Traditional Open Fire Research Articles

Emission of volatile organic compounds during open fire cooking with wood biomass: Traditional three-stone open fire vs. gasifier cooking stove in rural Kenya

Cooking with wood biomass fuels releases hazardous air pollutants, including volatile organic compounds (VOCs), that often disproportionally affect women and children. This study, conducted in Kwale and Siaya counties in Kenya, employed thermal desorption gas chromatography – mass spectrometry to analyse VOC emissions from cooking with a wood biomass three-stone open fire vs. top-lit updraft gasifier stove. In kitchens with adequate ventilation, total VOC levels increased from 35–252 μg∙m−3 before cooking to 2235–5371 μg∙m−3 during open fire cooking, whereas use of a gasifier stove resulted in reduced emissions from cooking by 48–77 % (506–2778 μg∙m−3). However, in kitchens with poor ventilation, there was only a moderate difference in total VOC levels between the two methods of cooking (9034–9378 μg∙m−3 vs. 6727–8201 μg∙m−3 for the three-stone open fire vs. gasifier stove, respectively). Using a non-target screening approach revealed significantly increased levels of VOCs, particularly benzenoids, oxygenated and heterocyclic compounds, when cooking with the traditional open fire, especially in closed kitchens, highlighting the effects of poor ventilation. Key hazardous VOCs included benzene, naphthalene, phenols and furans, suggesting potential health risks from cooking. In kitchens with good ventilation, use of the gasifier stove markedly reduced emissions of these priority toxic VOCs compared to cooking with an open fire. Thus, substituting open fires with gasifier stoves could help to improve household air quality and alleviate health risks. The study revealed that VOCs were present prior to cooking, possibly originating from previously cooked food (buildup) or the outside environment. VOC emissions were also exacerbated by reduced air flow in high humidity during rainfall, suggesting an area for further research. The findings underscore the importance of adopting cleaner cooking technologies and enhancing kitchen ventilation to mitigate the impacts of VOCs in developing countries.

Homogeneous single-coil induction heating achieved by structure design

Domestic induction heating shows advantages over traditional open fire heating, but the uneven temperature distribution in the pan is still one of the problems to be solved. In this work, to improve the heating uniformity of the induction cooker, the finite element analysis (FEA) is employed to investigate the relationship between the structure of induction coil and the temperature distribution in the heating pan. The results indicate that the structure of single-coil can be optimized by varying the winding turns in different positions. More uniform temperature distribution in the pan has been obtained by increasing the number of turns at the center and edge of the coil. The advance of this design is to achieve uniform induction heating without redesigning the power source or adding an additional coil. Based on the simulation results, the refined induction coil has been fabricated and assembled into a commercial domestic induction cooker with little modification of the power supply system. A specific parameter named relative standard deviation (RSD) is proposed to define the temperature uniformity. By real-time temperature measurement, the improved heating uniformity has been demonstrated for the refined system. The present work provides a cost-effective and efficient solution to improve heating performance of domestic induction cooker.

Air Quality Modeling of Cooking Stove Emissions and Exposure Assessment in Rural Areas

Cooking stoves produce significant emissions of PM2.5 in homes, causing major health impacts in rural communities. The installation of chimneys in cooking stoves has been documented to substantially reduce indoor emissions compared to those of traditional open fires. Majority of the emissions pass through chimneys to the outdoors, while some fraction of the emissions leak directly into the indoor air, which is defined as fugitive emission. Indoor PM2.5 concentrations are then the result of such fugitive emissions and the infiltration of outdoor neighborhood pollutants. This study uses a combination of the one-contaminant box model and dispersion models to estimate the indoor PM2.5 household concentration. The results show that the contributions of outdoor infiltration to indoor PM2.5 concentrations increase with higher packing densities and ventilation rates. For a case study, under WHO recommended ventilation conditions, the 24 h average mass concentration is ~21 μg/m3, with fugitive concentration accounting for ~90% of the total exposure for highly packed communities. These results help to identify the potential benefits of intervention strategies in regions that use chimney stoves.

