Break Dhaka's Winter PM2.5 Spike at Source: A Dry-Season Emissions Lockdown

Diagnosis

Dhaka suffers an annual winter PM2.5 spike that has placed the city at world #1 for air pollution across multiple years (per the curated problem note). This is not a freak event. It is a predictable seasonal pattern: every dry season, the same combination of dust, combustion, and stagnant air recurs. The damage lands on the same population each time, with the heaviest burden on children, the elderly, outdoor workers, and people with respiratory conditions. Because the spike is seasonal and recurring, it is also forecastable and therefore preventable through advance source control rather than emergency reaction. The policy failure to date is that enforcement is reactive and year-round-diffuse, while the emissions are concentrated in a predictable window. The lead body, the Department of Environment (DoE), already holds the mandate; what is missing is a pre-committed, calendar-bound operating regime that activates before the air degrades, not after.

Recommended actions

1. Pre-season dry-weather emissions lockdown (DoE). DoE should issue an annual gazette circular, dated to take effect before the onset of the dry season, that suspends or tightly restricts the highest-emitting activities during the spike window: non-compliant brick kiln firing, open roadside and waste burning, and uncovered demolition. Mechanism: a standing seasonal directive under DoE's environmental enforcement authority, renewed each year on a fixed calendar trigger. Observable signal that it is working: kiln firing permits suspended on schedule and a measurable drop in open-burning enforcement violations during the window versus prior dry seasons.
2. Brick kiln conversion and seasonal shutdown enforcement (DoE). Brick kilns are a structural winter source. DoE should pair the seasonal directive with a phased mandate moving kilns to cleaner firing technology, backed by inspection drives during the firing season and revocation of operating clearance for kilns that fire without compliant technology. Mechanism: DoE clearance and licensing power plus targeted seasonal inspection teams. Observable signal: share of operating kilns holding compliant-technology clearance rises year over year, and non-compliant kilns are visibly idle during the window.
3. Construction and road dust suppression order (DoE with city authorities). Issue a binding dust-control standard for construction sites and exposed roadways during the spike window: mandatory site enclosure, covered material transport, and water spraying on dust-prone corridors. Mechanism: a DoE dust-control compliance order, enforced jointly with municipal authorities, with stop-work powers for repeat violators. Observable signal: documented enclosure and spraying compliance on inspected major sites, and a fall in dust-related complaints during the window.
4. Greenbelt and dust-buffer planting (Forest Department, supporting DoE). Mobilize the Forest Department, named as the supporting body, to expand and maintain green buffers along the most dust-exposed corridors and at the urban edge to trap particulates over successive seasons. Mechanism: a Forest Department planting and maintenance programme with survival-rate accountability, coordinated with DoE's source map. Observable signal: planted and surviving buffer coverage along priority corridors increases season over season.
5. Seasonal public health alert and advance public notice (DoE). DoE should publish a standing, plain-language seasonal air-quality alert protocol so the public, schools, and workplaces receive advance warning before each spike window opens, with guidance on outdoor exposure. Mechanism: a DoE-issued seasonal alert protocol distributed through public channels. Observable signal: alerts issued on schedule before the window each year, with confirmed reach to schools and health facilities.

Sequencing (first 12 months)

First, DoE drafts and gazettes the seasonal lockdown circular and the dust-control order, because the legal instrument unlocks every enforcement action that follows. Second, with the directive in force, DoE stands up the seasonal inspection teams for kilns, construction sites, and open burning. Third, DoE publishes the public alert protocol so the demand side and the enforcement side activate together. In parallel, the Forest Department begins buffer planting timed to the planting calendar so the slowest-maturing intervention starts earliest. By the end of the first dry season under the regime, DoE has a baseline of enforcement actions and compliance rates to tighten the directive the following year.

Risks and constraints

The binding constraints are political and institutional, not technical. Brick kilns and construction are economically entrenched, so seasonal shutdowns face strong pushback and risk being quietly waived. DoE's enforcement capacity is limited relative to the number of dispersed sources, so a paper directive without funded inspection teams will not bite. Jurisdiction is split: DoE leads, but dust control and street-level enforcement depend on city authorities, creating coordination gaps. The Forest Department buffer work is slow to mature and vulnerable to low seedling survival without maintenance funding. Each of these is a reason to pre-commit the regime on a fixed calendar with named owners, rather than relying on discretionary in-season response.

Bottom line

Dhaka's winter PM2.5 spike is predictable, recurring, and source-driven, which makes it controllable through a pre-committed, calendar-triggered DoE enforcement regime aimed at kilns, dust, and burning. The decision now is to convert reactive scramble into a standing seasonal lockdown with named owners and observable compliance signals, so the city stops re-earning world #1 every dry season.