproductive.”

Not all doctors hold the same opinion. Contrary to the PGI doctors, Dr Robin Gupta, consultant pulmonology, Paras Health, Panchkula, confirmed that exposure to “poor” air quality is akin to smoking cigarettes, posing significant risks to lung health. He said, “The AQI levels above 100 can cause irreversible damage. AQI between 101 and 200 is comparable to smoking 4-10 cigarettes per day. It goes up to 10-20 cigarettes per day for 201-300 level and around 20 cigarettes per day for 300 level.” Common harmful pollutants in AQI >100 are particulate matter (PM), nitrogen dioxide (NO2), ozone (O3) and carbon monoxide (CO).

Effects of ‘poor’ AQI

• Inflammation and oxidative stress
• Reduced lung function and capacity
• Increased risk of respiratory diseases
• Increases risk of cardiovascular ailment and stroke
• Premature mortality

Comparative risks

• AQI 201-300: Smoking 10-20 cigarettes/day
• AQI 301-400: Smoking 20-30 cigarettes/day
• AQI 401-500: Smoking 30-40 cigarettes/day

(As told by Dr Robin Gupta from Paras Health, Panchkula)