Biomass Stoves Research Articles

Prenatal Household Air Pollution Exposure, Cord Blood Mononuclear Cell Telomere Length and Age Four Blood Pressure: Evidence from a Ghanaian Pregnancy Cohort.

Associations between prenatal household air pollution exposure (HAP), newborn telomere length and early childhood blood pressure are unknown. Methods: Pregnant women were randomized to liquefied petroleum gas (LPG) stove, improved biomass stove or control (traditional, open fire cook stove). HAP was measured by personal carbon monoxide (CO) (n = 97) and fine particulate matter (PM2.5) (n = 60). At birth, cord blood mononuclear cells (CBMCs) were collected for telomere length (TL) analyses. At child age four years, we measured resting blood pressure (BP) (n = 97). We employed multivariable linear regression to determine associations between prenatal HAP and cookstove arm and assessed CBMC relative to TL separately. We then examined associations between CBMC TL and resting BP. Results: Higher prenatal PM2.5 exposure was associated with reduced TL (β = −4.9% (95% CI −8.6, −0.4), p = 0.03, per 10 ug/m3 increase in PM2.5). Infants born to mothers randomized to the LPG cookstove had longer TL (β = 55.3% (95% CI 16.2, 109.6), p < 0.01)) compared with control. In all children, shorter TL was associated with higher systolic BP (SBP) (β = 0.35 mmHg (95% CI 0.001, 0.71), p = 0.05, per 10% decrease in TL). Increased prenatal HAP exposure is associated with shorter TL at birth. Shorter TL at birth is associated with higher age four BP, suggesting that TL at birth may be a biomarker of HAP-associated disease risk.

Fabricators and End-Users of Single-Pot Biomass Stoves: Conceptualizing, Hypothesis and Performance Metrics for Developing Energy Sustainability Framework

In this study, interviewer-based questionnaires of 67 variables were administered to local fabricators and end-users of single-pot biomass stoves (SPBS) in Ghana. Additionally, two randomly selected traditional and improved SPBS were lab-tested using standard performance metrics. From the study, the relationship between fabricators and end-users was conceptualized based on selected indicators and assumptions. The study results indicated that the primary design resources for fabrication were patterns and templates, and that major challenges to fabrication were lack of training in design principles, standards and safety, poor emission efficiency and financial sustainability. Whereas end-users of improved SPBS were less affected by heat and smoke, end-users of traditional SPBS were mostly affected. From hypothesis test, because the calculated χ2cal = 24.05, and is greater than the tabulated χ2crit = 3.841, it is concluded that there is a relationship between heat, smoke effect and gender, and that female end-users of traditional SPBS were particularly affected during cooking. The traditional SPBS emitted more CO2 and CO than improved SPBS. Comparatively, 38% more end-users of traditional SPBS observed charcoal ash residue in the cooking area than improved SPBS users. Four basic practices of managing ashes from SPBS are developed. Finally, a fabricator and end-user framework are developed for energy sustainability and quality improvement.

Efficient biomass cooking in Africa for climate change mitigation and development

<h2>Summary</h2> Nearly three billion people continue to use woodfuels for their daily cooking. The global policy discourse increasingly emphasizes clean fuels, notably gas and electricity, but these are expensive, and their supply chains typically interrupted, especially in rural areas. As an alternative, this paper shows that fuel-efficient biomass stoves could contribute climate mitigation potentials in Sub-Saharan Africa that today exceed the total CO₂-equivalent emissions of a medium-sized European country. Abatement costs of these solutions are low at $2 to $10 per ton CO₂ equivalent. Furthermore, we highlight where emissions are greatest and demonstrate that cooking-related emissions may double by 2050. We argue that a rapid dissemination policy should be based on two crucial steps. First, fuel-efficient stoves should be field-tested region by region and adapted to satisfy local cooking needs. Second, cookstoves that have proven to be adopted by users should be heavily subsidized at scale to accelerate uptake.

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.

Household air pollution and blood markers of inflammation: A cross-sectional analysis.

