Search

Background: Exposure to household air pollution from polluting domestic fuel (solid fuel and kerosene) represents a substantial global public health burden and there is an urgent need for rapid transition to clean domestic fuels. Gas for cooking and heating might possibly affect child asthma, wheezing, and respiratory health. The aim of this review was to synthesise the evidence on the health effects of gaseous fuels to inform policies for scalable clean household energy., Methods: In this systematic review and meta-analysis, we summarised the health effects from cooking or heating with gas compared with polluting fuels (eg, wood or charcoal) and clean energy (eg, electricity and solar energy). We searched PubMed, Scopus, Web of Science, MEDLINE, Cochrane Library (CENTRAL), Environment Complete, GreenFile, Google Scholar, Wanfang DATA, and CNKI for articles published between Dec 16, 2020, and Feb 6, 2021. Studies eligible for inclusion had to compare gas for cooking or heating with polluting fuels (eg, wood or charcoal) or clean energy (eg, electricity or solar energy) and present data for health outcomes in general populations. Studies that reported health outcomes that were exacerbations of existing underlying conditions were excluded. Several of our reviewers were involved in screening studies, data extraction, and quality assessment (including risk of bias) of included studies; 20% of studies were independently screened, extracted and quality assessed by another reviewer. Disagreements were reconciled through discussion with the wider review team. Included studies were appraised for quality using the Liverpool Quality Assessment Tools. Key health outcomes were grouped for meta-analysis and analysed using Cochrane's RevMan software. Primary outcomes were health effects (eg, acute lower respiratory infections) and secondary outcomes were health symptoms (eg, respiratory symptoms such as wheeze, cough, or breathlessness). This study is registered with PROSPERO, CRD42021227092., Findings: 116 studies were included in the meta-analysis (two [2%] randomised controlled trials, 13 [11%] case-control studies, 23 [20%] cohort studies, and 78 [67%] cross-sectional studies), contributing 215 effect estimates for five grouped health outcomes. Compared with polluting fuels, use of gas significantly lowered the risk of pneumonia (OR 0·54, 95% CI 0·38-0·77; p=0·00080), wheeze (OR 0·42, 0·30-0·59; p<0·0001), cough (OR 0·44, 0·32-0·62; p<0·0001), breathlessness (OR 0·40, 0·21-0·76; p=0·0052), chronic obstructive pulmonary disease (OR 0·37, 0·23-0·60; p<0·0001), bronchitis (OR 0·60, 0·43-0·82; p=0·0015), pulmonary function deficit (OR 0·27, 0·17-0·44; p<0·0001), severe respiratory illness or death (OR 0·27, 0·11-0·63; p=0·0024), preterm birth (OR 0·66, 0·45-0·97; p=0·033), and low birth weight (OR 0·70, 0·53-0·93; p=0·015). Non-statistically significant effects were observed for asthma in children (OR 1·04, 0·70-1·55; p=0·84), asthma in adults (OR 0·65, 0·43-1·00; p=0·052), and small for gestational age (OR 1·04, 0·89-1·21; p=0·62). Compared with electricity, use of gas significantly increased risk of pneumonia (OR 1·26, 1·03-1·53; p=0·025) and chronic obstructive pulmonary disease (OR 1·15, 1·06-1·25; p=0·0011), although smaller non-significant effects were observed for higher-quality studies. In addition, a small increased risk of asthma in children was not significant (OR 1·09, 0·99-1·19; p=0·071) and no significant associations were found for adult asthma, wheeze, cough, and breathlessness (p>0·05). A significant decreased risk of bronchitis was observed (OR 0·87, 0·81-0·93; p<0·0001)., Interpretation: Switching from polluting fuels to gaseous household fuels could lower health risk and associated morbidity and mortality in resource-poor countries where reliance on polluting fuels is greatest. Although gas fuel use was associated with a slightly higher risk for some health outcomes compared with electricity, gas is an important transitional option for health in countries where access to reliable electricity supply for cooking or heating is not feasible in the near term., Funding: WHO., Competing Interests: Declaration of interests We declare no competing interests., (Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.)

