Cookstove Technologies Research Articles

CFD simulation of a forced draft biomass cookstove for different airflow conditions

Households in developing countries rely on traditional cooking methods despite low-efficiency and high risks of air pollution and health. Various improved biomass cookstove technologies have been developed to address this issue, but there is still room for improvement in biomass cooking technology. This research aims to enhance the biomass cookstove by investigating its performance under different air inlet conditions using computational fluid dynamics analysis. The impact of air flow rate and the position of the secondary air inlet on the thermal efficiency of the biomass cookstove is examined. The eddy dissipation combustion model and k-epsilon turbulence model are utilized in ANSYS Fluent to simulate the combustion process. The cookstove's performance is assessed at three different air flow rates (0.01, 0.02, and 0.03 kg/s) and at two different secondary air inlet positions. The highest thermal efficiency is observed at secondary air inlet located 50 mm below the outlet at a flow rate of 0.03 kg/s. The computational findings from this investigation show a significant connection between the air inlet conditions and the thermal efficiency of the biomass cookstove. Repositioning the secondary air inlet to a location with more available space for complete combustion improves thermal efficiency compared to traditional designs.

Impact of Kitchen Structure and Cookstove Technology on Respiratory Health of Rural Women Exposed to Indoor Air Pollution in Khyber Pakhtunkhwa, Pakistan

Incomplete combustion of polluting fuels (PF) is a major source of indoor pollution which poses severe risks of acute respiratory infections to women’s health such as cough, phlegm, and breathing difficulties. This article investigates the net impact of kitchen structural factors including the location of the kitchen and number of windows in the kitchen and cookstove technology on acute respiratory symptoms of rural women involved in cooking practices. A household survey was conducted to collect primary data from 250 rural households in Khyber Pakhtunkhwa province. Around 66 percent of rural households exclusively used polluted fuel for cooking which caused 4 respiratory symptoms among poor women. The results of the Poisson regression model revealed that the use of polluted energy in the enclosed kitchen was four times more responsible for respiratory symptoms than in the open kitchen; while an improved cookstove in the enclosed kitchen was three times more effective in controlling respiratory involvements . Concerted efforts are required to adopt short-term mitigation strategies such as improved stoves and efficient kitchen design.

A Review of Improved Cooker Stove Utilization Levels, Challenges and Benefits in Sub-Saharan Africa

Many attempts to enhance cooking stoves have been implemented in Sub-Saharan Africa (SSA). These programs aim to limit indoor air pollution, improve the lives of women, reduce the usage of fuel (charcoal), which reduces deforestation, alleviate the financial burden of energy costs on low-income people, and improve user health by lowering environmental toxins. Other objectives include reducing global warming and improving the social well-being of people in developing countries. The efficiency of the Improved Cookstove programs has gotten mixed evaluations. Several of the projects fell short of their planned objectives, however some did. The use, challenges, and benefits of programs to enhance cookstoves across sub-Saharan Africa are examined in this essay. It starts by looking at a few specific Cookstove technologies, which are divided into groups according on the fuels they burn and whether or not they are mobile. It has been found that factors such as the technical compatibility of the stoves with social expectations, the conformity to local needs and cultures, the attitude of the users, who are frequently reluctant to adopt new technology, and the price of the stove all affect how challenging the programs are. Also, "bottom-up" strategies ensure the program's success by involving users and regional artisans in the creation of a self-sustaining sector.

Evolutions in Gaseous and Liquid Fuel Cook-Stove Technologies

The rapidly growing global demand for pollutant-free cooking energy has proliferated the research and development of energy efficient and clean cook-stoves. This paper presents a comprehensive review on the gradual improvements in cook-stove designs, focusing on gaseous and liquid fuel-operated cook-stoves around the world. Various literatures concerning the technical aspects such as design and testing, are brought together to provide an insight into the present status of developments in cook-stoves. This review of cook-stove performance covers topics such as stable operating conditions, flame propagation aspects, heat transfer and temperature distribution within the burner, fuel consumption, thermal efficiency, and emissions. Covering both laboratory-scale and field studies, the various cook-stove technologies reported so far are summarized with relevant comments regarding their commercial viabilities. The numerical modeling of combustion in cook-stoves; human health and the environmental impacts of unclean cooking technologies; and various schemes, strategies, and governmental initiatives for the promotion of cleaner cooking practices are also presented, with suggestions for future work.

