Causes and Consequences of Indoor Air Pollution: An Experimental Investigation in Bangladesh


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Principal Investigator
  • Henry J. Kaiser, Jr. Professor
  • Professor, Health Policy
  • Senior Fellow, FSI
  • Senior Fellow, SIEPR
  • Professor, Economics (by courtesy)
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Senior Fellow
  • Professor, Pediatrics
  • Senior Fellow, FSI
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Lynn Hildemann, PhD
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Ahmed Mushfiq Mobarak, PhD
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Imran Matin, PhD
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Nasima Akter, PhD

Project background:

The leading killer of children worldwide in 2004 was acute respiratory infections, accounting for 22 percent of all communicable child deaths. Epidemiological studies identify indoor air pollution as a key culprit, and have reported powerful associations between exposure to indoor air pollution and symptoms of acute respiratory infections. The burning of biomass fuel sources (such as brush or dung) within the household is thought to be the main contributor to indoor air pollution, so women who cook and their children are particularly affected. Despite these significant health hazards, half of the world's population and more than 75 percent of South Asians continue to rely on dung, brush and wood as their primary energy source for cooking and heating.

There are several important weaknesses in the current scientific knowledge about indoor air pollution. First, nearly all existing evidence on the health consequences of such pollution is based on observational studies, making it difficult to establish true causal relationships. Second, the broader socio-economic consequences of biomass combustion and indoor air pollution are not well understood. Third, no study has explicitly asked the question: Why do so many rural households continue to use inferior cooking practices with potentially devastating health consequences? Simple explanations based on financial costs seem insufficient given the enormous harm that indoor air pollution is believed to cause. Answering this question is critical to designing large-scale interventions and policies that will effectively combat indoor air pollution.

Project goals:

This research project has four goals: (1) To understand why people in developing countries continue to use cooking practices harmful to human health, when improved stoves and fuel appear to be readily available, (2) To estimate the causal impact of indoor air pollution on symptoms of respiratory disease, (3) To establish a lasting partnership between Stanford and a leading research-oriented NGO in Bangladesh -- the Bangladesh Rural Advancement Committee, or BRAC, and (4) To provide opportunities for Stanford students to develop and conduct scholarly projects in Bangladesh.

Project activities and intervention:

In the first phase of this project, completed in March 2006, Grant Miller, Mushfiq Mobarak and collaborators at BRAC held individual and group meetings in Bangladesh with local physicians, public health specialists, environmental scientists, demographers and economists who have conducted field research throughout the country. The research team then conducted focus-group sessions with scores of women in rural field sites, asking them open-ended questions aimed at understanding their practices, attitudes and preferences related to cooking practices and fuel sources. These focus groups were coupled with home visits to better understand the nuances of rural cooking practices.

In the second phase of the project (currently underway), BRAC fieldworkers under Miller's direction are conducting a door-to-door pilot survey seeking information on the above-mentioned issues, and they are offering households new, cleaner cooking stoves under a variety of experimental conditions, with a target of signing up 500 participants.

After completing these two phases in the spring of 2006, the full-scale project will begin in the summer. Researchers will conduct a full-scale field experiment, offering various financial and behavioral incentives to some 3,000 households to use a modified, cleaner version of the traditional cooking stove. Researchers will examine the extent to which these incentives influence participants to switch to cleaner cooking stoves and fuels. They will also track the various experimental groups and the control group, for two or more years, to determine how many people in each group develop acute respiratory infections.

Building permanent relationships in Bangladesh:

A leading objective of this project is to establish a lasting relationship with BRAC which will foster further collaboration across Stanford's schools and departments and provide previously unavailable training and research opportunities for Stanford's students in economics, medicine, environmental science and engineering. BRAC is one of the largest development NGOs in the world, with a long history of conducting community programs and research projects in health, education, and economic and social development.