The quality of Dhaka's air is getting worse yet again after having undergone a substantial deal of improvement for around two months during the Covid-induced shutdown countrywide.
The Air Quality Index says the capital city's air has become "very unhealthy" which was "good" two months ago. Dhaka's air quality began deteriorating in September.
Environmental experts have attributed the aggravation in air pollution in Dhaka to dry weather, resumption of development works and increased vehicular emissions.
Health experts have expressed concern that the degrading air quality may cause different respiratory issues among people and weaken their immune system, which may ultimately raise the Covid-19 mortality rate in the country.
"Air pollution is rising mainly because the dry season is coming in Bangladesh and development works have been restarted," said Golam Rabbi, programme associate of Environment and Social Development Organisation (Esdo).
At the same time, several ongoing development projects and the construction of high-rise buildings are producing a lot of dust which is polluting the air, he added.
Another major source of air pollution in Dhaka is vehicular emissions, Rabbi continued, referring to a World Health Organisation warning that if this trend continues, city dwellers will be more vulnerable to Covid-19.
In this context, Dr Be-Nazir Ahmed, former director of Communicable Disease Control (CDC) at the Directorate General of Health Services (DGHS), said polluted air can weaken respiratory and immune systems for which people might be vulnerable to coronavirus infection.
Dusty air also can cause other complexities like asthma, pneumonia, obstructive lung diseases, bronchitis and respiratory infections, he also said.
So, it is a matter of fear that if patients suffer from any of such diseases they may get infected with Covid-19. This might increase mortality from the virus, he added.
Air pollution alone claims thousands of lives each year in Bangladesh. The most common diseases, which air pollution is contributing to, are lung cancer, heart disease, stroke and both chronic and acute respiratory diseases, including asthma and child pneumonia, according to the World Health Organisation.
According to World Health Statistics 2018, the mortality rate related to air pollution in Bangladesh is 149 in every 100,000 people.
Meanwhile, a recent global study – State of Global Air 2020 – states that the number of deaths due to air pollution in Bangladesh is increasing alarmingly, with 173,500 having died in 2019 and 123,000 in 2018.
The study reveals a shocking picture of Bangladesh being 9th among the top 10 countries with the highest level of outdoor Ambient Particulate Matter (PM2.5) which is capable of entering the deep respiratory tract and causing severe health damage.
Around 74,000 deaths have occurred only for this particulate. Further, household air pollution from solid fuel accounted for 94,800 deaths. Moreover, the country was 4th among the top 10 countries with highest ozone exposure, as per the study.
In the South Asia region, Bangladesh saw the third highest number of deaths due to air pollution in 2019 with the entire region witnessing over 2.1 million deaths for the same reason.
According to the World Bank's Country Environmental Analysis 2018, urban environmental pollution is already imposing a significant cost on Bangladesh's economy.
The WB assessed the economic cost of 2015, which was estimated at $1.40 billion in all urban areas of Bangladesh, and at $310 million in Dhaka alone. This is equivalent to 0.7% and 0.2% of the country's 2015 gross domestic product (GDP) respectively.
Taking into account the broader welfare impacts of mortality, the economic impact is estimated at $6.52 billion in urban Bangladesh, which is $1.44 billion in Dhaka alone.
The government is working to reduce air pollution in Dhaka, said Ziaul Haque, director of the environment department.
"We have formulated an 'Air Cleaner Act', and work is underway for the law's approval," he also said, adding the act will help to curb vehicular emissions and unwise constructions.
Besides, a committee has also been formed, following High Court directives, with different departments, which has already formulated a guideline. The guideline specifies the responsibilities of different ministries and departments in curbing air pollution, he noted.