Cooking for communities, children and cows: Lessons learned from institutional cookstoves in Nepal

Despite a long history of Improved Cookstove (ICS) interventions by Non-Governmental Organizations, International Development partners and the Government of Nepal, the majority of rural Nepalese people cook on a traditional open fire for their large-scale cooking needs due to a significant lack of approved institutional-scale cooking solutions. Whilst 65.8% of rural Nepalese households cook with biomass as their primary fuel source to satisfy their personal energy needs, there is no information collected on institutional cooking use by the Government of Nepal. In this paper our main objective was to design, implement and evaluate a novel Institutional Improved Cookstove (IICS) to satisfy this gap and following its manufacturing and testing in a Government of Nepal approved test center, to identify the complex contextual factors that often override the technical capabilities of IICS. Our three-phase method combined qualitative and quantitative research approaches, as well as north-south collaborations involving a transdisciplinary research team to create an integrated systems approach taking into account the voices of all key energy stakeholders. Phase 1 included UK based co-design and testing at the University of Nottingham in 2017 to develop a novel IICS that could be used in rural Nepal. Phase 2 involved adapting the design to accommodate contextual factors highlighted by Nepalese partners and to meet testing requirements at a Government of Nepal approved testing center in late 2017. Phase 3 was conducted between December 2017 and April 2020 and focused on piloting the novel IICS in a range of locations, altitudes, socio-economic and cultural settings, monitoring sustained use and obtaining user feedback. We present our results through three case studies that highlight the highly contextualized nature of IICS adoption and sustained use, the importance of stacking, usability and cost savings, and a number of pathways to scale in an institutional setting.

Adoption and fuel use efficiency of mirt stove in Dilla district, southern Ethiopia

Half of the world's population relies on biomass fuels for cooking and heating, which contributes to global forest depletion that leads to environmental and human health impacts. Although biomass consumption is unavoidable, using Mirt stoves save biomass fuel consumption and time for cooking. Currently, improved cooking stoves (ICS) are disseminating worldwide including sub-Saharan countries. However, studies on factors that influence the adoptions and fuel-saving performance of ICS were limited. This study was carried out to assess factors that determine the adoption and fuel use efficiency of Mirt stoves in Dilla district, Southern Ethiopia. Data were collected using questionnaires from 384 households. To test fuel use efficiencies a triplicate controlled cooking test (CCT) was made. The data gathered from questionnaires and CCT were analyzed using binary logistic regression and t -test statistical tools, respectively. The regression results revealed that marital status, household income and availability of stoves were significantly ( P < 0.05) affecting the adoption of Mirt stoves. Distance, culture, and fixed nature of the stoves showed negative significant effect ( P < 0.01) on adoption. The CCT result showed Mirt stoves save 31% fuelwood consumption over traditional open fire stoves. However, the statistical t - test showed insignificant ( P > 0.05) difference in the length of time to bake a given amount of Injera and the amount of charcoal extracted. Our result suggested that improve cooking stoves like Mirt stove could ease the burden fuelwood collection of rural households and the efforts made to improve the adoption of Mirt stove could be successful when ICS dissemination programs consider socio-economic and market-related factors into account.

A novel clean combustion technology for solid fuels to efficiently reduce gaseous and particulate emissions

Approximately three billion people worldwide rely on solid fuels for cooking and heating with traditional stoves or open fires, resulting in severe air pollution which leads to approximately four million premature deaths every year. Here, we present a novel clean combustion technology (NCT) to overcome the inherent defects of existing technologies and reduce emissions from solid fuel combustion. We compared gaseous and particulate emissions from coal combustion between a prevailing traditional domestic stove and an NCT stove. The average reductions were 99% for particulate matter with dynamic diameter less than 2.5 μm (PM2.5), 99% for organic carbon (OC), 98% for elemental carbon (EC), 96% for carbon monoxide (CO), 93% for methane (CH4), 91% for volatile organic compounds (VOCs), 89% for ammonia (NH3), and 99% for carbonyl sulfur (COS). The average coal combustion efficiency was enhanced from 52.6% in the traditional stove to 92.6% in the NCT stove. The novel technology was also successfully applied to the construction of an industrial boiler with a similar or better reduction in air pollutants than the NCT stove. The emission factors of various pollutants from the NCT stoves and boilers fueled with bituminous coal are comparable to those from advanced coal-fired power plants. The wide application of the NCT worldwide, especially in developing countries, would be beneficial to individual health, local air quality, and global climate change.

