Despite widespread use of unclean cooking fuels (UCF) in India, evidence from nationally representative data on its association with visual impairment was lacking. We used a population-based nationwide survey of adults aged 45 years and older that included reported UCF and measured visual impairment. We estimated that 44.8% (95% CI: 42.6, 47.1) of older adults in India lived in households that used UCF. Age- and sex-adjusted prevalence of visual impairment was estimated to be 33.0% (95% CI: 31.0, 34.9) in the older population that did not use UCF and 9.0 percentage points (pp) (95% CI: 8.9, 9.1) higher among those who did. Among those who used UCF, age- and sex-adjusted prevalence of low distance vision was 4.3 pp (95% CI: 4.2, 4.4) higher, prevalence of low near vision was 8.0 pp (95% CI: 7.9, 8.1) higher, and prevalence of blindness was 1.0 pp (95% CI: 0.9, 1.0) higher. After controlling for a rich array of sociodemographic characteristics and state fixed effects, we estimated that use of UCF was associated with higher prevalence of visual impairment by 3.2 pp (95% CI: 1.4, 5.0), low distance vision by 1.8 pp (95% CI: 0.7, 2.9), and low near vision by 3.2 pp (95% CI: 1.3, 5.0). Doubly robust estimates of these differences were slightly larger. Blindness was not significantly partially associated with use of UCF (95% CI: -0.4, 0.6). We did not find support for the hypotheses that the visual impairment risk associated with use of UCF was even larger for females and in households without a separate kitchen or ventilation. The older population of India is highly reliant on UCF that is very strongly associated with visual impairment. Impaired vision should not be overlooked among the harms associated with UCF.

Uptake of clean cooking fuels (CCF), such as liquefied petroleum gas (LPG), in place of traditional cooking fuels such as wood, charcoal, and kerosene can improve public health by reducing household air pollution exposures. Though studies have cross-sectionally examined socioeconomic determinants of cooking fuel adoption, little is known about socioeconomic disparities in CCF use over time. Data from the third (2005–06) and fourth (2015–16) rounds of the National Family Health Survey covering 109,041 and 601,509 households, respectively, were used to examine inequities in CCF use in India. While CCF use in India increased nationally from 25% in 2005–06 to 44% in 2015–16, the adoption of CCF varied widely across states and socio-economic groups. Approximately 2% of households in the poorest wealth quintile gained access to LPG during the study period, compared with an increase of 10% or more among households in the middle or richer wealth quintiles; the LPG access gap between the low (0.2%) and middle class (19.2%) was 19% in 2005–06 and nearly doubled to 35% (2.5% vs. 37.4%, respectively) in 2015–16. At the state level, there was a four-fold difference in the uptake of CCF over the two survey periods. The use of CCF increased by less than 10% in Himachal Pradesh, Bihar, Assam, Manipur, Mizoram, and Meghalaya as compared to the increases of at least 30% in Tamil Nadu (42%), undivided Andhra Pradesh (34%), and Kerala (30%). Further, in wealthier states (Delhi, Goa, Punjab, Haryana, Tamil Nadu, Kerala, and undivided Andhra Pradesh), CCF use increased by more than 20% among the poorest individuals compared with less than 1% among the poorest families in lower income states (Tripura, Meghalaya, Madhya Pradesh, Jharkhand, Chhattisgarh, Bihar). To promote a more equitable clean energy transition, poorer and rural Indian households should be prioritized for CCF promotion programs.

Birth weight is positively associated with physical and cognitive development of children and adversely associated with the use of unclean cooking fuels. Though studies have examined the contextual determinants of birth weight, no attempt has been made to understand the association of gradient of cooking fuels with birth weight in India. The objective of this paper is to understand the association of type of cooking fuel with low birth weight in India. Unit data from the fourth round of the National Family Health Survey (NFHS) (2015–16), covering 8206 singleton births from four states of India, was used in the analysis. These states reported more than 80% of birth weights by way of health cards issued by a public authority. Linear regression analysis was used to estimate mean birth weight, adjusting for confounders. We computed a new wealth index, excluding electricity and cooking fuels, using principal component analysis to capture the economic gradient of cooking fuel. Our results suggest a strong gradient of cooking fuels on mean birth weight. The adjusted mean birth weight in households using electricity was 2957 g (95% CI: 2939–2975). It was 2908 g (95% CI: 2907–2910) for LPG, 2792 g (95% CI: 2784–2801) for biogas, 2819 g (95% CI: 2809–2829) for kerosene, 2841 g (95% CI: 2816–2866) for coal/lignite/charcoal, and 2834 g (95% CI: 2831–2836) in households using biomass. A difference of 165 g in predicted mean birth weight was found among children born in households that used electricity in relation to those that used biogas. The difference in relation to kerosene, coal/lignite/charcoal, and biomass was 138 g, 116 g, and 123 g respectively. Significant differences in mean birth weight were also observed by wealth quintiles, mother's underweight, social groups, birth interval, and mother's anemia status. Findings from the study suggest to strengthen the policies on access to clean fuels and meet the interconnected goals of sustainable development.