Background: Relatively clean cooking fuels such as liquefied petroleum gas (LPG) emit less fine particulate matter (PM 2·5 ) and carbon monoxide (CO) than polluting fuels (eg, wood, charcoal). Yet, some clean cooking interventions have not achieved substantial exposure reductions. This study evaluates determinants of between-community variability in exposures to household air pollution (HAP) across sub-Saharan Africa., Methods: In this measurement study, we recruited households cooking primarily with LPG or exclusively with wood or charcoal in peri-urban Cameroon, Ghana, and Kenya from previously surveyed households. In 2019-20, we conducted monitoring of 24 h PM 2·5 and CO kitchen concentrations (n=256) and female cook (n=248) and child (n=124) exposures. PM 2·5 measurements used gravimetric and light scattering methods. Stove use monitoring and surveys on cooking characteristics and ambient air pollution exposure (eg, walking time to main road) were also administered., Findings: The mean PM 2·5 kitchen concentration was five times higher among households cooking with charcoal than those using LPG in the Kenyan community (297 μg/m 3 , 95% CI 216-406, vs 61 μg/m 3 , 49-76), but only 4 μg/m 3 higher in the Ghanaian community (56 μg/m 3 , 45-70, vs 52 μg/m 3 , 40-68). The mean CO kitchen concentration in charcoal-using households was double the WHO guideline (6·11 parts per million [ppm]) in the Kenyan community (15·81 ppm, 95% CI 8·71-28·72), but below the guideline in the Ghanaian setting (1·77 ppm, 1·04-2·99). In all communities, mean PM 2·5 cook exposures only met the WHO interim-1 target (35 μg/m 3 ) among LPG users staying indoors and living more than 10 min walk from a road., Interpretation: Community-level variation in the relative difference in HAP exposures between LPG and polluting cooking fuel users in peri-urban sub-Saharan Africa might be attributed to differences in ambient air pollution levels. Thus, mitigation of indoor and outdoor PM 2·5 sources will probably be critical for obtaining significant exposure reductions in rapidly urbanising settings of sub-Saharan Africa., Funding: UK National Institute for Health and Care Research., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

This study assessed the performance of modeling approaches to estimate personal exposure in Kenyan homes where cooking fuel combustion contributes substantially to household air pollution (HAP). We measured emissions (PM 2.5 , black carbon, CO); household air pollution (PM 2.5 , CO); personal exposure (PM 2.5 , CO); stove use; and behavioral, socioeconomic, and household environmental characteristics (eg, ventilation and kitchen volume). We then applied various modeling approaches: a single-zone model; indirect exposure models, which combine person-location and area-level measurements; and predictive statistical models, including standard linear regression and ensemble machine learning approaches based on a set of predictors such as fuel type, room volume, and others. The single-zone model was reasonably well-correlated with measured kitchen concentrations of PM 2.5 (R 2  = 0.45) and CO (R 2  = 0.45), but lacked precision. The best performing regression model used a combination of survey-based data and physical measurements (R 2  = 0.76) and a root mean-squared error of 85 µg/m 3 , and the survey-only-based regression model was able to predict PM2.5 exposures with an R 2 of 0.51. Of the machine learning algorithms evaluated, extreme gradient boosting performed best, with an R 2 of 0.57 and RMSE of 98 µg/m 3 ., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: Increasing use of cleaner fuels, such as liquefied petroleum gas (LPG), and abandonment of solid fuels is key to reducing household air pollution and realising potential health improvements in low-income countries. However, achieving exclusive LPG use in households unaccustomed to this type of fuel, used in combination with a new stove technology, requires substantial behaviour change. We conducted theory-grounded formative research to identify contextual factors influencing cooking fuel choice to guide the development of behavioural strategies for the Household Air Pollution Intervention Network (HAPIN) trial. The HAPIN trial will assess the impact of exclusive LPG use on air pollution exposure and health of pregnant women, older adult women, and infants under 1 year of age in Guatemala, India, Peru, and Rwanda., Methods: Using the Capability, Opportunity, Motivation-Behaviour (COM-B) framework and Behaviour Change Wheel (BCW) to guide formative research, we conducted in-depth interviews, focus group discussions, observations, key informant interviews and pilot studies to identify key influencers of cooking behaviours in the four countries. We used these findings to develop behavioural strategies likely to achieve exclusive LPG use in the HAPIN trial., Results: We identified nine potential influencers of exclusive LPG use, including perceived disadvantages of solid fuels, family preferences, cookware, traditional foods, non-food-related cooking, heating needs, LPG awareness, safety and cost and availability of fuel. Mapping formative findings onto the theoretical frameworks, behavioural strategies for achieving exclusive LPG use in each research site included free fuel deliveries, locally acceptable stoves and equipment, hands-on training and printed materials and videos emphasising relevant messages. In the HAPIN trial, we will monitor and reinforce exclusive LPG use through temperature data loggers, LPG fuel delivery tracking, in-home observations and behavioural reinforcement visits., Conclusion: Our formative research and behavioural strategies can inform the development, implementation, monitoring and evaluation of theory-informed strategies to promote exclusive LPG use in future stove programmes and research studies., Trial Registration Number: NCT02944682, Pre-results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ.)

