Use Of Solid Fuels Research Articles

The Causal Impact of Solid Fuel Use on Mortality – A Cross- Country Panel Analysis

Biomass consumption causes indoor air pollution which impairs health and environment. In this paper, we examine the causal relationship between biomass fuel consumption and measures of life expectancy and infant and child mortality. Using 13 years of cross-country panel data which covers 105 countries over the period 2000-2012, we applied fixed effect model and instrumental variable regression. We find that solid fuel combustion causes increase in infant and child mortality and decreases in male and female life expectancy. A back-of-the envelope calculation suggests that, if the solid fuel consumption gap between low-income and lower-middle income countries were reduced by 50 percent, infant and child mortality in the low-income countries decrease by 16.5 and 29.8 per thousand respectively, and life expectancy would increase by 1.0 and 1.5 years for males and females respectively. Our findings suggest that governments, particularly of developing countries, should focus efforts to reduce solid fuel use.

Solid Fuel Use and the Progression of Multimorbidity in Middle-Aged Chinese Participants: A Prospective Cohort Study.

Objectives: This study aimed to examine the association of solid fuel use for cooking and heating with the progression of multimorbidity. Methods: A total of 5,437 participants from the China Health and Retirement Longitudinal Study were included. Multivariate logistic regression models were used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for the associations of the independent and joint effects of solid fuel use for cooking and heating with the progression of multimorbidity. Results: The proportion of participants reporting solid fuel use for both cooking and heating was 59.0% at baseline. Solid fuel use for both cooking and heating was associated with the progression of multimorbidity (adjusted OR: 1.42, 95% CI: 1.19-1.70), compared with clean fuel use for both. Conclusion: Solid fuel use for cooking and heating play an important role in the progression of multimorbidity. Therefore, solid fuel reduction should be considered in developing multimorbidity control and prevention programmes.

Associations of Household Solid Fuel Use With Falls and Fall-Related Injuries in Middle-Aged and Older Population in China: A Cohort Study.

Objective: This study evaluated the associations of solid fuels with incidence of falls and fall-related injuries. Methods: Data were taken from wave 1∼4 of the China Health and Retirement Longitudinal Study, including 15,651 participants aged 45years and older. Modified Poisson regression was used to examine the associations of solid fuels with falls and fall-related injuries. Results: Modified Poisson regression analysis showed that solid fuels users for cooking had an increasing incidence of falls and fall-related injuries, with RR of 1.211 (95% CI: 1.124, 1.305) and 1.248 (95% CI: 1.107, 1.408); for heating had an incidence, with RR of 1.178 (95% CI: 1.062, 1.306) and 1.134 (95% CI: 0.963, 1.335); combined for cooking and heating, with RR of 1.247 (95% CI: 1.105, 1.408) and 1.185 (95% CI: 0.982, 1.431). Conclusion: Our study suggests that solid fuel use is associated with a higher incidence of falls and fall-related injuries among adults aged 45 years and older in China. It is necessary to restrict solid fuel use to reduce household air pollution and make stronger environmental protection policies to improve household environment.

