Who adopts improved fuels and cookstoves? A systematic review

Development and Performance Evaluation of Biomass-Based Injera Baking Gasifier Stove: A Case Study of Clean Cooking Technologies in Ethiopia

The primary energy source in Ethiopia is biomass. Over 80% of Ethiopians are rural dwellers who rely on biomass energy for lighting and cooking. In most parts of Ethiopia, injera is traditionally baked using an open fire, a three stone, or a device using woody biomass. These baking stoves have very low efficiency and consume a significant amount of fuel. Moreover, these traditional baking stoves have released large amounts of indoor air pollution, which has led to different types of health-related risks, especially for women and children in the country. Therefore, the aim of this study was to investigate efficient and fuel-saving injera baking technologies. Rigorously, an injera baking gasifier stove was designed, developed, and characterized in detail through water boiling and control cooking test methods. The indoor air pollution level was evaluated using particulate matter measuring instruments. The result indicated that the developed gasifier stove had a thermal efficiency of 21.8%. Furthermore, an 86% fuel savings performance was demonstrated by the controlled cooking test for the injera baking gasifier stove. The average emission concentrations of particulate matter and carbon monoxide were 608 µg/m3 and 9 ppm, respectively, during indoor air pollution determination. The study showed that injera baking gasifier stoves are a promising cooking technology for societies where baking is mostly dependent on traditional biomass fuel.

Assessment of the association between health problems and cooking fuel type, and barriers towards clean cooking among rural household people in Bangladesh

BACKGROUND

In low- and middle-income countries, households mainly use solid fuels like wood, charcoal, dung, agricultural residues, and coal for cooking. This poses significant public health concerns due to the emission of harmful particles and gases. To address these issues and support Sustainable Development Goals (SDGs), adopting cleaner cooking fuels like electricity and gas are acknowledged as a viable solution. However, access to these cleaner fuels is limited, especially in rural areas.

METHODS

This study conducted a face-to-face survey with 1240 individuals in rural Bangladesh to explore the link between health issues and cooking fuel type, as well as barriers to transitioning to clean cooking. Using a convenient sampling technique across four divisions/regions, the survey gathered socio-demographic and health data, along with information on clean cooking barriers through a semi-structured questionnaire. Binary and multivariable logistic regression analyses were then employed to identify significant associations between cooking fuel type and health problems.

RESULTS

The study revealed that a majority of participants (73.3%) relied on solid fuel for cooking. The use of solid fuel was significantly correlated with factors such as lower education levels, reduced family income, location of residence, and the experience of health issues such as cough, chest pressure while breathing, eye discomfort, diabetes, asthma, and allergies. Economic challenges emerged as the foremost obstacle to the adoption of clean cooking, accompanied by other contributing factors.

CONCLUSION

The use of solid fuel in rural Bangladeshi households poses substantial health risks, correlating with respiratory, eye, cardiovascular, and metabolic issues. Lower education and income levels, along with specific residential locations, were associated with higher solid fuel usage. Economic challenges emerged as the primary obstacle to adopting clean cooking practices. These findings emphasize the need for implementing strategies to promote clean cooking, address barriers, and contribute to achieving Sustainable Development Goal targets for health and sustainable energy access in Bangladesh.

Spatial variation and factors associated of solid fuel use in Ethiopia a multilevel and spatial analysis based on EDHS 2016

Cooking and heating using solid fuels, such as dung, wood, agricultural residues, grass, straw, charcoal, and coal, is a main source of household air pollution. This indoor combustion encompasses a diversity of health detrimental pollutants, especially for people from low-income countries like Ethiopia since solid fuels are accessible easily at a lesser cost. Limited studies done showing factors affecting in choosing fuel type and no study, which revealed spatial heterogeneity of solid fuel used based on such nationally representative data. Therefore, this study, aimed at investigating spatial variation and determinants of solid fuel use in Ethiopia. This study was done using the data from the Ethiopian Demographic and Health Survey 2016, a national representative sample (16,650) households were included. Spatial and Multi-level logistic regression analysis was done by considering the DHS data hierarchal nature. Variables in the final model with a p-value < 0.05 were reported as significant predictors of using solid fuel. All analyses were done using ArcGIS V.10.7.1 and STATA V.14 software. The finding of this study revealed that 90.8% (95% CI (87.9%, 91.2%)) of households depend on solid fuel for cooking. Based on the final model ;Male household head (AOR 1.38, 95% CI (1.12-1.71)), age of household head (AOR 1.61, 95% CI (1.20, 2.17)), and 1.49 (OR 1.49, 95% CI (1.12, 1.99)) respectively for the age classes of < 30, and 30-40, education attainment no education (OR 3.14, 95% CI (1.13, 8.71)) and primary education (AOR 2.16, 95% CI (2.78, 5.96), wealth index Poorest (AOR 11.05, 95% CI (5.68, 15.78)), Poorer (OR 5.19, 95% CI (5.43, 13.19)), Middle (OR 3.08, 95% CI (2.44, 8.73)), and Richer (OR 1.30, 95IC (1.07, 13.49)) compared to richest, and not accessibility of electricity (AOR 31.21, 95% CI (35.41, 42.67)), were individual-level factors significantly associated with using solid fuel. Community-level factors like households found at large city (AOR 2.80, 95CI (1.65, 4.77)), small city (AOR 2.58, 95% CI (1.55, 4.32)) town (AOR 4.02, 95% CI (2.46, 6.55)), and countryside (AOR 14.40, 95% CI (6.23, 21.15)) compared households found in capital city, community level media exposure (AOR 6.00, 95% CI (4.61, 7.82)) were statistically predictors in using solid fuel for cooking. This finding revealed that a large proportion of households in Ethiopia heavily depend on biomass, especially wood, for cooking. There was a greater disparity on solid fuel use for cooking in Ethiopia. Implementing major policy interventions should be introduced to reduce solid fuel use for cooking and inequalities in accessing clean fuel in Ethiopia.

Housing and health outcomes: evidence on child morbidities from six Sub-Saharan African countries

BACKGROUND

The connection between healthy housing status and health is well established. The quality of housing plays a significant role in infectious and non-communicable as well as vector-borne diseases. The global burden of disease attributable to housing is considerable with millions of deaths arising from diarrheal and respiratory diseases annually. In sub-Saharan Africa (SSA), the quality of housing remains poor although improvements have been documented. There is a general dearth of comparative analysis across several countries in the sub-region. We assess in this study, the association between healthy housing and child morbidity across six countries in SSA.

METHODS

We use the Demographic and Health Survey (DHS) data for six countries where the most recent survey collected health outcome data on child diarrhoea, acute respiratory illness, and fever. The total sample size of 91,096 is used in the analysis (representing 15, 044 for Burkina Faso, 11, 732 for Cameroon, 5, 884 for Ghana, 20, 964 for Kenya, 33, 924 for Nigeria, and 3,548 for South Africa). The key exposure variable is healthy housing status. We control for various factors associated with the three childhood health outcomes. These include quality housing status, residency (rural/urban), age of the head of the household, mother's education, mother's BMI status, marital status, mother's age, and religious status. Others include the child's gender, age, whether the child is from multiple or single births, and breastfeeding status. Inferential analysis using survey-weighted logistic regression is employed.

RESULTS

Our findings indicate that housing is an important determinant of the three outcomes investigated. Compared to unhealthier housing, healthy housing status was found to be associated with reduced odds of diarrhoea in Cameroon [Healthiest: aOR = 0.48, 95% CI, (0.32,0.71), healthier: aOR = 0.50, 95% CI,(0.35,0.70), Healthy: aOR = 0.60, 95% CI, (0.44,0.83), Unhealthy: aOR = 0.60, 95% CI, (0.44,0.81)], Kenya [Healthiest: aOR = 0.68, 95% CI, (0.52,0.87), Healtheir: aOR = 0.79, 95% CI, (0.63,0.98), Healthy: aOR = 0.76, 95% CI, (0.62,0.91)], South Africa[Healthy: aOR = 0.41, 95% CI, (0.18, 0.97)], and Nigeria [Healthiest: aOR = 0.48, 95% CI,(0.37,0.62), Healthier: aOR = 0.61, 95% CI,(0.50,0.74), Healthy: aOR = 0.71, 95%CI, (0.59,0.86), Unhealthy: aOR = 0.78, 95% CI, (0.67,0.91)], and reduced odds of Acute Respiratory Infection in Cameroon [Healthy: aOR = 0.72, 95% CI,(0.54,0.96)], Kenya [Healthiest: aOR = 0.66, 95% CI, (0.54,0.81), Healthier: aOR = 0.81, 95% CI, (0.69,0.95)], and Nigeria [Healthiest: aOR = 0.69, 95% CI, (0.56,0.85), Healthier: aOR = 0.72, 95% CI, (0.60,0.87), Healthy: aOR = 0.78, 95% CI, (0.66,0.92), Unhealthy: aOR = 0.80, 95% CI, (0.69,0.93)] while it was associated with increased odds in Burkina Faso [Healthiest: aOR = 2.45, 95% CI, (1.39,4.34), Healthy: aOR = 1.55, 95% CI, (1.09,2.20)] and South Africa [Healthy: aOR = 2.36 95% CI, (1.31, 4.25)]. In addition, healthy housing was significantly associated with reduced odds of fever among children in all countries except South Africa [Healthiest: aOR = 2.09, 95% CI, (1.02, 4.29)] where children living in the healthiest homes had more than double the odds of having fever. In addition, household-level factors such as the age of the household head, and place of residence were associated with the outcomes. Child-level factors such as breastfeeding status, age, and sex, and maternal-level factors such as education, age, marital status, body mass index (BMI), and religion were also associated with the outcomes.