Understanding burn injuries in children—A step toward prevention and prompt first aid

This study was designed to examine knowledge, attitude and practices with regards to burns prevention and first aid in the Indian community.A total of 83 caregivers aged 19 and 40 years (mean 29 years) participated in survey. Sixty-one percent of those who responded to the survey had some knowledge of first aid, mostly through health education at schools (59%). Very few (2%) received first aid education from health workers. Approximately 2/3 of responders (66–70%) were aware of applying cool running water to a burn and to stop drop and roll in case of a flame burn. However, the same number also listed a myriad of household remedies that they would use as first aid. 66–71% responders were aware of some situational risks in the home and community but only 27% considered young children to be at greater risk. 31% responders had an enclosed kitchen and 16% were still cooking on the floor. A large percentage (83%) cooked outside on a traditional wooden open fire. A quarter of the responders still used oil lamps on the floor and had little regard for the flammability of clothes.There was a weak positive correlation between knowledge and attitude (r-square 0.379) and attitude and practice (r-square 0.373), but no correlation between knowledge and practice (r-square 0.089).Our survey suggests that many responders have limited knowledge of effective first-aid techniques and live in high-risk environments. The major sources of first aid information were from school-based health education, social and electronic media. These resources can be utilized to further disseminate knowledge on first aid and practical prevention techniques.

Analysis of potential fuel savings, economic and environmental effects of improved biomass cookstoves in rural Ethiopia

Unsustainable utilization of solid biomass fuels with inefficient traditional cookstoves has long been a major challenge to ensuring energy and environmental security in Ethiopia. Against the backdrop of this problem, several models of improved biomass cookstoves (ICSs) have been developed and distributed in the country. Yet, little is known about the effect of these ICSs on household’s fuelwood consumption and the environment. The aim of this study was to examine the potential woodfuel savings, economic and environmental effects of three ICSs (Mirt, Gonziye, and Tikikil) in rural Ethiopia from a cross-sectional study of 605 sample households and direct energy consumption measurements in four rural districts. Inferential statistics and cost-benefit analysis were used to analyse the data. The results showed that compared with the traditional open fire tripod; the use of ICSs could reduce household’s fuelwood consumptions on average by 1.72–2.08 tons per household per year. These fuelwood savings translate to potential emissions reductions of 2.82–3.43 tCO2e per stove per year. The results from the cost-benefit analysis (CBA) indicated that investment in these ICSs could provide a net economic benefit of ETB 7204 to 10,381 (US$ 265 to 382) during the 2–5 years lifespan of the stoves. The benefit-cost ratios of these ICSs were calculated between 16.5:1 and 35.0:1. The implication is that promoting the use of Mirt, Gonziye and Tikikil stoves is a viable option and an essential component of the strategy for improving the energy-efficiency and well-being of rural communities while also contributing to the sustainable utilization of biomass resources, and mitigation of climate change in Ethiopia and beyond.