PS-P03-11: EFFECT OF CLEANER COOKING FUEL (LPG) ON CARDIOPULMONARY HEALTH IN WOMEN FROM RURAL MAHARASHTRA

Background and Objective: Air pollution generated due to the use of solid fuels is recognized to be an environmental and health risk globally, especially in developing countries. Exposure to household air pollution is estimated to kill 3.8 million people worldwide. Major victims are women who are the immediate users. In an attempt to address this issue, the Indian government launched the Pradhan Mantri Ujjwala Yojana (PMUY) which provides clean LPG cooking gas to first-time users. However, it is majorly being promoted as a scheme about providing cooking gas to those who don’t have it but the health benefits of the scheme are not being focused. Accordingly, this study aimed to evaluate the effect of LPG on cardiopulmonary health in women. Design and method: A total of 997 healthy women participants (808 primary cooks and 189 secondary cooks) who cooked either with biomass or with LPG were enrolled. Systolic (SBP) and diastolic blood pressure (DBP), blood glucose was measured in all study participants and data on 24-hour personal exposure to fine particulate matter < 2.5 μm (PM2.5) and lung function (by spirometry) were measured on a subset using a standard protocol. Socio-demographic data, cooking practices and other information were collected using a validated questionnaire. Descriptive analysis was done in SPSS v26. Results: Results highlighted that SBP, DBP, mean arterial pressure, pulse pressure and glucose level were significantly higher in the biomass group compared to the LPG group in both primary and secondary cooks. The prevalence of hypertension in primary and secondary cooks was 29.5 and 33.6 respectively in biomass users compared to 21.1 and 13.4 in LPG users. Higher number of obstructive airway pattern (n = 10; 6.4% vs n = 2 1.3%), restrictive airway pattern (n = 31; 19.7 % vs n = 19; 12.5 %) and small airway obstruction (n = 55; 35.0 % vs n = 22; 14.4 %) was observed in biomass group compared to LPG group respectively. After adjusting for age, BMI and study group, it was seen that biomass exposure index (odds ratio [OR] 2.288; 95% confidence interval [CI] 1.169, 4.479, P = 0.016) and PM2.5 levels (OR 1.065; 95% CI 1.035, 1.096, P < 0.001) significantly increased the odds of having hypertension. Conclusions: Based on preliminary analysis, it can be concluded that the use of biomass is significantly associated with an increased risk of hypertension and impaired lung function. Thus, adoption of cleaner cooking fuels like LPG will have meaningful clinical and public health benefits.

Енергетичні складові сталого розвитку в країнах Європейського Союзу та в Україні

The energy components of sustainable development in the countries of the European Union have been analyzed, in particular according to goal 7 “Affordable and clean energy”, directions of the European Green Deal, taking into consideration synergies and compromises, as well as cross-cutting factors in achieving the specified indicators. It is shown that in 2019, the EU’s energy dependence on energy imports by types of fuel was: oil and oil products – more than 90 %, natural gas – about 80 %, solid fossil fuels – about 40 %. During 2014–2019, the decrease in the use of solid fuels (−4.9 %) was compensated by the increase in the use of renewable energy sources and biofuels (+2 %), as well as by the increase in the use of natural gas (+3.4 %), which could not cause a significant reduction in the share of fossil fuel use and a reduction in emissions of greenhouse gas – carbon dioxide CO2, at the same time the total dependence of EU countries on fuel imports increased from 54.4 to 60.7 % (by 6.3 %), which negatively affects the achievement of energy indicators of sustainable development. In 2019, the total share of renewable energy sources was 19.7 % with an ambitious goal of reaching 32 % in 2030. The energy components of sustainable development in Ukraine are analyzed. It is shown that, in particular, according to goal 7 “Affordable and clean energy”, the progress of the specified indicators is characterized by a low probability of achievement; in 2019, the share of coal imports in Ukraine was 68.6 %, oil – 76.7 %, natural gas – 45.1 %, and the total share of imports of primary energy resources by 2030 should be reduced to a level of not less than 12 % and the share of energy from renewable sources should reach 17 %. Based on a comparison of the energy components of sustainable development in the countries of the European Union and in Ukraine, the main requirements for energy indicators and tasks of sustainable development for Ukraine and its regions are proposed. These requirements differ in the addition of energy indicators and tasks of sustainable development in Ukraine with indicators that are monitored in the countries of the European Union and were not used in Ukraine before, as well as the introduction of indicators that take into consideration the energy characteristics of the regions of Ukraine. An adaptive structure of energy tasks and indicators for the regions of Ukraine is proposed.

An econometric model of household electricity consumption. A case study of Poland