Assessment of Improved Biomass Cookstove Technologies and Kitchen Characteristics on Indoor Air Quality and Fuel Consumption in Rural Settings of Western, Kenya

Purpose: This study investigated the impact of increased levels of indoor air pollution (IAP) caused due to biomass burning using different technologies in the rural households of Western, Kenya. A comparative assessment of the impact of traditional cookstoves (TCS) and improved cookstoves (ICS) coupled with the characteristics of kitchen was conducted to estimate the PM2.5 and CO concentrations in the micro-environments of kitchen and living area of the households.
 Methodology: The study incorporated both extensive and intensive real-time indoor air quality (IAQ) monitoring during the two cooking sessions of the day. A multi-stage sampling technique was used in this study and the total target population was 383; where 204 households were selected as the sample size for HH survey and 56 households were selected for indoor air pollution monitoring. Influence of the different types of kitchen characteristics; enclosed, semi-enclosed and open was also comprehensively analyzed to measure its impact on the IAQ. Both UCB-PATS instrument and CO loggers were launched in kitchens for 24 hours. The Kitchen Performance Test (KPT) was applied to demonstrate the effectiveness of stove interventions on household fuel consumption. The pollutant concentrations were reported in terms of 24-h, 1-h peak cooking and long-term time scales. Data was analyzed using Statistical Packages for the Social Sciences (SPSS). Multiple regression analysis was undertaken to evaluate the association between pollutant concentration and kitchen characteristics and to determine a set of variables that best predict the pollutants. Units of analysis included means, standard deviations, minimum values, median values and maximum values and IQR. Spearman’s rank correlation coefficients (r) were used to assess the relationship between mean daily kitchen CO concentrations and kitchen PM2.5 concentrations in order to determine whether all kitchen PM2.5 concentrations were as a result of biomass combustion or there were other microenvironment PM2.5 sources. One-way ANOVA was used to compare the quantified fuel use from different stoves and further multiple tests of mean separation were done according to Tukey’s test of significance at p < 0.05.
 Findings: The results of the study highlighted that households with improved cookstoves that included the Cheprocket and mud rocket stoves consumed 1.5 kg/day (95% CI: 1.3, 5.8) and 1.3 kg/day (95% CI: 1.2, 5.9) less fuel than households with three-stone stoves respectively. The multiple regression models indicated that well ventilated kitchens (β = 2.556, SE = 1.646, p = .036) using ICS, with cemented floors (β = -.091, SE = .026, p = .001) using Chepkube stove and higher number of windows (β = -4.475, SE = 2.841, p = .031) using Cheprocket stove; (β = -.446, SE = .042, p = .030) using rocket stove; (β = -.045, SE = .010, p = .000) using Chepkube stove were associated with lower kitchen PM2.5 concentrations. The study concludes that usage of ICS coupled with efficient designing of the kitchen can improve the overall IAQ of the household along with immense health benefits.
 Recommendation: Overall, the study emphasized the need of more user education for improved stoves users for behavioural change to reduce PM and CO kitchen concentrations and exposure.

