The association of household fine particulate matter and kerosene with tuberculosis in women and children in Pune, India.

OBJECTIVES: Household air pollution (HAP) is a risk factor for respiratory disease, however has yet to be definitively associated with tuberculosis (TB). We aimed to assess the association between HAP and TB. METHODS: A matched case-control study was conducted among adult women and children patients with TB and healthy controls matched on geography, age and sex. HAP was assessed using questionnaires for pollution sources and 24-hour household concentrations of particulate matter <2.5 µm in diameter (PM2.5). RESULTS: In total, 192 individuals in 96 matched pairs were included. The median 24-hour time-weighted average PM2.5 was nearly seven times higher than the WHO's recommendation of 25 µg/m3, and did not vary between controls (179 µg/m3; IQR: 113-292) and cases (median 157 µg/m3; 95% CI 93 to 279; p=0.57). Reported use of wood fuel was not associated with TB (OR 2.32; 95% CI 0.65 to 24.20) and kerosene was significantly associated with TB (OR 5.49, 95% CI 1.24 to 24.20) in adjusted analysis. Household PM2.5 was not associated with TB in univariate or adjusted analysis. Controlling for PM2.5 concentration, kerosene was not significantly associated with TB, but effect sizes ranged from OR 4.30 (95% CI 0.78 to 30.86; p=0.09) to OR 5.49 (0.82 to 36.75; p=0.08). CONCLUSIONS: Use of kerosene cooking fuel is positively associated with TB in analysis using reported sources of exposure. Ubiquitously high levels of particulates limited detection of a difference in household PM2.5 between cases and controls.

Secondhand Smoke Exposure and Validity of Self-Report in Low-Income Women and Children in India.

BACKGROUND: There is limited validation of self-reported measures for secondhand smoke (SHS) exposure in low- and middle-income countries. We evaluated the validity of standard self-reported measures among women and children in urban India. METHODS: Structured questionnaires were administered, and household air and hair samples were analyzed for nicotine concentration. RESULTS: In total, 141 households of 70 child and 71 adult participants were included. Air nicotine was detected in 72 (51%) homes, and 35 (75%) child and 12 (56%) adult participants had detectable hair nicotine. Correlation between air and hair nicotine was significant in children (r = 0.5; P = .0002) but not in adults (r = -0.1; P = .57). Poor correlation was found between self-reported measures of exposure and both air and hair nicotine. No questions were significantly correlated with hair nicotine, and the highest-magnitude correlation with air nicotine was for how often someone smoked inside for adults (r = 0.4; P = .10) and for home preparation of mishri (a smokeless tobacco product prepared for consumption by roasting) for children (r = 0.4; P = .39). The highest value for sensitivity by using air nicotine as the gold standard was for whether people smelled other families preparing mishri (47%; 95% confidence interval: 31-62) and prepared mishri in their own homes (50%; 95% confidence interval: 19-81). CONCLUSIONS: These results raise caution in using or evaluating self-reported SHS exposure in these communities. More appropriate questions for this population are needed, including mishri preparation as a source of SHS exposure.

Sources of household air pollution and their association with fine particulate matter in low-income urban homes in India.

INTRODUCTION: Household air pollution (HAP) is poorly characterized in low-income urban Indian communities. MATERIALS AND METHODS: A questionnaire assessing sources of HAP and 24 h household concentrations of particulate matter less than 2.5 microns in diameter (PM2.5) were collected in a sample of low-income homes in Pune, India. RESULTS: In 166 homes, the median 24 h average concentration of PM2.5 was 167 µg/m3 (IQR: 106-294). Although kerosene and wood use were highly prevalent (22% and 25% of homes, respectively), primarily as secondary fuel sources, high PM2.5 concentrations were also found in 95 (57%) homes reporting LPG use alone (mean 141 µg/m3; IQR: 92-209). In adjusted linear regression, log PM2.5 concentration was positively associated with wood cooking fuel (GMR 1.5, 95% CI: 1.1-2.0), mosquito coils (GMR 1.5, 95% CI: 1.1-2.1), and winter season (GMR 1.7, 95% CI: 1.4-2.2). Households in the highest quartile of exposure were positively associated with wood cooking fuel (OR 1.3, 95% CI: 1.1-1.5), incense (OR 1.1, 95% CI: 1.0-1.3), mosquito coils (OR 1.3, 95% CI: 1.1-1.6), and winter season (OR 1.2, 95% CI: 1.1-1.4). DISCUSSION: We observed high concentrations of PM2.5 and identified associated determinants in urban Indian homes.