CONCLUSIONS

The dissimilarity of findings across similar covariates and the multiple relations between healthy housing and under 5 morbidity patterns show unequivocally the heterogeneity that exists across African countries and the need to account for different contexts in efforts to seek an understanding of the role of healthy housing in child morbidity and general health outcomes.

Cooking and future risk of all-cause and cardiopulmonary mortality

Cooking is practiced worldwide and is associated with multiple social, economic and environmental factors; thus, understanding cooking-related health effects would have broad public health implications. Here, we show that after an average 9.9 years of follow-up for 510,106 Chinese adults, always cooking with clean fuels was associated with lower risks of all-cause (0.90 [95% confidence interval 0.87-0.93]; P = 1.39 × 10-9), cardiovascular (0.83 [0.78-0.87]; P = 6.83 × 10-11) and respiratory (0.88 [0.79-0.99]; P = 0.026) mortality compared with non-cooking, of which 50.1% (14.5-85.6%) to 66.0% (38.5-85.8%) could be attributed to increased household physical activity. The mortality risks decreased with extended duration of cooking with clean fuels in dose-response manners, with the lowest hazard ratios of 0.74 (0.68-0.80; P = 1.20 × 10-13) for all-cause and 0.62 (0.55-0.71; P = 3.15 × 10-12) for cardiovascular mortality among never-smokers reported over 25 years of cooking. Our findings suggest lower future mortality risks may be gained only when cooking with clean fuels.

Trends of ischemic heart disease mortality attributable to household air pollution during 1990-2019 in China and India: an age-period-cohort analysis

Cardiovascular diseases (CVD) caused by household air pollution (HAP) have sparked widespread concern globally in the recent decade. Meanwhile, increased ischemic heart disease (IHD) mortality has been the leading cause of worldwide CVD deaths. Both China and India experienced a high IHD burden and high exposure to HAP. The present study aimed to estimate and compare the long-term trends of HAP-attributable IHD mortality in the two countries. The data of this study were extracted from the Global Burden of Diseases (GBD) Study 2019. The age-period-cohort (APC) analysis was utilized to estimate the independent trends of the age, period, and cohort effects from 1990 to 2019. The age-standardized mortality rates (ASMRs) of HAP-attributable IHD have fallen faster in China than in India for both sexes. The local drift and net drift values were < 0 for all age groups in both countries. The age effects in both countries and sexes increased with time, suggesting age is a risk factor for IHD; conversely, period and cohort effects in China demonstrated a faster decline in both genders than in India. It indicated that China has been more successful than India in decreasing HAP-attributable IHD mortality.

Facilitators and barriers to the implementation of improved solid fuel cookstoves and clean fuels in low-income and middle-income countries: an umbrella review

2·6 billion people rely on solid fuels for cooking or heating. Accelerating access to cleaner solutions is crucial to reduce the negative effects of solid fuel use. Despite abundant evidence on how to implement these solutions, previous attempts have been disappointing. An overview of the evidence is missing and the translation of the evidence into practice is poor. We conducted an umbrella review using eight databases to: consolidate evidence on the factors that influence the implementation of improved solid fuel cookstoves and clean fuels in low-income and middle-income countries; weigh the level of confidence in existing evidence; and develop two practical implementation strategy tools. We identified 31 relevant reviews (13 systematic reviews and 18 narrative reviews) that covered over 479 primary studies. We found 15 implementation factors supported by the highest level of evidence. Regarding improved solid fuel cookstoves, these factors included: cost; knowledge and beliefs about the innovation; and compatibility. For clean fuels these factors included: cost; knowledge and beliefs about the innovation; and external policy and incentives. The factors were synthesised into the Cleaner Cookstove Implementation Tool and the Clean Fuel Implementation Tool. These tools can be used to optimise the implementation of cleaner cooking solutions, thereby improving health, environmental, climate, and gender equity outcomes.

Non-adoption decision of biogas in rural Pakistan: use of multinomial logit model

In 2009, Pakistan introduced a subsidized biogas program to disseminate clean and affordable energy in rural areas. However, the adoption rate did not appear as expected. Therefore, the present study aims to examine the determinants behind the non-adoption of biogas digesters. Detailed information via a structured questionnaire was obtained from biogas adopters and non-adopters, and analyses were performed in two levels. Initially, the study used the multinomial logit regression to elicit the non-adoption behavior. Results depicted family size, risk aversion, cook education (women), kitchen (inside the home), home structure, and non-availability of inputs as significant factors behind non-adoption. Detailed analysis also revealed that the factors like the age of household head, area of the house, cook education (women), location of the kitchen (inside the home), and the distance of the house to the bus stop (minutes) lead towards the potential adoption of biogas. The study also investigated the potential factors behind the long-term sustainability of biogas digesters with the help of binary logit. The results depicted that the kitchen's location (inside the house), cook education (women), training, and subsidy significantly and positively impact the biogas plant's probability of being functional. Based on these results, the study suggested that policymakers increase women's education in rural areas, provide a subsidy to reduce costs and risk, and arrange training for adopters.

Substantial transition to clean household energy mix in rural China

The household energy mix has significant impacts on human health and climate, as it contributes greatly to many health- and climate-relevant air pollutants. Compared to the well-established urban energy statistical system, the rural household energy statistical system is incomplete and is often associated with high biases. Via a nationwide investigation, this study revealed high contributions to energy supply from coal and biomass fuels in the rural household energy sector, while electricity comprised ∼20%. Stacking (the use of multiple sources of energy) is significant, and the average number of energy types was 2.8 per household. Compared to 2012, the consumption of biomass and coals in 2017 decreased by 45% and 12%, respectively, while the gas consumption amount increased by 204%. Increased gas and decreased coal consumptions were mainly in cooking, while decreased biomass was in both cooking (41%) and heating (59%). The time-sharing fraction of electricity and gases (E&G) for daily cooking grew, reaching 69% in 2017, but for space heating, traditional solid fuels were still dominant, with the national average shared fraction of E&G being only 20%. The non-uniform spatial distribution and the non-linear increase in the fraction of E&G indicated challenges to achieving universal access to modern cooking energy by 2030, particularly in less-developed rural and mountainous areas. In some non-typical heating zones, the increased share of E&G for heating was significant and largely driven by income growth, but in typical heating zones, the time-sharing fraction was <5% and was not significantly increased, except in areas with policy intervention. The intervention policy not only led to dramatic increases in the clean energy fraction for heating but also accelerated the clean cooking transition. Higher income, higher education, younger age, less energy/stove stacking and smaller family size positively impacted the clean energy transition.

Urban Households' Biomass Energy Fuel Stacking and Its Implications for Sustainable Development Goal Seven: The Case of Jimma Town, Ethiopia

Sustainable development goal seven aims to provide access to affordable, reliable, sustainable, and modern energy for all by 2030, but its progress and energy stacking conditions have not been evaluated. This study aims to assess the urban household energy profile and link its state to sustainable development goals. This study employs a cross-sectional study design on 265 households selected by systematic random sampling from a town called Jimma in Ethiopia and collects the data using interview-based semi-structured questionnaires. The study obtains information from all the selected households. The results show that more than 80% of the households have a grid electricity connection, but more than 85% of the households regularly use firewood and charcoal for cooking. On average, households use about 1236 kg of firewood and 630 kg of charcoal per year. Most households report power interruption, inability to afford electricity costs, and personal preferences for relying on biomass energy for cooking. Over 98% of the households use electricity for lighting, but few use it for appliances. This shows an inherent challenge attributed to the cooking energy services provided by biomass energy sources despite the accessibility of electricity. This shows the significant impacts of biomass energy stacking which connection to electricity alone cannot solve.

