Coal Stoves Research Articles

Abstract 3238: Annual coal use and stove improvement in relation to cause-specific mortality in a 36-year cohort analysis among anthracite coal users in Xuanwei, China

Abstract Emissions from burning solid fuels contribute substantially to the global disease burden. Xuanwei (XW), China, has among the highest lung cancer rates in the world, which has been attributed to the use of bituminous (“smoky”) coal for cooking and heating. Anthracite (“smokeless”) coal is also used in XW and is considered a “cleaner” fuel source compared to bituminous coal, but it emits high-levels of certain indoor pollutants (e.g. nitrogen dioxide and sulfur dioxide) and the disease burden associated with its use has not been well characterized. To evaluate the impact of anthracite coal use and stove improvement on all- and cause-specific mortality, we conducted a cohort study in which 42,400 XW residents were followed from 1976-2011. We ascertained information on fuel use, stove improvement, and lifestyle factors using questionnaires, and mortality data were obtained from hospital records and death certificates. Sex-specific multivariable Cox regression models were used to estimate the hazard ratio (HR) of all- and cause-specific mortality in relation to time-dependent annual coal tonnage use (median: 2 tons/year; 25th and 75th percentile = 1 and 3 tons/year, respectively) and stove improvement among 4,486 lifetime anthracite coal users. Compared to subjects who used <2 tons of anthracite coal/year, higher annual tonnage was associated with increased total mortality (HR=1.16, 95% CI =1.03-1.30 in men; HR=1.18, 95% CI =1.02-1.37 in women), total respiratory disease mortality (HR=1.52, 95% CI =1.16-1.99 in men; HR=1.74, 95% CI=1.28-2.36 in women), which was driven by pneumonia, and total cancer mortality in men (HR=1.66, 95% CI=1.09-2.51) but not women. Lung cancer mortality was non-significantly increased and liver cancer mortality was significantly increased in both men and women for use of ≥2 tons of anthracite coal/year. Suggestive positive associations in relation to higher tonnage were also observed for ischemic heart disease. Changing from the traditional use of an unvented firepit to a portable or vented stove was associated with a reduction in overall mortality (HR=0.70, 95% CI=0.61-0.80 in men; HR=0.72, 95% CI=0.61-0.85 in women). Consistent sex-specific reductions in risk were observed for pneumonia and ischemic heart disease mortality, and a non-significant reduction in total cancer mortality was also observed for those who changed to using a portable or vented stove. Our findings suggest that anthracite coal use contributes to the burden of mortality in XW. This study emphasizes the importance of reducing the use of anthracite coal, which is still widely used in China for indoor cooking and heating, in favor of alternative fuel sources such as gas/electricity where possible. Citation Format: Bryan Bassig, Bingshu E. Chen, Wei Jie Seow, Roel Vermeulen, Jinming Zhang, Wei Hu, Jason Wong, Bofu Ning, H.Dean Hosgood, Yunchao Huang, Kaiyun Yang, George S. Downward, Lützen Portengen, Nathaniel Rothman, Qing Lan. Annual coal use and stove improvement in relation to cause-specific mortality in a 36-year cohort analysis among anthracite coal users in Xuanwei, China [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3238.

Field measurements of solid-fuel cookstove emissions from uncontrolled cooking in China, Honduras, Uganda, and India

