Biomass Fuel Use and Risk of Cataract: Systematic Review and Meta-Analysis.

Aims: There is an increasing recognition of the putative association between the use of biomass fuels and the risk of cataracts. However, the exact strength of this association is currently unknown. Our aim was to synthetically quantify the association between biomass fuel use and cataract. Study Design: Systematic review and meta-analysis. Methodology: Using results from the MEDLINE®, Scopus®, Web of Science® and Google® searches, we conducted a random-effects meta-analysis of the published studies. We also conducted subgroup meta-analyses, meta-regressions and sensitivity analyses to determine the contribution of potential confounders to between-study heterogeneity which was measured by the tau-squared and I2 statistics. Summary effect sizes (SES) were estimated using the DerSimonian and Laird method and the 95% confidence intervals (CI) and 95% prediction intervals (PI) were also estimated. Publication bias was examined using funnel plots and Egger’s test. Results: In spite of significant between-study heterogeneity (I2 70%, p=8.1x10-5), biomass fuel use was associated with a significantly increased risk of cataract (SES 2.12; 95% CI 1.61-2.80; 95% PI 0.88-5.09). Age-, gender- and other methodological differences did not significantly contribute to between-study heterogeneity but Indian studies showed a statistically significant association between biomass fuel use and cataract. Statistically homogeneous studies (n = 8) showed an SES of 2.01 (95% CI and PI 1.67-2.41). Conclusion: Synthetic evidence from observational studies indicates that biomass fuel use may increase the risk of cataract. Public health initiatives aimed at avoidance of biomass fuel use may reduce the burden of cataracts especially in settings where biomass fuels are commonly used.

Effect of indoor air pollution during cooking on peak expiratory flow rate and its association with exposure index in rural women.

Routine exposure to domestic cooking fuels is an important source of indoor air pollution causing deterioration of lung function. We conducted a community based cross-sectional study in 760 non-smoking rural women involved in household cooking with four types of cooking fuels i.e. Biomass, Kerosene stove, Liquid Petroleum Gas (LPG) and Mixed (combination of two and more cooking fuels). Peak Expiratory Flow Rate (PEFR) less than 80% of the predicted was considered as abnormal PEFR. The overall prevalence of abnormal PEFR was found to be 29.1% with greater predominance among biomass fuel users (43.3%) with high risk ratio (1.86) as compared to kerosene (0.63), LPG (0.75) and mixed (0.66) fuel users. However the pair wise comparison of different groups of cooking fuels by Marascuilo procedure reported significant differences within different groups except kerosene - mixed group. The study also demonstrated a negative correlation between observed PEFR and exposure indices in different cooking fuels (r=–0.51). Our results indicate that prolonged exposure to cooking fuels particularly biomass fuels as a source of cooking adversely affects PEFR in nonsmoking rural women.