BACKGROUND: Indoor air pollution remains a significant public health concern in urban slums of developing countries, with tobacco smoke being a major contributor. This study aims to estimate indoor air pollutants and its associated factors in smoking households located in urban slums of Kerala (India).
METHODS: This cross-sectional analysis uses baseline data from a cluster randomized trial conducted in urban slums of Cochin Corporation, Kerala. Data were collected from 657 households with active indoor smokers and included details on household characteristics and smoking behaviors. Direct measurements of particulate matter 2.5 (PM_2.5) and particulate matter 10 (PM₁₀) were done using a real-time air quality monitor placed in the main living area of each household. Continuous variables were reported as median [Q1, Q3] and categorical variables as frequency with percentages. Multivariable logistic regression identified factors associated with pollutant levels.
RESULTS: Among the 657 households surveyed, majority (63.9%) belonged to a lower socioeconomic status. Overcrowding was observed in 38% of homes, while inadequate ventilation was seen in 70%. The median concentrations of PM_2.5 and PM₁₀ were 29.6 [14.9, 48.7] µg/m³ and 31.1 [16.4, 50.8] µg/m³ respectively. Multivariable regression showed that lower socioeconomic background (aOR 1.7, 95% CI: 1.1, 2.5) and households without a multimorbid smoker (aOR 7.7, 95% CI: 1.0, 58.2) were more likely to get exposed to PM_2.5 ≥ 15 µg/m³. Whereas households with an employed female (aOR 1.7, 95% CI: 1.1, 2.4) and where biomass was used as a cooking fuel (aOR 2.1, 95% CI: 1.2, 3.7) were more likely to get exposed to PM₁₀ ≥ 45 µg/m³.
CONCLUSIONS: Findings from the study revealed elevated levels of PM_2.5 and PM₁₀. Interventions to reduce indoor smoking should target households with low socioeconomic background, with otherwise healthy smokers, with employed women, and households using biomass fuel, to protect vulnerable urban populations.