Low-cost interventions to reduce emissions and fuel consumption in open wood fires in rural communities

In this study, we use water boiling tests (WBTs), controlled cooking tests (CCTs) and in-home kitchen performance tests (KPTs) to analyze changes in fuel consumption and emissions resulting from low-cost modifications to traditional open fires. The modifications consist of adding rock-beds, ceramic grates or metal grates to open fires. In both traditional and modified stoves, cooking pots are supported over the fire using iron bars, which is a common practice in rural Vietnamese households. The modifications increase airflow through the combustion zone and improve combustion efficiency. The rocks and grate also decrease the distance between the fire and cooking pot, improving heat transfer. These low-cost modifications improve stove performance in many categories: 38–58% reduction in wood consumption and 51–84% reduction in emissions measured in WBTs; 34–37% reduction in wood consumption during simulated cooking with CCTs; and 31–45% reductions in per capita wood consumption measured during KPTs. Grates performed better than rock-beds in nearly all tests. Surveys implemented in parallel with KPTs indicated favorable user perceptions of all low-cost options. The modifications result in lower fuelwood consumption and emissions, resulting in social and environmental benefits, but they are unlikely reduce health impacts, which many policies and programs now prioritize. Nevertheless, there are numerous situations in which these options may be appropriate. In remote, rural or otherwise marginalized communities, clean cooking options may be inaccessible for the foreseeable future. Low-cost modifications like rock beds and grates, which require minimal training and changes in cooking habits, could reduce the impacts of open fires. Similarly, in places where clean cooking options are accessible, but stove “stacking” with open fires persists, these options could present a cost-effective way to achieve a “cleaner stack”.

Women exposure to household air pollution after an improved cookstove program in rural San Luis Potosi, Mexico

The state government of San Luis Potosí (SLP), Mexico implemented an improved cookstove (ICS) program in rural areas. As part of the comprehensive program evaluation, we compared fine particulate material (PM2.5) concentrations in kitchens and patios in treated (TH), and non-treated households (NTH), and analyzed pollutant levels according to patterns of fuels and devices use reported by the women.A panel study was conducted in 728 households (357 TH and 371 NTH) in three regions of SLP including two sampling rounds in 2015–16. Data on exposure determinants, ICS conditions and cooking practices were collected. Daily PM2.5 in kitchen and patio was measured in a subsample. The average treatment effect was estimated using the double difference method. We constructed a mixed linear model to estimate PM2.5 levels for the entire study sample and obtained personal exposure according to time-activity logs.NTH had lower socioeconomic status compared to TH. The average daily PM2.5 concentrations in NTH compared to TH were 155.2 and 92.6 μg/m3 for kitchen and 35.4 and 39.8 μg/m3 for patio, respectively. PM2.5 levels showed significant regional differences but no significant treatment effect. In many cases, the ICS was added to previous open fire and LPG use (stacking). The household size, kitchen ventilation, relative humidity, temperature and the ratio of indoor/outdoor PM2.5 concentration were significant predictors of kitchen PM2.5 levels. The daily PM2.5 personal exposure was significantly reduced using ICS in good conditions or LPG (57 μg/m3) compared to the traditional open fire (86 μg/m3).This study strengthens the evidence on the potential daily PM2.5 exposure reduction for women using an ICS in good conditions or LPG, displacing the polluting open fire. Comprehensive strategies tailored to the sociocultural context of the communities are needed to implement clean energy programs that achieve adoption and sustained use of ICS or LPG.

Factors influencing the adoption of biochar-producing gasifier cookstoves by households in rural Kenya

Fuel wood is the main source of cooking and heating energy in developing countries. However, it is combusted in inefficient cookstoves, leading to more fuel use and human health problems resulting from exposure to smoke. Thus new, efficient cooking systems that can address some of these problems are required. This study examined gasifier cookstove use in Kwale County, Kenya, and factors influencing adoption. Gasifier stoves were issued for free to 50 households, which were surveyed after 2–3months of use. The results showed that the stove was used by 96% of the households at varying frequencies, 40% of them used it almost every day with 4% switching to only using the new stove. All the users appreciated it because it saved fuel, produced less smoke, and produced charcoal to use for either cooking or soil amendment. Compared with the traditional three-stone open fire, the gasifier stove was reported to be easier to clean (98% of respondents), easier to adjust the heat (88%), easier to handle (58%), caused less exposure to heat (96%) and was cleaner for pots and the kitchen (98%). Another reported benefit of the gasifier stove was that it needed no tending (i.e., adjusting wood and blowing to keep the flames burning). The gasifier stove was mainly used to cook foods that required a short cooking time and many preferred to use it to cook dinner. However, the households encountered some challenges with using the gasifier stoves. For example, fuel preparation, reloading, and lighting were reported as challenges by 42%, 77% and 19%, respectively, of the 83% of households who reported challenges. These challenges could be overcome by improving stove design and by devising innovative ways of cutting fuel into small pieces.