Assessment of Sustainable Biomass Energy Technologies in Pakistan Using the Analytical Hierarchy Process

Pakistan is not merely confronting the energy crisis but also dealing with the scarcity of economical technologies for the utilization of energy resources. From the basic resources, renewable energy is one of the considerable resources. Due to environmental issues related to greenhouse gases (GHGs) and air pollution in Pakistan, the other energy resources are constricted. In rural areas, biomass resources are a fundamental need for domestic purposes. The prominent reason for environmental degradation and deforestation is due to ineffective use of such resources. Biomass resources for heating and cooking purposes are abundantly available in rural areas of Pakistan. In this context, this study helps us select the applicable cookstove technologies for the Sindh province for the proper utilization of biomass resources. The AHP (analytical hierarchy process) was used as the central methodology for the cookstove ranking. Concerning its improvement, four main criteria corresponding to 12 sub-criteria were considered for the selection of three cookstove technologies, i.e., traditional cookstoves (TCS), efficient cookstoves (ECS), and biogas cookstoves (BCS). The final decision of the AHP framework exposed the ECS technology as the advantageous technology, followed by the BCS and TCS, respectively. To analyze the results, a sensitivity analysis of the major results has also been carried out, and under the final ranking matrix, the ECS alternative got the highest weightage, nearly 36.56%, based on the developed model.

Thermal performance and heat storage behaviour of three pots improved cookstove

The use of biomass cookstoves is widespread in the household sector of developing nations. Still, these stoves are inefficient and emit a lot of pollution, including gaseous pollutants such as CO, particulate matter, and other pollutants, due to insufficient thermal and combustion efficiency. The three pots improved cookstove was developed to enhance cooking efficiency for rural and low-income urban homes to address these issues. This cookstove consists of three burners that enable best heat utilization as it permits cooking on three pots simultaneously. Statistical analysis was made with ANOVA tool and t-test. The results were found significant at 5% level of significance. Moreover, developed cookstove has thermal efficiency and power rating of 34.45% and 1.72 kW, respectively. Typical CO, CO2, PM2.5 emissions were recorded as 8.8 ppm, 628 ppm, and 0.97 μg/m3, respectively based on findings of emission test. Although increased cookstove adoption is critical to addressing the public health issue, efforts to distribute cookstove technologies have been hampered, and adoption rates in many developing nations are reported to be very low. Thus, the policymaker should think about implementing such a cooking system in rural areas that minimizes the amount of fuelwood used and preserve the environment.

Emission minimization of a top-lit updraft gasifier cookstove based on experiments and detailed CFD analyses

Around 2.7 billion people worldwide have no access to clean cooking equipment, which leads to major health problems due to high emissions of unburned products (VOC, CO and soot). A top-lit updraft gasifier cookstove with forced draft was identified as the technology with the highest potential for reducing harmful emissions from incomplete combustion in simple cookstoves. The basic variant of the stove was equipped with a fan for efficient mixing of product gas with air and fired with pellets to increase the energy density of low-grade residues. The development was conducted based on water boiling test experiments for wood and rice hull pellets and targeted CFD simulations of flow, heat transfer and gas phase combustion with a comprehensive description of the reaction kinetics, which were validated by the experiments. Emphasis was put on the reduction of CO emissions as an indicator for the burnout quality of the flue gas. The optimisation was carried out in several steps, the main improvements being the design of a sufficiently large post-combustion chamber and a supply of an appropriate amount of primary air for a more stable fuel gasification. The experiments showed CO emissions <0.2 g/MJdel for wood and rice hull pellets, which corresponds to a reduction by a factor of about 15 to 20 compared to the basic forced draft stove concept. Furthermore, these values are between 5 and 10 times lower than published water boiling test results of the best available cookstove technologies and are already close to the range of automatic pellet furnaces for domestic heating, which are considered to be the benchmark for the best possible reduction of CO emissions.