Purpose: Electrical energy is in this day and age fundamental to the functioning of every household. The use of gas, heating oil or solid fuels for home heating also involves the supply of electricity. Today, electric power is the most environmentally friendly source of energy. Experience has shown that substitution of an oil heating system with a heat pump resulted in significant financial savings for the household. Design/methodology/approach: The purpose of this paper shall entail the construction of a multi-equation econometric model describing the mechanisms of electricity consumption in a specified household. The model takes the nature of a system of interdependent equations. Described shall be the monthly volume of electricity consumption, payment amount of for this energy (in PLN), and price per 1 MWh in a given month. Monthly time series from September 2015 to November 2022 have been used, which resulted in a time series with a count of 87 statistical observations. Findings: The econometric model of household electricity consumption presented in this paper confirms both the hypothesis about feedback between the variables USAGE and PRICE as well as the recursive effect of electricity consumption volume on its value in monetary units. In addition to the cognitive value of the econometric modeling results obtained, the empirical tool constructed makes enables forecast estimation of the energy consumption volume, its value and unit price in subsequent months, for at least 12 consecutive months. Practical implications: This type of research has great practical utility. They make it easier for rational interaction between electricity sellers and specific consumers. Social implications: Knowledge about the mechanisms of electricity consumption on the farm home may influence the rationalization of consumption and spending. This type of rationalization should have a positive impact on the environment natural, contributing to the reduction of greenhouse gas emissions. Originality/value: The novelty and originality of the work are the identification of the mechanism behavior of a single household consuming energy electric. Feedback between magnitudes revealed electricity consumption and its price on a specific farm home. The recipients of the work will be electricity sellers, consumers, and researchers of household market behavior. Keywords: econometric model, electricity consumption, interdependent equations. Category of the paper: Research paper. Case study.

Indoor Solid Fuel Use and Non-Neoplastic Digestive System Diseases: A Population-Based Cohort Study Among Chinese Middle-Aged and Older Population.

Objectives: We tended to explore the association of indoor air pollution (IAP) and non-neoplastic digestive system diseases (NNDSD) among the Chinese middle-aged and older population. Methods: From 2011 to 2018, we included 7884 NNDSD-free adults from the China Health and Retirement Longitudinal Study (CHARLS). Physician-diagnosed NNDSD was obtained by self-reported information at baseline and updated across follow-up surveys. We investigated the associations between baseline exposure of solid fuel use for cooking and/or heating and NNDSD diagnosed during follow-up through Cox proportional hazard models. Furthermore, we examined the relationship between cooking fuel switching and NNDSD diagnosed during follow-up. Results: Solid fuel use for cooking and/or heating was positively associated with NNDSD after adjusting for potential confounders. The risk of NNDSD among subjects who always use solid fuel for cooking (adjusted hazard ratio [aHR]: 1.42; 95% confidence interval [CI]: 1.09, 1.84) was higher than those with always clean fuels. Moreover, we found a lower NNDSD risk among participants who switched from solid to clean cooking fuel (aHR: 0.65; 95% CI: 0.49, 0.87) than those with always solid fuels. Conclusion: Our present study shows that indoor solid fuel use is a dependent risk factor for NNDSD. Moreover, switching to clean fuel may contribute to the prevention of digestive system illnesses.

Exposure to indoor air pollution and the cognitive functioning of elderly rural women: a cross-sectional study using LASI data, India

BackgroundThe majority of people in rural developing counties still rely on unclean and solid fuels for cooking, putting their health at risk. Adult and elderly women are most vulnerable due to prolonged exposure in cooking areas, and Indoor Air Pollution (IAP) may negatively impact their health and cognitive function. This study examines the effect of IAP on the cognitive function of middle-aged and elderly rural women in India.MethodsThe study utilized the data from the Longitudinal Ageing Study in India (LASI 2017–18, Wave-1). Bivariate analysis and multilevel linear regression models were applied to show the association between IAP and the cognitive abilities of rural women and results from regression were presented by beta coefficient (β) with 95% confidence interval (CI). Confounding factors such as age, education, health risk behaviours, marital status, monthly per capita consumption expenditure (MPCE), religion etc. were adjusted in the final model.ResultsThe study found that 18.71 percent of the rural women (n = 3,740) lived in Indoor Air Pollution exposed households. IAP was significantly found to be associated with the cognitive functional abilities among the middle and older aged rural women. Middle and older aged rural women exposed to IAP had lower cognitive functional abilities than non-exposed women. Comparing to the non-exposed group, the cognitive score was worse for those exposed to IAP in both the unadjusted (β = -1.96; 95%CI: -2.22 to -1.71) and the adjusted (β = -0.72; 95%CI: -0.92 to -0.51) models. Elderly rural women from lower socioeconomic backgrounds were more likely to have cognitive impairment as a result of IAP.ConclusionFindings revealed that IAP from solid fuels could significantly affect the cognitive health of elderly rural women in India, indicating the need for immediate intervention efforts to reduce the use of solid fuels, IAP and associated health problems.

