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Copenhagen Consensus Center

Bangladesh Priorities: Outdoor Air Pollution, Larsen

The research examined a simple retrofitting into “improved zigzag” kilns, all the way to the top-of-the-line new hybrid Hoffman kilns. Hybrid Hoffman kilns promise large overall benefits, but the technology requires great investment—Tk 160 million. Upgrading an existing fixed-chimney kiln into an improved zigzag kiln, on the other hand, is 40 times cheaper.


Strategy Takas of benefits per taka spent
Retrofit kilns 8
New hybrid kilns 3

This retrofit turns out to be the most promising strategy, which does about 8 takas of good for every taka spent. If such zigzag kilns were adopted across Dhaka, it would cut air pollution from kilns by 40 percent, saving more than 800 lives per year. This would cost about Tk 408 million annually over the operating life of the kilns. But the benefits would be immense. Annual health benefits alone would equal Tk 1.7 billion. The reduction in carbon emissions would be bring Tk 80 million in benefits. Moreover, the private kiln operators would get a number of benefits, like higher quality bricks and lower energy consumption. In total, the benefits to investors and owners will add another Tk 1.4 billion.

To achieve even greater environmental and financial benefits, kiln conversions and retrofits would eventually have to reach better technical and operational standards. Hybrid Hoffman kilns have the potential to yield health benefits worth Tk 2.5 billion per year across Dhaka. But the cost would be quite high, at Tk 3.3 billion annually. Each taka spent toward this end would do a little more than 3 takas of good, which is respectable, but not nearly as great as the 8 takas of good that retrofitting to improved zigzag kilns gives.

Spending to retrofit dirty and inefficient kilns into cleaner zigzag ones can do about 8 takas of good for every taka spent and help control the deadly outdoor air pollution in Bangladesh’s capital.