Traditional Stoves Research Articles

Presenting complaints and mortality in a cohort of 22 000 adult emergency patients at a local hospital in Nepal.

BackgroundThere is a need to develop sustainable emergency health care systems in low-resource settings, but data that analyses emergency health care needs in these settings are scarce. We aimed at assessing presenting complaints (PCs) and post-discharge mortality in a large emergency department population in Nepal.MethodsCharacteristics of adult patients who entered the emergency department (ED) in a hospital in Nepal were prospectively recorded in the local emergency registry from September 2013 until December 2016. To assess post-ED mortality, patient households were followed-up by telephone interviews at 90 days.ResultsIn 21892 included adults, the major PC categories were injuries (29%), abdominal complaints (23%), and infections (16%). Median age was 40 years and sex distribution was balanced. Among 3793 patients followed at 90 days, 8% had died. For respiratory and cardiovascular PCs, 90-day mortality were 25% and 23%. The highest mortality was in individuals with known chronic lung disease, in this group 32% had died by 90 days of ED discharge, regardless of PC. In women, illiteracy compared to literacy (adjusted odds ratio (aOR) = 7.0, 95% confidence interval (CI) = 2.1-23.6) and being both exposed to tobacco-smoking and traditional cooking stove compared to no smoke (aOR = 2.8, 95% CI = 1.6-4.9) were associated with mortality. The mortality was much higher among family-initiated discharged patients (17%, aOR = 5.4, 95% CI = 3.3-8.9) compared to doctor-initiated discharged (3%).ConclusionsOur report suggests that nearly one in ten patients seeking emergency health care died within 90 days. This finding is alarming and novel. Post-discharge studies need to be replicated and appropriate follow-up programs in low-resource settings where primary health care is underdeveloped are urgently needed.

Successes and Challenges of Improved Biomass Cooking Stoves Adoption along the Product Value Chain in Kilimanjaro Region, Tanzania

The aim of this study was to assess the adoption of ICS along the value chain. The existing studies have focused much on measuring adoption based on the user’s installation or purchase of the ICS and few have gone to the level of assessing other aspects along the ICS value chain. The argument of this paper is that adoption is a multidimensional concept that goes beyond the initial acquisition of the stove to the sustained use of the same. Using a cross-sectional study design data were collected from 294 households in two Districts of Kilimanjaro regions and were analyzed using both quantitative and qualitative approaches. The findings show that at the lower levels of value chain i.e. promotion and distributions the efforts have been somehow successful since people are aware of ICS benefits and negative effects of using traditional fuels and stoves. In addition, various stove distributors and technicians are in place. On the other hand, the uptake is limited since only 26% of all households had ICS in place of which only 22.1% had functional stoves. The intensity of ICS use is very limited and households have not integrated the stove into household cooking behavior. The study concludes that the stoves program implementers have adopted a disintegrated approach that disconnects various levels of the value chain. The efforts are much concentrated at lowers levels with limited interventions to address challenges limiting uptake, the intensity of use and sustained adoption. The study recommends that a holistic and integrated approach that will facilitate ICS adoption along the value chain should be adopted. This approach will facilitate forward and backward communications on challenges facing each level of the value chain.

“We cannot stop cooking”: Stove stacking, seasonality and the risky practices of household cookstove transitions in Nigeria

Drawing on qualitative data from three contrasting sites in Benue state, Nigeria, this paper explores how and why cooking system use and priorities vary over time and space as well as the influence of household air pollution (HAP)-related health risks on fuel and stove choices. The findings indicated that cooking system choices were constrained by economic and access considerations linked to spatio-temporal variations in fuel cost, availability and service quality coupled with socio-cultural and utilitarian influences on cooking practices. Respondents demonstrated strong preferences for wood-fuelled traditional stoves although shifts in fuel use between wet and dry seasons were observed. Stove and fuel ‘stacking’ were widely practised to meet different cooking requirements and minimise risks from (often seasonal) variations in fuel prices, access and reliability of supply. ‘Backsliding’ from clean to solid biomass fuels was observed when families outgrew their improved cookstoves or considered biomass to be more affordable, reliable, accessible or safer. There was limited awareness or concern about HAP-related health risks and smoke was valued for preserving food and signalling food security. Attention is drawn to the value of integrating household risk perceptions into improved cookstove promotion and behaviour change initiatives to better understand constraints to the adoption and sustained use of clean cooking systems. The paper concludes by highlighting the benefits of monitoring household cooking system stacks (rather than the ‘main’ fuel/stove used) for analysing how their components vary over space and time and providing insights into the effectiveness of measures taken to reduce HAP exposure.