Environmental and financial benefits of improved cookstove technologies in the central highlands of Ethiopia

This study assessed the potential contributions of improved cookstoves in increasing organic fertilizer availability for application to farmland, greenhouse gas emission mitigation and improvement of household finances using the Kitchen Performance Test, Controlled Cooking Test, household survey and focus group discussions. Substitution of a three-stone open fire with improved cookstoves significantly (p < 0.01) improved fuel use efficiency by 54% (highest) for the mirt stove with an additional biogas stove and 32% (lowest) for the mud stove without an additional biogas stove. The greenhouse gas emission reductions in carbon dioxide equivalents were 4534 (±32) kg y−1, 6370 (±42) kg y−1, 6953 (±51) kg y−1, 7661 (±43) kg y−1 for the mud stove, mirt stove, mud stove with an additional biogas stove and mirt stove with an additional biogas stove respectively. The average financial savings from the sale of surplus biomass fuel for the improved cookstoves were higher than the summed financial savings from substitution of commercial fertilizer, generation of carbon finance and replacement of kerosene for lighting. This explains why households usually prefer to sell surplus biomass fuels instead of using them as organic fertilizers. This finding suggests that wide scale adoption of fuel-efficient solid biomass stoves can contribute to the financial security of households, and may help to reduce green gas emissions, but will do little to increase the fertility of soils. By contrast, including biogas stoves will help to improve soil fertility by retaining at least some of the carbon and nutrients in bioslurry that will then be applied to the soil.

Biomass-fuelled improved cookstove intervention to prevent household air pollution in Northwest Ethiopia: a cluster randomized controlled trial

BackgroundHousehold air pollution from biomass fuels burning in traditional cookstoves currently appeared as one of the most serious threats to public health with a recent burden estimate of 2.6 million premature deaths every year worldwide, ranking highest among environmental risk factors and one of the major risk factors of any type globally. Improved cookstove interventions have been widely practiced as potential solutions. However, studies on the effect of improved cookstove interventions are limited and heterogeneous which suggested the need for further research.MethodsA cluster randomized controlled trial study was conducted to assess the effect of biomass-fuelled improved cookstove intervention on the concentration of household air pollution compared with the continuation of an open burning traditional cookstove. A total of 36 clusters were randomly allocated to both arms at a 1:1 ratio, and improved cookstove intervention was delivered to all households allocated into the treatment arm. All households in the included clusters were biomass fuel users and relatively homogenous in terms of basic socio-demographic and cooking-related characteristics. Household air pollution was determined by measuring the concentration of indoor fine particulate, and the effect of the intervention was estimated using the Generalized Estimating Equation.ResultsA total of 2031 household was enrolled in the study across 36 randomly selected clusters in both arms, among which data were obtained from a total of 1977 households for at least one follow-up visit which establishes the intention-to-treat population dataset for analysis. The improved cookstove intervention significantly reduces the concentration of household air pollution by about 343 μg/m3 (Ḃ = − 343, 95% CI − 350, − 336) compared to the traditional cookstove method. The overall reduction was found to be about 46% from the baseline value of 859 (95% CI 837–881) to 465 (95% CI 458–472) in the intervention arm compared to only about 5% reduction from 850 (95% CI 828–872) to 805 (95% CI 794–817) in the control arm.ConclusionsThe biomass-fuelled improved cookstove intervention significantly reduces the concentration of household air pollution compared to the traditional method. This suggests that the implementation of these cookstove technologies may be necessary to achieve household air pollution exposure reductions.Trial registrationThe trial project was retrospectively registered on August 2, 2018, at the clinical trials.gov registry database (https://clinicaltrials.gov/) with the NCT03612362 registration identifier number.

Assessment of clean cooking technologies under different fuel use conditions in rural areas of Northern India

