Air pollution is a major health crisis in South Asia, causing around 2 million deaths annually. Despite strict environmental laws, poor enforcement worsens the issue.

A study in Dhaka, Bangladesh, examines the adoption, effectiveness, and impact of air purifiers. Initial findings show purifiers reduce indoor pollution by 27%, though levels remain above WHO safety limits. Researchers will assess their effects on health, sleep, work performance, and income.

Few households own purifiers, likely due to low awareness. Even when given for free, usage is inconsistent, suggesting barriers like misinformation or low health priority. The study will test if information, pollution monitors, or covering electricity costs increase usage. It will also explore whether using purifiers reduces public demand for stronger pollution regulations.

Study Plan:

During the mini-baseline, 500 households were randomly selected to receive an air monitor. This random selection was done in the backend by the enumerator using a coinflip plugin in SurveyCTO.

For the baseline, 350 households were chosen to receive an air purifier using a slot machine plugin. When the enumerator or respondent taps the slot machine, it spins and randomly picks a value.

• If the value is 0, the respondent gets the air purifier for free.
• If the value is greater than 0, the respondent must pay that amount to get the air purifier.

Mini Baseline

The study begins with a short survey of 1,000 households. Out of these, 500 are randomly given an air monitor along with a chart explaining air pollution levels and related health risks, such as heart disease, stroke, and lung cancer. These households receive BDT 15 (USD 0.14) per day if their monitor sends data for at least 16 hours. The other 500 households receive similar payments to keep income levels balanced.

Baseline

Among the 500 households with monitors, 250 are further selected to receive an extra BDT 30 (USD 0.28) per week for correctly reporting their air quality and associated health risks. The rest receive a matching payment to maintain fairness.

A month later, all households are revisited for a detailed survey to understand their beliefs about air pollution and their willingness to pay for air purifiers. To ensure enough households receive purifiers for study purposes, 350 families get a purifier for free through a random selection process.

Endline

After receiving purifiers, these households are split into three groups. Two groups (100 households each) receive compensation for the electricity used by their purifiers, while the third group (150 households) receives no compensation. One treatment group gets daily payments for electricity costs, while the other receives monthly payments. The first payment is made after a week to build trust. The goal is to understand how financial incentives and information influence purifier use and whether they impact health, beliefs, and long-term air pollution solutions.

Findings

• Examines whether providing households with air monitors and incentives increases awareness of air pollution and willingness to buy air purifiers.
• Analyzes how costs, air monitors, and incentives influence air purifier usage and indoor air quality improvements.
• Evaluates the impact of air purifiers on health by tracking sick days, doctor visits, medical expenses, blood pressure, and lung capacity.
• Assesses whether better air quality enhances sleep and cognitive function.
• Investigates whether air purifier usage leads to higher productivity, increased work hours, and higher earnings.
• Explores whether access to air purifiers and monitors encourages greater support for broader air pollution control measures.

What's Next?

We reached out to the National Policy Development Committee (NPDC) with our policy suggestions. As a result, the government took action by starting a public awareness campaign. They are now sending mobile phone messages to inform and alert people about the issue. This effort helps raise awareness and encourages people to take necessary steps. We have also noticed that, as a result of our policy, the government has taken action by reducing the tax on importing air purifiers. This has made the price more affordable, allowing more people to buy them easily.

Engagement:

• Research Paper: Adoption, Use, and Effects of Air Purifiers in Households.
• Article: Dual Misbeliefs and Technology Adoption: Evidence from Air Purifiers in Bangladesh, explores why people hesitate to use air purifiers.
• Seminar: FASS Brown Bag Seminar: Why Don't Households in Severely Polluted Cities Adopt and Use Air Purifiers?, presented by Dr. Martin Mattson.
• Op-Ed: Breathing Easier: Making Clean Air Affordable for Everyone, discusses how to make air purifiers more accessible.