Synthetic oxygen carrier C28 compared to natural ores for chemical looping combustion with solid fuels in 80 kWth pilot plant experiments

Chemical Looping Combustion (CLC) is a highly efficient CO2 separation technology with no direct contact between combustion air and fuel. A metal oxide is used as oxygen carrier (OC) in a dual fluidized bed to generate clean CO2. The use of solid fuels, especially biomass, is the focus of current research, because of the possibility of “negative” CO2-emissions. The OC is a key component, because it must meet special requirements for solid fuels, which are different to gaseous fuels. Most frequently naturals ores or synthetic materials are used as OC. Synthetic OC are characterised by higher reactivity at the expense of higher costs. For this reason, so far not so many experiments have been conducted on a larger scale with synthetic OC on solid CLC. This work deals with the synthetic perovskite C28 and investigating the suitability as oxygen carrier in an 80 kWth pilot plant for chemical looping combustion with biogenic fuels. The experiments show a significantly increased combustion efficiency of 99.6 % compared to natural ores and a major influence of the solid circulation rate on general performance, whereby carbon capture rates up to 98.3 % were reached. Furthermore, the role of the fuel reactor's counter-current flow column and its impact on better gas conversion was investigated. C28 suffered no deactivation or degradation over the experimental time, but first traces of ash layer formation, phase shifting and attrition of fines could be detected. The focus of further research should lie on long-term stability and reactivity for their high impact on the economic scale up of C28.

Informally sourced solid fuel use: Examining its extent and characteristics of the users in the residential sector in Ireland

Developing effective policy solutions to transition away from the use of solid fuels for residential heating purposes can be hindered by the lack of reliable data on its use. One such issue is the extent of informal solid fuel use, that is, consumption from sources outside of formal commercial channels. This is an area which has been largely ignored in previous empirical research. Using a survey of residential solid fuel users, the extent of solid fuel use in the residential sector in Ireland from informal sources for two fuels, sod peat and wood, is quantified. Sod peat is found to be almost exclusively sourced informally while just over half of wood use is estimated to be sourced by households in this way. Factors including location, household income, being a primary user of the fuel and having strong cost motivations all effect the probability of sourcing solid fuels informally relative to formal sources. The sizeable extent to which informal sources of solid fuels are used in Ireland arising from the analysis in this paper, highlights the potential for substitution to this unregulated alternative. This should be carefully monitored for effective implementation of new and existing solid fuel regulations.

The impacts of non-farming income on rural household energy choices: Empirical evidence from China.

This study uses data from the China Family Panel Studies to analyze the possible impact of non-farming income on household energy choices. We use ordinary least squares and instrumental variable estimation methods to investigate the causal effect of non-farming income on household energy choices. We find that an increase in non-farming income assisted farmers in reducing their use of solid fuels in favor of clean energy. Our heterogeneity analysis, based on the average rural household income and geographical location of the village, shows that the energy upgrade effect of non-farming income is more obvious in high-income areas and suburbs closer to the county seat center. Further, we find that non-farming income has an impact on rural household energy choice mainly through the optimization of household energy-saving appliances and the enhancement of environmental awareness.

Associations of personal exposure to domestic heating and cooking fuel emissions and epidemiological effects on rural residents in the Fenwei Plain, China

Solid fuel combustion for domestic heating in northern China in the wintertime is of great environmental and health concern. This study assesses personal exposure to particulate matter with different aerodynamic diameters and multiple gaseous pollutants from 123 rural residents in Yuncheng, the Fenwei Plain. The subjects are divided into groups based on the unique energy source applied, including biomass, coal, and electricity/no heating activities. The health effects of the exposures are expressed with four urinary biomarkers. The personal exposure levels to three different aerodynamic particle sizes (i.e., PM10, PM2.5, and PM1) of the electricity/no heating group are 5.1 % –12 % lower than those of the coal group. In addition, the exposure levels are 25 %–40 % lower for carbon monoxide (CO) and 10.8 %–20.3 % lower for ozone (O3) in the electricity/no heating group than the other two fuel groups. C-reactive protein (CRP) in the urine of the participants in biomass and coal groups is significantly higher than that in the electricity/no heating group, consistent with the observations on other biomarkers. Increases in 8-hydroxy-2 deoxyguanosine (8-OHdG), interleukin-8 (IL-8), and vascular endothelial growth factor (VEGF) are observed for the exposures to higher concentrations of air pollutants. For instance, PMs and nitrogen dioxide (NO2) show significant impacts on positive correlations with 8-OHdG and IL-8, while O3 positively correlates with CRP. PM1 exhibits higher effects on the biomarkers than the gaseous pollutants, especially on VEGF and IL-8. The study indicates that excessive use of traditional domestic solid fuels could pose severe health effects on rural residents. The promotion of using clean energy is urgently needed in the rural areas of northern China.