Cookstoves have wide-reaching impacts on human health, air quality, and the climate. We measured emissions from uncontrolled cooking in 41 households in China, Honduras, Uganda, and India using a portable sampler. Test sites were chosen to cover a range of stove types (traditional and “improved”), fuels (wood, charcoal and coal), and cooking practices. We report test-integrated fuel-based emission factors (EFs) of fine particulate matter (PM2.5) mass, organic carbon (OC), elemental carbon (EC), as well as real time EFs of carbon monoxide (CO), black carbon (BC), total particle number, and particle size distributions. There was substantial house-to-house variability in emissions; the distribution of EFs were also highly positively skewed by several “superemitter” stoves in China (those with PM2.5 EFs 5–20 times greater than the median value). The highest PM2.5 mass emission factors were measured in China (median:10.3 g/kg-fuel), and the lowest in Uganda (median: 1.7 g/kg-fuel). The median PM2.5 mass EFs in wood-burning stoves in Honduras and India were similar: 3.7 g/kg-fuel and 4.1 g/kg-fuel, respectively. However, Indian stoves had higher EC EFs then Honduran stoves, demonstrating that emissions depend on more that fuel type; regional differences, such as cooking styles and stove design, may influence aerosol properties as well. Coal and charcoal stoves had higher OC:EC than wood stoves. The differences between the CO, PM2.5, and OC:EC ratios of “improved” and traditional stoves in India and Honduras were not statistically significant. To the best of our knowledge, we report the first cookstove source size distributions measurements from uncontrolled in-home cooking. These distributions varied between countries, which will influence local radiative effects. Particle size distributions from stoves tested in China, Honduras, and India were unimodal in the size range measured, with geometric mean diameters (GMDs) of 66 nm, 48 nm, and 76 nm, respectively. The median GMD of particles emitted from Ugandan charcoal stoves was 39, and when all tests are averaged, the resulting distribution appears tri-modal, with modes near 15, 30, and 100 nm. Real-time emissions data reveal high BC and particle number emissions during startup and fuel additions, which can be seen in the positively skewed distributions. Emissions of BC were most skewed, indicating that they were highly event-driven, followed by total particle number. CO emissions were more evenly spread across cooking events.

Dampness problems in Tianjin dwellings: A cross-sectional study of associations with building characteristics and lifestyles

This study investigated the association of building characteristics and occupant behaviours with building dampness indicators. Data were from a cross-sectional study in urban Tianjin and rural Cangzhou, China, from 2013 to 2014. We studied two fundamental types of Chinese dwellings: bungalows typical of rural locales and apartments in low- and high-rise buildings typical of urban settings. Occupants of bungalows reported more dampness indicators than apartment dwellers. Risk factors for one or more dampness indicators included natural ventilation without fans, older dwellings and coal stove or Kang heating system (a brick bed installed in the bedroom for heating and sleeping). All these factors were typical of bungalows, which generally used older building technologies including non-insulated external walls, wooden frame windows, electric fans for cooling and no exhaust fan ventilation. Occupant behaviours that decreased the risk for dampness indicators included frequent window opening and daily cleaning, regardless of the type of dwelling. Indoor dampness was highly correlated with mouldy and humid odour, and paradoxically (although not a new finding) with the perception of air dryness.

Tackling Air Pollution in Krakow

Data used in order to determine the level of pollutants present in the air in Krakow came from three air quality monitoring stations located in Bulwarowa street, Bujaka street and Krasińskiego avenue. Based on these data, an analysis was performed concerning air quality in Krakow in 2010-2016. Also, a correlation analysis was performed to investigate the relation between air quality parameters and meteorological parameters, such as: wind, precipitation, temperature. An analysis of the results obtained showed that two factors are critical for the variability of air pollution in Krakow. The first of them is low-stack emissions from coal stoves and boilers. The other factor is the type of atmospheric circulation. It has been determined that the worst air quality occurs in the heating season as the prevailing circulation is anticyclonic (high-pressure) characterised by low temperature, lack or small amount of precipitation, weak wind and thermal inversion. The paper presents preventive measures aimed at reducing the amount of pollutants in Krakow. It has been found that in order to reduce the level of air pollution in Krakow, especially in the heating season, it is necessary to intensify operations aimed at eliminating coal and wood stoves and boilers.

Energy Analysis of a Complementary Heating System Combining Solar Energy and Coal for a Rural Residential Building in Northwest China.

In order to utilize solar energy to meet the heating demands of a rural residential building during the winter in the northwestern region of China, a hybrid heating system combining solar energy and coal was built. Multiple experiments to monitor its performance were conducted during the winter in 2014 and 2015. In this paper, we analyze the efficiency of the energy utilization of the system and describe a prototype model to determine the thermal efficiency of the coal stove in use. Multiple linear regression was adopted to present the dual function of multiple factors on the daily heat-collecting capacity of the solar water heater; the heat-loss coefficient of the storage tank was detected as well. The prototype model shows that the average thermal efficiency of the stove is 38%, which means that the energy input for the building is divided between the coal and solar energy, 39.5% and 60.5% energy, respectively. Additionally, the allocation of the radiation of solar energy projecting into the collecting area of the solar water heater was obtained which showed 49% loss with optics and 23% with the dissipation of heat, with only 28% being utilized effectively.