Understanding Household Energy Transitions: From Evaluating Single Cookstoves to “Clean Stacking” Alternatives

The pervasiveness of “stacking” between traditional and clean fuels/stoves is moving the household clean cooking research and policy agenda from programs that are centered on one-fuel or stove, to multi-clean fuel/device interventions that could result in a more effective displacement of traditional biomass stoves. However, there is little recognition and knowledge of the benefits realistic clean-stacking cooking solutions can have on indoor air quality and health. In this paper, particulate matter (PM2.5) and carbon monoxide (CO) concentration levels that are associated with stove-stacking options (Patsari-U-shaped open fire (U-type), Patsari-liquefied petroleum gas (LPG) stove, U-type-LPG, and Patsari-U-type-LPG) common within rural Mexico were evaluated while using a controlled cooking cycle (CCC) from the Purepecha Highlands, which mimics the most common dishes prepared daily within the region as well as their sequential arrangement. The results confirms that the WHO Interim Target-1 (IT1) of 35 μg/m3 for PM2.5 is exceeded whenever woodburning open fires are part of the stacking combination (Patsari-U-type 107 ± 9 μg/m3, U-type-LPG 131 ± 55 μg/m3 and Patsari-U-type-LPG 107 ± 22 μg/m3). However, well-designed and properly operated woodburning chimney stoves, such as the Patsari can meet the IT1, either used exclusively (21 ± 8 μg/m3) or as a “clean stacking” option with LPG (24 ± 5 μg/m3). Given stove stacking patterns, evaluating the health and environmental consequences of stove transitions while assuming the total replacement of traditional fires by clean cooking options will lead to misplaced expectations, and programs should evaluate more realistic “clean-stacking” options.

Volatile organic compounds emissions from traditional and clean domestic heating appliances in Guanzhong Plain, China: Emission factors, source profiles, and effects on regional air quality

Solid (biomass and coal) fuels burned for residential heating are major sources of atmospheric volatile organic compounds (VOCs). In this study, VOC samples were collected in-situ from chimneys in 10 typical heating scenarios in rural areas of the Guanzhong Plain. A modified SUMA canister approach was then employed, followed by gas chromatography/mass spectrometry analysis. Emission factors (EFs) (as received basis) of targeted non-methane VOCs (NMVOCs) varied from 90.3 ± 29.3 to 12300 ± 1510 mg kg−1 in descending order of fuel wood > maize straw > bitumite ≫ anthracite (p < 0.05). Both clean stove and coal briquetting technologies effectively reduced VOC EFs compared with traditional heating methods. The EFs of methane (CH4) had similar characteristics to those of NMVOCs. However, they yielded different correlations with CO because of their differing mechanisms of formation. Coefficient of divergence (CD) values showed that a semi-gasifier has a limited effect on changing VOC profiles compared with a traditional stove using the same fuels. However, different types of fuel produce CD values over 0.50, which should therefore be classified as different sub-categories in source apportionment models. Correlation analysis showed that volatile matter content (V%) and modified combustion efficiency (MCE) were the two primary factors influencing NMVOC and CH4 emissions. A stepwise linear regression analysis showed that V%, MCE, and element nitrogen content (N%) can be used to predict total VOC (TVOCs, including CH4 and NMVOCs) emissions with regression coefficients of 0.23, −72.8 and −6.53, respectively (R2 = 0.92, p < 0.001). Ozone formation potential (OFP) EFs from burning solid fuel ranged from 72 to 18680 mg kg−1, with an approximate 50% contribution from alkenes. VOCs from burning solid fuel were equivalent to 62 to 22200 mg kg−1 secondary organic aerosol formation potential (SOAP), most of which (>95%) were contributed by aromatics. A semi-gasifier and coal briquettes were effective in reducing TVOC emissions, even when used in conjunction with a traditional stove and fuels. It is estimated that over 15,000 ton year−1 emissions can be reduced in Guanzhong Plain by adopting a semi-gasifier and coal briquettes, resulting in a 57,000 and 65,000 ton year−1 reduction of OFP and SOAP emissions, respectively. These results demonstrate that the use of clean heating technologies in Guanzhong Plain has considerable potential in relation to emissions reduction and thus provides a feasible solution to mitigate VOCs and related secondary pollutants emitted by residential solid fuel burning.