A follow-up study after an improved cookstove intervention in rural Mexico: Estimation of household energy use and chronic PM2.5 exposure

The benefits of improved biomass cookstoves (ICS) depends on their adoption and sustained use. Few studies have documented if and how they are used more than five years after being introduced.We conducted a 9-year prospective cohort study among young rural women in the highlands of Michoacan, Mexico. Participants had received a Patsari ICS during a community trial either in 2005 or 2006. With retrospective information collected in 2012–13, we studied the households' energy use, ICS survival, and cooking practices during the follow-up period. Using an exposure model constructed with personal PM2.5 measurements in a subsample of homes at the time of the initial trial in 2005, we estimated the exposure associated with different energy use patterns during the follow-up period.The ICS had a mean lifespan of 4 years, after which more than half of the stoves were not in use; therefore, the use of open fire increased, particularly among the indigenous communities. ICS use peak was achieved two years after the initial trial, either exclusively or combined with open fire. Yearly household energy use and other variables were used to estimate chronic air pollution exposure. Mean PM2.5 exposure during the follow-up period ranged from 51 to 319 μg/m3; the median was 102 and 146 μg/m3 for mainly ICS and mainly open fire use, respectively.The ICS has a useful period after which it needs maintenance, repair, or replacement. Unfortunately, many programs have not afforded a follow-up component. Exposure to biomass smoke air pollutants can be reduced by using an ICS instead of the traditional open fire. Household energy strategies should ensure equitable access to clean energy options adapted to local needs and preferences with culturally appropriate technology implemented on a sustainable perspective.

Lali'an Versus Improved Cook Stoves: How Change Happens in Urban Households in Timor‐Leste

AbstractMost households in Timor‐Leste use lali'an, a traditional open fire method of cooking that has considerable environmental, health, and social impacts. Many of these impacts can be mitigated using simple, low‐cost, and more fuel‐efficient improved cook stoves (ICSs). Drawing on qualitative data from householders, key informants, and the researcher's observations, this article explores women's experiences of using ICS in Timor‐Leste. It outlines the economic and time cost for households using lali'an, and the health, social, and economic benefits of ICSs. Using the information–motivation–behavioral skills model, this study explores the dynamics of the decision‐making process and behavior change related to cooking technology. The findings show that women are primarily responsible for the household kitchen; however, they are not always in a position to make the decision to adopt an ICS. It is therefore imperative that the introduction and promotion of ICS to households in Timor‐Leste be accessible to women, as investment and awareness‐raising regarding ICS will contribute much to the satisfaction of women's basic needs, children's health, and reduction of deforestation in Timor‐Leste.

Traditional cooking practices and preferences for stove features among women in rural Senegal: Informing improved cookstove design and interventions

Nearly half the world’s population burns solid fuel for cooking, heating, and lighting. The incomplete combustion of these fuels is associated with detrimental health and environmental effects. The design and distribution of improved cookstoves that increase combustion efficiency and reduce indoor air pollution are a global priority. However, promoting exclusive and sustainable use of the improved stoves has proved challenging. In 2012, we conducted a survey in a community in rural Senegal to describe stove ownership and preferences for different stove technologies. This report aims to describe local stove and fuel use, to identify household preferences related to stove features and function, and to elicit the community perceptions of cleaner-burning stove alternatives with a focus on liquid propane gas. Similar to many resource-limited settings, biomass fuel use was ubiquitous and multiple stoves were used, even when cleaner burning alternatives were available; less than 1% of households that owned a liquid propane stove used it as the primary cooking device. Despite nearly universal use of the traditional open fire (92% of households), women did not prefer this stove when presented with other options. Propane gas, solar, and improved cookstoves were all viewed as more desirable when compared to the traditional open fire, however first-hand experience and knowledge of these stoves was limited. The stove features of greatest value were, in order: large cooking capacity, minimal smoke production, and rapid heating. Despite the low desirability and smoke emisions from the traditional open fire, its pervasive use, even in the presence of alternative stove options, may be related to its ability to satisfy the practical needs of the surveyed cooks, namely large cooking capacity and rapid, intense heat generation. Our data suggest women in this community want alternative stove options that reduce smoke exposure, however currently available stoves, including liquid propane gas, do not address all of the cooks’ preferences.