Fine PM emission factors from residential burning of solid fuels using traditional cast-iron coal stoves

Residential burning of solid fuels is a major source of fine particulate matter (PM2.5), which degrades indoor and ambient air quality in low-income settlements. The adverse impact of fine particulate emissions on the environment and human health is well-documented in other countries such as China and India; however, there is need for local studies to report on emission factors from residential burning of solid fuels. An emission factor quantifies the total mass of a pollutant emitted per amount of fuel burned. Emission factor is an input parameter in air quality modelling to forecast a pollutant concentrations over time and when calculating total emissions from a specific source. Local emission factors are central to managing air quality for they give results that are representative of the source compared with international emission factors. Quantifying emissions, understanding household fuel use patterns and interaction with the stove (stove operation behaviour) during a burning event is fundamental when designing emission control strategies. The aim of the study is to quantify fine particulate matter emissions from residential coal burning using systematic field measurements. The objectives of the study are (i) to characterize stove operation behavior effect on the emissions and (ii) to quantify PM2.5 emission factors using field measurements. Isokinetic (2015) and direct (2014) stack sampling tests were done to observe how PM emissions profiles change with stove operation behavior and to quantify PM2.5 emitted per kilogram of fuel burned. Fine PM emission profiles change with stove operation behavior with an emission factor ranging 6.8 g.kg-1 and 13.5 g.kg-1. The study results implies that residential coal burning is a major source of fine particulate matter in the residential area. As demonstrated that stove operation behaviour affect stove to fuel combination emissions; it is therefore suggested that those factors leading to increase emissions should be kept minimum.

Performance analysis of solar thermal system for heating of a detached house in harsh cold region of Mongolia

Abstract Ulaanbaatar is one of the top five cities with worst air quality because of the use of raw coal in the Ger District. The objective of this paper is to analyze the environmental significance of solar heating system with triple heat sources including the solar collector, coal stove, and electric heater for a simple detached house in the harsh cold and dry climate. A long-term measurement was conducted in a Ger district of Ulaanbaatar city, Mongolia. Based on the measurement of the solar thermal system for 8 months, from October 2015 to May 2016, it was found that the average collector efficiency was 49.8% and system efficiency was 37%. The study also reported monthly performance of the system. The dust deposition on the glass tubes of the evacuated tube solar collector considerably decreased the performance, especially during winter season.

Emission factors of polycyclic and nitro-polycyclic aromatic hydrocarbons from residential combustion of coal and crop residue pellets

Polycyclic aromatic hydrocarbons (PAHs) and nitro-polycyclic aromatic hydrocarbons (NPAHs) are toxic pollutants mainly produced during fossil fuel combustion. Domestic coal stoves, which emit large amounts of PAHs and NPAHs, are widely used in the Chinese countryside. In this study, emission factors (Efs) for 13 PAH species and 21 NPAH species for four raw coal (three bituminous and one anthracite), one honeycomb briquette, and one crop residue pellet (peanut hulls) samples burned in a typical Chinese rural cooking stove were determined experimentally. The PAH and NPAH Efs for the six fuels were 3.15–49 mg/kg and 0.32–100 μg/kg, respectively. Peanut hulls had very high Efs for both PAHs and NPAHs, and honeycomb briquettes had the lowest Efs. 2-Nitropyrene and 2-nitrofluoranthene, which are NPAHs typically found in secondary organic aerosol, were detected in the emissions from some fuels, suggesting that chemical reactions may have occurred in the dilution tunnel between the flue gas leaving the stove and entering the sampler. The 1-nitropyrene to pyrene diagnostic ratios for coal and peanut hulls were 0.0001 ± 0.0001 and 0.0005, respectively. These were in the same order of magnitude as reference ratios for emissions during coal combustion. The 6-nitrobenzo[a]pyrene to benzo[a]pyrene ratios for the fuels were determined, and the ratios for coal and peanut hulls were 0.0010 ± 0.0001 and 0.0014, respectively. The calculated potential toxic risks indicated that peanut hull emissions were very toxic, especially in terms of NPAHs, compared with emissions from the other fuels.

