Residential Biomass Burning Research Articles

Extreme Exposure Levels of PCDD/Fs Inhaled from Biomass Burning Activity for Cooking in Typical Rural Households.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), emitted during biomass combustion, are carcinogenic chemicals. The association between indoor biomass burning and PCDD/Fs inhalation exposure levels is still poorly understood. This study first reports direct measurement of personal exposure to PCDD/Fs in real-world households with wood combustion. In homes where biomass burning is used for cooking, toxic equivalent quantity (TEQ) PCDD/Fs concentrations were found to be 545 ± 251 fg I-TEQ/m3 in kitchens, with levels of 4.5-, 6.9-, and 13.3-fold higher than those in living rooms (122 ± 92 fg I-TEQ/m3), bedrooms (79 ± 27 fg I-TEQ/m3), and ambient air (41 ± 15 fg I-TEQ/m3), respectively. PCDD/Fs exposure levels in populations using biomass fuels for cooking (353 ± 110 fg I-TEQ/m3) were 4.3-fold higher than those in the control groups (82 ± 32 fg I-TEQ/m3). Additionally, the average cancer risks for biomass cooking person were approximately 3.1-fold higher than those in factory workers. Overall, residents of household that use biomass fuels for cooking have the highest known risk of PCDD/Fs exposure. These results highlight that aiming to mitigate the PCDD/Fs exposure risk in the general population, the focus of dioxin emission source control measures should shift from industrial sectors to residential biomass combustion.

Industrial and wildfire aerosol pollution over world heritage Lake Baikal

Lake Baikal is the biggest reservoir of fresh water with unique flora and fauna; presently it is negatively affected by climate change, water warming, industrial emissions, shipping, touristic activities, and Siberian forest fires. The assessment of air pollution - related Baikal's ecosystem damage is an unsolved problem. Ship, based expedition exploring the Baikal atmospheric aerosol loading, was performed over the lake area in July 2018. We combine the aerosol near - water and vertical distributions over the Lake Baikal basin with meteorological observations and air mass transportation simulations. Lidar sounding of aerosol fields in the troposphere assesses the atmospheric background in the pristine areas and the pollution during fire-affected periods. Aerosol optical properties (scattering and spectral absorption) converted to the particle number size, black carbon (BC) mass, and Absorption Angstrom Exponent (AAE) provide the inside into aerosol characterization. Transport of industrial emissions from Krasnoyarsk and Irkutsk regions, and wildfire plumes from Republic of Yakutia relates the pollution sources to the increased concentrations of fine particle numbers, PM10 and BC mass over Southern and Northern/Central Baikal, respectively. The highest PM10 and BC are associated to the harbor and touristic areas of intensive shipping and residential biomass burning. Deposition estimates applied to aerosol data exhibit the pollution fluxes to water surface over the whole Baikal area. AAE marks the impact of coal combustion, residential biomass burning, and wildfires indicating the high pollution level of the Lake Baikal ecological system .

Fine particles from village air in northern China in winter: Large contribution of primary organic aerosols from residential solid fuel burning.

Rural residential emissions contribute significantly to regional air pollution in China, but our understanding on how residential solid fuel burning influences the village outdoor air quality is limited. In this study, we compared the fine particulate matter (PM2.5) composition and individual particle characteristics from 11 to 18 January 2017at a village and an urban site in northern China. At the village site, each day was divided into four periods: cooking (07:30-10:00; 16:00-17:00), daytime (10:00-16:00), heating (17:00-24:00), and midnight (00:00-07:30) periods. The highest PM2.5 concentration occurred during the cooking period (236±88μgm-3), which was characterized by high concentrations of K+ and abundant primary OM-K particles (i.e., organic matter mixed with K-salts) emitted from residential biomass burning. The second highest PM2.5 concentration was found during the heating period (161±97μgm-3), and the PM2.5 contained abundant spherical primary OM particles (i.e., tarballs) emitted from residential coal burning. The primary emissions from residential solid fuel burning resulted in 75% of the village OM by mass consisting of primary OM and 67% of the village aerosol particles by number internally mixing with primary OM particles. The village PM2.5 composition was different from that of the urban PM2.5, with the former containing more OM (47% vs 32%) and less secondary inorganic ions (30% vs 46%). Individual primary OM-K and tarballs were abundant in the village air. These results suggest a large contribution of village residential emissions in the winter to village air pollution. Our study highlights that the residential health in villages of northern China should be paid more attention because of high PM2.5 concentrations and abundant toxic particles during the cooking and heating periods per day in winter.