Visualization and analysis of mapping knowledge domains for the global transition towards clean cooking: a bibliometric review of research output from 1990 to 2020

Current statistics report that 2.6 billion households across the globe rely on polluting and inefficient cooking fuels and technologies, posing death-threatening health risks to people mainly from developing countries/regions. Several studies on clean cooking have been conducted with the emergence of international organizations such as the Clean Cooking Alliance to raise awareness. In the current study, a bibliometric tool, CiteSpace, was employed to analyze the 877 documents retrieved from the SCI-EXPANDED, SSCI, and A&HCI databases on clean cooking research from 1990 to 2020. The results reveal that interest in clean cooking research took a sharp rise in the last decade, especially after 2016. The research field has become increasingly interdisciplinary but has mostly centered on environment, energy, and health. The most productive countries/regions in this field are the USA, India, England, and China. The keyword and citation analyses indicate that research in this field mostly focuses on adverse impacts of household air pollution from unclean cooking fuels and technologies on the environment and public health particularly, in developing countries/regions. Also, the drivers and barriers to the large-scale adoption of clean cooking fuels and technologies have become a topic of interest in recent years. The three most studied clean cooking fuels among various regions are LPG, biogas, and electricity. This study synthesizes global research on clean cooking and may be beneficial to other researchers in understanding current trends in this field and serve as a guide for concentrating on the most important topics.

Does educated labor force is managing the green economy in BRCS? Fresh evidence from NARDL-PMG approach

It is observed that an educated labor force can increase the absorption capacity of the economy and improve the effectiveness of green technologies that lead to a reduction in potential CO2 emissions. The study investigates whether an educated labor force contributes to the management of the green economy or not in BRCS economies. Panel ARDL-PMG and NARDL-PMG approaches have been employed for empirical analysis for data ranging from 1995 to 2019. According to the ARDL-PMG results, a highly educated labor force contributes to alleviating CO2 emissions in the long run. In contrast, the findings of NARDL-PMG infer that positive component of a highly educated labor force has a significant negative impact on CO2 emissions, while negative component of a highly educated labor force has a positive impact on CO2 emissions in the long run. The study suggests that BRCS countries' policymakers should promote education and training for the labor force to maintain a reduction in CO2 emissions.

Subsidized LPG Scheme and the Shift to Cleaner Household Energy Use: Evidence from a Tribal Community of Eastern India

Traditional fuels have both environmental and health impacts. The transition from traditional to clean cooking fuel requires significant public policy actions. The Pradhan Mantri Ujjwala Yojana (PMUY) is one of the primary policies launched in India to eradicate energy poverty among households. Past studies have focused on the drivers that motivate rural households to adopt clean energy and identified the bottlenecks for adoption of clean energy in developing countries. PMUY’s success in terms of scale and pace is critical in the national drive to provide access to clean energy fuel to each citizen. The present study focuses on two objectives. First, we investigate the intensity of adoption and refill of LPG under the PMUY scheme. Second, we use household and other demographic characteristics to examine the factors that influence households’ decision on using LPG as a cooking fuel. Empirical results show that rapid growth has been witnessed in the provision of subsidized LPG connections. However, the annual average refill status stands at two LPG cylinders per beneficiary household indicating that the majority of the beneficiaries have failed to refill their LPG cylinders. This imbalance between rapid enrollment of LPG and limited refill among beneficiary households indicate the continued usage of traditional sources of energy for cooking. From the primary survey conducted in the rural tribal communities of Odisha, we observe that household income and education played a significant role in adoption of LPG and continued usage of LPG gas. Additionally, the logit and ordered probit models identify that membership in self-help groups, accessibility and awareness of LPG are the major adoption drivers. In conclusion, policy makers need to address the challenge of refill status among PMUY consumers. Further, educating households on health benefits through SHG and creating accessibility at village level can actively increase the usage of LPG.

Substitution strategies for cooking energy: To use gas or electricity?

The Chinese government has called for clean and effective energy substitution for cooking in rural areas. This paper assesses the environmental and economic impacts of various types of cooking fuels and stoves. According to the assessment results, the environmental impacts are highly influenced by the types of fuels and the efficiency of stoves used for cooking. Using biogas, liquefied petroleum gas (LPG), and natural gas for cooking instead of solid fuels can significantly reduce environmental emissions. To provide 1 megajoule (MJ) of useful cooking heat, the environmental costs of lump coal, honeycomb briquettes, and straw are the largest, estimated to be 80.4 yuan/MJ, 73.1 yuan/MJ, and 71.4 yuan/MJ, respectively. In addition, the economic assessment results show that the most expensive source of cooking fuel is LPG, with an average annual cost of 1700 yuan, while the cost of straw and firewood is the cheapest, at less than 100 yuan. The average annual cost of electricity is higher than that of natural gas. Regarding the substitution effects, using natural gas for cooking is better than using electricity. The environmental benefit of electricity substitution is only 10%-20% of natural gas substitution, and the corresponding increasing cost for residents is 1.5 times that of natural gas substitution.

Pregnant Women's Exposure to Household Air Pollution in Rural Bangladesh: A Feasibility Study for Poriborton: The CHANge Trial

The use of liquefied petroleum gas (LPG) for cooking is a strategy to reduce household air pollution (HAP) exposure and improve health. We conducted this feasibility study to evaluate personal exposure measurement methods to representatively assess reductions in HAP exposure. We enrolled 30 pregnant women to wear a MicroPEM for 24 h to assess their HAP exposure when cooking with a traditional stove (baseline) and with an LPG stove (intervention). The women wore the MicroPEM an average of 77% and 69% of the time during the baseline and intervention phases, respectively. Mean gravimetric PM_2.5 mass and black carbon concentrations were comparable during baseline and intervention. Temporal analysis of the MicroPEM nephelometer data identified high PM_2.5 concentrations in the afternoon, late evening, and overnight during the intervention phase. Likely seasonal sources present during the intervention phase were emissions from brick kiln and rice parboiling facilities, and evening kerosene lamp and mosquito coil use. Mean background adjusted PM_2.5 concentrations during cooking were lower during intervention at 71 μg/m³, versus 105 μg/m³ during baseline. Representative real-time personal PM_2.5 concentration measurements supplemented with ambient PM_2.5 measures and surveys will be a valuable tool to disentangle external sources of PM_2.5, other indoor HAP sources, and fuel-sparing behaviors when assessing the HAP reduction due to intervention with LPG stoves.

The mirror mechanism in schizophrenia: A systematic review and qualitative meta-analysis

BACKGROUND

Mirror neuron system (MNS) consists of visuomotor neurons that are responsible for the mirror neuron activity (MNA), meaning that each time an individual observes another individual performing an action, these neurons encode that action, and are activated in the observer's cortical motor system. Previous studies report its malfunction in autism, opening doors to investigate the underlying pathophysiology of the disorder in a more elaborate way and coming up with new rehabilitation methods. The study of MNA function in schizophrenia patients has not been as frequent and conclusive as in autism. In this research, we aimed to evaluate the functional integrity of MNA and the microstructural integrity of MNS in schizophrenia patients.

METHODS

We included case-control studies that have evaluated MNA in schizophrenia patients compared to healthy controls using a variety of objective assessment tools. In August 2022, we searched Embase, PubMed, and Web of Science for eligible studies. We used an adapted version of the NIH Quality Assessment of Case-Control Studies tool to assess the quality of the included studies. Evidence was analyzed using vote counting methods of the direction of the effect and was tested statistically using the Sign test. Certainty of evidence was assessed using CERQual.

RESULTS

We included 32 studies for the analysis. Statistical tests revealed decreased MNA (p = 0.002) in schizophrenia patients. The certainty of the evidence was judged to be moderate. Investigations of heterogeneity revealed a possible relationship between the age and the positive symptoms of participants in the included studies and the direction of the observed effect.

DISCUSSION

This finding contributes to gaining a better understanding of the underlying pathophysiology of the disorder by revealing its possible relation to some of the symptoms in schizophrenia patients, while also highlighting a new commonality with autism.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO identifier: CRD42021236453.