Indoor air quality in urban and rural kindergartens: short-term studies in Silesia, Poland

More than 80% of people living in urban areas who monitor air pollution are exposed to air quality levels that exceed limits defined by the World Health Organization (WHO). Although all regions of the world are affected, populations in low-income cities are the most impacted. According to average annual levels of fine particulate matter (PM2.5, ambient particles with aerodynamic diameter of 2.5 μm or less) presented in the urban air quality database issued by WHO in 2016, as many as 33 Polish cities are among the 50 most polluted cities in the European Union (EU), with Silesian cities topping the list. The aim of this study was to characterize the indoor air quality in Silesian kindergartens based on the concentrations of gaseous compounds (SO2, NO2), PM2.5, and the sum of 15 PM2.5-bound polycyclic aromatic hydrocarbons (PAHs), including PM2.5-bound benzo(a)pyrene (BaP), as well as the mutagenic activity of PM2.5 organic extracts in Salmonella assay (strains: TA98, YG1024). The assessment of the indoor air quality was performed taking into consideration the pollution of the atmospheric air (outdoor). I/O ratios (indoor/outdoor concentration) for each investigated parameter were also calculated. Twenty-four-hour samples of PM2.5, SO2, and NO2 were collected during spring in two sites in southern Poland (Silesia), representing urban and rural areas. Indoor samples were taken in naturally ventilated kindergartens. At the same time, in the vicinity of the kindergarten buildings, the collection of outdoor samples of PM2.5, SO2, and NO2 was carried out. The content of BaP and the sum of 15 studied PAHs was determined in each 24-h sample of PM2.5 (indoor and outdoor). In the urban site, statistically lower concentrations of SO2 and NO2 were detected indoors compared to outdoors, whereas in the rural site, such a relationship was observed only for NO2. No statistically significant differences in the concentrations of PM2.5, PM2.5-bound BaP, and Σ15 PAHs in kindergartens (indoor) versus atmospheric (outdoor) air in the two studied areas were identified. Mutagenic effect of indoor PM2.5 samples was twice as low as in outdoor samples. The I/O ratios indicated that all studied air pollutants in the urban kindergarten originated from the ambient air. In the rural site concentrations of SO2, PM2.5 and BaP in the kindergarten were influenced by internal sources (gas and coal stoves).

Emission factors of fine particulate matter, organic and elemental carbon, carbon monoxide, and carbon dioxide for four solid fuels commonly used in residential heating by the U.S. Navajo Nation

ABSTRACTMost homes in the Navajo Nation use wood as their primary heating fuel, often in combination with locally mined coal. Previous studies observed health effects linked to this solid-fuel use in several Navajo communities. Emission factors (EFs) for common fuels used by the Navajo have not been reported using a relevant stove type. In this study, two softwoods (ponderosa pine and Utah juniper) and two high-volatile bituminous coals (Black Mesa and Fruitland) were tested with an in-use residential conventional wood stove (homestove) using a modified American Society for Testing and Materials/U.S. Environmental Protection Agency (ASTM/EPA) protocol. Filter sampling quantified PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 μm) and organic (OC) and elemental (EC) carbon in the emissions. Real-time monitoring quantified carbon monoxide (CO), carbon dioxide (CO2), and total suspended particles (TSP). EFs for these air pollutants were developed and normalized to both fuel mass and energy consumed. In general, coal had significantly higher mass EFs than wood for all pollutants studied. In particular, coal emitted, on average, 10 times more PM2.5 than wood on a mass basis, and 2.4 times more on an energy basis. The EFs developed here were based on fuel types, stove design, and operating protocols relevant to the Navajo Nation, but they could be useful to other Native Nations with similar practices, such as the nearby Hopi Nation.Implications: Indoor wood and coal combustion is an important contributor to public health burdens in the Navajo Nation. Currently, there exist no emission factors representative of Navajo homestoves, fuels, and practices. This study developed emission factors for PM2.5, OC, EC, CO, and CO2 using a representative Navajo homestove. These emission factors may be utilized in regional-, national-, and global-scale health and environmental models. Additionally, the protocols developed and results presented here may inform on-going stove design of the first EPA-certified wood and coal combination stove.