Household air pollution (HAP) from biomass stoves is a leading risk factor for cardiopulmonary outcomes; however, its toxicity pathways and relationship with inflammation markers are poorly understood. Among 180 adult women in rural Peru, we examined the cross-sectional exposure-response relationship between biomass HAP and markers of inflammation in blood using baseline measurements from a randomized trial. We measured markers of inflammation (CRP, IL-6, IL-10, IL-1β, and TNF-α) with dried blood spots, 48-h kitchen area concentrations and personal exposures to fine particulate matter (PM2.5 ), black carbon (BC), and carbon monoxide (CO), and 48-h kitchen concentrations of nitrogen dioxide (NO2 ) in a subset of 97 participants. We conducted an exposure-response analysis between quintiles of HAP levels and markers of inflammation. Markers of inflammation were more strongly associated with kitchen area concentrations of BC than PM2.5 . As expected, kitchen area BC concentrations were positively associated with TNF-α (pro-inflammatory) concentrations and negatively associated with IL-10, an anti-inflammatory marker, controlling for confounders in single- and multi-pollutant models. However, contrary to expectations, kitchen area BC and NO2 concentrations were negatively associated with IL-1β, a pro-inflammatory marker. No associations were identified for IL-6 or CRP, or for any marker in relation to personal exposures.

Laboratory estimation of elemental and organic carbon emissions from advanced biomass stoves in Senegal

In this study, we tested a natural draft gasifier, currently implemented in Senegal and the traditional three stones fire (TSF) in the laboratory, using the protocol of water boiling test (WBT). Pollutants emissions from three types of biomass full were investigated in this work. Our results show that, burning the same wood (Cordyla Pinnata, dimb), the gasifier had a fuel consumption 37% lower than the traditional three stones, and decrease emissions factors of fine particulate matter (PM) by 74%, organic carbon (OC) by 59 % and elemental carbon (EC) by 55%. The gasifier has also shown to reduce fuel used and emissions compared with the three stones using Casuarina Equisetifolia (Filao) though to a minor extent: 24 % in fuel consumption and emissions reduction of 53% of PM, 55% of OC and 18% EC. The micro-gasifier using typha pellets is the cooking system the most efficient with a reduction 70% of fuel and more than 85% of emissions comparing to the 3-stones-dimb combination. Our results agree with other studies and confirm that gasifier have a very low fuel consumption and low emissions of climate forcing particles. Further field studies are needed to evaluate the adoption of these new stoves and fuels and to analyze fuel consumption and emissions under real-world cooking practice

The effect of clean cooking interventions on mother and child personal exposure to air pollution: results from the Ghana Randomized Air Pollution and Health Study (GRAPHS).

Background:Clean cooking interventions to reduce air pollution exposure from burning biomass for daily cooking and heating needs have the potential to reduce a large burden of disease globally.Objective:To evaluate the air pollution exposure impacts of a fan-assisted efficient biomass-burning cookstove and a liquefied petroleum gas (LPG) stove intervention in rural Ghana.Methods:We randomized 1 414 households in rural Ghana with pregnant mothers into a control arm (N = 526) or one of two clean cooking intervention arms: a fan-assisted efficient biomass-burning cookstove (N = 527) or an LPG stove and cylinder refills as needed (N = 361). We monitored personal maternal carbon monoxide (CO) at baseline and six times after intervention and fine particulate matter (PM2.5) exposure twice after intervention. Children received three CO exposure monitoring sessions.Results:We obtained 5 655 48-hour maternal CO exposure estimates and 1 903 for children, as well as 1 379 maternal PM2.5 exposure estimates. Median baseline CO exposures in the Control, improved biomass, and LPG arms were 1.17, 1.17, and 1.30 ppm, respectively. Based on a differences-in-differences approach, the LPG arm showed a 47% reduction (95% CI: 34–57%) in mean 48-hr CO exposure compared to the control arm. Mean maternal PM2.5 exposure in the LPG arm was 32% lower than the control arm during the post-intervention period (52 ± 29 μg/m3 vs 77 ± 44 μg/m3). The biomass stove did not meaningfully reduce CO or PM2.5 exposure.Conclusions:We show that LPG interventions lowered air pollution exposure significantly compared to three-stone fires. However, post-intervention exposures still exceeded health-relevant targets.Significance:In a large controlled trial of cleaner cooking interventions, an LPG stove and fuel intervention reduced air pollution exposure in a vulnerable population in a low-resource setting.

