Household Solid Fuel Research Articles

The impact of solid fuel use on major depression and the buffering effect of outdoor time in the UK adults: A 12-year cohort study

BackgroundThis study aims to investigate age- and gender-specific effects of household solid fuels for heating on major depression and buffering effects of outdoor time in a high-income country. MethodsData were obtained from the UK Biobank. Participants with complete information on our studied variables and no prior diagnosis of major depression at baseline were included. Cox proportional hazards regression models were used to examine the effects of household solid fuels for heating on major depression. Subgroup analyses were conducted to investigate the buffering effects of outdoor time in summer and winter. Sensitivity analyses were performed to test the robustness of the main findings. ResultsOf 255,505 participants (50.2 % women), the 12-year cumulative incidence of major depression was 4.4 %. Household solid fuels for heating increased the risk of major depression only in women aged <45 years (HR (95%CI) = 1.30 (1.04, 1.63)). In this group, the solid fuel effect was moderated by outdoor time spending both in summer (HR (95%CI), ≤2 h/day: 1.61 (1.13, 2.28); >2 h/day: 1.13 (0.84, 1.52)) and winter (≤1 h/day: 1.35 (1.01, 1.08); >1 h/day: 1.24 (0.86, 1.77)). LimitationsSelf-reported measures might lead to recall bias and some potential confounders, such as ventilation efficiency, were not measured and controlled in data analyses. ConclusionsYounger women are more vulnerable to the impact of domestic air pollution on major depression. Promoting outdoor activities is a cost-effective and efficient approach to mitigating the risk of major depression caused by household solid fuels.

Rate and Change in Household Solid Fuels Usage Among Residents Aged 40 and Older - China, from 2014-2015 to 2019-2020.

Solid fuel combustion is a significant source of household air pollution and an important risk factor for chronic obstructive pulmonary disease (COPD). This study presents the rates and change in the use of solid fuels for cooking and heating in China. Based on data from the Chinese Chronic Obstructive Pulmonary Disease Surveillance, the research estimated the rates and change of solid fuels usage for cooking and heating from 2014-2015 to 2019-2020 and the rate of primary cooking solid fuels usage in 2019-2020, and analyzed the association between solid fuels usage and COPD. The rates of solid fuels usage for cooking and heating significantly decreased, dropping from 45.3% to 28.0% and from 33.5% to 23.2%, respectively. Usage rates were higher among rural residents, with 47.2% using it for cooking and 37.7% for heating in 2019-2020. The usage of solid fuels for cooking is associated with increased risk of COPD. Among rural residents, combined usage of biomass and coal for cooking (OR=1.29, 95% CI: 1.12, 1.48) and using coal as primary fuel for cooking (OR=1.18, 95% CI: 1.00, 1.38) are associated with higher risk of COPD. The usage of biomass for cooking is associated with an increased risk of COPD in urban residents (OR=1.17, 95% CI: 1.03, 1.32). The study demonstrates a significant decline in the use of household solid fuels. Nevertheless, high utilization rates persist among individuals in rural settings and those from lower socioeconomic backgrounds. It is of great public health importance to propose targeted fuel substitution measures for various solid fuels in different regions to reduce the risk of COPD.

Emission characteristics of VOCs emitted from household stove combustion in the north of China

The emissions of volatile organic compounds (VOCs) arising from household stove combustion of different fuels common in North China were quantified. Using a dilution tunnel sampling system and gas chromatography-mass spectrometry analysis, 107 different C2–C12 VOCs were identified in flue gases of four household solid fuels (coal briquette, honeycomb briquette, wood, and cornstalk), whose emission factors were 670 ± 550, 1322 ± 686, 1200 ± 1923, 8670 ± 8380 mg kg−1, respectively. Alkenes and alkynes contributed the most to the VOC emitted from the combustion of honeycomb briquettes (50.1%), wood (46.3%), and cornstalks (56.9%). N-Alkanes were the dominant VOC (43.9%) from coal briquette combustion. Ethane and ethene were the most abundant individual species found in the flue gas of coal briquettes, wood, and cornstalks, accounting for 60.4%, 59.8%, and 67.9% of the emissions, respectively. The VOC emitted from coal briquettes, honeycomb briquettes, wood, and cornstalks exhibited significantly different chemical reactivities. The OH reactivity of the VOCs from cornstalk combustion was 9–270 times greater than that of the other fuels. The differences in the atmospheric reactivity of emissions would suggest that cornstalk combustion should be prioritised in any strategy to reduce ozone pollution.