Effectiveness of interventions to reduce household air pollution from solid biomass fuels and improve maternal and child health outcomes in low- and middle-income countries: A systematic review and meta-analysis

Interventions to reduce household air pollution (HAP) are key to reducing associated morbidity and mortality in low- and middle- income countries (LMICs); especially among pregnant women and young children. This systematic review aims to determine the effectiveness of interventions aimed to reduce HAP exposure associated with domestic solid biomass fuel combustion, compared to usual cooking practices, for improving health outcomes in pregnant women and children under five in LMIC settings. A systematic review and meta-analysis was undertaken with searches undertaken in MEDLINE, EMBASE, CENTRAL, GIM, ClinicalTrials.gov, and Greenfile in August 2020. Inclusion criteria were experimental, non-experimental, or quasi-experimental studies investigating the impact of interventions to reduce HAP exposure and improve associated health outcomes among pregnant women or children under 5 years. Study selection, data extraction, and quality assessment using the Effective Public Health Practice Project tool were undertaken independently by two reviewers. Seventeen out of 7293 retrieved articles (seven pregnancy, nine child health outcome; 13 studies) met the inclusion criteria. These assessed improved cookstoves (ICS; n = 10 studies), ethanol stoves (n = 1 study), and Liquefied Petroleum Gas (LPG; n = 2 studies) stoves interventions. Meta-analysis showed no significant effect of ICS interventions compared to traditional cooking for risk of preterm birth (n = 2 studies), small for gestational age (n = 2 studies), and incidence of acute respiratory infections (n = 6 studies). Although an observed increase in mean birthweight was observed, this was not statistically significant (n = 4). However, ICS interventions reduced the incidence of childhood burns (n = 3; observations = 41 723; Rate Ratio: 0.66 [95% CI: 0.45-0.96]; I² : 46.7%) and risk of low birth weight (LBW; n = 4; observations = 3456; Odds Ratio: 0.73 [95% CI: 0.61-0.87]; I² : 21.1%). Although few studies reported health outcomes, the data indicate that ICS interventions were associated with reduced risk of childhood burns and LBW. The data highlight the need for the development and implementation of robust, well-reported and monitored, community-driven intervention trials with longer-term participant follow-up.

Lack of access to clean fuel and piped water and children's educational outcomes in rural India

Investments in clean fuel and piped water are often recommended in developing countries on health grounds. This paper examines an alternative channel, the relationship between piped water and access to liquefied petroleum gas (LPG) and children's educational outcomes. Results based on the second round of the India Human Development Survey (2011-12) for rural India show that children aged 6-14 years, living in households that rely on free collection of water and cooking fuel, have lower mathematics scores and benefit from lower educational expenditures than children living in households that do not collect water and fuel. Moreover, gender inequality in this unpaid work burden also matters. In households where the burden of collection is disproportionately borne by women, child outcomes are significantly lower, particularly for boys. The endogeneity of choice to collect or purchase water and cooking fuel are modeled via Heckman selection and the entropy balancing method.

Exploring smoke: an ethnographic study of air pollution in rural Malawi

Air pollution adversely affects human health, and the climate crisis intensifies the global imperative for action. Low-/middle-income countries (LMIC) suffer particularly high attributable disease burdens. In rural low-resource settings, these are linked to cooking using biomass. Proposed biomedical solutions to air pollution typically involve ‘improved cooking technologies’, often introduced by high-income country research teams. This ethnography, set in a rural Malawian village, aimed to understand air pollution within its social and environmental context. The results provide a multifaceted account through immersive participant observations with concurrent air quality monitoring, interviews and participatory workshops. Data included quantitative measures of individuals’ air pollution exposures paired with activity, qualitative insights into how smoke is experienced in daily life throughout the village, and participants’ reflections on potential cleaner air solutions. Individual air quality monitoring demonstrated that particulate levels frequently exceeded upper limits recommended by the WHO, even in the absence of identified sources of biomass burning. Ethnographic findings revealed the overwhelming impact of economic scarcity on individual air pollution exposures. Scarcity affected air pollution exposures through three pathways: daily hardship, limitation and precarity. We use the theory of structural violence, as described by Paul Farmer, and the concept of slow violence to interrogate the origins of this scarcity and global inequality. We draw on the ethnographic findings to critically consider sustainable approaches to cleaner air, without re-enacting existing systemic inequities.

Towards Sustainable Development Goal 7 “Universal Access to Clean Modern Energy”: National Strategy in Rwanda to Scale Clean Cooking with Bottled Gas

More than 90% of Rwandans rely on polluting solid fuels to meet their cooking needs. The negative impacts on health, climate, and the environment have led the Rwandan government to set a target of halving that number to 42% by 2024. A National Master Plan to promote scale up of liquefied petroleum gas (LPG) has been developed to define (i) the necessary market conditions, (ii) public and private sector interventions, and (iii) the expected societal impacts. Findings are reported from modelling scenarios of scaling LPG use towards the 2024 policy target and the 2030 target for “universal access to clean modern energy” (SDG7). Household LPG use is projected to increase from 5.6% in 2020 to 13.2% by 2024 and 38.5% by 2030. This level of adoption could result in a reduction of 7656 premature deaths and 403,664 disability-adjusted-life-years (DALYs), as well as 243 million trees saved. Reductions in carbon dioxide and black carbon emissions equivalents (CO2e and BCe, respectively) are estimated to reach 25.6 million MT and 14.9 MT, respectively, by 2030. While aggressive policy intervention is required, the health, environmental, and developmental benefits are clear. Implementation of the Rwanda National LPG Master Plan will provide a model for other sub-Saharan African countries to address the priorities for cessation of reliance on solid fuels as an energy source.

Why energy access is not enough for choosing clean cooking fuels? Evidence from the multinomial logit model

The transition to sustainable energy requires an assessment of drivers of the use of clean and dirty fuels for cooking. Literature highlights the importance of access to clean fuel for switching from dirty fuels to clean fuels. Though access to cleaner fuels, such as electricity promotes clean fuel use, it does not necessarily lead to a complete transition to the use of clean fuels. Households continue using traditional fuels in addition to the clean fuels. The main objective of this paper is to explain the choice of dirty cooking fuels even when access to electricity is provided. We use nationally representative household survey data to study the household energy use decisions in three middle-income countries, namely, India, Kazakhstan, and the Kyrgyz Republic. The study discusses the role of access to natural gas, free fuel, convenience or multi-use of fuels featured by the heating system installed, built-in environment, and other socio-economic factors in household fuel choice for cooking. The results show that access to natural gas increases the likelihood of opting for clean fuel, while the availability of free fuel in rural areas and the coal-based heating system promote the use of solid fuels.

Indoor unclean fuel cessation linked with adult cognitive performance in China

Both indoor unclean fuel use and CVD associates with cognitive function. Indoor fuel has transitioned from the use of unclean fuel to clean fuel in recent years in China. The aim of this study was to evaluate the association between adult cognitive function and such a transition and to investigate the potential role of CVD in this association. 7112 participants (26- to 98-years of age) with 12,676 observations living in twelve provinces of China from 1997 to 2015 were extracted based on having complete data. The associations, combined effects, and further mediation effects between indoor unclean fuel use and its transition, CVD, and cognitive function were tested using regression models, stratified analyses, the relative excess risk due to interaction (RERI), mediation analysis methods, and sensitivity analyses. Between 1997 and 2015, cooking fuel use coal and wood went down a lot in China, from a baseline of 26.9% to 6.1%, from 30.1% to 11.5%, respectively. Such a transition showed a positive association with delayed verbal recall (B = 0.288, p < 0.01), especially in rural area, subjects with age ≥ 65 years old, and women (all P < 0.05). The combined effect of the presence of hypertension during a baseline visit and such a transition on changes in delayed verbal recall was antagonistic (RERI = -0.529, p < 0.05). Moreover, the development of hypertension explained more than 50% of such a fuel transition-related decline of verbal memory. The transition of household energy to clean fuel was associated with a higher adult cognitive function. The presence or the development of CVD appeared to affect the association between indoor air pollution and cognitive function, which suggests a need to further optimize prevention of concurrent CVD and risk factor control in adults at higher risk for cognitive impairment and with indoor unclean cooking fuel, especially in potentially susceptible subgroups.

Investigating Cooking Activity Patterns and Perceptions of Air Quality Interventions among Women in Urban Rwanda

Household air pollution (HAP) from biomass cooking with traditional stoves is a major cause of morbidity and mortality in low-and-middle-income countries (LMICs) worldwide. Air quality interventions such as improved cookstoves (ICS) may mitigate HAP-related impacts; however, poor understanding of contextual socio-cultural factors such as local cooking practices have limited their widespread adoption. Policymakers and stakeholders require an understanding of local cooking practices to inform effective HAP interventions which meet end-user needs. A semi-structured questionnaire was administered to 36 women residing in biomass-cooking fuel households in Kigali, Rwanda to identify cooking activity patterns, awareness of HAP-related health risks and ICS intervention preferences. Overall, 94% of respondents exclusively used charcoal cooking fuel and 53% cooked one meal each day (range = 1-3 meals). Women were significantly more likely to cook outdoors compared to indoors (64% vs. 36%; p < 0.05). Over half of respondents (53%) were unaware of HAP-related health risks and 64% had no prior awareness of ICS. Participants expressed preferences for stove mobility (89%) and facility for multiple pans (53%) within an ICS intervention. Our findings highlight the need for HAP interventions to be flexible to suit a range of cooking patterns and preferred features for end-users in this context.

