Reducing air pollution in Bangladesh

Sustainability Problem

  • Nearly 70% of people in cities are exposed to air pollution exceeding recommended levels; WHO counts 15 of the 20 most polluted cities in India and Asia.
  • The World Health Organization (WHO) estimates that 7 million premature deaths are linked to air pollution.

Summary of “How better technology can make city air cleaner—and help save lives” by Dr. Bjorn Lomborg

  • Dhaka in Bangladesh has air pollution rates 13-16 times higher than the international quality standard during the dry season, making it one of the most polluted cities in the world. Air pollution prematurely kills approximately 14,000 people from Dhaka ever year.
  • The primary driver of air pollution is the city’s brick industry, which creates 4 billion bricks per year for construction.
  • The widespread use of fixed-chimney kilns, which are energy inefficient, highly polluting and are run on poor-quality coal, is exacerbating the air pollution issue.
  • Hybrid Hoffman kilns are very efficient, but prohibitively expensive to adopt. However a simple retrofit of existing fixed-chimney kilns is 40 times cheaper with similar benefits.
  • The retrofit creates a more efficient kiln by distributing the heat in a zigzag pattern. This not only improves the quality of the bricks, but reduces fuel usage by one-fifth, reduces waste, and simultaneously reduces air pollution by 40%.
  • More of the bricks produced in the “zigzag” kiln are of better quality and command a higher price in the market. This, combined with reduced energy costs, makes conversion attractive to kiln owners.


  • Health Services
  • The environment
  • The citizens of Dhaka
  • Kiln operators
  • Construction industry


  • It takes 3 months to retrofit a fixed-chimney kiln into a zigzag kiln and costs 4 million takas per kiln ($50K USD).
  • Kiln operators can realize their investment in less than 4 years. Spending money on outdoor air pollution through kiln improvements does 8 takas of good for every taka spent.



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