Household air pollution (HAP) caused by the combustion of solid fuels for cooking and heating is responsible for almost 5% of the global burden of disease. In response, the World Health Organisation (WHO) has recommended the urgent need to scale the adoption of clean fuels, such as liquefied petroleum gas (LPG), in low and middle-income countries (LMICs). To understand the drivers of the adoption and exclusive use of LPG for cooking, we analysed representative survey data from 3343 peri-urban and rural households in Southwest Cameroon. Surveys used standardised tools to collect information on fuel use, socio-demographic and household characteristics and use of LPG for clean cooking. Most households reported LPG to be clean (95%) and efficient (88%), but many also perceived it to be expensive (69%) and unsafe (64%). Positive perceptions about LPG's safety (OR = 2.49, 95% CI = 2.04, 3.05), cooking speed (OR = 4.31, 95% CI = 2.62, 7.10), affordability (OR = 1.7, 95% CI = 1.38, 2.09), availability (OR = 2.17, 95% CI = 1.72, 2.73), and its ability to cook most dishes (OR = 3.79, 95% CI = 2.87, 5.01), were significantly associated with exclusive LPG use. Socio-economic status (higher education) and household wealth (higher income) were also associated with a greater likelihood of LPG adoption. Effective strategies to raise awareness around safe use of LPG and interventions to address financial barriers are needed to scale wider adoption and sustained use of LPG for clean cooking, displacing reliance on polluting solid fuels.

Background: The Cameroon government has set a target that, by 2030, 58% of the population will be using Liquefied Petroleum Gas (LPG) as a cooking fuel, in comparison with less than 20% in 2014. The National LPG Master Plan (Master Plan) was developed for scaling up the LPG sector to achieve this target., Objectives: This study aimed to estimate the potential impacts of this planned LPG expansion (the Master Plan) on population health and climate change mitigation, assuming primary, sustained use of LPG for daily cooking., Methods: We applied existing and developed new mathematical models to calculate the health and climate impacts of expanding LPG primary adoption for household cooking in Cameroon over two periods: a ) short-term (2017-2030): Comparing the Master Plan 58% target with a counterfactual LPG adoption of 32% in 2030, in line with current trends; and b ) long-term (2031-2100, climate modeling only), assuming Cameroon will become a mature and saturated LPG market by 2100 (73% adoption, based on Latin American countries). We compared this with a counterfactual adoption of 41% by 2100, in line with current trends., Results: By 2030, successful implementation of the Master Plan was estimated to avert about 28,000 ( minimum = 22,000 , maximum = 35,000 ) deaths and 770,000 ( minimum = 580,000 maximum = 1   million ) disability-adjusted life years. For the same period, we estimated reductions in pollutant emissions of more than a third in comparison with the counterfactual, leading to a global cooling of - 0.1   milli   ° C in 2030. For 2100, a cooling impact from the Master Plan leading to market saturation (73%) was estimated to be - 0.70   milli   ° C in comparison with to the counterfactual, with a range of - 0.64 to - 0.93   milli   ° C based on different fractions of nonrenewable biomass., Discussion: Successful implementation of the Master Plan could have significant positive impacts on population health in Cameroon with no adverse impacts on climate. https://doi.org/10.1289/EHP4899.

Approximately four million people die each year in low- and middle-income countries from household air pollution (HAP) due to inefficient cooking with solid fuels. Liquid Petroleum Gas (LPG) offers a clean energy option in the transition towards renewable energy. This qualitative study explored lay knowledge of barriers and facilitators to scaling up clean fuels in Cameroon, informed by Quinn et al.'s Logic Model. The model has five domains and we focused on the user and community needs domain, reporting the findings of 28 semi-structured interviews (SSIs) and four focus group discussions (FGDs) that explored the reasons behind fuel use choices. The findings suggest that affordability, safety, convenience, and awareness of health issues are all important influences on decision making to the adoption and sustained use of LPG, with affordability being the most critical issue. We also found the ability of clean fuels to meet cooking needs to be central to decision-making, rather than an aspect of convenience, as the logic model suggests. Local communities provide important insights into the barriers and facilitators to using clean fuels. We adapt Quinn et al.'s logic model accordingly, giving more weight to lay knowledge so that it is better positioned to inform policy development.

