Health and Climate Impacts of Scaling Adoption of Liquefied Petroleum Gas (LPG) for Clean Household Cooking in Cameroon: A Modeling Study

Household Air Pollution Interventions to Improve Health in Low- and Middle-Income Countries: An Official American Thoracic Society Research Statement

Background: An estimated 3 billion people, largely in low- and middle-income countries, rely on unclean fuels for cooking, heating, and lighting to meet household energy needs. The resulting exposure to household air pollution (HAP) is a leading cause of pneumonia, chronic lung disease, and other adverse health effects. In the last decade, randomized controlled trials of clean cooking interventions to reduce HAP have been conducted. We aim to provide guidance on how to interpret the findings of these trials and how they should inform policy makers and practitioners.Methods: We assembled a multidisciplinary working group of international researchers, public health practitioners, and policymakers with expertise in household air pollution from within academia, the American Thoracic Society, funders, nongovernmental organizations, and global organizations, including the World Bank and the World Health Organization. We performed a literature search, convened four sessions via web conference, and developed consensus conclusions and recommendations via the Delphi method.Results: The committee reached consensus on 14 conclusions and recommendations. Although some trials using cleaner-burning biomass stoves or cleaner-cooking fuels have reduced HAP exposure, the committee was divided (with 55% saying no and 45% saying yes) on whether the studied interventions improved measured health outcomes.Conclusions: HAP is associated with adverse health effects in observational studies. However, it remains unclear which household energy interventions reduce exposure, improve health, can be scaled, and are sustainable. Researchers should engage with policy makers and practitioners working to scale cleaner energy solutions to understand and address their information needs.

Experimental hut and field evaluation of a metofluthrin-based spatial repellent against pyrethroid-resistant Anopheles funestus in Siaya County, western Kenya

BACKGROUND

Spatial repellents (SR) may complement current vector control tools and provide additional coverage when people are not under their bednets or are outdoors. Here we assessed the efficacy of a metofluthrin-based SR in reducing exposure to pyrethroid-resistant Anopheles funestus in Siaya County, western Kenya.

METHODS

Metofluthrin was vaporized using an emanator configured to a liquid petroleum gas (LPG) canister, placed inside experimental huts (phase 1) or outdoors (phase 2), and evaluated for reductions in human landing rate, density, knockdown and mortality rates of An. funestus, which are present in high density in the area. To demonstrate the mosquito recruiting effect of LPG, a hut with only an LPG cooker but no metofluthrin was added as a comparator and compared with an LPG cooker burning alongside the emanator and a third hut with no LPG cooker as control. Phase 2 evaluated the protective range of the SR product while emanating from the centre of a team of mosquito collectors sitting outdoors in north, south, east and west directions at 5, 10 and 20 feet from the emanating device.

RESULTS

Combustion of LPG with a cook stove increased the density of An. funestus indoors by 51% over controls with no cook stove. In contrast, huts with metofluthrin vaporized with LPG combustion had lower indoor density of An. funestus (99.3% less than controls), with knockdown and mortality rates of 95.5 and 87.7%, respectively, in the mosquitoes collected in the treated huts. In the outdoor study (phase 2), the outdoor landing rate was significantly lower at 5 and 10 feet than at 20 feet from the emanator.

CONCLUSIONS

Vaporized metofluthrin almost completely prevented An. funestus landing indoors and led to 10 times lower landing rates within 10 feet of the emanator outdoors, the first product to demonstrate such potential. Cooking with LPG inside the house could increase exposure to Anopheles mosquito bites, but the use of the metofluthrin canister eliminates this risk.

A global review of the state of the evidence of household air pollution's contribution to ambient fine particulate matter and their related health impacts