The study was conducted to assess the performance of improved and traditional cookstoves using wood as a fuel and three combinations of other fuel mixes – (i) wood and cow dung, (ii) wood and mustard stalks, and (iii) cow dung and mustard stalks). Energy and emission parameters such as specific energy consumption (SEC), emission factors (EFs) of carbon monoxide (CO), particulate matter (PM) and black carbon (BC) were used to compare four different types of cookstoves. These included top-feed forced draft (TF-FD), top-feed natural draft (TF-ND), front-feed natural draft (FF-ND) and front-feed traditional (FF-TR) cookstoves. Controlled cooking test (CCT) was used as the test protocol. The results showed the performance of improved cookstove technologies can vary based on the fuel used for cooking. It was observed that emission factors for PM and CO increased by 67–96% and 45–90% respectively when all three improved cookstoves were tested with three fuel combinations against wood as cooking fuel. Among the tested cookstoves, a marked difference was observed between performance of forced draft and natural draft cookstoves. Forced draft cookstoves emitted higher amount of all pollutant emissions compared to natural draft cookstoves when used with mustard stalks in combination with either wood or cowdung. The results are of critical importance given that forced draft cookstoves have been promoted in geographical regions where fuel mix use is prevalent. Therefore, forced draft cookstove might not be the right choice when the goal is climate mitigation and reduction in impact on human health. It is imperative to study comprehensively the influence of various field variables on performance of cookstoves, which have severe implications on the performance of cookstoves.

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

BackgroundAmong 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.MethodsAs 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.ResultsThe 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.ConclusionsExtremely 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.

Environmental and Financial Benefits of Improved Cookstove Technologies in the Central Highlands of Ethiopia

This study assessed the potential contributions of improved cookstoves in enhancing organic fertilizer availability for application to farmland, greenhouse gas emission mitigation and improvement of household finances using the Kitchen Performance Test and Controlled Cooking Test. Substitution of a three-stone open fire with improved cookstoves significantly (p<0.01) improved fuel use efficiency by 54% (highest) for the mirt stove together with biogas and 32% (lowest) for the mud stove without biogas. The greenhouse gas emission reductions in carbon dioxide equivalents were 4534(±32) kg y -1 , 6370(±42) kg y -1 , 6953(±51) kg y -1 , 7661(±43) kg y -1 for the mud stove, mirt stove, mud stove with biogas and mirt stove with biogas respectively. The average financial savings from the sale of surplus biomass fuel for the improved cookstoves were higher than the summed financial savings from substitution of commercial fertilizer, generation of carbon finance and replacement of kerosene for lighting. This explains why households usually prefer to sell surplus biomass fuels instead of using them as organic fertilizers. This finding suggests that wide scale adoption of fuel-efficient solid biomass stoves can contribute to the financial security of households, and may help to reduce deforestation, but will do little to increase the fertility of soils. By contrast, including biogas stoves will help to improve soil fertility by retaining at least some of the carbon and nutrients in bioslurry that will then be applied to the soil.

Carcinogenic risk from exposure to PM2.5 bound polycyclic aromatic hydrocarbons in rural settings.

In the study, first-time personal exposure level of polycyclic aromatic hydrocarbons (PAHs) was measured during cooking hours in participants of three different types of kitchen both in the particulate and gaseous phase using traditional and improved cookstoves. Along with that, indoor particulate matter (PM) concentration was also estimated during the cooking hours to examine the impact of intervention in different kitchens. The results of the study clearly revealed that the kitchen characteristics and type of cookstove technology have a significant impact on PM2.5, PM1 and PAHs concentration. Cookstoves intervention has resulted in maximum reduction of PM1 i.e. 75% in an enclosed kitchen followed by semi-enclosed and open kitchen having 71% and 52%, respectively. In addition, correlation analysis of PM2.5 and PM1 with PAHs showed a strong association (r2=0.9), showing the affinity of PAHs to bind to fine range of particles. Health risk assessment was also carried out to assess the PM daily dose and carcinogenic and non-carcinogenic risk due to inhalation of PAHs. The study confirmed the personal concentration of PAHs compounds was significantly high (p<0.05) during use of traditional cookstove compared to improved cookstove among all the three kitchens. Furthermore, to measure the toxicity levels, PAHs concentrations have been converted to benzo[a]pyrene equivalence for calculating cancer and non-cancer effects using toxicity equivalency factors. The overall lifetime carcinogenic risk was the highest 2.5E-03, 6.4E-04 among women who prepared meals in the enclosed kitchen compared to 8.4E-04, 1.3E-04 in semi-enclosed and 2.2E-04, 4.6E-05 in the open kitchen during use of traditional and improved cookstoves, respectively, which exceeded the US EPA standard i.e. 1×10-6. The study underlined the importance of personal monitoring for exposure, and risks-based studies along with the time-activity of user to measure the actual inhalation risk for the participants. These findings indicated that women are exposed to hazardous smoke in the indoor kitchen and are at greater risk of developing cancer, especially in rural areas.