Pyrolysis and Gasification of Biomass and Waste

The use of renewable solid fuels, including biomass, is of great importance in today’s society [...]

Estimating the burden of disease attributable to household air pollution from cooking with solid fuels in South Africa for 2000, 2006 and 2012.

Household air pollution (HAP) due to the use of solid fuels for cooking is a global problem with significant impacts on human health, especially in low- and middle-income countries. HAP remains problematic in South Africa (SA). While electrification rates have improved over the past two decades, many people still use solid fuels for cooking owing to energy poverty. To estimate the disease burden attributable to HAP for cooking in SA over three time points: 2000, 2006 and 2012. Comparative risk assessment methodology was used. The proportion of South Africans exposed to HAP was assessed and assigned the estimated concentration of particulate matter with a diameter <2.5 μg/m3 (PM2.5) associated with HAP exposure. Health outcomes and relative risks associated with HAP exposure were identified. Population-attributable fractions and the attributable burden of disease due to HAP exposure (deaths, years of life lost, years lived with disability and disability-adjusted life years (DALYs)) for SA were calculated. Attributable burden was estimated for 2000, 2006 and 2012. For the year 2012, we estimated the attributable burden at provincial level. An estimated 17.6% of the SA population was exposed to HAP in 2012. In 2012, HAP exposure was estimated to have caused 8 862 deaths (95% uncertainty interval (UI) 8 413 - 9 251) and 1.7% (95% UI 1.6% - 1.8%) of all deaths in SA, respectively. Loss of healthy life years comprised 208 816 DALYs (95% UI 195 648 - 221 007) and 1.0% of all DALYs (95% UI 0.95% - 1.0%) in 2012, respectively. Lower respiratory infections and cardiovascular disease contributed to the largest proportion of deaths and DALYs. HAP exposure due to cooking varied across provinces, and was highest in Limpopo (50.0%), Mpumalanga (27.4%) and KwaZulu-Natal (26.4%) provinces in 2012. Age standardised burden measures showed that these three provinces had the highest rates of death and DALY burden attributable to HAP. The burden of disease from HAP due to cooking in SA is of significant concern. Effective interventions supported by legislation and policy, together with awareness campaigns, are needed to ensure access to clean household fuels and improved cook stoves. Continued and enhanced efforts in this regard are required to ensure the burden of disease from HAP is curbed in SA.

Indoor air pollution from solid fuels use, inflammation, depression and cognitive function in middle-aged and older Chinese adults

BackgroundFew studies have focused on the influence of indoor air pollution on depression and cognitive impairment; besides, the underlying mechanism is not well-established. ObjectiveThis study aimed to fill the above gaps by exploring the underlying influence mechanism of solid fuel use, the major cause of indoor air pollution, with the risk of depression and cognitive impairment. MethodsThis data came from China Health and Retirement Longitudinal Study (CHARLS) 2015 dataset. Self-reported household cooking fuels were collected and categorized as clean fuels and solid fuels. High-sensitivity C-reactive protein (CRP) and white blood cells (WBC) were used to measure inflammation. Depression and cognitive function were assessed by using standardized questionnaires. ResultsRespondents had an average Center for Epidemiologic Studies Depression Scale (CESD-10) scores of 7.68 (SD = 6.14) and cognitive function scores of 15.97 (SD = 4.84). In the whole sample, 36.4 % of respondents used solid fuels use, but this proportion was much greater among those living in rural areas (78.38 %). Compared with clean fuel users, solid fuel users had more depression and worse cognitive function. After adjusting for confounders, indoor air pollution was significantly associated with depression and cognitive function respectively (β = −0.444, p < 0.001; β = 0.656, p < 0.001). Indoor air pollution was significantly related to the WBC (β = 0.170, p < 0.01), but not for the CRP. The WBC mediated the association between indoor air pollution and depression (β = 0.026, p < 0.01). ConclusionIn conclusion, solid fuel use was significantly associated with a higher risk of depression and cognitive impairment. Furthermore, we found that solid fuel use influences depression partly via the inflammatory profile.