Promoting LPG, clean woodburning cookstoves or both? Climate change mitigation implications of integrated household energy transition scenarios in rural Mexico

This study examines the expected mitigation of greenhouse gases (GHG) and black carbon emissions associated with the transition from traditional biomass to clean fuels and clean woodburning cookstoves (CCS) in the Mexican residential sector for the period 2014–2030. We developed a spatial-explicit model at a county level to understand the GHG trade-offs associated with different spatial-temporal CCS and clean fuels dissemination strategies. A business as usual (BAU) and three alternative scenarios with different targets for CCS and LPG dissemination were constructed. Results show that a scenario focusing exclusively on a fast LPG-penetration does not deliver the largest GHG benefits, as there is substantial stacking with traditional open fires. On the contrary, the combination of CCS plancha-type stoves disseminated in regions with high non-renewable fuelwood harvesting (fNRB) together with LPG, allows minimizing of stacking with traditional fires and provide the largest benefits. Also, different scenarios result in contrasting spatial distribution of target counties and mitigation benefits, and therefore have important public policy implications. Cumulative mitigation ranged from 50 MtCO2e to 126.3 MtCO2e, depending on the scenario, representing from 14% to 35% of BAU emissions, and up to 11% of projected country GHG emissions to 2030. A sensitivity analysis also showed that despite the variation across three of the main variables affecting GHG’s emissions, the CCS-fNRB-LPG scenario remains the most effective and the high LPG penetration scenario remains the most unfavorable. The study helped to identify 200 high-priority municipalities (8% of total) located in the Center-South of Mexico encompassing 30% national FW consumption, 31% total FW users, and 55% of total GHG mitigation. In these high-priority counties a win–win policy in terms of social, health and environmental objectives may be achieved in the short-term, improving the efficacy of public policies related to GHG mitigation, universal access to clean energy, and sustainable development.

Investigating Health-Relevant Air Pollution Concentration Linkages across Multiple Seasons during Indoor Cookstove Campaign in Rural India

Biomass combustion in residential cookstoves is a major source of air pollution and a large contributor to the global burden of disease. Carbon financing offers a potential funding source for health-relevant energy technologies in developing countries. We conducted a randomized intervention study to evaluate air pollution impacts of a carbon finance-approved cookstove intervention in rural South India. Prior research on this topic often has used time-integrated measures of indoor air quality. Here, we employed real-time monitors, thereby allowing investigation of diurnal and hourly trends in concentrations. We measured 24h indoor concentrations of fine particulate matter (PM2.5), black carbon (BC) and carbon monoxide (CO) in intervention households (used newer, rocket-type stoves) and control households (&amp;#8220;nonintervention&amp;#8221;; continued using traditional open fire stoves). We conducted &amp;#8220;per protocol&amp;#8221; versus &amp;#8220;intent to treat&amp;#8221; analyses, and compared 24h averages of air pollutants versus cooking hours only averages. Cookstoves were associated with non-significant reductions in CO (1.5 ppm, p&amp;#61;0.28) and PM2.5 (148 &amp;#956;g/m3, p&amp;#61;0.46) but increased BC concentration (39 &amp;#956;g/m3, p&amp;lt;0.05) and the ratio of BC/PM2.5 (25%, p&amp;lt;0.05) during cooking-relevant hours-of-day relative to controls. Calculated median effective air exchange rates based on decay in CO concentrations were stable between seasons (season 1: 2.5 h-1, season 2: 2.8 h-1).