Acute differences in pulse wave velocity, augmentation index, and central pulse pressure following controlled exposures to cookstove air pollution in the Subclinical Tests of Volunteers Exposed to Smoke (SToVES) study

Household air pollution emitted from solid-fuel cookstoves used for domestic cooking is a leading risk factor for morbidity and premature mortality globally. There have been attempts to design and distribute lower emission cookstoves, yet it is unclear if they meaningfully improve health. Using a crossover design, we assessed differences in central aortic hemodynamics and arterial stiffness following controlled exposures to air pollution emitted from five different cookstove technologies compared to a filtered air control. Forty-eight young, healthy participants were assigned to six 2-h controlled treatments of pollution from five different cookstoves and a filtered air control. Each treatment had a target concentration for fine particulate matter: filtered air control = 0 μg/m3, liquefied petroleum gas = 10 μg/m3, gasifier = 35 μg/m3, fan rocket = 100 μg/m3, rocket elbow = 250 μg/m3, three stone fire = 500 μg/m3. Pulse wave velocity (PWV), central augmentation index (AIx), and central pulse pressure (CPP) were measured before and at three time points after each treatment (0, 3, and 24 h). Linear mixed models were used to assess differences in the outcomes for each cookstove treatment compared to control. PWV and CPP were marginally higher 24 h after all cookstove treatments compared to control. For example, PWV was 0.15 m/s higher (95% confidence interval: -0.02, 0.31) and CPP was 0.6 mmHg higher (95% confidence interval: -0.8, 2.1) 24 h after the three stone fire treatment compared to control. The magnitude of the differences compared to control was similar across all cookstove treatments. PWV and CPP had no consistent trends at the other post-treatment time points (0 and 3 h). No consistent trends were observed for AIx at any post-treatment time point. Our findings suggest higher levels of PWV and CPP within 24 h after 2-h controlled treatments of pollution from five different cookstove technologies. The similar magnitude of the differences following each cookstove treatment compared to control may indicate that acute exposures from even the cleanest cookstove technologies can adversely impact these subclinical markers of cardiovascular health, although differences were small and may not be clinically meaningful.

Enhancing LPG Adoption in Ghana

TPS 641: Policies, interventions, communication, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Background: Three billion individuals worldwide rely on biomass fuel for cooking and heating, and health conditions resulting from household air pollution (HAP) are responsible for an estimated 3.9 million avoidable deaths annually. The conditions under which individuals sustain use of clean cookstoves are not well understood. Methods: The Enhancing LPG Adoption in Ghana (ELAG) study was a factorial cluster-randomized intervention trial targeting mothers in Kintampo, Ghana. The first component is a behavior change intervention based on the Risks, Attitudes, Norms, Abilities, and Self-regulation (RANAS) model. RANAS aligns these five behavioral factors with clean cookstove adoption and sustained use. A second intervention improved LPG availability by offering a direct-delivery refueling service with no delivery fee. The interventions were integrated via a factorial design. 27 communities were assigned to: the control arm, the educational intervention, the delivery, or a combined intervention. Outcome measures include pre/post assessments on the RANAS model behavioral factors and minutes of stove use in the last 6 months of ELAG, tracked with stove use monitors. Results: A total of 780 participants were enrolled and randomized across four arms: 218 in the control arm, 196 to the educational intervention, 193 for direct delivery of fuel, and 173 to the combined intervention. Participants were tracked for a range of 10-12 months. There was a mean of 0.2 and a range of 0-5 self-reported cylinder refillings across the cohort. Conclusion: Recipients of improved or clean cookstoves rarely completely adopt the new technology. Instead, they often practice partial adoption (fuel stacking). Consequently, interventions are needed to influence adoption patterns and simultaneously to understand drivers of fuel adoption. Ensuring uptake, adoption, and sustained use of improved cookstove technologies can lead to HAP reductions and improvements in public health.