Performance improvement of biomass combustion-basedstove byimplementing internally air-distribution

This research aimed to enhance the performance of biomass combustion-based stove. Thermal performances were assessed in terms of power output (Pout), specific fuel consumption (SFC), thermal efficiency (ηth), and burning rate (BR). These performances were expected to meet the minimum standards established by the Indonesian biomass stove alliance regarding the use of a healthy and energy-saving of biomass stove in Indonesia. The stove tested was an improved stove with an advantage on the air distributor by adding a component to administrate air combustion needed placed on the centre of the combustion zones. This is a very effective way to distribute air for combustion required where the air could reach all the fuel and the combustion product that occupy entire the combustion zones to ensure high combustion zone temperature. Coconut shell was used as feedstock. This biomass was found abundant in Indonesia and was widely used as heat source by burning it directly. The coconut shell was sized uniformly about 5 cm x 5 cm, dried by utilizing sun energy. To estimate the stove performances, several combustion tests was carried out where the air flow rate into the stove (Qa) and the amount of biomass fuel (mb) referred as the air–fuel ratio (A/F) were considered. The Water Boiling Test (WBT) was performed to assess this improved stove. Parameter required such as initial mass of coconut shell, the mass of residual ash, the initial mass of water, mass of water after boiling, and the time required to boil as well as combustion flame temperature were recorded and used to determine the performance of the improved stove studied.

Emissions Measurements from Household Solid Fuel Use in Haryana, India: Implications for Climate and Health Co-benefits.

A large concern with estimates of climate and health co-benefits of "clean" cookstoves from controlled emissions testing is whether results represent what actually happens in real homes during normal use. A growing body of evidence indicates that in-field emissions during daily cooking activities differ substantially from values obtained in laboratories, with correspondingly different estimates of co-benefits. We report PM2.5 emission factors from uncontrolled cooking (n = 7) and minimally controlled cooking tests (n = 51) using traditional chulha and angithi stoves in village kitchens in Haryana, India. Minimally controlled cooking tests (n = 13) in a village kitchen with mixed dung and brushwood fuels were representative of uncontrolled field tests for fine particulate matter (PM2.5), organic and elemental carbon (p > 0.5), but were substantially higher than previously published water boiling tests using dung or wood. When the fraction of nonrenewable biomass harvesting, elemental, and organic particulate emissions and modeled estimates of secondary organic aerosol (SOA) are included in 100 year global warming commitments (GWC100), the chulha had a net cooling impact using mixed fuels typical of the region. Correlation between PM2.5 emission factors and GWC (R2 = 0.99) implies these stoves are climate neutral for primary PM2.5 emissions of 8.8 ± 0.7 and 9.8 ± 0.9 g PM2.5/kg dry fuel for GWC20 and GWC100, respectively, which is close to the mean for biomass stoves in global emission inventories.

Household Air Pollution from Biomass Fuel for Cooking and Adverse Fetal Growth Outcomes in Rural Sri Lanka.

The aim of this study was to investigate the impact of biomass fuel for cooking on adverse fetal growth outcomes in Sri Lanka. A cross-sectional study of mothers recruited at maternity clinics in rural communities in Sri Lanka’s Central Province was undertaken. Data pertaining to household air pollution and fetal growth parameters were collected using an interviewer-administered questionnaire. Logistic regression models, adjusted for potential confounders, were used to evaluate the impact of biomass fuel for cooking on low birth weight (LBW) and small for gestational age (SGA) parameters. Findings showed that exposure to biomass cooking fuels during pregnancy was associated with an increased risk of LBW adjusted odds ratio (aOR) 2.74 (95% CI 1.08–6.96) and SGA (aOR: 1.87, 95% CI 1.03–3.41) compared with the use of clean energy. The risk of LBW was highest for traditional biomass stoves compared to improved biomass stoves (aOR: 3.23, 95% 1.17–8.89) and biomass use in kitchens without a chimney compared to kitchens with a chimney (aOR: 4.63, 95% 1.54–13.93). Similar trends were observed for SGA.

“If you haven’tshaoguo’ed, you haven’t eaten”

Biomass stoves, or shaoguo, are used exclusively in rural China for everyday cooking. Making use of agricultural wastes, these improved cook stoves are an economically efficient way to prepare foods and provide a complex taste profile to the everyday wheat-based staples cooked in them. Nevertheless, these stoves are associated with rural backwardness and failures of rural development. In this article, I understand shaoguo as a productive part of making home and belonging for families affected by urban migration. Considering the ways that shaoguo indexes rural identity and social belonging, I think through the connections between cooking and creating spaces of home.