Chronic obstructive pulmonary disease (COPD) and air pollution: The case of Morocco

Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide. Available evidence suggests that air pollution is a factor associated with COPD. The present work aimed to review the epidemiological evidence for the effect of air pollution on COPD in Morocco. We conducted a literature search of the Scopus, Web of Science, Pub Med, and Google Scholar databases for published studies on the effect of air pollution on all respiratory diseases, including COPD. Any study on the effect of air pollution on the development or aggravation of respiratory diseases, published in English or French, was included in this review. Of the 1384 studies identified in the initial phase, eleven studies were eligible for inclusion in this review. Only two studies were found on the association between air pollution and the development of COPD in Morocco. The first study showed a significant association between the use of solid fuels for cooking and the development of COPD in Moroccan women. The second study revealed a statistically significant association between ambient air pollution by sulphur dioxide (SO2) and the risk of developing COPD. No research was found on the effect of air pollutants as a factor in the aggravation of COPD in affected individuals. The review has highlighted important research gaps regarding the effect of air pollution on COPD in Morocco. Therefore, future studies with long follow-up periods and precise and objective measurements of the effect of air pollutant exposure on the development or exacerbation of COPD on a national scale are certainly needed.

Household air pollution, adherence to a healthy lifestyle, and risk of cardiometabolic multimorbidity: Results from the China health and retirement longitudinal study

BackgroundThe adverse health effects of household air pollution have been widely explored, but few studies have evaluated the effects of household air pollution on the risk of cardiometabolic multimorbidity (CMM), a pressing public health concern worldwide. Thus, we aimed to investigate whether exposure to household use of polluting fuels is associated with morbid CMM and, if so, whether a healthy lifestyle could mitigate this association. MethodsIn this prospective, nationwide representative cohort of the China Health and Retirement Longitudinal Study (CHARLS), participants free of CMM (defined as the coexistence of 2 or more of the following: heart disease, stroke, and diabetes or high blood sugar) were included in 2011–2012 and followed for CMM incidence until 2018. Household air pollution was measured as the use of solid fuels for cooking and heating. The healthy lifestyle score was determined by six factors, physical activity, smoking, body mass index, total cholesterol, blood glucose, and blood pressure, and categorized into three groups (unhealthy, 0–1 factors; intermediate, 2–4; and healthy, 5–6). Cox proportional hazards models investigated associations between household air pollution and incident CMM. The potential modifier effect of a healthy lifestyle score was tested through stratified analyses. ResultsAmong 7125 eligible participants, 239 incident cases of CMM were identified over a median follow-up of 7.0 years. After adjustment for potential confounders, the use of solid household fuels for heating was associated with more significant hazards of CMM (adjusted hazard ratio [HR] 1.71, 95 % confidence interval [CI] 1.28 to 2.28), while use for cooking (HR, 1.14; 95 % CI, 0.85 to 1.52) was not. Compared with participants in the unhealthy group, those in the healthy and intermediate groups had considerably lower CMM risk, with adjusted HRs (95 % CI) of 0.17 (0.09 to 0.31) and 0.39 (0.29 to 0.53), respectively, regardless of the household air pollution category. Importantly, when participants adhered to a healthy lifestyle, exposure to household air pollution was no longer significantly associated with a higher risk of CMM (adjusted HR 1.77, 95 % CI 0.51 to 6.12; P = 0.369). ConclusionsHousehold usage of polluting fuels was significantly associated with a higher risk of CMM, and adherence to a healthy lifestyle may mitigate this adverse effect. From a broader perspective, our findings underscore the importance of public health policies and interventions targeting multiple exposures (air pollution, physical activity, smoking, etc.) in enhancing the prevention of detrimental cardiometabolic health effect.