Acute changes in C-reactive protein and lipoproteins following controlled exposures to cookstove air pollution in the Subclinical Tests of Volunteers Exposed to Smoke (SToVES) Study

TPS 722: Low and middle income countries: indoor air pollutants, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Background/Aim. Household air pollution from solid-fuel cookstoves is an important risk factor for morbidity and mortality worldwide. Improved cookstoves have been designed to reduce exposure to household air pollution, but whether such stoves meaningfully improve health remains unclear. We assessed the effect of pollution emitted from multiple cookstoves on acute changes in C-reactive protein (CRP) and lipoproteins (total cholesterol, high-density lipoprotein [HDL], low-density lipoprotein [LDL], triglycerides) using a controlled-, crossover-exposure design. Methods. Young, healthy participants (n=48) were assigned to sequences of six, 2-hour controlled exposures of pollution from five cookstoves and a filtered-air control. Each controlled exposure, spaced at least two weeks apart, had a fine particulate matter target concentration (µg/m3): control (0); liquefied petroleum gas (10); semi-gasifier (35); fan rocket (100); rocket elbow (250); open fire (500). CRP and lipoproteins were measured before and three timepoints after exposures (0, 3, 24 hours). Linear mixed models were used to assess differences in outcomes for cookstove exposures versus control. Results. CRP was lower 3 hours after and higher 24 hours after cookstove exposures versus control. Triglycerides were higher 24 hours after cookstove exposures versus control. LDL was lower 24 hours after cookstove exposures versus control. For example, CRP was 0.07 ln-mg/L higher (95% confidence interval [CI]: -0.07, 0.21), triglycerides were 0.11 ln-mg/dL higher (95% CI: 0.00, 0.23), and LDL was 2.7 mg/dL lower (95% CI: -7.5, 2.2) 24 hours after the open fire exposure versus control. Results were similar across cookstove types at the 24-hour post-exposure timepoint. Results from other timepoints (0, 3 hours) and outcomes (total cholesterol, HDL) were consistent with null associations. Conclusions. Short-term controlled exposures to air pollution from improved and traditional cookstoves acutely impact CRP and lipoproteins. These findings may provide insight into benefits of new and current cookstove technologies. This abstract does not represent EPA policy.

Clean Cookstove Technology Use for Energy Efficiency in the School System

Globally, clean cookstoves represent the best substitute for open fire biomass stoves in order to reduce greenhouse gas emissions from fuelwood. Prospects to transfer this technology to Botswana are being explored. Our research objectives were to transfer the clean Institutional Cookstove (IC) technology to Okavango Research Institute (ORI), quantify the amount of mopane (Colophospermum mopane) fuelwood it consumes in comparison to the traditional biomass energy system, and analyze its potential to be used as a substitute for the open fire cooking method. The clean IC technology transfer to ORI was successfully completed before testing its energy efficiency and financial viability. It consumed approximately two-thirds less fuelwood than the traditional three stone stove. This presents an opportunity for a reduction in greenhouse gas emissions from fuelwood consumption in Botswana. This is a critical consideration in an environment where there is limited readily available fuelwood. The use of clean cookstoves allows enhanced carbon sequestration by live mopane woodland resources. A financial viability analysis of implementing the clean IC in primary schools showed that it has the potential to save money spent on fuelwood. Our case study provides essential pertinent results on the energy efficiency of the developed prototype, which forms a basis for further research on the use of clean cookstoves for mitigating greenhouse gas emissions from fuelwood consumption in Botswana and the entire Cubango-Okavango River Basin. A comprehensive analysis of cultural barriers to adoption of the technology will be carried out through piloting the construction of the clean cookstove.