Benefits of Improved Cook Stoves: Evidence from Rural Bangladesh

Reduction of biomass fuel consumption, improved health outcomes of household members and time savings for households are the key intended benefits of Improved Cook Stove (ICS). This paper attempts an empirical verification of these targeted benefits of the ICS, named Bondhu Chula, in ruralBangladesh. Propensity score matching (PSM), a quasi-experimenteconometric method, has been applied using the 2018 household survey data of Bangladesh Institute of Development Studies (BIDS) that collected information from 600 users of Bondhu Chula and 396 users of traditional cook stoves. The analysis reveals that the use of Bondhu Chula on the averagesaves about 50 kg of biomass fuel consumption per month per household, i.e. 30-37 per cent of biomass fuel consumption compared to households using traditional cook stoves. Bondhu Chula was also found to have provided improved health outcomes by reducing indoor air pollution and led to reduced household cooking time. Despite the observed benefits of the use of ICS, the progress towards the adoption of ICS across the country is not satisfactory and there is a large opportunity to scale-up the use of ICS. The evidence provides justification for such a policy move.

Investigation into Trace Elements in PM10 from the Baking of Injera Using Clean, Improved and Traditional Stoves: Emission and Health Risk Assessment

Particulate matter with aerodynamic diameters < 10 µm (PM10) emitted during the baking of Ethiopian’s traditional staple food Injera (a flatbread mostly made from Teff flour and baked upon a circular griddle) was collected for analysis. Emissions of inhalable particles from three types of stoves, clean, improved, and traditional stoves, were tested to determine the elemental composition and to assess the short-term exposure and health risk of the particles in the indoor microenvironment. The PM10 was collected with the help of a portable sampling unit with multi-fraction dust samplers, and its elemental composition was determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The mean concentration of PM10 pollutant using clean, improved, traditional stoves were 139, 259 and 571 µg m−3, respectively. The concentrations of trace elements (Fe, Cd, As, Cr, Pb, B, Ni, Co, Sn, Cu and Zn) bound in PM10 during the use of improved, traditional stove and clean stoves ranged from below detection limit (BDL) to 632, BDL to 0.499 and BDL to 0.078 µg m−3, respectively. The carcinogenic and non-carcinogenic risks of the exposed person to trace elements bound in PM10 were assessed according to the US Environmental Protection Agency prescription. Although the US National Quality Standard is 150 µg/m3 for 24 h, the results showed that the likelihood that an average person has either carcinogenic or non-carcinogenic health impacts by using any of the three stoves over a lifetime at a frequency of twice a week is very low. However, the PM10 contribution of wood-burning stoves to the total daily exposure is high.