Comparison of air pollutant emissions and household air quality in rural homes using improved wood and coal stoves

Air pollutant emissions, fuel consumption, and household air pollution were investigated in rural Hubei, central China, as a revisited evaluation of an intervention program to replace coal use by wood in gasifier stoves. Measured emission factors were comparable to the results measured two years ago when the program was initiated. Coal combustion produced significantly higher emissions of CO2, CH4, and SO2 compared with wood combustion; however, wood combustion in gasifier stoves had higher emissions of primary PM2.5 (particles with diameter less than 2.5 μm), Elemental Carbon (EC) and Organic Carbon (OC). In terms of potential impacts on climate, although the use of wood in gasifier stoves produced more black carbon (6.37 vs 910 gCO2e per day per capita from coal and wood use) and less SO2 (-684 vs -312), obvious benefits could be obtained owing to greater OC emissions (-15.4 vs -431), fewer CH4 emissions (865 vs 409) and, moreover, a reduction of CO2 emissions. The total GWC100 (Global Warming Potential over a time horizon of 100 years) would decrease by approximately 90% if coal use were replaced with renewable wood burned in gasifier stoves. However, similar levels of ambient particles and higher indoor OC and EC were found at homes using wood gasifier stoves compared to the coal-use homes. This suggests critical investigations on potential health impacts from the carbon-reduction intervention program.

Air pollution and inhalation exposure to particulate matter of different sizes in rural households using improved stoves in central China

Household air pollution is considered to be among the top environmental risks in China. To examine the performance of improved stoves for reduction of indoor particulate matter (PM) emission and exposure in rural households, individual inhalation exposure to size-resolved PM was investigated using personal portable samplers carried by residents using wood gasifier stoves or improved coal stoves in a rural county in Central China. Concentrations of PM with different sizes in stationary indoor and outdoor air were also monitored at paired sites. The stationary concentrations of size-resolved PM in indoor air were greater than those in outdoor air, especially finer particles PM0.25. The daily averaged exposure concentrations of PM0.25, PM1.0, PM2.5 and total suspended particle for all the surveyed residents were 74.4±41.1, 159.3±74.3, 176.7±78.1 and 217.9±78.1μg/m3, respectively. Even using the improved stoves, the individual exposure to indoor PM far exceeded the air quality guideline by WHO at 25μg/m3. Submicron particles PM1.0 were the dominant PM fraction for personal exposure and indoor and outdoor air. Personal exposure exhibited a closer correlation with indoor PM concentrations than that for outdoor concentrations. Both inhalation exposure and indoor air PM concentrations in the rural households with gasifier firewood stoves were evidently lower than the reported results using traditional firewood stoves. However, local governments in the studied rural areas should exercise caution when widely and hastily promoting gasifier firewood stoves in place of improved coal stoves, due to the higher PM levels in indoor and outdoor air and personal inhaled exposure.

Coal-derived low smoke fuel assessment through coal stove combustion testing

A study was undertaken to investigate the production of low smoke fuel from coal currently used in low-income households in South Africa. Pyrolysis of large coal lumps was studied as a possible production method, and an optimum production temperature (550°C) was found to yield a viable alternative fuel. Combustion tests of the low smoke fuel in well instrumented coal stove experiments showed that the benefits thereof included: reductions of approximately 80%, 90% and 35% less particulate matter, volatile organic compounds (VOC’s) and sulfur dioxide emissions, respectively, when compared to raw medium rank C bituminous coal. Further research is required to develop this low smoke fuel with the end goal of large-scale production and performance trials in low-income households, in collaboration with the end users, as well as industry.

