For five days Dhaka has been at the top of the list of the world's cities with the most polluted air. Neither Delhi in India nor Ulaanbaatar in Mongolia has been able to dislodge it, according to monitoring by AirVisual, an international organisation that tracks air quality around the world. But the organisation mainly measures air quality outdoors, so its monitoring gives no information on the air inside homes.

Abdus Salam, a professor in Dhaka University's chemistry department, has long been researching the quality of indoor air in the capital. According to his observations, indoor and outdoor air in Dhaka have become almost equally polluted.

Professor Salam measured outdoor and indoor air quality in the Dhaka University area on 14, 19, 23 and 28 January. On two days the indoor air was worse than the outdoor air, and on the other two days the outdoor air was worse. The difference between indoor and outdoor air quality was 10 to 12 per cent, the Dhaka University research found.

Meanwhile, on 28 January two organisations, the Royal College of Physicians and the Royal College of Paediatrics and Child Health, published a report on indoor air pollution. It said Bangladesh is notable among the countries where children are most at risk from indoor air pollution. In most rural households in Bangladesh, women cook by burning cow dung, wood, jute sticks and straw, which seriously pollutes the air indoors.

The report, titled "The Inside Story: Health Effects of Indoor Air Quality on Children and Young People", said many babies in rural Bangladesh die within a week of birth because of polluted indoor air. Most babies are born underweight (less than 2.5 kg). Those who survive show poor mental and physical growth and suffer from various long-term illnesses.

Explaining why indoor and outdoor air are equally bad, Professor Abdus Salam told Prothom Alo that in rural areas the air indoors, mainly in the kitchen, is more polluted than elsewhere because biomass fuel is burned for cooking. But in cities, polluted indoor air mainly comes from outside. Because of air movement and weather, outdoor air is often better than indoor air, since once polluted air gets inside a home it cannot get out. To protect children and the elderly from this kind of pollution, they should move about more, because anyone who stays still is more exposed to pollution, he said.

Earlier, in 2018, Professor Salam measured air pollution at 10 educational institutions in the capital on behalf of Dhaka University's chemistry department. Measurements of fine particulate matter (PM1, PM2.5 and PM10) and volatile organic compounds in the air of classrooms and playgrounds showed these substances, harmful to the human body, were four to five times above World Health Organization standards. Fine airborne particles are harming children's health too. The researchers found that besides disrupting children's normal breathing, air pollution caused various complications.

Asked about this, A K M Rafique Ahmed, director general of the Department of Environment, told Prothom Alo: "We have started shutting down all sources of air pollution. Besides closing illegal brick kilns, we have taken steps to control dust from construction work. We have also held a meeting with the country's air pollution experts to decide what must be done to control air pollution. Based on their opinions, we are going to start more anti-pollution activities."

The University of Oxford in the UK has regularly monitored indoor air quality in almost every country in the world since 2014. According to its latest report, published in November 2019, indoor air quality in rural Bangladesh poses a serious health risk to children and the elderly. By its estimate, 70,345 people in Bangladesh died of indoor air pollution in 2017, most of them newborns who died within a week of birth.

Source: Prothom Alo. First published in Bengali on The Agro News.