Direct exposure to household fine particulate air pollution (HAP) associated with inefficient combustion of fuels (wood, charcoal, coal, crop residues, kerosene, etc.) for cooking, space-heating, and lighting is estimated to result in 2.3 (1.6-3.1) million premature yearly deaths globally. HAP emitted indoors escapes outdoors and is a leading source of outdoor ambient fine particulate air pollution (AAP) in low- and middle-income countries, often being a larger contributor than well-recognized sources including road transport, industry, coal-fired power plants, brick kilns, and construction dust. We review published scientific studies that model the contribution of HAP to AAP at global and major sub-regional scales. We describe strengths and limitations of the current state of knowledge on HAP's contribution to AAP and the related impact on public health and provide recommendations to improve these estimates. We find that HAP is a dominant source of ambient fine particulate matter (PM2.5) globally - regardless of variations in model types, configurations, and emission inventories used - that contributes approximately 20 % of total global PM2.5 exposure. There are large regional variations: in South Asia, HAP contributes ∼ 30 % of ambient PM2.5, while in high-income North America the fraction is ∼ 7 %. The median estimate indicates that the household contribution to ambient air pollution results in a substantial premature mortality burden globally of about 0.77(0.54-1) million excess deaths, in addition to the 2.3 (1.6-3.1) million deaths from direct HAP exposure. Coordinated global action is required to avert this burden.

A critical review on the bio-mediated green synthesis and multiple applications of magnesium oxide nanoparticles

Nowadays, advancements in nanotechnology have efficiently solved many global problems, such as environmental pollution, climate change, and infectious diseases. Nano-scaled materials have played a central role in this evolution. Chemical synthesis of nanomaterials, however, required hazardous chemicals, unsafe, eco-unfriendly, and cost-ineffective, calling for green synthesis methods. Here, we review the green synthesis of MgO nanoparticles and their applications in biochemical, environmental remediation, catalysis, and energy production. Green MgO nanoparticles can be safely produced using biomolecules extracted from plants, fungus, bacteria, algae, and lichens. They exhibited fascinating and unique properties in morphology, surface area, particle size, and stabilization. Green MgO nanoparticles served as excellent antimicrobial agents, adsorbents, colorimetric sensors, and had enormous potential in biomedical therapies against cancers, oxidants, diseases, and the sensing detection of dopamine. In addition, green MgO nanoparticles are of great interests in plant pathogens, phytoremediation, plant cell and organ culture, and seed germination in the agricultural sector. This review also highlighted recent advances in using green MgO nanoparticles as nanocatalysts, nano-fertilizers, and nano-pesticides. Thanks to many emerging applications, green MgO nanoparticles can become a promising platform for future studies.

Complex dynamics in sustaining clean cooking and food access through a pandemic: A COVID-19 impact study in peri-urban Cameroon

Access to clean energy for cooking is central to achieving Sustainable Development Goal 7. Latest predictions suggest that this goal will not be met by 2030, with further setbacks due to the COVID-19 pandemic. We investigated the impacts of COVID-19 restrictions on household cooking fuel, practices and dietary behaviours in a peri-urban community in Central Cameroon. Using surveys (n = 333) and qualitative semi-structured interviews (n = 12), we found negative financial impacts and high levels of food insecurity, with 83 % and 56 % of households reporting reduced income and insufficient food, respectively. Households reduced food intake and cooking frequency and relied more heavily on local sources (e.g., farmland) to feed their families. Changes in primary cooking fuel were less pronounced and fuel choice was inherently linked to cooking behaviours, with some households utilising LPG more often for simple tasks, such as reheating food. Local systems were key in sustaining food and fuel access and households demonstrated resilience by employing numerous mechanisms to overcome challenges. Our findings underline the vulnerability of households in maintaining sufficient food intake and sustaining clean cooking, highlighting how policy needs to take a nuanced approach considering food-energy dynamics and strengthening local systems to ensure access to clean energy is resistant to system shocks.

The role of liquefied petroleum gas in decarbonizing India: fresh evidence from wavelet-partial wavelet coherence approach