Narrative review: respiratory tract microbiome and never smoking lung cancer.

The lung microbiome was previously thought to be a sterile environment where only gaseous exchange takes place, but recent studies have shown the presence of microbiota in the lung. This review investigates the current literature on the effects of an environmental driven dysbiosis on the healthy oral and respiratory microbiome and its relationship to lung cancer risk in never-smokers. An online electronic search was performed on PubMed of all English-language literature using combinations of the following keywords: "lung cancer", "dysbiosis", "non-smokers", "oral microbiome", and "respiratory microbiome". All population-based studies reporting results on oral and/or respiratory microbiome in adults were considered for our narrative review. Metagenomic analyses have been performed on isolated samples from healthy participants and compared to samples from those with lung cancer. Research shows that a decrease in alpha diversity of microbes in the oral microbiome is associated with increased risk of lung cancer, along with differences in beta diversity in the sputum of lung cancer cases and healthy controls. Further, several studies have observed that significant changes in the abundance of genera such as increased abundance of Lactobacillales, Bacilli, and Firmicutes associated with an increased lung cancer risk among participants with exposure to certain household solid fuels. These findings suggest potential carcinogenic processes such as increased inflammation associated with changes in flora. Additionally, studies showed that increase in certain taxa such as Bacteroides and Spirochetes might have a protective effect on lung cancer risk. The review also provides insight into how understanding the microbial changes can be beneficial for lung cancer treatment and disease-free survival. Larger studies in different populations need to be performed to strengthen the current associations between microbial diversity and lung cancer risk.

Association between Household Solid Fuel Use and Sarcopenia Risk among Middle-Aged and Older Adults in China: A Nationwide Population-Based Cohort Study.

Household solid fuel have been associated with changes of handgrip strength, and exposure to ambient air pollution might be one risk factor of sarcopenia. However, the prospective association between household solid fuel use and sarcopenia remains limited. A total of 11,924 participants (5,723 men (48%) and 6,201 women (52%) with the average age was 59.17 ± 9.57 years) from the China Health and Retirement Longitudinal Study 2011 were included in cross-sectional analyses. 7,507 participants at baseline were included in longitudinal analyses and were followed up in 2015. Sarcopenia status was defined according to the Asian Working Group for Sarcopenia 2019 (AWGS 2019) criteria. In cross-sectional analyses, the participants who used solid fuel for cooking and heating had higher prevalence of sarcopenia than those who used clean fuel. During the follow-up, 302 (4.02%) participants experienced sarcopenia. In the longitudinal analysis, after multivariable adjustment of age, sex and other risk factors, individuals who used solid fuel for cooking had an elevated risk of new-onset sarcopenia, with corresponding odds ratio of 1.32 (95% confidence interval, 1.03-1.71). Consistently, individuals reported solid fuels use for heating were associated with 20% (odds ratio=1.20, 95% confidence interval: 1.01-1.56) increased risk of sarcopenia. In addition, a self-reported switch from clean to solid fuel for cooking appeared to have an increased sarcopenia risk (odds ratio=1.20, 95% confidence interval: 1.02-1.43). Using household solid fuel for cooking and heating was associated with increased risk of sarcopenia prevalence and incidence.

Associations between Household Solid Fuel Use, Obesity, and Cardiometabolic Health in China: A Cohort Study from 2011 to 2018.

This study aims to explore the longitudinal relationship between solid fuel use and CMD incidence based on a nationally representative follow-up cohort study. A total of 6038 participants of the China Health and Retirement Longitudinal Study (CHARLS) were enrolled in the study. CMD is a cluster of diseases that include heart disease, stroke, and type 2 diabetes. Cox proportional-hazards regression models were used to examine the association between solid fuel use and the incidence or multimorbidity of CMD. The interactions between overweight or obesity and household air pollution on CMD incidence were also investigated. In the present study, solid fuel use from cooking or heating, separately or simultaneously, was positively associated with CMD incidence. Elevated solid fuel use was significantly associated with a higher risk of CMD incidence (HR = 1.25, 95% CI: 1.09, 1.43 for cooking; HR = 1.27, 95% CI: 1.11, 1.45 for heating). A statistically significant interaction between household solid fuel and OW/OB on the incidence of CMD and Cardiometabolic multimorbidity was also observed (p < 0.05). Our findings show that household solid fuel is a risk factor for the incidence of CMD. Therefore, reducing household solid fuel use and promoting clean energy may have great public health value for the prevention of CMD.