Feasibility study of TEG-integrated biomass cook stove for electrical power generation specific to rural areas with inadequate electricity

ABSTRACT Access to standard form of energy in cooking and lighting has been a serious concern among most of the people residing in rural parts of the world. More than 2 billion people concentrated mostly in rural areas of India and sub-Saharan Africa use firewood in inefficient (thermal efficiency is <8–10%) traditional cook stoves. Around 15% of input energy from fuel is stored within the stove body as waste heat. Further, the annual per capita electricity consumption is just over 1000 kWh compared to world average of more than 3000 kWh. Whereas, the figure drops to 314 kWh in the northeastern state of Assam, India. Thermoelectric generator (TEG) can be used to recover the waste heat and utilize it in the conversion into electricity on the principle of Seebeck effect. This research work is attempted to test the feasibility of integrating a TEG module with an Ministry of New and Renewable energy (MNRE)-approved improved clay made cook stove named Sukhad using fundamental heat transfer and thermoelectric equations. Preliminary tests of the TEG-integrated cook stove showed a potential of generating 2.7 W of electrical power and illuminating a 3 W LED bulb.

Characterisation of Indoor PM2.5 and CO concentrations in households using charcoal and wood biomass fuel in Kigali, Rwanda

PDS 72: Environmental health issues in LMIC, Exhibition Hall (PDS), Ground floor, August 28, 2019, 10:30 AM - 12:00 PM Background: Household Air Pollution from biomass cooking with traditional stoves in poorly ventilated households is a major cause of morbidity and mortality in low-income settings worldwide. In Rwanda, about 85% of the population still depend on biomass as the primary source of domestic energy, with wood and charcoal the predominant fuels sources. This study is the first research investigation in urban Rwanda of indoor PM2.5 and CO levels associated with biomass fuel cooking activities. Methods: We conducted a household and cooking activity survey among 40 biomass fuel households in Nyarugenge District, Kigali. In addition we performed air quality monitoring for particulate matter (PM) and carbon monoxide (CO) within those 20 households in which cooking was performed exclusively indoors. Pollutant concentrations were measured at one-minute intervals, using the IQ Air Visual Pro sensor (PM2.5) and electrochemical COA1 (CO) detector adapter devices respectively. Results: Overall, the majority of households (75%) used exclusively charcoal fuel with the remainder using wood and charcoal. In the majority of households (90%) in which monitoring was performed, mean pollutant concentrations were in excess of WHO Air Quality (WHO-AQ) Standards with 24-hour values of 93 µgm-3 and 35.1 ppm for PM2.5 and CO respectively. In those four households where cooking was performed once daily, average CO concentrations were below WHO-AQ Standards. Charcoal fuel was associated with lower average concentrations (CO, PM2.5) compared to those households using a mixture of charcoal and wood fuel (p<0.001). Conclusion: Our findings suggest that household air quality levels associated with charcoal and wood combustion in Kigali, Rwanda exceed WHO AQ standards and are in the hazardous range for human health. Efforts are required to evaluate the impact of household energy policies which facilitate access to cleaner fuel sources and develop effective structural ventilation, educational intervention measures or behavioural change campaigns in this context.

Air Quality, Home Heating, and Well-Being under Beijing’s Ban on Household Coal Burning

OPS 02: Environmental epidemiology and policy, Room 315, Floor 3, August 28, 2019, 1:30 PM - 3:00 PM Background/aim: In response to severe and persistent haze, the Chinese Air Pollution Prevention and Control Action Plan includes regional coal consumption caps in key northern regions. In Beijing, the municipal government has designated coal restricted areas throughout the province, offering subsidies to nighttime electricity rates and for electric-powered heat pumps to replace traditional coal heating stoves. We compared treated and untreated villages in the Beijing province to investigate three dimensions of outcomes of the policy: fuel use and economic behavior, subjective well-being, and indoor environmental conditions. Methods: Our study design consists of 302 door-to-door surveys in six villages, with one treated and one un-treated village in each of three districts chosen to represent different socioeconomic and geographic conditions present in peri-urban Beijing. We measured indoor temperature and fine particulate matter levels (PM2.5) in a subset of homes in each village. Results: Coal use was absent in treated villages in two districts, and significantly lower in the treated as compared with the untreated village in one district where adherence to the coal ban was not complete. In homes in the two coal-restricted villages adhering to the coal ban, average (standard deviation) outdoor-subtracted, indoor 24-h PM2.5 concentrations (0.145 (0.218) mg-m-3) were lower compared with untreated homes (0.275 (0.244) mg-m-3). In the middle-income district, where the transition to electric heating was complete, satisfaction with life (SWL) and satisfaction with living conditions (SWC) were higher (+0.6 and +1.0 on the 0–10 scale) in the treated village than the untreated. By contrast, in the least affluent district, both satisfaction measures were lower (-1.0, -1.5) in the treated village compared with the untreated. Conclusions: Our results suggest that sudden household energy transition can be effective, given available technology for leap-frogging to high-efficiency electric heating, and generous public support for the program.