PENGENALAN DAN PEMANFAATAN TUNGKU BIOMASA DENGAN PEMBAKARAN BERSIH BAGI PENGUSAHA IKAN KAYU (KEUMAMAH) DI KOTA BANDA ACEH

Keumamah is made from the preservation of eastern little tuna (Euthynnus affinis). For keumamah production, boiling of fresh eastern little tuna in water, is one of the main process which requires a lot of energy. The keumamah producers utilize three-stone like stove with wood biomass as the fuel. The stove adoption is economically motivated since the fuel is cheaper than other form of commercial energy and relatively easy to obtain. However, the stove is inefficient and wasting the wood. Inefficient burning of wood releases smoke and volatile organic compounds (VOC) which are dangerous to human health and harmful for the environment. Therefore, in this community development program, two keumamah producers, located near Lampulo fish harbour - in Banda Aceh, were introduced to better practices in utilizing biomass wood as energy source. They were firstly given the information on the reverse impacts on health and environment introduced by three-stone like stove. The team has developed an improved biomass stove with improved efficiency, less fuel consumption and much cleaner combustion. Later this clean better design biomass stove with its advantages was introduced. From the test of performance, the stoves showed: 1) faster cooking time; 2) reduce fuel consumption by nearly 30%; 3) reduced smoke; and 4) flexible usage of working space with modular design. It is the intentions of this program for the stove to benefit the keumamah producers and their workers with less expending for fuel and cleaner work environment.

Cooking stoves and risk of birth defects in urban China

IntroductionBirth defects are a leading cause of infant death. Pregnant women spend a large amount of time indoors, and little research from population-based studies has investigated the association between indoor air pollution and birth defects. We aimed to examine whether using coal, biomass, or electromagnetic stoves for cooking is associated with risk of birth defects compared to using gas stoves. MethodsA birth cohort study was conducted from 2010 to 2012 in Lanzhou, China. Cases (n = 264) were singleton births with birth defects, which were defined as abnormalities of structure or function, including metabolism, presented at birth based on the International Classification of Diseases (ICD)-10 codes. Controls (n = 9926) were defined as singleton live births without birth defects. Unconditional logistic regression models were employed to estimate the association adjusting for confounding variables. ResultsCompared to gas stoves for cooking, biomass (OR = 2.66, 95%CI: 1.38–5.13), and electromagnetic stove (OR = 1.90, 95%CI: 1.26–2.88) for cooking were associated with an increased risk of birth defects. The significant associations remained among non-congenital heart disease (CHD) defects but not CHDs. ConclusionsUsing biomass or electromagnetic stoves for cooking during pregnancy was associated with an increased risk of birth defects. Additional studies are warranted to confirm these novel findings. Studies with larger sample size or greater statistical power are also warranted to better estimate the associations for individual birth defects.

Design and analysis of novel biomass stove

In this paper, discussing in detail on how the thermal efficiency of the cooking stove fuelled by firewood can be increased to achieve maximum efficiency. For this purpose, a biomass stove is fabricated and tested domestically for regular household chores. Unlike regular biomass stoves, a number of design optimizations were made while fabrication to achieve the end goal. Biomass energizes are still being used by large number of populations in remote areas around the globe where the access to LPG gas stoves is limited because of location proximity and economy. Its simplistic design makes it unsuitable to perform any controlled test because they are known to display lots of variability in their performance. So, the other objective of this paper is to comprehend and characterize range of process involved inside the biomass stove and put forth a thorough analysis on all the variables to better configure for future use.

Production processes and statistical analysis of ceramic liner-hole parameters for sustainability and improved thermal efficiency of clean biomass stoves

In engineering, ceramic liners are used as heat retention, insulation, and wear-resistant components for industrial and domestic applications. However, due to lack of production standards, particularly under small industrial operations, there is variation in liner-hole diameter and inter-hole spacing of liners used in clean biomass stoves. This study assessed the production processes and analysed ceramic liner-hole diameters and inter-hole spacings for standardisation. Standardising liner-hole parameters is a major process towards sustainability and improved efficiency. Methods employed were − material composition, particle size distribution analysis, study of production processes, and 51 liner-hole diameters and 66 inter-holes spacing were randomly sampled and analysed. The results indicated material composition of clay (70%), sand (23%), and sawdust (7%) of various particle sizes. A flow chart diagram of 7 production processes was created for standardisation. At 95% C.I, liner-hole diameter of Ø20.8 ± 2(0.66) mm and inter-hole spacing of 27.5 ± 2(1.06) mm were determined. Mean liner-hole diameter of Ø21.03 mm resulted in a relatively high thermal efficiency, ηT =37%. For practical applications, liner-hole diameter of Ø21 mm and inter-hole spacing of 30 mm are recommended. Standardising the production processes and the liner-hole parameters will contribute to sustainable production and thermal efficiency improvement.

