Indoor air pollution and exposure analysis in different residential dwellings of a South Asian urban city

Rapid urbanization increases the population density in urban regions, which compromises the standard of living. This study analyzed the concentration of indoor particulate matter in urban clusters where significant socioeconomic differences exist within the same geographical domain. Particulate matters (PM₁₀, PM_2.5, and PM₁) were measured in two major indoor microenvironments (kitchen and bedroom) along with outdoors of the selected households during winter, summer, and monsoon seasons. Four major income groups were considered for the study. A poorly ventilated kitchen was found to have higher concentrations of PM₁₀ (247 µg/m³), PM_2.5 (200 µg/m³), and PM₁ (153 µg/m³), respectively. Indoor, PM₁ contributed ∼40 to 85% to PM₁₀. During winter, the seasonal mean I/O ratio of PM₁₀, PM_2.5, and PM₁ ranged between 1.1 and 1.8 in bedroom and 0.8 and 2.2 in kitchen. The influence of outdoor particulate matter concentration on indoor air was observed to be high during winter, followed by summer and monsoon. The higher concentration in kitchen leads to an exposure of 0.10 µg, and in bedroom, it was 0.11 µg for adults with a higher breathing rate. The exposure depends on the concentration and exposure time. The PM_2.5 depositions were found more in the lower lung regions.