Monitoring impacts of clean cookstoves and fuels with the Fuel Use Electronic Logger (FUEL): Results of pilot testing

Objective, affordable, and unobtrusive monitoring tools are needed to quantify in-field performance and increase user acceptance rates of clean cookstoves and fuels. To meet this need, researchers have developed the Fuel Use Electronic Logger (FUEL), a sensor-based system that monitors the mass of a household fuel supply and cookstove temperature over time to quantify cookstove adoption and use, fuel consumption, and extrapolate to air quality and climate emissions. Following proof-of-concept studies in Honduras and Uganda, a pilot study was conducted in 44 rural Ugandan households monitoring over an average of 45 days. The purpose of these studies was to evaluate sensor usability and technical performance, inform algorithm development, and demonstrate how FUEL data can be used to quantify key stove performance metrics. Usability results indicated that the FUEL accurately monitored fuel consumption 88% of monitoring days, and 78% of households continued to use the fuel holder without the sensor 8 months after the monitoring period. Fuel consumption was reported per cooking event, day, monitoring period, household, and per capita. Results showed high daily variability in each household, suggesting that longer monitoring durations are needed, with estimation error decreasing from 72% at 4 days to 6.5% relative to a 25-day monitoring period. Cooking duration paired with fuel consumption also provided indicators of average firepower and therefore operational practices across households. Use of emission factors with fuel consumption data estimated carbon savings, showing that stacking of an improved and traditional stove will contribute to higher fuel consumption and carbon emissions per capita than households using a single improved stove. These results highlight the potential of the FUEL system to aid in more effective and accurate quantification of long-term technical performance and adoption, while increasing the transparency and impact of improved cookstove projects.

Access to Modern Energy Initiatives by Rural Household in Homa Bay County, Kenya

The failure to provide energy access continues in many parts of the world today. It is estimated that three million people in the world lack access to energy infrastructure and use biomass solid fuels such as charcoal firewood, dung or crop residue for cooking. Apart from being highly inefficient, these traditional, open fire cookstoves produce toxic particulates that cause indoor air pollution and contribute to around four million premature deaths per year especially among women and children. The paper based on a study undertaken in Homa Bay is focused on identifying the energy initiatives in Homa Bay County, and how consumers perceive ICS with respect to traditional stoves. The study used Ex post facto research design using mixed method to collect data which was obtained using data collection instruments such as questionnaires, FGD, Key informant interview schedules and researcher’s observation.&nbsp; The study used systematic and cluster sampling to get a representative data. The study was based on the capability approach theory that people ought to be made equal in their capabilities or at least in their basic capabilities. The study found that household cooking technologies came from two main source namely three stone fire and Kenya ceramic jiko. The main sources of household cooking fuel were biomass, kerosene and LPG. Use of open fire and overdependence on solid biomass resulted in respiratory illness and eye discomfort caused by IAP and black carbon. Low adoption of solar and electricity resulted in high use of kerosene tin lamp as source of light. The study concludes that there is a need to strengthen efforts to promote use of ICS, which use biomass in a more efficient way. The promotion and distribution of ICS should be linked with funding for climate-related projects, with the aim of reducing the cost of the stoves and creating added economic incentives to replace old, inefficient cookstove models.