Ambient Air Pollution: Health Hazards to Children

Ambient air pollution is produced by sources including vehicular traffic, coal-fired power plants, hydraulic fracturing, agricultural production, and forest fires. It consists of primary pollutants generated by combustion and secondary pollutants formed in the atmosphere from precursor gases. Air pollution causes and exacerbates climate change, and climate change worsens health effects of air pollution. Infants and children are uniquely sensitive to air pollution, because their organs are developing and they have higher air per body weight intake. Health effects linked to air pollution include not only exacerbations of respiratory diseases but also reduced lung function development and increased asthma incidence. Additional outcomes of concern include preterm birth, low birth weight, neurodevelopmental disorders, IQ loss, pediatric cancers, and increased risks for adult chronic diseases. These effects are mediated by oxidative stress, chronic inflammation, endocrine disruption, and genetic and epigenetic mechanisms across the life span. Natural experiments demonstrate that with initiatives such as increased use of public transportation, both air quality and community health improve. Similarly, the Clean Air Act has improved air quality, although exposure inequities persist. Other effective strategies for reducing air pollution include ending reliance on coal, oil, and gas; regulating industrial emissions; reducing exposure with attention to proximity of residences, schools, and child care facilities to traffic; and a greater awareness of the Air Quality Index. This policy reviews both short- and long-term health consequences of ambient air pollution, especially in relation to developmental exposures. It examines individual, community, and legislative strategies to mitigate air pollution.

Firewood, forests, and fringe populations: Exploring the inequitable socioeconomic dimensions of Liquified Petroleum Gas (LPG) adoption in India

Liquified petroleum gas (LPG) is an important clean fuel alternative for households that rely on burning biomass for daily cooking needs. In India, Pradhan Mantri Ujjwala Yojana (PMUY) has provided poor households with LPG connections since 2016. We investigate cooking fuel use in households to determine the impact of the policy in the Central Indian Highlands Landscape (CIHL). The CIHL has a large population of marginalized social groups, including Indigenous, Scheduled Tribe, Schedule Caste, and Other Backward Caste people. We utilize survey data from 4,994 households within 500 villages living in forested regions collected in 2018 and a satellite-derived measure of forest availability to investigate the household and ecological determinants of LPG adoption and the timing of this adoption (pre- or post-2016). In addition, we document patterns of firewood collection and evaluate the extent to which households acquiring LPG change these activities. The probability of cooking with LPG was lowest for marginalized social groups. We observe that households recently adopting LPG, likely through PMUY, are poorer, more socially marginalized, less educated, and have more forest available nearby than their early-adopter counterparts. While 90% of LPG-using households continue to use firewood, households that have owned LPG for more years report spending less time collecting firewood, indicating a waning reliance on firewood over time. Policies targeting communities with marginalized social groups living near forests can further accelerate LPG adoption and displace firewood use. Despite overall growth in LPG use, disparities in access to clean cooking fuels remain between socioeconomic groups in India.

Status of energy utilization and factors affecting rural households' adoption of biogas technology in north-western Ethiopia

The National Biogas Policy of Ethiopia introduces plans for the implementation of biogas technologies in rural areas. However, rural households' decision to adopt biogas energy technology has been influenced by different socio-economic and institutional factors. This research was therefore undertaken to determine the actual energy consumption status and factors impacting the adoption of biogas technology by rural households in northwestern Ethiopia. Primary data from 182 randomly chosen households and 15 key informants were obtained. Different databases, such as journal articles, annual accounts, and unpublished papers, were used to gather secondary data. The data were analyzed using social science statistical package (SPSS 21st edition) tools using descriptive statistics, chi-square test, and independent-sample t-test. The results indicated that about 84.2% of the households have been using traditional biomass fuels (fuelwood, agricultural crop residue, dung cake, and charcoal) for baking Enjera and heating while the remaining 17.6% of the households have been using biogas energy. The kerosene lamp, battery cell, small size solar panel, and biogas were energy sources for lighting. The higher installation costs, inadequate water availability, shortage of cow dung, and lack of awareness were the main factors that hinder biogas installation in the study site. An independent sample t-test result revealed a statistically significant mean difference of the average time spent (in hours) to collect fuelwood per week between biogas technology adopters (M = 9.563, SD = 4.697) and non-adopters (M = 11.887, SD = 4.703; t (180) = 2.539, p = 0.012). In addition, findings of the binary logistic regression showed that education, access to markets, heads of cattle, and electronic media were the principal factors affecting biogas technology adoption significantly in the study area.

Household Smoke-Exposure Risks Associated with Cooking Fuels and Cooking Places in Tanzania: A Cross-Sectional Analysis of Demographic and Health Survey Data

Household smoke-exposure risk (SER) can be defined through the assessment of cooking fuels (smoke and no smoke-producing) and cooking places (indoor and outdoor) related information, which represent different levels of household air pollution. This study aimed to explore the prevalence and geographical variations in smoke-exposure risks (SERs) associated with indoor and outdoor cooking practices and use of smoke-producing and non-smoke-producing cooking fuels in Tanzania. We further investigated the social and spatial features associated with household SERs. We defined an indicator variable, the household SER, using country-level, cross-sectional data on cooking fuels and cooking places obtained from the 2015–2016 Tanzania Demographic and Health Survey and then estimated zone-level average SERs. We used an ordered logistic regression model to assess the social and spatial characteristics associated with household SER. We identified 76.4% of the 12,425 households that practiced indoor cooking using smoke-producing fuels as having a high SER. High-level SER was more prevalent in the Central, Southern highland, and Southwest highland zones. Overall, wealthier households, female-headed households, and households with higher education attainments were more likely to be categorized as households with very low SER. Meanwhile, households headed by older individuals and with larger family sizes were less likely to be in the very low SER category. The prevalence of high SER is a major public health concern in Tanzania. Improved cooking stoves and cleaner fuels should be adopted simultaneously to minimize the adverse effects associated with household SER.

Enhancing LPG Adoption in Ghana (ELAG): A Trial Testing Policy-Relevant Interventions to Increase Sustained Use of Clean Fuels

Rural Ghanaians rely on solid biomass fuels for their cooking. National efforts to promote the Sustainable Development Goals include the Rural Liquefied Petroleum Gas Promotion Program (RLP), which freely distributes LPG stoves, but evaluations have demonstrated low sustained use among recipients. Our study objective was to assess if cheap and scalable add-on interventions could increase sustained use of LPG stoves under the RLP scheme. We replicated RLP conditions among participants in 27 communities in Kintampo, Ghana, but cluster-randomized them to four add-on interventions: a behavioral intervention, fuel delivery service, combined intervention, or control. We reported on the final 6 months of a 12-month follow-up for participants (n = 778). Results demonstrated increased use for each intervention, but magnitudes were small. The direct delivery intervention induced the largest increase: 280 min over 6 months (p < 0.001), ∼1.5 min per day. Self-reported refills (a secondary outcome), support increased use for the dual intervention arm (IRR = 2.2, p = 0.026). Past literature demonstrates that recipients of clean cookstoves rarely achieve sustained use of the technologies. While these results are statistically significant, we interpret them as null given the implied persistent reliance on solid fuels. Future research should investigate if fuel subsidies would increase sustained use since current LPG promotion activities do not.

The Impact of Antiretroviral Therapy on Neurocognitive Outcomes Among People Living with HIV in Low- and Middle-Income Countries (LMICs): A Systematic Review

Low and middle-income countries (LMICs) are the epicenter of the HIV epidemic. The scale-up of antiretroviral therapy (ART) has reduced mortality, but HIV-associated neurocognitive impairment (HANI) remains prevalent, which impacts functional performance, medication adherence, and quality of life. We aimed to evaluate the effect of ART on neurocognitive outcomes among people living with HIV/AIDS in LMICs and to identify determinants of these outcomes. We searched electronic databases and reference lists for studies published between 1996 and 2019. Two reviewers screened the primary studies for inclusion and performed the critical appraisal. Results were synthesized using the 'Synthesis without meta-analysis' approach through simple vote counting. We identified 31 studies conducted across four regions (Africa, Asia, South America, and Eastern Europe). Nine studies were cross-sectional, 15 were prospective, and seven were randomized controlled trials. The majority of the articles showed improved neurocognitive performance with ART use but found no association with treatment duration, regimen, central penetrating effectiveness, and conventional biomarkers. Despite the lack of appropriate norms and not accounting for practice effect in most studies, the evidence suggests ART is useful in the treatment of HIV-associated neurocognitive impairment (HANI) but limited in addressing legacy effects, and peripheral, and central viral reservoirs. Improved early ART treatment programs, viral reservoir eradication strategies, and identification of novel biomarkers will be critical in efforts to minimize HIV-associated neurocognitive impairment. PROSPERO registration: CRD42020152908.

