A new study at the Jahangirnagar University (JU) reveals that indoor air in Dhaka is significantly more polluted than outdoor air.
Research on the indoor air quality of 43 homes found an average pollution level of 75.69 µg/m³-nearly five times higher than the WHO guidelines.
In some homes, pollution levels exceeded 200 µg/m³, posing severe health risks.
Dhaka's indoor air quality is extremely concerning compared to many global cities.
Conducted under the leadership of Dr Md Shakhaoat Hossain, associate professor at Jahangirnagar University’s Public Health and Informatics Department and Head of the Air Quality, Climate Change, and Health (ACH) Lab, the study titled “Characterizing Indoor Air Quality and Identifying Factors Influencing Air Quality at Home Microenvironment in Dhaka City” was published in the renowned Indoor Environments journal.
The data for the study was collected using the "convenient sampling" method.
The study identifies outdoor air intrusion as the primary cause of indoor pollution, contributing to 40% of the problem.
Polluted air enters through windows or gaps, impacting indoor quality.
Prolonged cooking is the second major contributor, significantly increasing PM2.5 levels, especially during cooking sessions lasting over 1.5 hours.
Regular cleaning and better ventilation systems help reduce indoor pollution.
Homes larger than 1,200 sq ft were found to have higher pollution levels.
The health risks include respiratory issues, heart disease, lung cancer, low birth weight, developmental problems, mental health decline, and premature death.
Vulnerable groups, such as children, the elderly, and those with pre-existing health conditions, are at the highest risk.
Research team member Afsana Yasmin said: “We have identified the sources. Keeping windows closed or using air conditioning during high outdoor pollution and ensuring proper kitchen ventilation during cooking can reduce pollution. Regular cleaning also plays a crucial role.”
The study highlighted that women, children, and individuals with existing health issues are the most affected, as they spend most of their time indoors.
It emphasized the need for immediate action to combat indoor air pollution, which could otherwise become a silent killer.
Improving window sealing and ventilation systems can effectively enhance indoor air quality.
Using eco-friendly, advanced stoves during cooking is especially vital for women’s health.
Policymakers must act swiftly and implement sustainable solutions.
Dr Hossain noted: “People spend 60-65% of their day indoors. A significant portion of daily air pollution exposure comes from indoor air. While we are often aware of outdoor pollution, we neglect indoor pollution. Identifying and controlling pollution sources is essential.”
He added that outdoor air intrusion significantly increases health risks for those indoors but can be controlled with proper measures.
A 2021 study in the Building and Environment Journal found that keeping windows closed could block up to 68% of PM2.5 intrusion.
He also recommended using air purifiers with HEPA filters to tackle indoor pollution.
Bangladesh remains one of the most polluted countries globally, with Dhaka ranking among the world’s most polluted cities.
According to the State of Global Air report (2019), indoor air pollution is the fourth leading cause of death in Bangladesh, claiming over 70,000 lives annually.
