The air quality in Dhaka is better than any other time in the past four years, according to data released by both public and private organisations.
Compared to the city's air quality in April last year, the amount of pollutants in the air is at least 12 per cent less this year, as per Prothom Alo's analysis of data derived from an international organisation that monitors global air quality, Air Visual.
According to the Department of Environment’s air quality monitoring centre, in April Dhaka’s air quality was 30 per cent better than the previous year.
The air in Dhaka is 20 per cent better for the past 46 days than the same period last year, according to a study conducted by Stamford University Bangladesh. Many assume that the air quality improved due to the restriction on vehicles and construction work during the shutdown for coronavirus.
However, compared to other cities with higher air pollution in the world, Dhaka’s improvement is quite low. Cities like Delhi and Kolkata in India, Karachi in Pakistan, Kabul in Afghanistan made their way out of the list of top 10 cities with air pollution.
Meanwhile, Dhaka ranked between 1 and 5 in the list till Saturday night. Dhaka possessed the second place in the index by 7:00pm in the evening. Jakarta, Indonesia was in the first position while Hanoi of Vietnam stood third.
Director of the Air Quality Management under the Department of Environment, Ziaul Haque told Prothom Alo, as the two main sources of air pollution in the capital, transports and construction works, are halted right now, Dhaka’s air quality improved significantly.
“However, another key source of pollution are brick kilns. Almost 80 per cent of them are still operating, which is why the improvement is less than expected,” he added.
Department of Environment monitors air quality in 11 major cities of the country including Dhaka. Since 15 March, the organisation is not releasing air quality data of any other cities except the capital.
The government department updates the air quality information of Dhaka every two to three days. The organisation compared PM-10 and PM-2.5 fine particles in the air between March and April. It found that the amount of PM-10 in April decreased from 162 to 145 and the amount of PM 2.5 decreased from 68 to 45 micrograms compared to March.
According to the Department of the Environment, pollutants in air decreased as the main sources are now closed. The vehicles are moving much less than before. Construction is also closed in most parts of the city. In particular, the construction of large infrastructures such as Metrorail and Elevated Expressway has been halted which are the key reason of dusts in the city.
Abdus Salam, a professor at Dhaka University and an air quality expert, told Prothom Alo, “The government should take steps to maintain the improvement in air quality during lockdown.”
“For that, government should ease the lockdown slowly and can plan to keep different area closed for a day in every month in future to keep up the improvements in the air quality,” he added.
According to Stamford University’s Center for Atmospheric Pollution Studies, the number of days when Dhaka had very unhealthy air was 5 between 25 March and 9 May in 2019. During the same period this year it has been reduced to two days. Unhealthy ‘air quality’ days have been reduced from 16 to 10 days. On the other hand, the number of days of medium quality air, or good air, was 2 days last year, this year it has increased to 12 days.
Professor Kamruzzaman Majumder of the university said, “ We have to evaluate the time more deeply. We can also identify which sources of air pollution in Dhaka can be reduced during this time so that plans can be made to improve the air quality in Dhaka in the future.”
*This report, which originally appeared in Prothom Alo's print edition, has been rewritten in English by Farjana Liakat