Current status of household polluting fuel use in adults aged 40 years and older in China, 2014

Objective: To analyze the status and distribution characteristics of household polluting fuel use in China. Methods: The data were collected from the adults aged ≥40 years who were recruited through multi-stage stratified cluster sampling in 2014-2015 COPD surveillance conducted in 31 provinces (autonomous regions and municipalities) in China. A total of 75 107 adults aged ≥40 years in 125 surveillance points were surveyed in face to face interview. Polluting fuels included biomass fuels (wood, dung, crop residues and charcoal), coal (including coal dust and lignite) and kerosene. The weighted percentage of family using polluting fuels, combustion method for cooking or heating and ventilation installation with 95%CI were estimated by complex sampling design. Results: According to the survey results from 75 075 adults, the percentage of family using polluting fuels for cooking or heating was 59.9% (95%CI: 54.2%-65.7%), the percentage in rural areas was significantly higher than that in urban areas (P<0.001). As for different polluting fuels, the percentage of using only biomass fuels for cooking or heating was 25.9% (95%CI:20.5%-31.3%), the percentage of using only coal (including kerosene) was 18.9% (95%CI: 13.2%-24.7%), and the percentage of using both biomass fuels and coal was 15.1% (95%CI: 10.8%-19.4%). Among seven geographic areas in China, the percentages of using biomass fuels ranged from 53.8% in southern China to 23.0% in northern China (P=0.039), the percentages of using coal (including kerosene) ranged from 59.5% in northwestern China to 22.3% in southern China (P=0.001). Among the families using polluting fuels, the percentages of mainly using traditional open fires and stoves were 21.3% (95%CI: 16.9%-25.8%) and 31.5% (95%CI: 25.8%-37.2%), respectively; the percentage of having ventilation installation was72.7% (95%CI: 66.9%-78.5%). Conclusions: Household polluting fuel use is common in China, but differs with area, traditional fuel combustion method is widely used, the coverage of ventilation installation need to be improved. In order to promote COPD prevention and control, it is necessary to develop strategies on fuels and fuel combustion method improvement to reduce indoor air pollution resulted from household fuel combustion.

Real-time indoor measurement of health and climate-relevant air pollution concentrations during a carbon-finance-approved cookstove intervention in rural India

Biomass combustion in residential cookstoves is a major source of air pollution and a large contributor to the global burden of disease. Carbon financing offers a potential funding source for health-relevant energy technologies in low-income countries. We conducted a randomized intervention study to evaluate air pollution impacts of a carbon-finance-approved cookstove in rural South India. Prior research on this topic often has used time-integrated measures of indoor air quality. Here, we employed real-time monitors (∼24 h measurement at ∼ minute temporal resolution), thereby allowing investigation of minutely and hourly temporal patterns. We measured indoor concentrations of fine particulate matter (PM2.5), black carbon (BC) and carbon monoxide (CO) in intervention households (used newer, rocket-type stoves) and control households (“nonintervention”; continued using traditional open fire stoves). Some intervention households elected not to use only the new, intervention stoves (i.e., elected not to follow the study-design protocol); we therefore conducted analysis for “per protocol” versus “intent to treat.” We compared 24 h averages of air pollutants versus cooking hours only averages. Implementation of the per protocol intervention cookstove decreased median concentrations of CO (by 1.5 ppm (2.8 − 1.3; control − per protocol), p = 0.28) and PM2.5 (by 148 μg/m3 (365 − 217), p = 0.46) but increased BC concentration (by 39 μg/m3 (26 − −12), p < 0.05) and the ratio of BC/PM2.5 (by 0.25 (−0.28 − −0.03), p < 0.05) during cooking-relevant hours-of-day relative to controls. Calculated median effective air exchange rates based on decay in CO concentrations were stable between seasons (season 1: 2.5 h−1, season 2: 2.8 h−1). Finally, we discuss an analytical framework for evaluating real-time indoor datasets with limited sample sizes. For the present study, use of real-time (versus time-averaged) equipment substantially reduced the number of households we were able to monitor.

