Air pollution is one of the deadliest environmental concerns for human beings. In 2019, it contributed to 6.7 million deaths worldwide. Worryingly, 20 percent of newborn deaths in the world have been due to air pollution. In the State of Global Air Report 2020, it is ranked fourth among global risk factors for mortality, after high blood pressure, tobacco consumption, and poor diet.

Victims of air pollution are mostly the poor as their exposure is higher than others'.

They live in large cities without basic amenities. Currently, nearly half of the world's population live in the cities—which is likely to rise to 70 percent by 2050. Bangladeshi cities are vulnerable to air pollution due to vehicular emissions, industrial pollution, and large-scale construction activities. Large cities such as Dhaka are particularly vulnerable to air pollution. Urbanisation is a natural process and a global phenomenon, but urbanisation in Dhaka is alarming. It is overcrowded—the densest city in the world in terms of population size. Like all megacities in the world, Dhaka attracts millions of people from all over the country for better economic opportunities. However, a large number of them end up working in the informal sector and living in poor conditions with limited facilities. Infrastructural development and other basic services fall far short of what the city's residents require. They also become victims of environmental pollution, which is more acute in this megacity—according to the Air Quality Index (AQI), Dhaka is one of the worst polluted cities in the world.

According to the State of Air Quality Report 2020, Bangladesh was ranked ninth among the top 10 countries with the highest population-weighted annual average PM2.5 exposures in 2019. PM2.5 indicates atmospheric particulate matters with a diameter of 2.5 micrometres or smaller. PM2.5 affects lung functions and can cause asthma and heart problems. Exposure to PM2.5 for a long period can increase chronic bronchitis and reduce lung functions. There is also PM10 (particulate matter with a diameter of 10 micrometres or smaller) in Dhaka's air, which is no less harmful. PM10 can enter the lungs through the throat and nose and can cause asthma, bronchitis, heart disease, and stroke. Both PM2.5 and PM10 can cause premature deaths as well.

The economic cost of air pollution is also very high. By increasing health costs and reducing people's ability to work, it affects the total economic output and GDP growth.

During the Covid-19 lockdowns in the last two years, there was some reduction in air pollution around the world. Closure of most physical economic activities, infrastructure construction, transportation, and educational institutions contributed to this change. However, as soon as world economies started opening up, pollution started to rise as well.

Appropriate policy measures and their effective implementation are necessary to address this challenge in a meaningful manner.

One way to control air pollution is to adopt the command-and-control approach, through which a government directly controls man-made pollution. In Bangladesh, this method has been adopted through various policies setting caps for pollution levels for the industries. For example, Bangladesh Environment Conservation Act, 1995 was an important move towards environmental protection as it established the Department of Environment (DoE), which is empowered to take action against a polluting entity. This law was followed up with the formulation of the Environmental Conservation Rules, 1997, which determines the emission level of pollutants according to the nature of the industries. Another important step was enacting the environment court laws in 2000 and 2010 to take measures for offences related to environmental pollution. The other relevant policies include the National Environmental Policy, 2018, and Brick Manufacturing and Brick Kiln Establishment (Control) Act, 2013 (amended in 2021). Some sections of the Road Transport Act, 2018 also stipulate controlling motor vehicle emissions.

While all these are positive initiatives, their implementation is quite challenging in a country like Bangladesh. It is not uncommon that certain pressure groups always try to influence the regulatory bodies and get away with the crimes of polluting beyond the level set by the DoE. That is why we still see unfit vehicles on the road, or brick kilns operating in full capacity across the country. At times, it becomes a source of rent seeking.

The other instrument to curb air pollution is economic incentives through various fiscal measures, such as emission tax and liability payment for pollution. This approach makes the polluting entities pay for their actions. Interest subsidies on loans for purchasing emission treatment plants is also a market incentive for pollution control. The government earning from emission taxes can be used for the social protection of the poor and other social development activities. Here, the implementation-related problems arise again. In Bangladesh, in many cases, there are difficulties in getting relevant and correct information to determine tax on a polluting industry. Particularly, information on the actual income or profit is not often reported. Therefore, the tax imposed on a polluter may be lower than the actual cost created through harming the environment.

Both methods are difficult to be applied properly in Bangladesh due to weak governance and lack of resources. Moreover, how these will impact the poor and low-income groups should also be taken into consideration. Strict implementation of the environmental policies may reduce livelihood opportunities of the poor, who rely on nature to make a living. Therefore, while implementing environmental measures, fiscal policies must be crafted to provide social protection to the poor.

Dr Fahmida Khatun is executive director at the Centre for Policy Dialogue (CPD). Views expressed in this article are the author's own.