Emission of fine particles (PM2.5) from residential biomass combustion in Croatia and how to reduce it

Wood burning in residential appliances is very represented in the Republic of Croatia. It is a main or an additional form of heating for many households in rural and urban areas and is therefore an important source of air pollution. The choice of energy and the combustion appliance used in home have a significant impact on PM2.5 emissions. The paper informs the reader about PM2.5 emissions, their main sources and impacts on human health, environment, climate, air quality, and the reason why PM2.5 emissions from residential wood burning are harmful. Paper also gives an overview of spatial PM2.5 emission distribution in Croatia, their five air quality zones and four agglomerations. The paper analyses the sources and their contribution to PM2.5 emissions with the relevance of PM2.5 emissions from residential plants, the use of fuels in residential plants and their contribution to PM2.5 emissions and PM2.5 emissions by fuel combustion technologies in residential sector. Appropriate strategies, policies, and actions to reduce the impact of residential biomass (wood) burning on the environment, air quality and human health are considered.

Sources of particulate-matter air pollution and its oxidative potential in Europe

Particulate matter is a component of ambient air pollution that has been linked to millions of annual premature deaths globally1-3. Assessments of the chronic and acute effects of particulate matter on human health tend to be based on mass concentration, with particle size and composition also thought to play a part4. Oxidative potential has been suggested to be one of the many possible drivers of the acute health effects of particulate matter, but the link remains uncertain5-8. Studies investigating the particulate-matter components that manifest an oxidative activity have yielded conflicting results7. In consequence, there is still much to be learned about the sources of particulate matter that may control the oxidative potential concentration7. Here we use field observations and air-quality modelling to quantify the major primary and secondary sources of particulate matter and of oxidative potential in Europe. We find that secondary inorganic components, crustal material and secondary biogenic organic aerosols control the mass concentration of particulate matter. By contrast, oxidative potential concentration is associated mostly with anthropogenic sources, in particular with fine-mode secondary organic aerosols largely from residential biomass burning and coarse-mode metals from vehicular non-exhaust emissions. Our results suggest that mitigation strategies aimed at reducing the mass concentrations of particulate matter alone may not reduce theoxidative potential concentration. If theoxidative potential can be linked to major health impacts, it may be more effective to control specific sources of particulate matter rather than overall particulate mass.

Parent, alkylated, oxygenated and nitrated polycyclic aromatic hydrocarbons in PM2.5 emitted from residential biomass burning and coal combustion: A novel database of 14 heating scenarios.

To characterize the emissions of polycyclic aromatic hydrocarbons (PAHs) from residential biomass burning and coal combustion in field environments, smoke samples were collected from the combustion of six types of biomass in heated kangs and four types of coal in traditional stoves and semi-gasifier stoves. The emission factors (EFs) of the total PAH were in the range of 84.5-344mg/kg for biomass burning, with lower EFs for biomass with higher densities, and in the range of 38.0-206mg/kg for coal combustion, with lower EFs for coals with higher maturity. Moreover, EFs were lower from high-density biomass fuels (wood trunk, 84.5±11.3mg/kg) than low-maturity coals (bituminous coal, 206±16.5mg/kg). Parent, oxygenated, alkylated, and nitrated PAHs accounted for 81.1%, 12.6%, 6.2%, and 0.1%, respectively, of the total-PAH EFs from biomass burning, and 84.7%, 13.8%, 1.4%, and 0.1%, respectively, of the total-PAH EFs from coal combustion. PAH source profiles differed negligibly between biomass fuels but differed significantly between bituminous coal and anthracite coal fuels. The characteristic species of sources were phenanthrene, 9-fluorenone, and 2-nitrobiphenyl for biomass burning, and were phenanthrene, benzo[ghi]perylene, 1,4-naphthoquinone, and 2-nitrobiphenyl for coal combustion. The ratios of benzo[b]fluoranthene/(benzo[b]fluoranthene+benzo[k]fluoranthene) were 0.40-0.45 for biomass burning and 0.89-0.91 for coal combustion, and these significantly different values constitute unique markers for distinguishing these fuels in source apportionment. Benzo[a]pyrene-equivalent factor emissions were 2.79-11.3mg/kg for biomass and 7.49-41.9mg/kg for coal, where parent PAHs contributed 92.0%-95.1% from biomass burning and 98.6%-98.8% from coal combustion. Total-PAH emissions from residential heating were 1552t across Shaanxi province, to which wheat straw (445t) in biomass burning and bituminous coal (438t) in coal combustion were the highest contributors. Results from this study provide crucial knowledge for the source identification of PAHs as well as for the design of abatement strategies against pollutant emissions.