Associations of Household Solid Fuel Use With Falls and Fall-Related Injuries in Middle-Aged and Older Population in China: A Cohort Study.

Objective: This study evaluated the associations of solid fuels with incidence of falls and fall-related injuries. Methods: Data were taken from wave 1∼4 of the China Health and Retirement Longitudinal Study, including 15,651 participants aged 45years and older. Modified Poisson regression was used to examine the associations of solid fuels with falls and fall-related injuries. Results: Modified Poisson regression analysis showed that solid fuels users for cooking had an increasing incidence of falls and fall-related injuries, with RR of 1.211 (95% CI: 1.124, 1.305) and 1.248 (95% CI: 1.107, 1.408); for heating had an incidence, with RR of 1.178 (95% CI: 1.062, 1.306) and 1.134 (95% CI: 0.963, 1.335); combined for cooking and heating, with RR of 1.247 (95% CI: 1.105, 1.408) and 1.185 (95% CI: 0.982, 1.431). Conclusion: Our study suggests that solid fuel use is associated with a higher incidence of falls and fall-related injuries among adults aged 45 years and older in China. It is necessary to restrict solid fuel use to reduce household air pollution and make stronger environmental protection policies to improve household environment.

The increased medical burden associated with frailty is partly attributable to household solid fuel: A nationwide prospective study of middle-aged and older people in China

BackgroundFrail individuals often face a high medical burden, and household solid fuel use is associated with a range of functional declines or diseases, but evidence on the relationship between household solid fuel and frailty and the resulting medical burden is limited. We aim to investigate the effect of household solid fuel on frailty and further quantify how much of the increased medical burden associated with frailty is attributable to household solid fuel. MethodsThe prospective data were from the China Health and Retirement Longitudinal Study, 4685 non-frail participants at baseline were included. Inverse probability weighting was used to balance the covariates between groups. The modified Poisson regression was used to analyze the association of household solid fuel (including baseline and switching across three-wave survey) with frailty, and the generalized linear model was used to analyze the association of frailty with the change in medical burden. Further, the increased medical burden associated with frailty attributable to household solid fuel was quantified. ResultsUsing solid fuel for cooking (RR = 1.29, 95%CI, 1.07–1.57), heating (RR = 1.38, 95%CI, 1.09–1.73), or both (RR = 1.40, 95%CI, 1.05–1.86) had a higher risk of frailty than using clean fuel. In addition, the risk of frailty generally increases with the times of solid fuel use across the three-wave survey. Then, frailty participants had a greater increase in the annual number of hospitalizations (β = 0.11, 95%CI, 0.02–0.19) and annual costs of hospitalizations (β = 2953.35, 95%CI, 1149.87–4756.83) than those non-frailty. Heating coal caused the largest frailty-related increase in the annual number of hospitalizations and annual costs of hospitalizations, with 0.04 and 1195.40, respectively. ConclusionThe increased medical burden associated with frailty was partly attributable to household solid fuel, which suggested that intervention targeting household solid fuels can delay frailty and thus reduce individual medical burden.

AIR QUALITY ANALYSIS BASED ON AIR POLLUTION STANDARD INDEX (ISPU)

Poor air quality can cause various negative impacts. Air pollution kills 7 million people every year, or one in eight premature deaths each year. This problem makes it the biggest environmental health risk in the world. Urban and rural air pollution in Southeast Asia is double the WHO standard, 40% of the population is polluted by household solid fuels. Diseases caused by air pollution 424,000 deaths in Southeast Asia. One of the places with vehicle activities that have a high risk of air pollution is one of the ports. The purpose of this study was to determine the air quality based on the Air Pollution Standards Index (ISPU). This type of research used quantitative methods categorized in time series research. The subject of this research is the ambient air. Samples were taken using a portable gas detector with a sample size of 30 times the measurement time. The data collection technique is using tools and data analysis using one sample t test and one way ANOVA. Univariate analysis of PM10 parameters obtained the highest average results during the day, namely 130.6 g/Nm³, CO parameters obtained the highest average results during the day, namely 1627.6 g/Nm³, NO2 parameters obtained the highest average results during the day, namely 130.3 g /Nm³, the highest average yield of SO2 parameter during the day is 53.3 g/Nm³. The results of the one sample t test show that Ho is rejected and Ha is accepted. The results of the average measurement of the levels of Particulate (PM10), Carbon Monoxide (CO), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2) are not the same as the quality standard of the Air Pollution Standard Index (ISPU) that has been set.