Mapping development and health effects of cooking with solid fuels in low-income and middle-income countries, 2000–18: a geospatial modelling study

More than 3 billion people do not have access to clean energy and primarily use solid fuels to cook. Use of solid fuels generates household air pollution, which was associated with more than 2 million deaths in 2019. Although local patterns in cooking vary systematically, subnational trends in use of solid fuels have yet to be comprehensively analysed. We estimated the prevalence of solid-fuel use with high spatial resolution to explore subnational inequalities, assess local progress, and assess the effects on health in low-income and middle-income countries (LMICs) without universal access to clean fuels. We did a geospatial modelling study to map the prevalence of solid-fuel use for cooking at a 5 km × 5 km resolution in 98 LMICs based on 2·1 million household observations of the primary cooking fuel used from 663 population-based household surveys over the years 2000 to 2018. We use observed temporal patterns to forecast household air pollution in 2030 and to assess the probability of attaining the Sustainable Development Goal (SDG) target indicator for clean cooking. We aligned our estimates of household air pollution to geospatial estimates of ambient air pollution to establish the risk transition occurring in LMICs. Finally, we quantified the effect of residual primary solid-fuel use for cooking on child health by doing a counterfactual risk assessment to estimate the proportion of deaths from lower respiratory tract infections in children younger than 5 years that could be associated with household air pollution. Although primary reliance on solid-fuel use for cooking has declined globally, it remains widespread. 593 million people live in districts where the prevalence of solid-fuel use for cooking exceeds 95%. 66% of people in LMICs live in districts that are not on track to meet the SDG target for universal access to clean energy by 2030. Household air pollution continues to be a major contributor to particulate exposure in LMICs, and rising ambient air pollution is undermining potential gains from reductions in the prevalence of solid-fuel use for cooking in many countries. We estimated that, in 2018, 205 000 (95% uncertainty interval 147 000-257 000) children younger than 5 years died from lower respiratory tract infections that could be attributed to household air pollution. Efforts to accelerate the adoption of clean cooking fuels need to be substantially increased and recalibrated to account for subnational inequalities, because there are substantial opportunities to improve air quality and avert child mortality associated with household air pollution. Bill & Melinda Gates Foundation.

Maps of solid-fuel use and household air pollution

Nearly 3 million people are estimated to die from household air pollution every year, the overwhelming majority of whom live in low-income and middle-income countries (LMICs).1 Reliance on solid-fuel use for cooking, heating, and lighting substantially contributes to household air pollution. Thus, replacing solid fuels with clean energy sources in LMICs is a priority goal for public health.2 In view of the substantial health burden attributable to household air pollution, access to affordable clean energy is one of the Sustainable Development Goals (SDGs) set by the UN in 2015, which are to be achieved by 2030.

Organic aerosol sources in Krakow, Poland, before implementation of a solid fuel residential heating ban

Krakow is a pollution hot-spot in Europe which is thought to be caused mainly by a high use of coal combustion (power plants, residential heating). Here, we quantify the impact of coal burning on air quality in the city of Krakow before the use of solid fuels for residential heating was banned within the city of Krakow. The particulate matter (PM) was collected on 126 24-hour filter samples (January to September, both PM1 and PM10, i.e., with an aerodynamic diameter smaller than 1 μm and 10 μm, respectively) and analyzed with an aerosol mass spectrometer and the sources of the organic aerosol (OA) quantified. Secondary OA (SOA) likely from residential heating was the main contributor to winter-time OA (78 % in PM1, 57 % in PM10) and was composed of equal parts of fossil and non-fossil emissions. Additionally, fresh solid fuel combustion emissions from residential heating contributed to OA during winter (coal combustion OA (CCOA): 12 %, biomass burning OA (BBOA): 3 %). While BBOA contributed substantially to water-soluble OA, COOA was found to be water-insoluble and thus not identified as part of water-soluble OA. Together with the fairly low water-solubility of winter oxygenated OA (WOOA, 29 %), this leads to a low overall water-solubility of organic carbon during winter (35 %). In contrast, spring and summer were characterized by more soluble organic carbon (71 % in PM1, 55 % in PM10) which was dominated by biogenic sources (non-fossil), i.e., fine biogenic secondary oxygenated OA (summer oxygenated OA (SOOA): 35 % in PM1) and coarse primary biological OA (PBOA: 54 % in PM10). Overall, here we provide information on OA's sources needed to evaluate the success of mentioned efforts to improve air quality in Krakow in future studies.