The benefits of action to reduce household air pollution (BAR-HAP) model: A new decision support tool

Cooking with polluting and inefficient fuels and technologies is responsible for a large set of global harms, ranging from health and time losses among the billions of people who are energy poor, to environmental degradation at a regional and global scale. This paper presents a new decision-support model–the BAR-HAP Tool–that is aimed at guiding planning of policy interventions to accelerate transitions towards cleaner cooking fuels and technologies. The conceptual model behind BAR-HAP lies in a framework of costs and benefits that is holistic and comprehensive, allows consideration of multiple policy interventions (subsidies, financing, bans, and behavior change communication), and realistically accounts for partial adoption and use of improved cooking technology. It incorporates evidence from recent efforts to characterize the relevant set of parameters that determine those costs and benefits, including those related to intervention effectiveness. Practical aspects of the tool were modified based on feedback from a pilot testing workshop with multisectoral users in Nepal. To demonstrate the functionality of the BAR-HAP tool, we present illustrative calculations related to several cooking transitions in the context of Nepal. In accounting for the multifaceted nature of the issue of household air pollution, the BAR-HAP model is expected to facilitate cross-sector dialogue and problem-solving to address this major health, environment and development challenge.

Incentivizing Elimination of Biomass Cooking Fuels with a Reversible Commitment and a Spare LPG Cylinder

In India, approximately 480,000 deaths occur annually from exposure to household air pollution from the use of biomass cooking fuels. Displacing biomass use with clean fuels, such as liquefied petroleum gas (LPG), can help reduce these deaths. Through government initiatives, most Indian households now own an LPG stove and one LPG cylinder. Many households, however, continue to regularly use indoor biomass-fueled mud stoves (chulhas) alongside LPG. Focusing on this population in rural Maharashtra, India, this study (N = 186) tests the effects of conditioning a sales offer for a spare LPG cylinder on a reversible commitment requiring initially disabling indoor chulhas. We find that almost all relevant households (>98%) were willing to accept this commitment. Indoor chulha use decreased by 90% (95% CI = 80% to 101%) when the sales offer included the commitment, compared to a 23% decrease (95% CI = 14% to 32%) without it. For both treatment groups, we find that 80% purchased the spare cylinder at the end of the study.

Effectiveness of Gas and Chimney Biomass Stoves for Reducing Household Air Pollution Pregnancy Exposure in Guatemala: Sociodemographic Effect Modifiers

Household air pollution (HAP) due to solid fuel use during pregnancy is associated with adverse birth outcomes. The real-life effectiveness of clean cooking interventions has been disappointing overall yet variable, but the sociodemographic determinants are not well described. We measured personal 24-h PM_2.5 (particulate matter <2.5 µm in aerodynamic diameter) thrice in pregnant women (n = 218) gravimetrically with Teflon filter, impactor, and personal pump setups. To estimate the effectiveness of owning chimney and liquefied petroleum gas (LPG) stoves (i.e., proportion of PM_2.5 exposure that would be prevented) and to predict subject-specific typical exposures, we used linear mixed-effects models with log (PM_2.5) as dependent variable and random intercept for subject. Median (IQR) personal PM_2.5 in µg/m³ was 148 (90-249) for open fire, 78 (51-125) for chimney stove, and 55 (34-79) for LPG stoves. Adjusted effectiveness of LPG stoves was greater in women with ≥6 years of education (49% (95% CI: 34, 60)) versus <6 years (26% (95% CI: 5, 42)). In contrast, chimney stove adjusted effectiveness was greater in women with <6 years of education (50% (95% CI: 38, 60)), rural residence (46% (95% CI: 34, 55)) and lowest SES (socio-economic status) quartile (59% (95% CI: 45, 70)) than ≥6 years education (16% (95% CI: 22, 43)), urban (23% (95% CI: -164, 42)) and highest SES quartile (-44% (95% CI: -183, 27)), respectively. A minority of LPG stove owners (12%) and no chimney owner had typical exposure below World Health Organization Air Quality guidelines (35 μg/m³). Although having a cleaner stove alone typically does not lower exposure enough to protect health, understanding sociodemographic determinants of effectiveness may lead to better targeting, implementation, and adoption of interventions.

Ecosystem-Based Approaches to Bioenergy and the Need for Regenerative Supply Options for Africa

Energy supply systems in the tropics and subtropics are marred with considerable negative impacts on ecosystems, for example, forest loss and habitat destruction. This document examines the role of ecosystems in household energy supply in Africa and explores pathways to ecosystem-based approaches to bioenergy generation by building on the regenerative economy concept. An ecosystem-based approach to bioenergy is an energy supply and utilization mechanism aimed at enhancing sustainable management of the sources of ecosystems with minimal trade-offs on/from other sectors directly linked to energy issues. Our analysis revealed that about 87% of energy supply to the population originated from agroecosystems and is challenged by the severe ecosystem degradation happening due to natural and anthropogenic factors. However, ecosystem restoration and effective use of agricultural residues could provide hope for making energy supply sustainable. Our analysis showed that restoring sparsely vegetated areas and degraded forest and savannahs, promotion of agroforestry in degraded agricultural lands, and use of agricultural residues could generate close to 71 billion gigajoules (GJ) of energy and provide sufficient energy for about 2.5 billion people if implemented in all potential areas identified. Ecosystem-based approaches to bioenergy along with a well-balanced involvement of sectors and industry actors coupled with knowledgeable management of the ecosystem could lead to beneficial outcomes for the society and environment.

Systems Science Approaches for Global Environmental Health Research: Enhancing Intervention Design and Implementation for Household Air Pollution (HAP) and Water, Sanitation, and Hygiene (WASH) Programs

BACKGROUND

Two of the most important causes of global disease fall in the realm of environmental health: household air pollution (HAP) and poor water, sanitation, and hygiene (WASH) conditions. Interventions, such as clean cookstoves, household water treatment, and improved sanitation facilities, have great potential to yield reductions in disease burden. However, in recent trials and implementation efforts, interventions to improve HAP and WASH conditions have shown few of the desired health gains, raising fundamental questions about current approaches.

OBJECTIVES

We describe how the failure to consider the complex systems that characterize diverse real-world conditions may doom promising new approaches prematurely. We provide examples of the application of systems approaches, including system dynamics, network analysis, and agent-based modeling, to the global environmental health priorities of HAP and WASH research and programs. Finally, we offer suggestions on how to approach systems science.

METHODS

Systems science applied to environmental health can address major challenges by a) enhancing understanding of existing system structures and behaviors that accelerate or impede aims; b) developing understanding and agreement on a problem among stakeholders; and c) guiding intervention and policy formulation. When employed in participatory processes that engage study populations, policy makers, and implementers, systems science helps ensure that research is responsive to local priorities and reflect real-world conditions. Systems approaches also help interpret unexpected outcomes by revealing emergent properties of the system due to interactions among variables, yielding complex behaviors and sometimes counterintuitive results.

DISCUSSION

Systems science offers powerful and underused tools to accelerate our ability to identify barriers and facilitators to success in environmental health interventions. This approach is especially useful in the context of implementation research because it explicitly accounts for the interaction of processes occurring at multiple scales, across social and environmental dimensions, with a particular emphasis on linkages and feedback among these processes. https://doi.org/10.1289/EHP7010.

Using longitudinal survey and sensor data to understand the social and ecological determinants of clean fuels use and discontinuance in rural Ghana

Efforts to reduce the health and ecological burdens of household biomass combustion are underway in Ghana, principally by promoting clean cookstoves and fuels. Recent studies have focused on the sustained use of clean cookstoves, but sometimes household adopt a new cookstove and then end use of that stove. In this study, we introduce a novel framework for understanding and encouraging household transitions to cleaner cooking: clean fuel discontinuance. We leveraged data from the Ghana Randomized Air Pollution and Health Study (GRAPHS) (N = 1412) where pregnant women received either improved biomass (BioLite) or dual burner LPG stoves for free. LPG users were given free LPG refills during GRAPHS. Weekly questionnaires were administered. Stove use monitors tracked a sub-cohort (n = 220) 6 months before and after the fuel subsidy. We examined social and ecological determinants of stove use and discontinuance. Overall intervention stove use adherence was high throughout GRAPHS, with self-reported use at 69% and 86% of participant-weeks for BioLite and LPG arms respectively. Participants used intervention stoves less for meals requiring vigorous stirring. Burns from intervention stoves decreased use among BioLite (RR: 0.96, p = 0.009), but not LPG users. Device breakage was mentioned as an impediment in 18% of free-text responses for LPG users and 1% for BioLite. Tree canopy within a spatial buffer-a plausible proxy for biomass fuels access-was the only variable explaining LPG discontinued stove use in adjusted Cox time-to-event analyses (HR = -0.56, p < 0.001). Future studies should consider the stove use discontinuance framework.

