Why is natural ventilation crucial for our health?

Natural ventilation is sometimes overlooked in Bangladesh's congested urban landscape, where high-rise structures jam the skyline and narrow alleys reflect the country's rapid expansion. However, as public health concerns grow, understanding and implementing natural ventilation in indoor areas becomes more important. Natural ventilation has a major impact on human health, influencing everything from respiratory health to mental well-being. Bangladesh, with its tropical environment, experiences high temperatures and humidity for a large portion of the year. In such settings, air conditioners and other artificial cooling technologies are frequently used. While these systems provide quick relief from the heat, they frequently have a chance of health consequences. Poorly ventilated spaces with insufficient air movement can serve as breeding grounds for a variety of health concerns. 

Natural ventilation provides both respiratory and psychological benefits. Proper ventilation and connection to the outdoors can improve mental health and comfort. The experience of fresh air and natural light can help with anxiety and despair. This is especially true in Bangladesh's urban areas, such as Dhaka and Chattogram, where high population density and minimal green space can contribute to feelings of confinement and tension. Practical examples from Bangladesh demonstrate the advantages of natural ventilation. In rural locations, traditional house designs frequently include airflow-promoting features such as courtyards and big windows. These architectural elements not only provide cooling, but they also improve the living environment by lowering indoor air pollutants. In contrast, modern urban flats frequently prioritise space efficiency over ventilation, resulting in the aforementioned health risks. 

One of the most significant issues is indoor air pollution. In Bangladesh, common causes of indoor pollution include cooking stoves, particularly those that burn biomass, tobacco smoke, and emissions from building materials and furniture. A study found that households that utilise traditional biomass burners have significantly higher levels of indoor particulate matter (PM2.5). These small particles can penetrate deep into the lungs and even into the bloodstream, causing respiratory and cardiovascular problems. The World Health Organisation (WHO) estimates that indoor air pollution causes approximately 46,000 fatalities in Bangladesh each year. 

Natural ventilation reduces these health hazards by allowing for the constant flow of interior and outdoor air. This process dilutes the concentration of indoor contaminants, lowering the risk of respiratory disorders. For example, a well-ventilated room can reduce PM2.5 concentrations to safer levels, as outdoor air, despite its own limitations, often has lower pollutant concentrations than interior air in poorly ventilated homes. Furthermore, natural ventilation helps to regulate indoor humidity levels. Maintaining optimum airflow is critical in countries like Bangladesh, where humidity can promote the growth of mould and mildew. Mould exposure has been related to a variety of health concerns, including allergic reactions, asthma, and other respiratory issues. A study conducted by the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) discovered that children living in mold-infested homes had a greater frequency of respiratory diseases. 

The Bangladesh government has recognised the need of improving indoor air quality. The Department of Environment has launched initiatives to promote the adoption of more efficient cooking stoves that emit less smoke. However, these efforts must be supplemented with building design standards that prioritise natural ventilation. Educational institutions also contribute to this shift. Schools and universities can implement natural ventilation ideas into their facilities. This not only improves air quality, but also fosters a positive learning environment. Furthermore, public awareness initiatives are necessary. Many people are ignorant of the health concerns connected with poor ventilation, as well as the basic steps that may be taken to alleviate them. For example, leaving windows open while cooking or employing exhaust fans can drastically reduce indoor pollution levels. Community health programmes can help educate the public about these practices. 

As Bangladesh becomes more urbanised, the difficulty of ensuring healthy interior settings will increase. Traditional design lessons, as well as current understandings of environmental health, must be blended into modern building methods. Natural ventilation should not be regarded as an old concept, but rather as an essential component of public health strategy. To summarise, the health ramifications of natural ventilation are evident and multifaceted. The benefits are numerous, ranging from reduced respiratory and cardiovascular ailments to improved mental health. In Bangladesh, where indoor air pollution is a major health concern, embracing natural ventilation can lead to healthier lifestyles and more sustainable urban development. The way forward requires a mix of old wisdom, technological innovation, and widespread public education. By putting natural ventilation first, Bangladesh can ensure that its progress does not come at the expense of its people's health. 

Sketch: TBS

Dr Sajal Chowdhury is an architect, educator at the Department of Architecture, CUET and researcher focusing on Environmental Experience Design, Architectural Science and Well-being.