Closing the gap between lab and field cookstove tests: Benefits of multi-pot and sequencing cooking tasks through controlled burning cycles

There is a critical need for developing wood-burning cookstoves lab tests that better reflect their field performance, and that can be used to complement existing standard tests. This is particularly true for Plancha-type cookstove stoves, widely disseminated in Latin America, where existing tests, like Water Boiling Test (WBT) and Controlled Cooking Test (CCT), are either not well suited to these stoves or do not capture the simultaneous and sequential arrangement of local cooking practices –i.e., multi-pot cooking, pre-heating of meals, and use of residual heat. In this paper, we developed a “controlled cooking cycle” or “controlled burning cycle” (CBC) test to study the benefits, in terms of fuelwood and pollutants emissions savings, of multi-pot cooking arising from the integration of cooking tasks. Tests were conducted on the Patsari stove, a plancha-type stove that has been widely disseminated in Mexico and in other regions of Central America. We first used CCTs to evaluate the comparative energy and emissions performance of the Patsari stove relative to a traditional U-shaped open fire (U-type) for the most common cooking practices carried out in the Purepecha Region of Michoacan. We also compared results from the CBC multi-pot cooking with results from simply conducting the cooking tasks in series. All the CCTs and CBCs were carried out in a simulated kitchen at GIRA facilities in Patzcuaro, Michoacan, Mexico with two local cooks who performed all the cooking tasks in the traditional/typical manner of the region. Results from CCTs showed Patsari benefits relative to the open fires, in terms of fuelwood consumption and CO and PM2.5 emissions savings, vary among cooking tasks and range from negligible to 63% depending on the parameter and the task. The sequential cooking and integration of these tasks in a CBC result in average savings of 65% for CO, 65% for PM2.5 and 35% for fuelwood relative to the U-type, and of between 30% and 44% savings with respect to simply conducting the cooking tasks in series in the same stove. The CBC fuelwood savings obtained here are comparable with field results from Kitchen Performance Tests (KPT) conducted regionally by other authors. The results confirm that multi-pot cooking and a smart sequential integration of tasks developed by local users are key to achieve the maximum benefits from plancha-type stoves, and need to be much better reflected in standard lab tests.

Household air pollution following replacement of traditional open fire with an improved rocket type cookstove.

Cooking with biomass fuel is an important source of household air pollution (HAP) in developing countries, and a leading risk factor for ill-health. Although various designs of "improved cookstoves" (ICS) have been promoted as HAP interventions in these settings, few of them have undergone in-field evaluation, partly due to the challenge of conducting field measurements in remote settings. In this study we assessed the change in carbon monoxide (CO) exposure following the replacement of the traditional three-stone stove with a popular ICS in 49 homes in Western Kenya. We also assessed the suitability of using kitchen CO as a proxy for kitchen PM2.5. Reduction in 48h mean kitchen CO was 3.1ppm (95% CI: -8.1, 1.8) and in personal CO was 0.9ppm (95% CI: -4.3, 2.6) following stove replacements. Overall, 48-h kitchen and personal CO exposures were lower after stove replacement (28% and 12%, respectively) but with wide confidence intervals that also suggested possible increases in exposure. There were statistically significant reductions in peak kitchen and personal CO concentrations represented by the 8-h 95th percentile: reductions of 26.1ppm (95% CI: -44.6, -7.6) and 8.0ppm (95% CI: -12.2, -3.8), respectively. This is equivalent to 53% reduction in kitchen CO and 39% reduction in personal CO. We found good correlation between kitchen CO and PM2.5 concentrations overall (r=0.73, n=33 over averaging periods approximating 1day), which varied by time of day and exposure setting. These variations limit the applicability of CO as a proxy measure for PM2.5 concentrations. A combination of interventions, including better designed stoves, improved ventilation and cleaner fuels, may be needed to reduce HAP to levels that are likely to improve health.