Characteristics of the source apportionment of primary and secondary inorganic PM2.5 in the Pearl River Delta region during 2015 by numerical modeling

Fine particulate matter (PM2.5) contains both primary and secondary components, and their source apportionment characteristics in the Pearl River Delta (PRD) region during 2015 were compared by applying an air quality model coupled with an on-line tracer-tagged module. The results of contributions from different source regions to primary PM2.5 (PPM2.5) and secondary inorganic PM2.5 (SIPM2.5) in four selected cities show that the effect of regional transport on the SIPM2.5 level is stronger than that on the PPM2.5 level in the PRD region. For both Guangzhou city and the average of the entire PRD region, the industrial (25–40%) and transportation (20–25%) sectors are major sources of PPM2.5 and SIPM2.5. However, the residential sector contributes approximately 25% to the PPM2.5 level, mainly from residential biomass burning, but accounts for only approximately 10% of the SIPM2.5 level. The relative importance of each sector to the contributions from local and regional transport indicates that industrial emissions appear to lead to regional air pollution, while the transportation emissions seem to mainly affect the local and surrounding areas. Considering the impact of regional contributions to air quality, efforts made to reduce emissions in each city could not only improve the local air quality but also benefit downstream regions. To further decrease the PM2.5 level, the local government of each city in the PRD region should not only continue to strengthen the control of local emissions, such as those from transportation and residential biomass burning, but also increase their focus on regional joint prevention and control strategies with upstream area (such as northern Guangdong Province, and Jiangxi, Fujian and Hunan provinces).

PAHs emissions from residential biomass burning in real-world cooking stoves in rural China

Indoor biomass burning is a major contributor to the emission of PAHs (polycyclic aromatic hydrocarbons) in China. To date, estimates of PAH emissions from the burning of biomass have involved considerable uncertainty, mostly from the lack of real-world measurements of emission factors. In this study, we conducted a comprehensive evaluation on PAH emissions from biomass burning in real-world cooking stoves in three Chinese provinces. PAH emission factors, in both particle- and gas-phase, from 11 fuel-stove combinations were measured and the provincial emissions were estimated based on the measured emission factors and fuel consumption. The measured PAH28 emission factors (including 16 US EPA priority PAHs and 12 non-priority PAHs) ranged from 42 mg/kg to 370 mg/kg, with an order of magnitude difference, which was mostly affected by fuel type. The emission factors measured in this study were generally higher than those reported in laboratory studies and were comparable with field studies. The gas-particle distribution indicated that the absorption of PAHs by organic carbon in particulate matter (PM) was the dominant sorption mechanism in gas-particle distribution. The composition profile was different from previous studies, especially for non-priority PAHs, which are highly toxic and should be given more attention. Following the disparities in composition profiles, our study suggests that source apportionment based on single- or multi-diagnostic ratios may lead to large bias and uncertainties. It appears that the toxicity potential of PAHs in northern China emitted from combustion of crop residues is greater than that in southern China where PAHs are mainly emitted from wood combustion.

Real-time emission and stage-dependent emission factors/ratios of specific volatile organic compounds from residential biomass combustion in China

The absence of emission factors (EFs) with high-time resolution primarily hinders developing high time-resolution emission inventory for air pollutants, which further restricted the accuracy of air quality modeling, especially for a pollution process. The real-time emission concentration of volatile organic compounds (VOCs) in the combustion process of eleven kinds of residential biomass fuels (RBFs) were studied using a high-resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS). The dynamic EFs for 18 types of VOCs were firstly obtained with the records of fuel consuming amounts by a balance of high precision. The RBFs burning lasted for about 3–15 min for each experiment with 53–130 g fuels burned. The VOCs concentrations of biomass combustion varied in 0–10 ppm, and exhibited single peak values at about 1–4 min for the entire burning processes. Aldoketones accounted for the largest proportion of the 18 types of VOCs (46.6%–53.6%), followed by methanol (29.2%–44.6%) and alkene (26.2%–31.7%). The real-time EFs of VOCs from RBFs burning firstly decreased to the lowest value of 0.001–3.84 mg/g, and then increased to about 0.23–148 mg/g until the end of combustion processes. The VOCs EFs of all biomass combustion in flaming (1.65 ± 1.55 mg/g) were lower than those in smoldering (16.0 ± 11.3 mg/g). The benzene to toluene (B/T) ratios peaked at 100–200 s of biomass burning processes and changed in 0.07–4.06 for different burning stages. It should be noted that isoprene which was always regarded as the marker for VOCs emitted from biogenic evaporation, can also be released from biomass fuels burning, with real time EFs of 3.16 ± 5.16 mg/g. Its emission amounts and relative importance from combustion sources should be assessed. The high time-resolution of VOCs emission concentrations, emission factors and specific species ratios provide new datasets. They would be useful for dynamic source apportionment and developing high-time resolution emission inventory of VOCs.

Global nature of airborne particle toxicity and health effects: a focus on megacities, wildfires, dust storms and residential biomass burning.