Analysis of Particulate Matter 2.5, carbon monoxide, carbon dioxide, CO/CO2 ratio and rate of fuel consumption from the use of biomass stove fueled by corncob and rice husk

This study was conducted to analyze PM2.5, CO and CO2 concentrations, CO/CO2 ratio, and the rate of fuel consumption due to the use of a biomass stove. Water Boiling Test Method was used to simulate cooking activities, which consisted of three phases, i.e., cold start (CS), hot start (HS), and simmering (SM). Biomass wastes used in this research were corncobs and rice husks. Based on the measurement results, for the corncob, PM2.5 concentrations were 239.823±60.83, 262.962±79.17, and 120.75±45.20μg/Nm3 at CM, HS, and SM phases, respectively. While for CO concentrations during the CM, HS, and SM phases were 36.984 ±3.67, 35.918±1.74, and 37.959±5.56 ppm, correspondingly. Moreover, 595,468±13.25, 611,492±7.73, and 565,205±18.50 ppm CO2 concentrations were detected during the CM, HS, and SM phases, respectively. Furthermore, for the rice husk biomass waste, PM2.5 concentrations of 158.579±14.07, 115.014±16.08, and 69.603±17.11 μg/Nm3 were observed during the CS, HS, and SM phases. While for CO concentrations during the CS, HS, and SM phases, the measured values were, in turn, 38.152±2.73, 38.152±5.02, and 36.422±4.72 ppm. Lastly, the measured CO2 concentrations were 593,647±8.28, 589,241±12.45, and 556,886±13.06 ppm for the CS, HS, and SM phases, respectively. PM2.5 and CO concentrations did not meet the air quality standards for both biomass wastes, while CO2 meets the air quality standard according to Indonesian Minister of Health Regulation No. 1077/2011. The CO/CO2 ratio of the biomass stove is above 0.02, while the specific fuel consumption rate, for corncob were 0.186, 0.135, and 0.238g/g, while for the rice husk were 0.238, 0.305, and 0.335g/g, during the cold start, hot start, and simmering phases.

Efficient Biomass Cooking in Africa for Climate Change Mitigation and Development

Nearly three billion people continue to use wood fuels for their daily cooking. The global policy discourse increasingly emphasizes clean fuels, notably gas and electricity. Yet, electricity and gas are expensive, and their supply chains are typically interrupted in rural areas. They will hence not reach the global poor soon, especially in Africa. As an alternative, this paper shows that fuel-efficient biomass stoves can contribute climate mitigation potentials in Sub-Saharan Africa that exceed the total CO2-equivalent emissions of a medium-sized European country. Abatement costs of this policy are low at $2 to 10 per ton. Furthermore, we demonstrate that cooking-related emissions will likely double by 2050. We conclude by arguing that a rapid dissemination policy should be based on two crucial steps: First, fuel-efficient stoves should be field-tested region by region and adapted to satisfy local cooking needs. Second, cookstoves that have proven to be adopted by users should be heavily subsidized at scale.

Impact of the wood-burning Justa cookstove on fine particulate matter exposure: A stepped-wedge randomized trial in rural Honduras