Exposures to Carbon Monoxide in a Cookstove Intervention in Northern Ghana

Biomass burning for home energy use is a major environmental health concern. Improved cooking technologies could generate environmental health benefits, yet prior results regarding reduced personal exposure to air pollution are mixed. In this study, two improved stove types were distributed over four study groups in Northern Ghana. Participants wore real-time carbon monoxide (CO) monitors to measure the effect of the intervention on personal exposures. Relative to the control group (those using traditional stoves), there was a 30.3% reduction in CO exposures in the group given two Philips forced draft stoves (p = 0.08), 10.5% reduction in the group given two Gyapa stoves (locally made rocket stoves) (p = 0.62), and 10.2% reduction in the group given one of each (p = 0.61). Overall, CO exposure for participants was low given the prevalence of cooking over traditional three-stone fires, with 8.2% of daily samples exceeding WHO Tier-1 standards. We present quantification methods and performance of duplicate monitors. We analyzed the relationship between personal carbonaceous particulate matter less than 2.5 microns (PM2.5) and CO exposure for the dataset that included both measurements, finding a weak relationship likely due to the diversity of identified air pollution sources in the region and behavior variability.

Improved Cookstoves and User Preferences of Rural Women in Ondo State, Nigeria: Estimates from Random Utility Maximization Model

Cleaner and more efficient cookstoves have the potential to generate social, economic, health and environmental benefits. Rural women will only purchase improved cookstoves that meet their cooking needs and priorities. The study analysed choice preferences of improved cookstoves by rural women households in the study area. Results from primary data shows that 77.5% of respondents are willing to pay for improved cookstove while 22.5% are not willing. While 43.8% are willing to pay for Envirofit, 19.1% went for KIKE Green Cookstove and 14.6% went for charcoal cookstove among those who are willing to buy. The logistic regression model estimates show that source of information on benefits was a significant factor influencing rural women’ decision on the purchase and uptake of clean cookstoves. Formal means of communication was effective as expected in creating required awareness among the rural people. Hence, there is need to increase awareness level on the opportunity cost of health risks of the continual use of traditional cookstoves. There is no relationship between awareness and willingness to pay for improved cookstoves, however, there is a significant relationship between health effect of traditional stoves and willingness to buy improved cookstove.

Impact of household air pollution exposure on rural India: A systemic review

All in developing nations about 50% population rely on solid unclean fuel in the form of animal dung cake, crop residue and wood for household energy and cooking. Solid biomass fuel is typically burnt in traditional cooking stove or chulha without chimney with incomplete combustion. As well as in rural areas children and women must go through the drudgery and health risk of collecting crop residue and fire wood. So the scheme of “Ujjwala Yojana” was commenced by the Prime Minister of India in 2016 and Rs. 8000 Cr. has been granted for the Yojana. The aim of this scheme was to provide safety for children and women in rural areas from health risk by furnishing with clean and safe cooking energy Liquid Petroleum Gas (LPG), so that they don’t have to deal their health issues in poor ventilated and smoky, blackish kitchen. Villagers were used traditional biomass stoves or chulha without chimney for cooking, boiling water and used for cooking cattle food. Aim of this review was to find out household air quality of rural areas using different solid unclean biomass fuel for example cow dung cake, crop remains and wood in terms of gaseous pollutants and particulate matter in kitchen area so the higher concentration of different gaseous pollutants i.e. carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2) and sulphur dioxide (SO2) were reported in the kitchen area during cooking hours. It can be concluded based on literature reviews that, there is significant health risk associated with increased concentration of gaseous pollutants and suspended particulate matters.

Differences in chemical composition of PM2.5 emissions from traditional versus advanced combustion (semi-gasifier) solid fuel stoves