Interventions implementing clean fuels to mitigate household air pollution in low- and middle-income countries have focused on environmental and health outcomes, but few have evaluated time savings. We performed a systematic review, searching for studies of clean fuel interventions that measured time use. A total of 868 manuscripts were identified that met the search criteria, but only 2 met the inclusion criteria. Both were cross-sectional and were conducted in rural India. The first surveyed the female head of household (141 using biogas and 58 using biomass) and reported 1.2 h saved per day collecting fuel and 0.7 h saved cooking, resulting in a combined 28.9 days saved over an entire year. The second surveyed the head of household (37 using biogas and 68 using biomass, 13% female) and reported 1.5 h saved per day collecting fuel, or 22.8 days saved over a year. Based on these time savings, we estimated that clean fuel use could result in a 3.8% or 4.7% increase in daily income, respectively, not including time or costs for fuel procurement. Clean fuel interventions could save users time and money. Few studies have evaluated this potential benefit, suggesting that prospective studies or randomized controlled trials are needed to adequately measure gains.

Competing Interests: The authors declare they have no actual or potential competing financial interests.

Background: Access to, and sustained adoption of, clean household fuels at scale remains an aspirational goal to achieve sufficient reductions in household air pollution (HAP) in order to impact on the substantial global health burden caused by reliance on solid fuels., Aim and Objectives: To systematically appraise the current evidence base to identify: (i) which factors enable or limit adoption and sustained use of clean fuels (namely liquefied petroleum gas (LPG), biogas, solar cooking and alcohol fuels) in low- and middle-income countries; (ii) lessons learnt concerning equitable scaling-up of programmes of cleaner cooking fuels in relation to poverty, urban-rural settings and gender., Methods: A mixed-methods systematic review was conducted using established review methodology and extensive searches of published and grey literature sources. Data extraction and quality appraisal of quantitative, qualitative and case studies meeting inclusion criteria were conducted using standardised methods with reliability checking., Findings: Forty-four studies from Africa, Asia and Latin America met the inclusion criteria (17 on biogas, 12 on LPG, 9 on solar, 6 on alcohol fuels). A broad range of inter-related enabling and limiting factors were identified for all four types of intervention, operating across seven pre-specified domains (i.e. fuel and technology characteristics, household and setting characteristics, knowledge and perceptions, financial, tax and subsidy aspects, market development, regulation, legislation and standards, and programme and policy mechanisms) and multiple levels (i.e. household, community, national). All domains matter and the majority of factors are common to all clean fuels interventions reviewed although some are fuel and technology-specific. All factors should therefore be taken into account and carefully assessed during planning and implementation of any small- and large-scale initiative aiming at promoting clean fuels for household cooking., Conclusions: Despite limitations in quantity and quality of the evidence this systematic review provides a useful starting point for the design, delivery and evaluation of programmes to ensure more effective adoption and use of LPG, biogas, alcohol fuels and solar cooking., Funding: This review was funded by the Department for International Development (DfID) of the United Kingdom. The authors would also like to thank the Evidence for Policy and Practice Information and Co-ordinating Centre (EPPI-Centre) for their technical support., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Globally, 2.8 billion people rely on household solid fuels. Reducing the resulting adverse health, environmental, and development consequences will involve transitioning through a mix of clean fuels and improved solid fuel stoves (IS) of demonstrable effectiveness. To date, achieving uptake of IS has presented significant challenges., Objectives: We performed a systematic review of factors that enable or limit large-scale uptake of IS in low- and middle-income countries., Methods: We conducted systematic searches through multidisciplinary databases, specialist websites, and consulting experts. The review drew on qualitative, quantitative, and case studies and used standardized methods for screening, data extraction, critical appraisal, and synthesis. We summarized our findings as "factors" relating to one of seven domains-fuel and technology characteristics; household and setting characteristics; knowledge and perceptions; finance, tax, and subsidy aspects; market development; regulation, legislation, and standards; programmatic and policy mechanisms-and also recorded issues that impacted equity., Results: We identified 31 factors influencing uptake from 57 studies conducted in Asia, Africa, and Latin America. All domains matter. Although factors such as offering technologies that meet household needs and save fuel, user training and support, effective financing, and facilitative government action appear to be critical, none guarantee success: All factors can be influential, depending on context. The nature of available evidence did not permit further prioritization., Conclusions: Achieving adoption and sustained use of IS at a large scale requires that all factors, spanning household/community and program/societal levels, be assessed and supported by policy. We propose a planning tool that would aid this process and suggest further research to incorporate an evaluation of effectiveness.