Toxic Dust: Measuring Awareness about Third-Hand Smoke Contamination in Homes Among Smokers and Non-smokers of Family...

Third-hand smoke (THS) poses significant health risks through persistent toxic residues, yet awareness remains inadequate, particularly in high-smoking populations like India. This study assessed THS knowledge gaps between smokers and non-smokers in Chennai households.

A community-based cross-sectional study surveyed 450 adults (225 smokers, 225 non-smokers) using multistage cluster sampling. A validated 20-item questionnaire measured THS knowledge, attitudes, and practices. Statistical analyses included t-tests, Chi-square tests, and logistic regression (SPSS v28, P < 0.05).

Non-smokers demonstrated significantly higher THS knowledge (mean score 6.7 vs. 4.1, P < 0.001; Cohen's d = 1.18). Logistic regression identified non-smoker status odds ratio [(OR] = 3.42, 95% confidence interval [CI]: 2.15-5.44) and higher education (OR = 2.89, 95% CI: 1.82-4.59) as strong knowledge predictors. Alarmingly, 65.8% of smokers (vs. 29.3% non-smokers, P < 0.001) erroneously believed cleaning eliminates THS, while only 12.4% maintained smoke-free homes (vs. 68.9% non-smokers, P < 0.001).

Substantial THS awareness gaps exist among smokers, compounded by misconceptions about exposure mitigation. Findings highlight the need for targeted educational interventions addressing these knowledge deficits, particularly focusing on proper cleaning practices and smoke-free home implementation. The study provides crucial baseline data for developing context-specific THS risk communication strategies in urban Indian settings.