A common strategy to improve indoor air quality in households burning coal and biomass is the introduction of advanced combustion solid fuel stoves, which can use existing fuels yet emit fewer pollutants. Chemical composition of PM is affected by numerous combustion parameters, but is often not considered in energy transitions, despite varying toxicity among chemical components. We analyzed PM2.5 emissions from combustion of solid fuels (coal, wood, and straw; whole and pelletized) in a variety of stoves (cookstoves and heating stoves; traditional and semi-gasifier, including forced versus natural draft and fixed versus reciprocating grate). To assess the effects of fuel and stove type on PM2.5 composition, we measured elemental carbon (EC), organic carbon (OC), water-soluble OC, water-soluble inorganic ions (e.g. SO42−, Cl−, K+), and organic molecular markers. PM2.5 emissions from traditional stoves were mostly carbonaceous: 76–90% organic matter (OM), 5–6% EC, and less than 2% inorganic ions. In contrast, semi-gasifier stoves emitted more inorganic PM2.5: on average, ions comprised 65%, 9% was OM, and 4% was EC. Within the semi-gasifier cookstoves, forced-draft cookstove emissions had lower OM (1–3%) and higher ion concentrations (84–88%) than the natural-draft cookstove (5–14% OM, 30–83% ions). Levoglucosan was detected in PM2.5 from combustion of wood in the traditional cookstove and biomass pellets in the natural-draft semi-gasifier cookstove, but not from wood pellets in the forced-draft semi-gasifier cookstove. Across a range of different fuels and stoves, stove type influenced emitted PM composition more than fuel type, underscoring the impact of combustion conditions on PM chemical composition.

Effects of a large-scale distribution of water filters and natural draft rocket-style cookstoves on diarrhea and acute respiratory infection: A cluster-randomized controlled trial in Western Province, Rwanda.

BackgroundUnsafe drinking water and household air pollution (HAP) are major causes of morbidity and mortality among children under 5 in low and middle-income countries. Household water filters and higher-efficiency biomass-burning cookstoves have been widely promoted to improve water quality and reduce fuel use, but there is limited evidence of their health effects when delivered programmatically at scale.Methods and findingsIn a large-scale program in Western Province, Rwanda, water filters and portable biomass-burning natural draft rocket-style cookstoves were distributed between September and December 2014 and promoted to over 101,000 households in the poorest economic quartile in 72 (of 96) randomly selected sectors in Western Province. To assess the effects of the intervention, between August and December, 2014, we enrolled 1,582 households that included a child under 4 years from 174 randomly selected village-sized clusters, half from intervention sectors and half from nonintervention sectors. At baseline, 76% of households relied primarily on an improved source for drinking water (piped, borehole, protected spring/well, or rainwater) and over 99% cooked primarily on traditional biomass-burning stoves. We conducted follow-up at 3 time-points between February 2015 and March 2016 to assess reported diarrhea and acute respiratory infections (ARIs) among children <5 years in the preceding 7 days (primary outcomes) and patterns of intervention use, drinking water quality, and air quality. The intervention reduced the prevalence of reported child diarrhea by 29% (prevalence ratio [PR] 0.71, 95% confidence interval [CI] 0.59–0.87, p = 0.001) and reported child ARI by 25% (PR 0.75, 95% CI 0.60–0.93, p = 0.009). Overall, more than 62% of households were observed to have water in their filters at follow-up, while 65% reported using the intervention stove every day, and 55% reported using it primarily outdoors. Use of both the intervention filter and intervention stove decreased throughout follow-up, while reported traditional stove use increased. The intervention reduced the prevalence of households with detectable fecal contamination in drinking water samples by 38% (PR 0.62, 95% CI 0.57–0.68, p < 0.0001) but had no significant impact on 48-hour personal exposure to log-transformed fine particulate matter (PM2.5) concentrations among cooks (β = −0.089, p = 0.486) or children (β = −0.228, p = 0.127). The main limitations of this trial include the unblinded nature of the intervention, limited PM2.5 exposure measurement, and a reliance on reported intervention use and reported health outcomes.ConclusionsOur findings indicate that the intervention improved household drinking water quality and reduced caregiver-reported diarrhea among children <5 years. It also reduced caregiver-reported ARI despite no evidence of improved air quality. Further research is necessary to ascertain longer-term intervention use and benefits and to explore the potential synergistic effects between diarrhea and ARI.Trial registrationClinical Trials.gov NCT02239250.