Longitudinal Associations Between Household Solid Fuel Use and Handgrip Strength in Middle-Aged and Older Chinese Individuals: The China Health and Retirement Longitudinal Study.

BackgroundHousehold solid fuel have been associated with changes of handgrip strength (HGS). However, no study has explored the longitudinal associations between household solid fuel use and HGS. Thus, the aim of our cohort study was to investigate the longitudinal associations between household fuel use and HGS.MethodsThe study was based on the China Health and Retirement Longitudinal Study. A handheld dynamometer was used to measure HGS. Household fuel use statuses were collected using questionnaires. Analyses of covariance were performed to examine the associations between household fuel use and HGS.ResultsThe study included 9,382 participants during a 4-year follow-up. The participants who used solid fuel for cooking had more decreases of HGS than those who used clean fuel (P < 0.0001). The least square means (95% CIs) of changes of HGS for participants who used solid fuel and those who used clean fuel for cooking were −1.67 (−2.15, −1.19) and−2.27 (−2.75, −1.79), respectively. The association between fuel use for heating and HGS was non-significant (P = 0.63). The interaction terms of sex to cooking fuel (P = 0.04) and smoking to cooking fuel (P < 0.001) were significant; men and participants who had ever smoked had higher decreases in HGS.ConclusionUsing household solid fuel for cooking but not heating was associated with more decreases in HGS. Proper ventilation and clean fuel should be promoted for public health.

Household Solid Fuel Use and Renal Decline: Results from the INTERMAP China Prospective Study

Household Solid Fuel Use and Renal Decline: Results from the INTERMAP China Prospective Study

Household Solid Fuel Use and Associated Factors in Ethiopia: A Multilevel Analysis of Data From 2016 Ethiopian Demographic and Health Survey.

Solid fuels are types of fuel that comprise coal, biomass, charcoal, wood, or straw and are used for cooking, heating, lighting, boiling water, and generating revenue at home. Globally, 3 billion of the world’s poorest people continue to rely on inefficient solid fuels, which produce health-damaging contaminants. In Ethiopia, more than 90% of households rely on wood as their primary source of energy. The actual and potential determinants of solid fuel use have not been fully identified, particularly at the national level in Ethiopia. Therefore, this study aimed to determine the magnitude of solid fuel use and its associated factors in Ethiopia. We used the Ethiopian Demographic and Health Survey (EDHS), which was conducted in 2016. The data was conducted using a 2-stage stratified cluster sampling approach. A total of 16 650 weighted samples were taken. Multilevel logistic regression models were fitted to identify factors associated with solid fuel use, and a cluster-level random intercept was introduced in the mixed model. An adjusted odds ratio with a 95% confidence level was reported to show the strength of the association and its significance. The goodness of fit of the model was checked using proportional change deviance (PCV). The magnitude of solid fuel use among households in Ethiopia was 94.03% (95% CI = 93.66, 94.37). Household heads completed in primary school (AOR, 3.09, 95% CI = 2.44, 3.91), outdoor cooking places (AOR, 4.13, 95% CI = 2.96, 5.76), and small peripheral regions (AOR, 14.44, 95% CI = 6.12, 34.04) were all significantly associated with solid fuel use. The intra-cluster correlation coefficient (ICC) showed that about 81% of the variations in the use of solid fuel were attributed to the difference at the 643 cluster level, but the remaining 19% were attributed to individual household factors. The PCV was 90%, which showed that the variation in solid fuel use among study households was explained by factors at both the individual and community levels. The deviation test of the fourth model had the lowest value (3528) and was chosen as the best-fitted model. Due to different influencing factors, the use of solid fuel is still high in Ethiopia. Promoting access to education and raising awareness toward solid fuel impact is very important.

Chemical Investigation of Household Solid Fuel Use and Outdoor Air Pollution Contributions to Personal PM2.5 Exposures.