Acute Effects on Blood Pressure Following Controlled Exposure to Cookstove Air Pollution in the STOVES Study.

BackgroundExposure to air pollution from solid fuel used in residential cookstoves is considered a leading environmental risk factor for disease globally, but evidence for this relationship is largely extrapolated from literature on smoking, secondhand smoke, and ambient fine particulate matter (PM 2.5).Methods and ResultsWe conducted a controlled human‐exposure study (STOVES [the Subclinical Tests on Volunteers Exposed to Smoke] Study) to investigate acute responses in blood pressure following exposure to air pollution emissions from cookstove technologies. Forty‐eight healthy adults received 2‐hour exposures to 5 cookstove treatments (three stone fire, rocket elbow, fan rocket elbow, gasifier, and liquefied petroleum gas), spanning PM 2.5 concentrations from 10 to 500 μg/m3, and a filtered air control (0 μg/m3). Thirty minutes after exposure, systolic pressure was lower for the three stone fire treatment (500 μg/m3 PM 2.5) compared with the control (−2.3 mm Hg; 95% CI, −4.5 to −0.1) and suggestively lower for the gasifier (35 μg/m3 PM 2.5; −1.8 mm Hg; 95% CI, −4.0 to 0.4). No differences were observed at 3 hours after exposure; however, at 24 hours after exposure, mean systolic pressure was 2 to 3 mm Hg higher for all treatments compared with control except for the rocket elbow stove. No differences were observed in diastolic pressure for any time point or treatment.ConclusionsShort‐term exposure to air pollution from cookstoves can elicit an increase in systolic pressure within 24 hours. This response occurred across a range of stove types and PM 2.5 concentrations, raising concern that even low‐level exposures to cookstove air pollution may pose adverse cardiovascular effects.

English

Around three million premature deaths annually are ascribed to household air pollution (HAP) arising from inefficient burning of biomass and emissions of products of incomplete combustion. The developing-world response has been widespread adoption of improved cookstove (ICS) technologies. This exploratory study evaluates variation in polycyclic aromatic hydrocarbon (PAH) attached to inhalable particulate matter (PM) in rural Malawi households adopting ICS use. PM literature supports HAP exposure to inhalable PM is lowered, albeit variably, compared to traditional fires, but remains significant. Similar is expected for PAH; however, datasets lack discerning PAH chemical-specific contributions to risks. The study introduces the Malawian context, invokes a PAH reconnaissance approach sampling kitchen soot ‘spots’ and residential dusts, and relates PAH occurrence to the two sample types collected and ICS types surveyed. The total PAH for dusts was low (c. 2 μg/g mean), with volatile 2-ring naphthalene dominant. Soot total PAH was much higher (c. 200 μg/g mean to a maximum of 815 μg/g). Soot from PM emissions poses a major primary health concern. Despite PAH trends not being obvious with ICS type (limited sample size) and the wide range in soot total PAH, soot PAH-fingerprints were well constrained with low variation of diagnostic PAH ratios, exhibiting n-ring fingerprints close to the soot median (0.1% 2-ring, 20% 3-ring, 61% 4-ring, 14% 5-ring, 5% 6-ring PAH). These corroborate the expected wood-related combustions sources, but also point to the needs to understand factors that control wide variations in PM and (total) PAH emitted as these control variations in HAP and differing risks posed to individual households. Further household-based research is thus recommended discerning relationships between PM emissions and PAH contents, driving the chemical-composition health risks. These should establish influences on PAH exposure arising from ICS type/model selected, operational modes, building/ventilation conditions, variable fuel sources and non-optimal ICS use. Key words: Improved cookstoves (ICS), polycyclic aromatic hydrocarbon (PAH), household air pollution (HAP), particulate matter (PM), Malawi, indoor air pollution (IAP).