Gender inequalities and household fuel choice in India

The use of solid cooking fuels-wood, straw, crop residue, and cow-dung cakes-is associated with higher levels of environmental pollution and health burden. However, even in an era when incomes have grown and poverty has declined, the proportion of Indian households using clean cooking fuels such as kerosene or Liquefied Petroleum Gas (LPG) has increased only slightly. Even among the wealthiest quintile, only about 40 percent of the households rely solely on clean fuel. Since the chores of cooking and collection of fuel remain primarily the domain of women, we argue that intra-household gender inequalities play an important role in shaping the household decision to invest in clean fuel. Analyses using data from the India Human Development Survey (IHDS), a panel survey of over 41,000 households conducted in two waves in 2004-05 and 2011-12, respectively, show that women's access to salaried work and control over household expenditure decisions is associated with the use of clean fuel.

Drivers of the Adoption and Exclusive Use of Clean Fuel for Cooking in Sub-Saharan Africa: Learnings and Policy Considerations from Cameroon

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.

Risk of Antibiotic-Resistant Staphylococcus aureus Dispersion from Hog Farms: A Critical Review

The World Health Organization has declared antibiotic resistance "one of the biggest threats to global health." Mounting evidence suggests that antibiotic use in industrial-scale hog farming is contributing to the spread of antibiotic-resistant Staphylococcus aureus. To capture available evidence on these risks, we searched peer-reviewed studies published before June 2017 and conducted a meta-analysis of these studies' estimates of the prevalence of swine-associated, antibiotic-resistant S. aureus in animals, humans, and the environment. The 166 relevant studies revealed consistent evidence of livestock-associated methicillin-resistant S. aureus (MRSA) in hog herds (55.3%) raised with antibiotics. MRSA prevalence was also substantial in slaughterhouse pigs (30.4%), industrial hog operation workers (24.4%), and veterinarians (16.8%). The prevalence of swine-associated, multidrug-resistant S. aureus (MDRSA)-with resistance to three or more antibiotics-is not as well documented. Nonetheless, sufficient studies were available to estimate MDRSA pooled prevalence in conventional hog operation workers (15.0%), workers' household members (13.0%), and community members (5.37%). Evidence also suggests that antibiotic-resistant S. aureus can be present in air, soil, water, and household surface samples gathered in or near high-intensity hog operations. An important caveat is that prevalence estimates for humans reflect colonization, not active infection, and the health risks of colonization remain poorly understood. In addition, these pooled results may not represent risks in specific locations, due to wide geographic variation. Nonetheless, these results underscore the need for additional preventive action to stem the spread of antibiotic-resistant pathogens from livestock operations and a streamlined reporting system to track this risk.

Determinants of household cooking fuels and their impact on women's health in rural Pakistan

Use of biomass with traditional cooking technologies causes indoor air pollution and is responsible for 3.5 million deaths globally. Women play the main role in biomass-based energy systems in developing countries. The current study attempted to estimate determinants of household cooking fuels and impacts of fuels on women's health in rural Pakistan. The results of the study show that 75.5% of the households in the study area use fuelwood, 44.4% use LPG, and 27.9% use crop residues for cooking. Households with LPG spend on average 3.02 h/day for cooking while households with biomass spend almost 4 h. Health expenditures of households using biomass are almost 25% higher than those using LPG. Use of traditional biomass with traditional devices was found to be having negative impacts on rural women's life. Household composition, education, income, access to electricity and LPG, and distance from the market were found to be significant factors affecting the choice of fuels for cooking. Clean energy and technologies and empowerment through education and awareness will help minimize the negative impacts of biomass fuels on women.

Health effects of household air pollution related to biomass cook stoves in resource limited countries and its mitigation by improved cookstoves

BACKGROUND

Household air pollution (HAP) related to cooking is associated with significant global morbidity and mortality. An estimated three billion people worldwide are exposed to cooking related HAP caused by solid fuel combustion. This exposure is highest for the vulnerable population of women and children resulting in significant cumulative health effects.

METHODS

A literature review was conducted for health effects of household air pollution related to biomass cookstoves in resource limited countries and to evaluate the effect of improved cookstoves on these health effects. We searched PubMed, Embase and Cochrane Library. We conducted searches in January 2018 with a repeat in February 2020. We included only studies conducted in resource limited countries, published in English, irrespective of publication year and studies that examined the health effects of HAP and/or studied the effects of improved cookstove (IC). Two authors independently screened journal article titles, abstracts and full-text articles to identify those that included the following search term: biomass cookstoves and health risks. We also assessed the limitations of IC with barriers to their uptake.

RESULTS

Health effects associated with HAP mostly include increased blood pressure (BP), dyspnea, childhood pneumonia, lung cancer, low birthweight and cardiovascular diseases. Being a global problem with divergent environmental factors including wide variety of fuel used, housing condition, foods prepared, climatic condition and social factors; most solutions though efficient seems inadequate. Improved cookstove (IC) mitigates emissions and improves short term health, though few randomized long-term studies could substantiate its long-standing continuance and health benefits.

CONCLUSION

There is ample data about the health effects of HAP, with some benefit with IC intervention for elevated blood pressure, dyspnea symptoms, mutagenicity and cardiovascular diseases. IC does not have any benefit in pregnancy outcomes or children health.

Affordability, Accessibility, and Awareness in the Adoption of Liquefied Petroleum Gas: A Case-Control Study in Rural India

Interventions in the clean cooking sector have focused on improved biomass stoves in a bid to address household air pollution (HAP) in low- and middle-income countries. These initiatives have not delivered adequate health and environmental benefits owing to the less than optimal performance of improved biomass stoves. There is an urgency to transition communities to cleaner cooking systems such as liquefied petroleum gas (LPG) to reduce the prevalence of HAP. Adoption of LPG also has challenges. This case-control cross-sectional study with 510 households examines how affordability, accessibility, and awareness (3As) are associated with LPG adoption in rural poor households of Andhra Pradesh, a state of India. Using binomial logistic regression analyses, the study examines the association of 3As with LPG adoption, adjusting for demographic predictors. Results show disparities in LPG adoption owing to affordability, accessibility, and awareness. Household income is positively associated with LPG adoption. Easy availability of biomass deters households from adopting LPG. Concerns for LPG safety reduces likelihood of LPG adoption. On the other hand, attending awareness campaigns on clean cooking benefits is strongly associated with LPG adoption. Awareness drives, primarily targeted marketing campaigns, could help expand LPG coverage among poorer households. This paper offers insights into the determinants of clean fuel adoption with implications for resource-poor settings across the world to advance energy justice and address energy poverty.

What Motivates Behavior Change? Analyzing User Intentions to Adopt Clean Technologies in Low-Resource Settings Using the Theory of Planned Behavior

Understanding and integrating the user’s decision-making process into product design and distribution strategies is likely to lead to higher adoption rates and ultimately increased impacts, particularly for those products that require a change in habit or behavior such as clean energy technologies. This study applies the Theory of Planned Behavior (TPB) in design for global development, where understanding the tendency to adopt beneficial technologies based on parsimonious approaches is critical to programmatic impact. To investigate robustness and applicability of behavioral models in a data scarce setting, this study applies TPB to the adoption of biomass cookstoves in a sample size of two remote communities in Honduras and Uganda before and after a trial period. Using multiple ordinal logistic regressions, the intention to adopt the technology was modeled. Results quantify the influence of these factors on households’ intentions to cook their main meals with improved cookstoves. For example, the intention of participants with slightly stronger beliefs regarding the importance of reducing smoke emissions was 3.3 times higher than average to cook more main meals with clean cookstoves. The quantitative method of this study enables technology designers to design and develop clean technologies that better suit user behavior, needs, and priorities. In addition, the data driven approach of this study provides insights for policy makers to design policies such as subsidies, information campaigns, and supply chains that reflect behavioral attributes for culturally tailored clean technology adoption initiatives. Furthermore, this work discusses potential sources of bias and statistical challenges in data-scarce regions, and outlines methods to address them.

The drivers of sustained use of liquified petroleum gas in India

Ninety-five per cent of Indian households now have access to liquified petroleum gas (LPG), with 80 million acquiring it under the Pradhan Mantri Ujjwala Yojana (PMUY) since 2016. Still, having a connection is not enough to eliminate household air pollution. Studying panel data from rural households in six major states from 2014-2015 and 2018, we assess the determinants of cooking energy transition from solid fuels to LPG. We find that PMUY beneficiaries have much lower odds of using LPG as the primary or exclusive fuel compared with general customers, irrespective of their economic status. Village-level penetration of LPG as a primary fuel and the years of LPG use positively influence its sustained use, while ease of access to freely available biomass and reliance on uncertain and irregular income sources hinder LPG use. The findings highlight the need to interlace cooking fuel policies with rural development, to enable a complete transition towards cleaner cooking fuels.