Direct observations of organic aerosols in common wintertime hazes in North China: insights into direct emissions from Chinese residential stoves

Abstract. Many studies have focused on the physicochemical properties of aerosol particles in unusually severe haze episodes in North China instead of the more frequent and less severe hazes. Consistent with this lack of attention, the morphology and mixing state of organic matter (OM) particles in the frequent light and moderate (L & M) hazes in winter in the North China Plain (NCP) have not been examined, even though OM dominates these fine particles. In the present work, morphology, mixing state, and size of organic aerosols in the L & M hazes were systematically characterized using transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy, atomic force microscopy, and nanoscale secondary ion mass spectrometer, with the comparisons among an urban site (Jinan, S1), a mountain site (Mt. Tai, S2), and a background island site (Changdao, S3) in the same hazes. Based on their morphologies, the OM particles were divided into six different types: spherical (type 1), near-spherical (type 2), irregular (type 3), domelike (type 4), dispersed-OM (type 5), and OM-coating (type 6). In the three sampling sites, types 1–3 of OM particles were most abundant in the L & M hazes and most of them were internally mixed with non-OM particles. The abundant near-spherical OM particles with higher sphericity and lower aspect ratio indicate that these primary OM particles formed in the cooling process after polluted plumes were emitted from coal combustion and biomass burning. Based on the Si-O-C ratio in OM particles, we estimated that 71 % of type 1–3 OM particles were associated with coal combustion. Our result suggests that coal combustion in residential stoves was a widespread source from urban to rural areas in NCP. Average OM thickness which correlates with the age of the air masses in type 6 particles only slightly increased from S1 to S2 to S3, suggesting that the L & M hazes were usually dry (relative humidity < 60 %) with weak photochemistry and heterogeneous reactions between particles and gases. We conclude that the direct emissions from these coal stoves without any pollution controls in rural areas and in urban outskirts contribute large amounts of primary OM particles to the regional L & M hazes in North China.

Emission of volatile organic compounds from domestic coal stove with the actual alternation of flaming and smoldering combustion processes

Volatile organic compounds (VOCs) emissions from the chimney of a prevailing domestic stove fuelled with raw bituminous coal were measured under flaming and smoldering combustion processes in a farmer's house. The results indicated that the concentrations of VOCs quickly increased after the coal loading and achieved their peak values in a few minutes. The peak concentrations of the VOCs under the smoldering combustion process were significantly higher than those under the flaming combustion process. Alkanes accounted for the largest proportion (43.05%) under the smoldering combustion, followed by aromatics (28.86%), alkenes (21.91%), carbonyls (5.81%) and acetylene (0.37%). The emission factors of the total VOCs under the smoldering combustion processes (5402.9 ± 2031.8 mg kg−1) were nearly one order of magnitude greater than those under the flaming combustion processes (559.2 ± 385.9 mg kg−1). Based on the VOCs emission factors obtained in this study and the regional domestic coal consumption, the total VOCs emissions from domestic coal stoves was roughly estimated to be 1.25 × 108 kg a−1 in the Beijing-Tianjin-Hebei region.

An important missing source of atmospheric carbonyl sulfide: Domestic coal combustion

AbstractCarbonyl sulfide (COS), carbon monoxide (CO), and sulfur dioxide (SO2) emissions generated from prevailing domestic coal stoves fueled with raw bituminous coal were studied under alternation cycles of flaming and smoldering combustion. The measurements in the laboratory and the farmer's house indicated that COS and CO emissions mainly occurred under the condition of flame extinguishment after coal loading, whereas SO2 emissions were mainly generated through combustion with flame. The COS emission factors for the domestic stoves in the laboratory and the farmer's house were recorded as 0.57 ± 0.10 g COS kg−1 and 1.43 ± 0.32 g COS kg−1, being approximately a factor of 50 and 125 greater than that generated from coal power plants, respectively. Based on the COS emission factors measured in this study, COS emission from only domestic coal combustion in China would be at least 30.5 ± 5.6 Gg S yr−1 which was 1 magnitude greater than the current COS estimation from the total coal combustion in China.