Numerical and experimental Analysis of Solar Injera Baking with a PCM Heat Storage

Today, many developing countries are using biomass as their primary energy supply. However, this energy affects the environment, health and safety of women and children. In addition, utilization of this energy using traditional cooking stoves is causing indoor air pollution and in turn health problems to millions of people. To overcome such problems, efforts are being made by researchers globally and are suggesting alternative safe energy sources. This paper demonstrates solar cooker with an integrated PCM thermal storage and heat transportation loop system suitable for high temperature applications. The system has designed to address Injera baking application. Injera, a fermented flat bread type, is the most common food type served three to four times a day in Ethiopia. Other countries like Eritrea, Somalia, Sudan and Yemen also use this food. The storage system has storing capacity of heat up to 250 0 C and it can retain this heat for about two days. The storage has coupled to a polar mounted concentrator, fixed receiver and used steam heat transfer fluid. The steam circulates naturally between the evaporator and condenser in a closed loop. The paper focuses on indirect charging, simultaneous charging-discharging and discharging of the stored heat for the purpose of Injera baking. The frying pan is a custom-made aluminum plate casted by embedding a 10mm coiled stainless steel steam pipe as heating element. The pan is 500mm in diameter and 30mm thick; and the fins are 20mm in diameter and 140mm long. The fins have immersed into a 20kg PCM, which is coupled to a 1.8m diameter parabolic dish collector. The solar fryer demonstrates Injera baking for average family size. Baking is tested from the stored heat, while storage is charging. A fully charged storage has supplied enough heat to baked average household Injera demands about 19Injeras and additional breads with the remaining heat. Keywords: Solar Injera baking; PCM charging; PCM storage; Solar Injera stove design; Solar cooking; Ethiopia.

Pellet-Fed Gasifier Stoves Approach Gas-Stove Like Performance during in-Home Use in Rwanda.

Nearly all households in Rwanda burn solid fuels for cooking. A private firm in Rwanda is distributing forced-draft pellet-fed semigasifier cookstoves and fuel pellets. We measured in-use emissions of pollutants including fine particulate matter (PM2.5), organic and elemental carbon (OC, EC), black carbon (BC), and carbon monoxide (CO) in 91 uncontrolled cooking tests (UCTs) of both pellet and baseline (wood; charcoal) stoves. We observed >90% reductions in most pollutant emission factors/rates from pellet stoves compared to baseline stoves. Pellet stoves performed far better than gasifier stoves burning unprocessed wood, and consistent with ISO tiers 4 and 5 for PM2.5 and CO, respectively. Pellet stoves were generally clean, but performance varied; emissions from the dirtiest pellet tests matched those from the cleanest traditional stove tests. Our real-time data suggest that events occurring during ignition and the end of testing (e.g., refueling, char burnout) drive high emissions during pellet tests. We use our data to estimate potential health and climate cobenefits from stove adoption. This analysis suggests that pellet stoves have the potential to provide health benefits far above previously tested biomass stoves and approaching modern fuel stoves (e.g., LPG). Net climate impacts of pellet stoves range from similar to LPG to negligible, depending on biomass source and upstream emissions.

Adoption of improved biomass stoves and stove/fuel stacking in the REACCTING intervention study in Northern Ghana

In order to support transitions away from open-fire cooking and toward cleaner household energy systems, a better understanding of users’ technology adoption patterns and preferences is needed. This paper highlights key factors influencing use of two types of biomass-burning stoves provided through the REACCTING (Research on Emissions, Air quality, Climate, and Cooking Technology in Northern Ghana) randomized intervention study. We examine traditional and improved stove use over a two year follow up period, finding that the more basic rocket stove was used at a higher rate than the higher-tech gasifier stove. While stove use patterns varied by stove group, region, primary cook occupation, and socioeconomic status, use of traditional stoves remained high across most groups. Users perceived that improved stoves were less suitable for cooking a staple dish, Tuo Zaafi (TZ), and technical problems (e.g., battery failures with the gasifier stove) also limited the effectiveness of the intervention. Moving forward, household energy policies should prioritize a range of technologies that have potential to meet local needs while delivering meaningful health and/or environmental benefits, recognizing that stove and fuel “stacking” is likely to persist. A greater focus on markets and enabling environments is needed to support sustainable and scalable energy transitions.