In communities with household solid fuel use, transitioning to clean stoves/fuels often results in only moderate reductions in fine particulate matter (PM2.5) exposures; the chemical composition of those exposures may help explain why. We collected personal exposure (men and women) and outdoor PM2.5 samples in villages in three Chinese provinces (Shanxi, Beijing, and Guangxi) and measured chemical components, including water-soluble organic carbon (WSOC), ions, elements, and organic tracers. Source contributions from chemical mass balance modeling (biomass burning, coal combustion, vehicles, dust, and secondary inorganic aerosol) were similar between outdoor and personal PM2.5 samples. Principal component analysis of organic and inorganic components identified analogous sources, including a regional ambient source. Chemical components of PM2.5 exposures did not differ significantly by gender. Participants using coal had higher personal/outdoor (P/O) ratios of coal combustion tracers (picene, sulfate, As, and Pb) than those not using coal, but no such trend was observed for biomass burning tracers (levoglucosan, K+, WSOC). Picene and most levoglucosan P/O ratios exceeded 1 even among participants not using coal and biomass, respectively, indicating substantial indirect exposure to solid fuel emissions from other homes. Contributions of community-level emissions to exposures suggest that meaningful exposure reductions will likely require extensive fuel use changes within communities.

Influence of Molding Technology on Thermal Efficiencies and Pollutant Emissions from Household Solid Fuel Combustion during Cooking Activities in Chinese Rural Areas

Resident combustion of solid fuel has been widely acknowledged as a high potential for pollutant reduction. However, there is a marked asymmetry between more pollutant emission and less burned volatiles of biomass and coal in the combustion process. To study the solid fuel optimum combustion form in a household stove, both the pollution reduction and energy efficient utilization of crop straws and coals were investigated. Taking the molding pressure and clay addition ratio as variable process conditions, the research of bio-coal briquette (made from the mixture of anthracite and biomass) was implemented in the range of 15~35 MP and 5~15%, respectively. Biomass and coal work complementarily for each other’s combustion property development. In particular, the pyrolysis gas produced by biomass low-temperature devolatilization is featured with low ignition point and is distributed in the bio-coal briquette. Its own combustion provides energy for anthracite particle combustion. Consequently, a positive effect was identified when bio-coal briquettes were used as residential fuel, and further improvement manifested in reducing more than 90% of particle matter (PM) and achieving about twice the thermal efficiencies (TEs) compared with the mass-weighted average values of coal briquettes and biomass briquettes. 88.8 ± 11.8%, 136.7 ± 13.7% and 81.4 ± 17.7% more TEs were provided by wheat straw–coal briquettes, rice straw–coal briquettes and maize straw–coal briquettes. 93.3 ± 3.1% (wheat straw–coal), 97.6 ± 0.2% (rice straw–coal) and 90.4 ± 2.2% (maize straw–coal) in terms of PM2.5 emission factors (EFs) was reduced. For bio-coal briquette, a 25 MPa and 10% addition were determined as the optimum molding pressure and clay addition ratio. Bio-coal briquettes with higher TEs and lower PM EFs will bring about substantial benefits for air quality promotion, human health and energy saving.

Toxicity of combustion-derived particles from Ethiopian household solid fuels in human bronchial epithelial cells

Toxicity of combustion-derived particles from Ethiopian household solid fuels in human bronchial epithelial cells

Association between household solid fuel use and tuberculosis: cross-sectional data from the Mongolian National Tuberculosis Prevalence Survey

BackgroundTuberculosis (TB) and indoor air pollution (IAP) are equally critical public health issues in the developing world. Mongolia is experiencing the double burden of TB and IAP due to solid fuel combustion. However, no study has assessed the relationship between household solid fuel use and TB in Mongolia. The present study aimed to assess the association between household solid fuel use and TB based on data from the Mongolian National Tuberculosis Prevalence Survey (MNTP Survey).MethodThe MNTP Survey was a nationally representative population-based cross-sectional survey targeting households in Mongolia from 2014 to 2015, with the aim of evaluating the prevalence of TB. The survey adopted a multistage cluster sampling design in accordance with the World Health Organization prevalence survey guidelines. Clusters with at least 500 residents were selected by random sampling. A sample size of 98 clusters with 54,100 participants was estimated to be required for the survey, and 41,450 participants were included in the final analysis of the present study. A structured questionnaire was used to collect information on environmental and individual factors related to TB. Physical examination, chest X-ray, and sputum examinations were also performed to diagnose TB.ResultsThe use of solid fuels for heating (adjusted odds ratio (aOR): 1.5; 95% confidence interval (CI): 1.1–2.1), male gender (aOR: 2.2; 95% CI: 1.6–3.2), divorced or widowed (aOR: 2.6; 95% CI: 1.7–3.8), daily smoker (aOR: 1.8; 95% CI: 1.3–2.5), contact with an active TB case (aOR: 1.7; 95% CI: 1.2–2.3), being underweight (aOR: 3.7; 95% CI: 2.4–5.7), and previous history of TB (aOR: 4.3; 95% CI: 3.0–6.1) were significantly associated with bacteriologically confirmed TB after adjusting for confounding variables.ConclusionThe use of solid fuels for heating was significantly associated with active TB in Mongolian adults. Increased public awareness is needed on the use of household solid fuels, a source of IAP.