Facilitators and barriers to improved cookstove adoption: a community-based cross-sectional study in Northwest Ethiopia

BACKGROUND

Among the environmental risk factors, household air pollution exposure from traditional cooking practices is one of the biggest killers globally, which mainly impacts developing countries where many families rely on traditional cooking practices. Although improved cookstove adoption is central to tackle this public health issue, the efforts to disseminate cookstove technologies have faced challenges, and the adoption rates are reported to be very low in many developing countries including Ethiopia. Therefore, this study aimed to determine the magnitude and identify potential factors that may act as facilitators or barriers to adoption from users' point of view.

METHODS

As part of the wider stove trial project, a cross-sectional study was conducted among a total of 5830 households under randomly selected clusters. The required data were collected through face-to-face interviews, and a backward stepwise logistic regression analysis technique was applied to evaluate the effect of potential predictor variables on adoption using adjusted odds ratio (AOR) as measures of effect.

RESULTS

The prevalence of adoption was found to be 12.3% (95% CI 11.5-13.2), and households headed by females (AOR 1.96; 95% CI 1.24-3.10), private house ownership (AOR 4.58; 95% CI 3.89-6.19), separate cooking location (AOR 1.84; 95% CI 1.49-2.78), fuel purchasing (AOR 2.13; 95% CI 1.64-2.76), health benefit (AOR 1.76; 95% CI 1.15-2.70), optimistic social interaction (AOR 1.81; 95% CI 1.46-2.26), traditional suitability (AOR 1.58; 95% CI 1.28-1.95), stove use demonstration experience (AOR 2.47; 95% CI 1.98-3.07), cheap price (AOR 2.48; 95% CI 1.91-3.21), availability (AOR 1.81; 95% CI 1.5-1, 2.17), fuel-saving benefit (AOR 1.63; 95% CI 1.18-2.24), and more durable stove (AOR 1.71; 95% CI 1.30-2.26) of cookstove played a significant role as facilitators to adoption. In addition, lower educational level of head (AOR 0.31; 95% CI 0.23-0.42) and fuel processing requirement (AOR 0.55; 95% CI 0.44-0.70) of cookstove were found to be barriers for adoption.

CONCLUSIONS

Extremely lower improved cookstove adoption was observed due to household- and setting-related, cookstove technology-related, user knowledge- and perception-related, and financial- and market development-related factors. Therefore, to gain successful adoption, implementers and policymakers should consider those important factors in the implementation of clean cooking solutions to the community.

Household energy choice for domestic cooking: distribution and factors influencing cooking fuel preference in Ouagadougou

Many studies have highlighted the link between indoor air pollution from the burning of solid fuels for cooking and heating and the occurrence of various health problems particularly in women and children under 5 years. In developing countries, solid fuels remain the main sources of energy. The purpose of this study aims to describe the distribution of household cooking fuel types and to analyze the factors influencing household cooking energy choice in Ouagadougou. A cross-sectional survey was conducted in 2017 in 3 neighborhoods of Ouagadougou. A total of 1734 household were randomly selected. We performed a multivariable logistic regression and a multinomial logistic regression to measure the relationship between selected determinants and households' primary cooking fuel. 59.53% of the households of Ouagadougou reported using solid fuels as the main cooking fuel. Wood is the most common primary cooking fuel used (43.93%), followed by LPG (40.41%) and then charcoal (15.60%). About 84% combine at least 2 types of energy for cooking. Cooking fuel choice is strongly influenced by the socioeconomic status, the family size, and also by the woman's educational attainment, her age and the main cooking fuel used in her parents' house. Actions aimed at reducing the impact of solid fuel use in the environment or health must consider these factors.

Health awareness and the transition towards clean cooking fuels: Evidence from Rajasthan

Ensuring affordable, reliable, sustainable and modern energy for all by 2030 is part of the internationally agreed Sustainable Development Goals (SDG7). With roughly 3 billion people still lacking access to clean cooking solutions in 2017, this remains an ambitious task. The use of solid biomass such as wood and cow dung for cooking causes household air pollution resulting in severe health hazards. In this context, the Indian government has set up a large program promoting the use of liquefied petroleum gas (LPG) in rural areas. While this has led millions of households to adopt LPG, a major fraction of them continues to rely heavily on solid biomass for their daily cooking. In this paper, we evaluate the effect of simple health messaging on the propensity of these households to use LPG more regularly. Our results from rural Rajasthan are encouraging. They show that health messaging increases the reported willingness to pay for LPG, and substantially increases actual consumption. We measure this based on a voucher, which can only be used if LPG consumption is doubled until a certain deadline. Households exposed to health messaging use the voucher about 30% more often than households exposed to a placebo treatment. We further show that the impact of our very brief, but concrete health messaging is close to the effect of a 10% price reduction for a new LPG cylinder. Finally, our study raises some interesting questions about gender-related effects that would be worth consideration in future research.

Cooking fuels and risk of all-cause and cardiopulmonary mortality in urban China: a prospective cohort study

BACKGROUND

Cooking practice has transitioned from use of solid fuels to use of clean fuels, with addition of better ventilation facilities. However, the change in mortality risk associated with such a transition remains unclear.

METHODS

The China Kadoorie Biobank (CKB) Study enrolled participants (aged 30-79 years) from ten areas across China; we chose to study participants from five urban areas where transition from use of solid fuels to clean fuels for cooking was prevalent. Participants who reported regular cooking (weekly or more frequently) at baseline were categorised as persistent clean fuel users, previous solid fuel users, or persistent solid fuel users, according to self-reported fuel use histories. All-cause and cardiopulmonary mortality were identified through linkage to China's Disease Surveillance Point system and local mortality records.

FINDINGS

Between June 24, 2004, and July 15, 2008, 226 186 participants living in five urban areas of China were enrolled in the CKB Study. Among 171 677 participants who reported cooking regularly (weekly or more frequently), 75 785 (44%) were persistent clean fuel users, 80 511 (47%) were previous solid fuel users, and 15 381 (9%) were persistent solid fuel users. During a mean of 9·8 (SD 1·7) years of follow-up, 10 831 deaths were documented, including 3819 cardiovascular deaths and 761 respiratory deaths. Compared with persistent clean fuel users, persistent solid fuel users had significantly higher risks of all-cause mortality (hazard ratio [HR] 1·19, 95% CI 1·10-1·28), cardiovascular mortality (1·24, 1·10-1·39), and respiratory mortality (1·43, 1·10-1·85). The excess risk of all-cause and cardiopulmonary mortality fell by more than 60% in 5 years after cessation of solid fuel use and continued to decrease afterwards. Use of ventilation was associated with lower all-cause mortality risk, even among persistent clean fuel users (HR 0·78, 0·69-0·89).

INTERPRETATION

Solid fuel use for cooking is associated with a higher risk of mortality, and cessation of solid fuel use cuts excess mortality risks swiftly and substantially within 5 years. Ventilation use also lowers the risk of mortality, even among people who persistently use clean fuels. It is of prime importance for both policy makers and the public to accelerate the transition from solid fuels to clean fuels and promote efficient ventilation to minimise further adverse health effects.

FUNDING

National Natural Science Foundation of China, Wellcome Trust, and Kadoorie Charitable Foundation.

Impacts of stove/fuel use and outdoor air pollution on chemical composition of household particulate matter

Biomass combustion for cooking and heating releases particulate matter (PM_2.5 ) that contributes to household air pollution. Fuel and stove types affect the chemical composition of household PM, as does infiltration of outdoor PM. Characterization of these impacts can inform future exposure assessments and epidemiologic studies, but is currently limited. In this study, we measured chemical components of PM_2.5 (water-soluble organic matter [WSOM], ions, black carbon, elements, organic tracers) in rural Chinese households using traditional biomass stoves, semi-gasifier stoves with pelletized biomass, and/or non-biomass stoves. We distinguished households using one stove type (traditional, semi-gasifier, or LPG/electric) from those using multiple stoves/fuels. WSOM concentrations were higher in households using only semi-gasifier or traditional stoves (31%-33%) than in those with exclusive LPG/electric stove (13%) or mixed stove use (12%-22%). Inorganic ions comprised 14% of PM in exclusive LPG/electric households, compared to 1%-5% of PM in households using biomass. Total PAH content was much higher in households that used traditional stoves (0.8-2.8 mg/g PM) compared to those that did not (0.1-0.3 mg/g PM). Source apportionment revealed that biomass burning comprised 27%-84% of PM_2.5 in households using biomass. In all samples, identified outdoor sources (vehicles, dust, coal combustion, secondary aerosol) contributed 10%-20% of household PM_2.5 .