Indoor Air Quality and Associated Public Health Impact in AC and Non‐AC Environments: A Case Study on Mymensingh, Bangladesh
Md. Monabbir Hossain, Md. Rased Hasan Sojib, Md. Azharul Islam, Md. Tariqul Islam, Md. Alim Miah, Maomao ZhangABSTRACT
Indoo air pollution poses a critical public health risk, particularly in rapidly urbanizing regions like Bangladesh, where inadequate ventilation and climatic conditions intensify exposure risks. This study investigated seasonal and diurnal variations in indoor air quality (IAQ) across AC and Non‐AC environments in Mymensingh, assessing compliance, pollutant correlations, and quantification of health risks (ELCR, HQ). Measurements of PM 1 , PM 2.5 , PM 10 , TVOCs, HCHO, temperature, and humidity were taken from 56 rooms (28 AC, 28 Non‐AC) during the monsoon and post‐monsoon seasons using real‐time monitors. During the post‐monsoon season, PM 2.5 levels in Non‐AC rooms reached 123.29 µg/m 3 in the afternoon, compared to 79.79 µg/m 3 in AC rooms, while PM 10 concentrations peaked at 145.32 µg/m 3 in Non‐AC environments and 89.75 µg/m 3 in AC rooms. TVOC levels were highest in AC rooms, reaching 884 µg/m 3 , likely due to limited ventilation, and HCHO concentrations in AC spaces (301.14 µg/m 3 ) consistently exceeded WHO guidelines. Temperature and humidity influenced pollutant dynamics, with PM levels positively correlated with temperature and HCHO negatively correlated. Health risk assessments revealed significant hazards during the post‐monsoon season, with children in Non‐AC environments facing high estimated lifetime cancer risks (ELCR) from PM 1 (5.16E‐03) and PM 2.5 (2.7E‐03), while AC environments showed elevated risks from HCHO (8.75E‐06). Hazard Quotients (HQ) for PM 2.5 (9.30) and PM 10 (3.21) in Non‐AC environments reached alarming levels, indicating severe non‐carcinogenic risks. Source apportionment using Positive Matrix Factorization (PMF) identified distinct pollutant sources, underscoring the complex interplay of indoor and outdoor factors. Spatial analysis highlighted central urban zones as high‐risk areas due to traffic emissions and commercial activities. These findings emphasize the dual burden of particulate exposure in Non‐AC spaces and chemical accumulation in AC environments, influenced by seasonal shifts. Policy reforms focusing on source reduction, improved building codes, and public awareness are crucial to mitigate health disparities in tropical urban settings.