Respiratory symptoms, lung function decrement and chronic obstructive pulmonary disease in pre-menopausal Indian women exposed to biomass smoke.

BACKGROUND: The impact of chronic exposure to smoke from biomass burning on respiratory health has been examined. METHODS: Six-hundred and eighty-one non-smoking women (median age 35 years) from eastern India who cook exclusively with biomass (wood, dung and crop residues) and 438 age-matched women from similar neighborhood who cook with liquefied petroleum gas (LPG) were examined. Pulmonary function test was done by spirometry. The concentrations of particulate matter having diameter of < 10 µm (PM10) and < 2.5 µm (PM2.5) in indoor air was measured by real-time aerosol monitor. RESULTS: Compared with LPG users, biomass users had greater prevalence of upper (50.9 versus 28.5%) and lower respiratory symptoms (71.8 versus 30.8%) and dyspnea (58.4 versus 19.9%). They showed reduction in all parameters measured by spirometer especially in mid-expiratory volume. PM10 and PM2.5 concentration in biomass using kitchen were 2-3-times more than LPG-using kitchen, and the decline in spirometry values was positively associated PM10 and PM2.5 levels in indoor air after controlling education, family income and kitchen location as potential confounders. Overall, 29.7% of biomass users and 16.4% of LPG users had deficient lung function, and restrictive type of deficiency was predominant. Chronic obstructive pulmonary disease (COPD) was diagnosed in 4.6% of biomass and 0.9% of LPG users. Women who predominantly used dung cake and did not possess separate kitchen had poorer lung function. CONCLUSION: Cumulative exposure to biomass smoke causes lung function decrement and facilitates COPD development even in non-smoking and relatively young pre-menopausal women.

Immune cells and cardiovascular health in premenopausal women of rural India chronically exposed to biomass smoke during daily household cooking.

Changes in cells of the immune system are important indicators of systemic response of the body to air pollution. The aim of this study was to investigate the immunological changes in rural women who have been cooking exclusively with biomass for the past 5 years or more and compare the findings with women cooking exclusively with liquefied petroleum gas (LPG). We conducted a cross-sectional analysis of the associations between indices of indoor air pollution (IAP) and a set of immune assays. Biomass users illustrated marked suppression in the total number of T-helper (CD4+) cells and B (CD19+) cells while appreciable rise was documented in the number of CD8+ T-cytotoxic cells and CD16+CD56+ natural killer (NK) cells. A consistent finding among biomass users was rise in regulatory T (Treg) cells. Among biomass users, peripheral lymphocyte subpopulations, Treg cells, and the number of typical monocytes (CD16-CD64+ cells), antigen presenting types (CD16+CD64- cells) and plasmacytoid cells (CD16-CD64- cells) were found to be significantly altered in those who daily cooked with dung in comparison to wood and crop residue users (p<0.05). Biomass users who cooked in kitchens adjacent to their living areas had significant changes in peripheral lymphocyte subpopulations, typical monocytes (CD16-CD64+) with high phagocytic activity and antigen presenting monocytes (CD16+CD64-) against women who cooked in separate kitchens (p<0.01). This study has shown that women who cooked exclusively with biomass fuel had alterations in immune defense compared with their neighbors who cooked with LPG.

Assessment of DNA damage by comet assay and fast halo assay in buccal epithelial cells of Indian women chronically exposed to biomass smoke.

Genotoxicity of indoor air pollution from biomass burning was evaluated in buccal epithelial cells (BECs) of 85 pre-menopausal Indian women who were engaged in cooking with biomass (wood, dung, crop residues) and 76 age-matched control women who were cooking with cleaner fuel liquefied petroleum gas (LPG). DNA damage was evaluated by comet assay and fast halo assay (FHA). The concentrations of particulate matter with aerodynamic diameters of less than 10 and 2.5 µm (PM(10) and PM(2.5), respectively) in indoor air were measured by real-time aerosol monitor. Generation of reactive oxygen species (ROS) was measured by flow cytometry and the level of superoxide dismutase (SOD) by spectrophotometry. Compared with control, BEC of biomass users illustrated 2.6-times higher comet tail % DNA (32.2 vs. 12.4, p < 0.001), 2.7-times greater comet tail length (37.8 µm vs. 14.2 µm, p < 0.001) and 2.2-times more olive tail moment (7.1 vs. 3.2, p < 0.001), suggesting marked increase in DNA damage. FHA also showed 5-times more mean nuclear diffusion factor (9.2 vs. 1.8, p < 0.0001) in BEC of biomass users, confirming sharp rise in DNA single strand breaks. Airway cells of biomass-using women showed 51% rise in ROS generation but 28% reduction in SOD, suggesting oxidative stress in the airways. Indoor air of biomass-using households had 3-times more PM(10) and PM(2.5) than LPG-using families, and DNA damage showed positive association with PM(10) and PM(2.5) levels controlling education, kitchen location and family income as potential confounders. In summary, chronic inhalation of biomass smoke elicits oxidative stress and extensive DNA damage in BEC.