Trial designWe evaluated the impact of a biomass stove intervention on fine particulate matter (PM2.5) concentrations using an individual-level, stepped-wedge randomized trial. MethodsWe enrolled 230 women in rural Honduran households using traditional biomass stoves and randomly allocated them to one of two study arms. The Justa stove, the study intervention, was locally-sourced, wood-burning, and included an engineered combustion chamber and chimney. At each of 6 visits over 3 years, we measured 24-hour gravimetric personal and kitchen PM2.5 concentrations. Half of the households received the intervention after Visit 2 and half after Visit 4. We conducted intent-to-treat analyses to evaluate the intervention effect using linear mixed models with log-transformed kitchen or personal PM2.5 (separately) as the dependent variable, adjusting for time. We also compared PM2.5 concentrations to World Health Organization (WHO) guidelines. ResultsArms 1 and 2 each had 115 participants with 664 and 632 completed visits, respectively. Median 24-hour average personal PM2.5 exposures were 81 μg/m3 (25th–75th percentile: 50–141 μg/m3) for the traditional stove condition (n=622) and 43 μg/m3 (25th–75th percentile: 27–73 μg/m3) for the Justa stove condition (n=585). Median 24-hour average kitchen concentrations were 178 μg/m3 (25th–75th percentile: 69–440 μg/m3; n=629) and 53 μg/m3 (25th–75th percentile: 29–103 μg/m3; n=578) for the traditional and Justa stove conditions, respectively. The Justa intervention resulted in a 32% reduction in geometric mean personal PM2.5 (95% confidence interval [CI]: 20–43%) and a 56% reduction (95% CI: 46–65%) in geometric mean kitchen PM2.5. During rainy and dry seasons, 53% and 41% of participants with the Justa intervention had 24-hour average personal PM2.5 exposures below the WHO interim target-3 guideline (37.5 μg/m3), respectively. ConclusionThe Justa stove intervention substantially lowered personal and kitchen PM2.5 and may be a provisional solution that is feasible for Latin American communities where cleaner fuels may not be available, affordable, or acceptable for some time.Clinicaltrials.gov: NCT02658383.

Effects of a Household Air Pollution Intervention with Liquefied Petroleum Gas on Cardiopulmonary Outcomes in Peru. A Randomized Controlled Trial.

Rationale: Approximately 40% of people worldwide are exposed to household air pollution (HAP) from the burning of biomass fuels. Previous efforts to document health benefits of HAP mitigation have been stymied by an inability to lower emissions to target levels. Objectives: We sought to determine if a household air pollution intervention with liquefied petroleum gas (LPG) improved cardiopulmonary health outcomes in adult women living in a resource-poor setting in Peru. Methods: We conducted a randomized controlled field trial in 180 women aged 25-64 years living in rural Puno, Peru. Intervention women received an LPG stove, continuous fuel delivery for 1 year, education, and behavioral messaging, whereas control women were asked to continue their usual cooking practices. We assessed for stove use adherence using temperature loggers installed in both LPG and biomass stoves of intervention households. Measurements and Main Results: We measured blood pressure, peak expiratory flow (PEF), and respiratory symptoms using the St. George's Respiratory Questionnaire at baseline and at 3-4 visits after randomization. Intervention women used their LPG stove exclusively for 98% of days. We did not find differences in average postrandomization systolic blood pressure (intervention - control 0.7 mm Hg; 95% confidence interval, -2.1 to 3.4), diastolic blood pressure (0.3 mm Hg; -1.5 to 2.0), prebronchodilator peak expiratory flow/height2 (0.14 L/s/m2; -0.02 to 0.29), postbronchodilator peak expiratory flow/height2 (0.11 L/s/m2; -0.05 to 0.27), or St. George's Respiratory Questionnaire total score (-1.4; -3.9 to 1.2) over 1 year in intention-to-treat analysis. There were no reported harms related to the intervention. Conclusions: We did not find evidence of a difference in blood pressure, lung function, or respiratory symptoms during the year-long intervention with LPG. Clinical trial registered with www.clinicaltrials.gov (NCT02994680).

In-use emissions from biomass and LPG stoves measured during a large, multi-year cookstove intervention study in rural India

We conducted an emission measurement campaign as a part of a multiyear cookstove intervention trial in two rural locations in northern and southern India. 253 uncontrolled cooking tests measured emissions in control and intervention households during three ~3-month-long measurement periods in each location. We measured pollutants including fine particulate matter (PM2.5), organic and elemental carbon (OC, EC), black carbon (BC) and carbon monoxide (CO) from stoves ranging from traditional solid fuel (TSF) to improved biomass stoves (rocket, gasifier) to liquefied petroleum gas (LPG) models. TSF stoves showed substantial variability in pollutant emission factors (EFs; g kg−1 wood) and optical properties across measurement periods. Multilinear regression modeling found that measurement period, fuel properties, relative humidity, and cooking duration are significant predictors of TSF EFs. A rocket stove showed moderate reductions relative to TSF. LPG stoves had the lowest pollutant EFs, with mean PM2.5 and CO EFs (g MJdelivered−1) >90% lower than biomass stoves. However, in-home EFs of LPG were substantially higher than lab EFs, likely influenced by non-ideal combustion performance, emissions from food and possible influence from other combustion sources. In-home emission measurements may depict the actual exposure benefits associated with dissemination of LPG stoves in real world interventions.