India is predominantly a fossil fuel-intensive South Asian country that has traditionally settled for higher economic gains at the expense of lower environmental quality. However, in the contemporary era, it has become essential for India to come up with viable solutions that can enable the nation to transform its economy into a low-carbon one. Although replacing fossil fuel use with renewable energy sources is assumed to be the ideal pathway to decarbonizing the Indian economy, achieving this clean energy transition involves a long-term process. Thus, the Indian government should rather consider adoption of interim solutions to the environmental pollution problems faced by the nation. Against this backdrop, this study looks at whether enhancing the consumption level of liquefied petroleum gas, a relatively cleaner fossil fuel, can help India reduce its carbon dioxide emissions figures and attain environmentally sustainable economic growth. The econometric analysis is designed as per the theoretical framework of the environmental Kuznets curve hypothesis whereby the effects of economic growth on carbon dioxide emissions are examined controlling for liquefied petroleum gas consumption in the context of India between 1990 and 2018. Based on the findings from the autoregressive distributed lag model bounds test analysis, it is witnessed that there are long-run cointegrating relationships among per capita levels of carbon dioxide emissions, real gross domestic product, and liquefied petroleum gas consumption of India. Besides, the environmental Kuznets curve hypothesis is found to be valid only in the short run; however, it does not sustain in the long run since the economic growth-carbon dioxide emissions nexus is observed to follow a U-shaped relationship in the long run. Moreover, higher liquefied petroleum gas consumption is found to boost carbon dioxide emissions in the short run while reducing it in the long run. Furthermore, the findings from the wavelet and partial wavelet coherence and causality analyses also advocate in favor of promoting the use of liquefied petroleum gas in India in order to significantly curb the energy use-related carbon dioxide emission figures of the nation. Hence, considering these important findings, this study recommends that the Indian government should design policies for augmenting liquefied petroleum gas into the national energy mix and also adopt relevant green economic growth strategies in order to facilitate environmentally-sustainable growth of its economy.

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.

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.

COVID-19 impacts on household energy & food security in a Kenyan informal settlement: The need for integrated approaches to the SDGs

This longitudinal study presents the joint effects of a COVID-19 community lockdown on household energy and food security in an informal settlement in Nairobi, Kenya. Randomly administered surveys were completed from December 2019-March 2020 before community lockdown (n = 474) and repeated in April 2020 during lockdown (n = 194). Nearly universal (95%) income decline occurred during the lockdown and led to 88% of households reporting food insecurity. During lockdown, a quarter of households (n = 17) using liquefied petroleum gas (LPG), a cleaner cooking fuel typically available in pre-set quantities (e.g. 6 kg cylinders), switched to polluting cooking fuels (kerosene, wood), which could be purchased in smaller amounts or gathered for free. Household size increases during lockdown also led to participants' altering their cooking fuel, and changing their cooking behaviors and foods consumed. Further, households more likely to switch away from LPG had lower consumption prior to lockdown and had suffered greater income loss, compared with households that continued to use LPG. Thus, inequities in clean cooking fuel access may have been exacerbated by COVID-19 lockdown. These findings demonstrate the complex relationship between household demographics, financial strain, diet and cooking patterns, and present the opportunity for a food-energy nexus approach to address multiple Sustainable Development Goals (SDGs): achieving zero hunger (SDG 2) and universal affordable, modern and clean energy access (SDG 7) by 2030. Ensuring that LPG is affordable, accessible and meets the dietary and cooking needs of families should be a policy priority for helping improve food and energy security among the urban poor.

COVID-19 impacts on household energy & food security in a Kenyan informal settlement: The need for integrated approaches to the SDGs

This longitudinal study presents the joint effects of a COVID-19 community lockdown on household energy and food security in an informal settlement in Nairobi, Kenya. Randomly administered surveys were completed from December 2019-March 2020 before community lockdown (n = 474) and repeated in April 2020 during lockdown (n = 194). Nearly universal (95%) income decline occurred during the lockdown and led to 88% of households reporting food insecurity. During lockdown, a quarter of households (n = 17) using liquefied petroleum gas (LPG), a cleaner cooking fuel typically available in pre-set quantities (e.g. 6 kg cylinders), switched to polluting cooking fuels (kerosene, wood), which could be purchased in smaller amounts or gathered for free. Household size increases during lockdown also led to participants' altering their cooking fuel, and changing their cooking behaviors and foods consumed. Further, households more likely to switch away from LPG had lower consumption prior to lockdown and had suffered greater income loss, compared with households that continued to use LPG. Thus, inequities in clean cooking fuel access may have been exacerbated by COVID-19 lockdown. These findings demonstrate the complex relationship between household demographics, financial strain, diet and cooking patterns, and present the opportunity for a food-energy nexus approach to address multiple Sustainable Development Goals (SDGs): achieving zero hunger (SDG 2) and universal affordable, modern and clean energy access (SDG 7) by 2030. Ensuring that LPG is affordable, accessible and meets the dietary and cooking needs of families should be a policy priority for helping improve food and energy security among the urban poor.