Association between household solid fuel use for cooking and sleep disturbance in rural China: findings from the China Kadoorie Biobank data

BackgroundSolid fuel use for cooking is a main source of household air pollution, particularly in rural China. Evidence on the association between household air pollution and sleep quality remains limited. This study aimed to examine the association between household solid fuels used for cooking and sleep disturbance. MethodsThe data of 283,170 adults from baseline survey of the China Kadoorie Biobank Study were included. Detailed information about exposure to solid fuels used for cooking were collected. Sleep disturbance was indicated as any of the three sleep disorders, including disorders of initiating and maintaining sleep, disorders of early morning awakening, and daytime dysfunction. Logistic regression analysis was used to examine the association between sleep disturbance and level of exposure to household solid fuels used for cooking. ResultsAbout 18% of participants reported sleep disturbance. Fully adjusted analysis indicated exposure to household solid fuels used for cooking was significantly associated with sleep disturbance. Compared to those with 0–3 years exposure (first tertile) to solid fuels used for cooking, the participants with 3–26 years exposure (second tertile) and >26 years exposure (third tertile) had greater odds of having sleep disturbance at 1.16 (95% CI: 1.12–1.19) and 1.33 (95% CI: 1.29–1.37) times, respectively. ConclusionsUse of household solid fuels is associated with prevalence of sleep disturbance; the longer duration of exposure to solid fuels use for cooking, the higher is the prevalence of sleep disturbance. Further study is warranted to examine the underlying mechanisms of the association.

Seasonal features of brown carbon in northern China: Implications for BrC emission control

As brown carbon (BrC) consists of a collection of light-absorbing organic compounds, there is unlikely an individual substance that can be used as a proxy of all BrC constituents. Hence, available methods for distinguishing BrC from black carbon (BC) are often flawed. Moreover, the use of household solid fuels for winter rural heating is a common practice in northern China that significantly contributes to air pollution; however, it is unclear whether the intensive consumption of solid fuels during the heating season influences the yearly BrC emissions and the seasonal features of ambient BrC in northern China, which is a concern for future BrC control. Thus, a reliable method is necessary for determining the concentrations and optical properties of ambient BrC in different seasons. In this study, four typical months were selected to represent the four seasons of the year in Beijing. Daily atmospheric samples were collected using quartz filters for the analysis of BrC and BC. The integrating sphere (IS) approach was used for the first time to separate the light absorption of BrC from that of BC in ambient PM2.5. We found that the yearly average abundance of BrC was 0.82 ± 0.44 μg m−3, peaking at 2.31 ± 0.44 μg m−3 in winter, followed by autumn, spring, and summer. Meanwhile, the solar energy absorption by BrC relative to that by BrC + BC across 350–850 nm (FBrC) was the highest in winter (21.78 ± 3.56%), followed by autumn (11.53 ± 5.29%), spring (6.38 ± 4.06%), and summer (4.26 ± 2.57%). The seasonal variations in BrC abundance and absorption share were consistent with the use of household heating practices (highest in winter and minor uses in late autumn and early spring), with biomass and/or coal being the dominant energy types. As low-efficiency burning of solid biomass fuels and fossil fuels is considered an important source of BrC, the aforementioned correlation suggests that rural residential heating plays a dominant role in controlling the seasonal features of BrC and should therefore be a main focus for BrC control in northern China. Hence, the ongoing pursuit of clean heating (switching from coal to gas or electricity) in northern China will help to mitigate the climate-warming effects of both BrC and BC and offset some of the adverse impacts of clean air efforts on climate. Our findings also have wider implications for pollution mitigation in other global regions that use solid fuels.

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.

The development of household Solid Oxide Fuel Cell co-generation system

The development of household Solid Oxide Fuel Cell co-generation system