Development and performance evaluation of a clean-burning stove

Many suburb and rural households in the world are still using small coal-fired stoves for cooking and heating, which traditionally has been associated with low-efficiency combustion devices and low-grade coal, and the consequent severe air pollution. Therefore, it is very urgent to develop and widely disseminate clean and efficient combustion technologies for household use. This paper reported the development and research of a novel clean coal technology which burns clean coal-biomass briquette in a novel clean-burning coal stove. In order to reduce the emission of nitrogen oxides and particulate matters, this stove is designed with a pyrolysis chamber and a combustion chamber. In order to improve the thermal efficiency, the secondary air ducks are arranged to recover the waste heat in the ash pit and use it to warm up the inlet secondary air; sulfur retention agent calcium oxide & magnesium oxide were added to reduce the emission of sulfur oxides; low-cost corn & wheat biomass was blended with coal to utilized agricultural waste, and reduce the cost and ash content of the briquette. The thermal efficiency and the pollutants emission of this new stove were compared with the conventional one-chamber stove. The results revealed that the thermal efficiency of the stove was improved to 68%, compared with the conventional stove of 50%, while the emissions of sulfur dioxide, nitrogen oxides and carbon monoxide were reduced significantly. The coal biomass-briquette was demonstrated to be excellent in sulfur dioxide retention compared with other types of local coal. In addition, a significant reduction in the indoor concentration of carbon monoxide and PM using coal biomass-briquette in the new stove was confirmed. Information from this study demonstrates the high thermal efficiency and environment-friendly feature of the newly designed coal stove and the coal biomass-briquette. This new clean coal technology has been successfully demonstrated in two counties of Shanxi Province in China, and has great potential for improving regional and indoor air quality.

Influence of different types of coals and stoves on the emissions of parent and oxygenated PAHs from residential coal combustion in China

To evaluate the influence of coal property and stove efficiency on the emissions of parent polycyclic aromatic hydrocarbons (pPAHs) and oxygenated PAHs (oPAHs) during the combustion, fifteen coal/stove combinations were tested in this study, including five coals of different geological maturities in briquette and chunk forms burned in two residential stoves. The emission factors (EFs) of pPAHs and oPAHs were in the range of 0.129–16.7 mg/kg and 0.059–0.882 mg/kg, respectively. The geological maturity of coal significantly affected the emissions of pPAHs and oPAHs with the lower maturity coals yielding the higher emissions. The chunk-to-briquette transformation of coal dramatically increased the emissions of pPAHs and oPAHs during the combustion of anthracite, whereas this transformation only elevated the emissions of high molecular weight PAHs for bituminous coals. The influence of stove type on the emissions of pPAHs and oPAHs was also geological-maturity-dependent. High efficiency stove significantly reduced the emissions of PAHs from those relatively high-maturity coals, but its influences on low-maturity coals were inconstant.

Evaluating the climate and air quality impacts of short-lived pollutants

Evaluating the climate and air quality impacts of short-lived pollutants

Comparison of carbon monoxide poisonings originated from coal stove and natural gas and the evaluation of Neutrophil/Lymphocyte ratio

Objective: The aim of our study is to present the epidemiologic, clinical, laboratory and prognosis differences between the coal stove origin poisoning and natural gas leakages. We also aimed to investigate relationship between the severity of clinical picture, prognosis, complications develop in CO poisoning with neutrophil/lymphocyte ratio (NLR) at the initial admission. Methods: All the acute carbon monoxide cases who applied to Ankara Training and Research Hospital Emergency Medicine Clinic between October 2009 and April 2010 were included to this prospective study. CO poisoning diagnosis was made by the history of CO poisoning with carboxyl hemoglobin (COHb) concentration is over 10%. 100 patients were included to our study. Results: Of the patients, 55(55%) were poisoned from the coal-stove and 45(45%) from natural gas leakage. The mean COHb level of the natural gas group was significantly high (p=0.01). The mean value of GCS of the natural gas group was significantly lower (p=0.018). The number of patients with indication for HBO therapy were 17 and 6 in the natural gas group and coal-stove group, respectively, being significantly higher in the natural gas group(p=0.001). There was no statistically significant relationship between the value of NLR and values of COHb, troponin, and GCS (p=0.872, p=0.470, and p=0.896, respectively). Conclusions: Carbon monoxide poisoning from natural gas leakage is more toxic than that from the coal-stove. There is no relationship between NLR at the time of presentation and the severity of clinical findings, prognosis and complications. Key words: Carbon monoxide poisoning, coal-stove; natural gas, Neutrophil/lymphocyte ratio