Explainer: Savar declared a 'Degraded Air Shed': What does it mean?

The government has declared Savar upazila in Dhaka district as a 'degraded air shed', prompting the Department of Environment to order the closure of all brick kilns in the area from September. 

Under the declaration, only tunnel kilns and hybrid hoffman kilns will be allowed to operate. The Department of Environment (DoE) has also prohibited the open burning of solid waste and restricted the approval of new industrial projects that may contribute to air pollution. The action plan is based on data from the DoE's Continuous Air Monitoring Stations (CAMS), which show that annual average concentrations of pollutants in Savar are nearly three times higher than the national standard.

A degraded air shed is an area where air quality has fallen below safe levels due to high concentrations of pollutants. According to Bangladesh's National Ambient Air Quality Standards, the safe annual limit for PM₂.₅ (fine particles) is 15 micrograms per cubic metre, and 50 micrograms per cubic metre for PM₁₀. For gases, the annual limits are 100 micrograms per cubic metre for nitrogen oxides (NOₓ) and 80 micrograms per cubic metre for sulphur dioxide (SO₂).

For carbon monoxide (CO), the maximum allowable concentration is 10 milligrams per cubic metre for one hour. The DoE's Continuous Air Monitoring Stations (CAMS) have recorded pollutant levels in Savar nearly three times above these national standards.

The designation of a 'degraded air shed' is made under Rule 5 of the Air Pollution (Control) Rules, 2022. Environment Adviser Syeda Rizwana Hasan said the step is intended to protect public health by reducing exposure to harmful pollutants, which can cause respiratory illnesses, cardiovascular problems, and other long-term health risks.

The government has taken similar steps before. In September 2024, the DoE announced that no new permits for brick kilns would be issued, and 3,491 kilns operating without environmental clearance were ordered to shut down. Kilns built illegally in hilly areas were also required to be relocated.

DoE officials say declaring degraded air sheds and enforcing restrictions on polluting industries is crucial for improving air quality in rapidly urbanising areas. Residents of Savar are expected to see immediate relief from smoke and dust, while the measures highlight the ongoing challenge of balancing industrial activity with environmental protection in Bangladesh.