BioLPG for Clean Cooking in Sub-Saharan Africa: Present and Future Feasibility of Technologies, Feedstocks, Enabling Conditions and Financing

Energy supply for clean cooking is a priority for Sub-Saharan Africa (SSA). Liquefied petroleum gas (LPG, i.e., propane or butane or a mixture of both) is an economically efficient, cooking energy solution used by over 2.5 billion people worldwide and scaled up in numerous low- and middle-income countries (LMICs). Investigation of the technical, policy, economic and physical requirements of producing LPG from renewable feedstocks (bioLPG) finds feasibility at scale in Africa. Biogas and syngas from the circular economic repurposing of municipal solid waste and agricultural waste can be used in two groundbreaking new chemical processes (Cool LPG or Integrated Hydropyrolysis and Hydroconversion (IH2)) to selectively produce bioLPG. Evidence about the nature and scale potential of bioLPG presented in this study justifies further investment in the development of bioLPG as a fuel that can make a major contribution toward enabling an SSA green economy and universal energy access. Techno-economic assessments of five potential projects from Ghana, Kenya and Rwanda illustrate what might be possible. BioLPG technology is in the early days of development, so normal technology piloting and de-risking need to be undertaken. However, fully developed bioLPG production could greatly reduce the public and private sector investment required to significantly increase SSA clean cooking capacity.

Pay-as-you-go liquefied petroleum gas supports sustainable clean cooking in Kenyan informal urban settlement during COVID-19 lockdown

Approximately 2.8 billion people rely on polluting fuels (e.g. wood, kerosene) for cooking. With affordability being a key access barrier to clean cooking fuels, such as liquefied petroleum gas (LPG), pay-as-you-go (PAYG) LPG smart meter technology may help resource-poor households adopt LPG by allowing incremental fuel payments. To understand the potential for PAYG LPG to facilitate clean cooking, objective evaluations of customers' cooking and spending patterns are needed. This study uses novel smart meter data collected between January 2018-June 2020, spanning COVID-19 lockdown, from 426 PAYG LPG customers living in an informal settlement in Nairobi, Kenya to evaluate stove usage (e.g. cooking events/day, cooking event length). Seven semi-structured interviews were conducted in August 2020 to provide context for potential changes in cooking behaviours during lockdown. Using stove monitoring data, objective comparisons of cooking patterns are made with households using purchased 6 kg cylinder LPG in peri-urban Eldoret, Kenya. In Nairobi, 95% of study households continued using PAYG LPG during COVID-19 lockdown, with consumption increasing from 0.97 to 1.22 kg/capita/month. Daily cooking event frequency also increased by 60% (1.07 to 1.72 events/day). In contrast, average days/month using LPG declined by 75% during lockdown (17 to four days) among seven households purchasing 6 kg cylinder LPG in Eldoret. Interviewed customers reported benefits of PAYG LPG beyond fuel affordability, including safety, time savings and cylinder delivery. In the first study assessing PAYG LPG cooking patterns, LPG use was sustained despite a COVID-19 lockdown, illustrating how PAYG smart meter technology may help foster clean cooking access.

Spatially Resolved Emission Factors to Reduce Uncertainties in Air Pollutant Emission Estimates from the Residential Sector

The residential sector is a major source of air pollutant emission inventory uncertainties. A nationwide field emission measurement campaign was conducted in rural China to evaluate the variabilities of realistic emission factors (EFs) from indoor solid fuel combustion. For a total of 1313 burning events, the overall average EFs (±standard deviation) of PM_2.5 were 8.93 ± 6.95 and 7.33 ± 9.01 g/kg for biomass and coals, respectively, and 89.3 ± 51.2 and 114 ± 87 g/kg for CO. Higher EFs were found from burning of uncompressed straws, while lower EFs were found from processed biomass pellets, coal briquettes, and relatively clean anthracite coals. Modified combustion efficiency was found to be the most significant factor associated with variations in CO EFs, whereas for PM_2.5, fuel and stove differences determined its variations. Weak correlations between PM_2.5 and CO indicated high uncertainties in using CO as a surrogate for PM_2.5. EFs accurately fit log-normal distributions, and obvious spatial heterogeneity was observed attributed to different fuel-stove combinations across the country. Emission estimation variabilities, which are determined by the interquartile ranges divided by the median values, were notably reduced when spatially resolved EFs were adopted in the inventory.

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.