Dhaka's air quality continued to be in the ‘moderate’ zone on Thursday as cyclone ‘Asani’ weakened into a depression, triggering showers. With an air quality index (AQI) score of 87 at 10am, the city ranked 17th in the list of world cities with the worst air quality. Also read: Dhaka's air quality turns 'moderate' Pakistan’s Lahore, Chile’s Santiago and Saudi Arabia’s Riyadh occupied the first three spots in the list, with AQI scores of 185, 162 and 154, respectively. An AQI between 101 and 200 is considered 'unhealthy', particularly for sensitive groups. Similarly, an AQI between 201 and 300 is said to be 'poor', while a reading of 301 to 400 is considered 'hazardous', posing serious health risks to residents. AQI, an index for reporting daily air quality, is used by government agencies to inform people how clean or polluted the air of a certain city is, and what associated health effects might be a concern for them. In Bangladesh, the AQI is based on five criteria pollutants -- Particulate Matter (PM10 and PM2.5), NO2, CO, SO2 and Ozone. Dhaka has long been grappling with air pollution issues. Its air quality usually turns unhealthy in winter and improves during the monsoon. A report by the Department of Environment (DoE) and the World Bank in March 2019 pointed out that the three main sources of air pollution in Dhaka "are brick kilns, fumes from vehicles and dust from construction sites". Also read:Dhaka’s air quality improves With the advent of winter, the city’s air quality starts deteriorating sharply due to the massive discharge of pollutant particles from construction work, rundown roads, brick kilns and other sources. Air pollution consistently ranks among the top risk factors for death and disability worldwide. Breathing polluted air has long been recognised as increasing a person’s chances of developing a heart disease, chronic respiratory diseases, lung infections and cancer, according to several studies. As per the World Health Organization (WHO), air pollution kills an estimated seven million people worldwide every year, largely as a result of increased mortality from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.

All necessary preparations have been taken in five coastal districts to face any possible situation that might arise due to cyclonic storm ‘Asani’. Barishal divisional administration has kept 4,915 shelter centres ready even though the Bangladesh Meteorological Department predicted that the cyclone is unlikely to hit the country's coastline.  Of these, 1,071 shelters have been prepared in Barishal district, 925 in Patuakhali, 1104 in Bhola, 712 in Pirojpur, 629 in Barguna and 474 in Jhalakathi. Two million people along with their livestock can take shelter at these centers. Besides, the Divisional Commissioner's Office has instructed the concerned officials to provide clean water, dry food and electricity in the shelters. CPP (Cyclone Preparedness Programme) volunteers have also been prepared, said a source at district administration. The Upazila Nirbahi Officers (UNOs) and various government and non-government organizations have already been instructed to remain alert. Amin-ul-Ahsan, Barishal Divisional Commissioner, said adequate preparations have been taken to face the possible cyclone. UNB Patuakhali correspondent reports: The coastal areas of Patuakhali district have been experiencing rainfall since Sunday morning, due to the impact of severe Cyclonic storm ‘Asani’ that is brewing over the Bay. The local Met office recorded 41.6 mm of rainfall activities around 6 pm on Monday. The local Department of Agriculture Extension (DAE) office asked the farmers to harvest their paddy as soon as possible to mitigate damage. Also read: Cyclone ‘Asani’ over Bay: Heavy rainfall likely in 3 divisions Rahat Hossain, an observer of Patuakhali Weather Office, said “Light to moderate rains are likely to continue for two more days in the district. The southern part of the country including Patuakhali is likely to be safe but it will likely make landfall in Odisha in India." Deputy Commissioner Mohammad Kamal Hossain, said “We will sit in a meeting after getting No 4 signal but we still are observing the situation.” Maritime ports of Chattogram, Cox’s Bazar, Mongla and Payra have been advised to hoist distant warning signal No 2. UNB Bhola correspondent reports, the local administration has kept 691 shelters ready to tackle the cyclone ‘Asani’. The local Met Office recorded 4.5 mm of rainfall from Monday morning until Monday noon. The authorities concerned have alerted the fishermen and residents of the coastal areas through loudspeakers. Meanwhile a sense of panic has been prevailing in the area. Deputy Commissioner of Bhola district said all out preparation has been taken and 13,600 volunteers of Red Crescent are ready to face any situation. Around noon on Monday, it was centered about 1105 Kms Southwest of Chattogram port,  1045 kms Southwest of Cox’s Bazar port, 1015 kms South-Southwest of Mongla port and 1000 kms South-Southwest  of Payra port, said a Met Office bulletin. It is likely to move in a northwesterly direction, it said.  State Minister for Disaster Management and Relief Dr Md Enamur Rahman on Sunday said there is no possibility of Cyclone Asani hitting Bangladesh coast. He said the cyclone is moving northwestwards and it will weaken while passing Odisha, Visakhapatnam, Bhubaneswar and West Bengal in India on May 12 and will turn into a low, he told reporters at his Secretariat office. The cyclone might cause storms and rains in Bangladesh but there will be no tidal surge, he added.