City wakes up to world’s third-worst air quality

Karachi ranked third on the United States Air Quality Index on Friday morning, grouped among the world's most polluted cities.

With an AQI of 281, Karachi was preceded only by Delhi and Lahore - ranking second with 359 AQI and first with 489 AQI, respectively - as the cities with the worst air quality in the world. Global scales typically rank good air quality between a 0-50 AQI. An AQI over a 100 is termed dangerous for the more vulnerable groups while an AQI past 150 is typically deemed unhealthy and an AQI above 300 is dubbed hazardous.

Poor air quality can have detrimental effects on public health and air pollution has been deemed the greatest environmental health risk currently by the World Health Organisation. Typically described as a 'silent killer' given that it is among the top most contributing causes of early death, air pollution can lead to lung tissue damage, cancer, early death and respiratory illnesses such as asthma, bronchitis and emphysema.

In the short term, it can cause difficulty breathing, chest pain, wheezing, coughing, general respiratory discomfort and irritation of the eyes, nose and throat. Of late, doctors and researchers across the world have also pointed towards a correlation between air pollution and deaths in patients whose lungs are weakened by Covid-19. Jawad Memon, of a private weather station, told The Express Tribune on Friday that the air pollution in the port city is likely to increase due to smog and low humidity.

The direction of wind in the city is changing due to Western disturbances entering the country and air pollution will likely decrease after November 16 when rainfall is expected in the city under this Western system, he said, advising citizens to wear masks. In 2019, Pakistan ranked as the country with the world's second worst air quality with an average AQI of 156. Bangladesh with an average AQI of 165 ranked first and India ranked fifth with an average AQI of 152 in 2019, according to IQAir, a Swiss air quality technology company that also monitors the AQI in major cities of the world.

Mumbai in India ranked as fourth most polluted city in the world on Friday morning with an AQI of 182, followed by Kabul, Afghanistan with an AQI of 175 and Bosnian city Sarajevo sixth with an AQI of 162.