Since air pollutants are difficult and expensive to control, a strong scientific underpinning to policies is needed to guide mitigation aimed at reducing the current burden on public health. Much of the evidence concerning hazard identification and risk quantification related to air pollution comes from epidemiological studies. This must be reinforced with mechanistic confirmation to infer causality. In this review we focus on data generated from four contrasting sources of particulate air pollution that result in high population exposures and thus where there remains an unmet need to protect health: urban air pollution in developing megacities, household biomass combustion, wildfires and desert dust storms. Taking each in turn, appropriate measures to protect populations will involve advocating smart cities and addressing economic and behavioural barriers to sustained adoption of clean stoves and fuels. Like all natural hazards, wildfires and dust storms are a feature of the landscape that cannot be removed. However, many efforts from emission containment (land/fire management practices), exposure avoidance and identifying susceptible populations can be taken to prepare for air pollution episodes and ensure people are out of harm’s way when conditions are life-threatening. Communities residing in areas affected by unhealthy concentrations of any airborne particles will benefit from optimum communication via public awareness campaigns, designed to empower people to modify behaviour in a way that improves their health as well as the quality of the air they breathe.

Optical properties and molecular compositions of water-soluble and water-insoluble brown carbon (BrC) aerosols in northwest China

Abstract. Brown carbon (BrC) contributes significantly to aerosol light absorption and thus can affect the Earth's radiation balance and atmospheric photochemical processes. In this study, we examined the light absorption properties and molecular compositions of water-soluble (WS-BrC) and water-insoluble (WI-BrC) BrC in PM2.5 collected from a rural site in the Guanzhong Basin – a highly polluted region in northwest China. Both WS-BrC and WI-BrC showed elevated light absorption coefficients (Abs) in winter (4–7 times those in summer) mainly attributed to enhanced emissions from residential biomass burning (BB) for heating of homes. While the average mass absorption coefficients (MACs) at 365 nm (MAC365) of WS-BrC were similar between daytime and nighttime in summer (0.99±0.17 and 1.01±0.18 m2 g−1, respectively), the average MAC365 of WI-BrC was more than a factor of 2 higher during daytime (2.45±1.14 m2 g−1) than at night (1.18±0.36 m2 g−1). This difference was partly attributed to enhanced photochemical formation of WI-BrC species, such as oxygenated polycyclic aromatic hydrocarbons (OPAHs). In contrast, the MACs of WS-BrC and WI-BrC were generally similar in winter and both showed few diel differences. The Abs of wintertime WS-BrC correlated strongly with relative humidity, sulfate and NO2, suggesting that aqueous-phase reaction is an important pathway for secondary BrC formation during the winter season in northwest China. Nitrophenols on average contributed 2.44±1.78 % of the Abs of WS-BrC in winter but only 0.12±0.03 % in summer due to faster photodegradation reactions. WS-BrC and WI-BrC were estimated to account for 0.83±0.23 % and 0.53±0.33 %, respectively, of the total down-welling solar radiation in the ultraviolet (UV) range in summer, and 1.67±0.72 % and 2.07±1.24 %, respectively, in winter. The total absorption by BrC in the UV region was about 55 %–79 % relative to the elemental carbon (EC) absorption.

Spring Aerosol in Urban Atmosphere of Megacity: Analytical and Statistical Assessment for Source Impacts

In the complex situation with the plurality of emissions, the important research task of assessing the air quality and potential sources through aerosol composition analyses remains for Moscow’s megacity environment. The light absorption, PM10 mass concentration, aerosol composition, and meteorological parameters in this urban background were measured during spring 2017, a period characterized by significant changes in the air temperature, mass advection, and solar radiation. The organic and elemental carbon (OC and EC) and 76 organic compounds, e.g., alkanes, polycyclic aromatic hydrocarbons (PAHs), oxidized PAHs, hopanes, anhydrosugars, polyols, primary and secondary saccharides, and HULIS, as well as 13 ions, including K+, a marker of biomass burning, have been quantified to determine the carbonaceous and inorganic chemical profiles of the aerosol. The correlation between the absorption Ångström exponent (AAE) and the levoglucosan concentration reveals the relative contributions of agricultural fires and residential biomass burning (BB) nearby to the urban aerosol composition. Combining detailed analytical and statistical approaches, we have identified and analyzed the specific chemical compounds that most accurately represent the variability of the aerosol composition. Principal component analysis (PCA) highlights the main factors for marker species related to gasoline/diesel traffic, BB, biogenic activity, and secondary formation in the atmosphere. Distinguishing the BB-affected periods allows us to evaluate daily changes in the aerosol composition in relation to the transported air masses and detected fires in the areas surrounding Moscow.

Aerosol from Biomass Combustion in Northern Europe: Influence of Meteorological Conditions and Air Mass History

Alkali-containing submicron particles were measured continuously during three months, including late winter and spring seasons in Gothenburg, Sweden. The overall aims were to characterize the ambient concentrations of combustion-related aerosol particles and to address the importance of local emissions and long-range transport for atmospheric concentrations in the urban background environment. K and Na concentrations in the particulate matter PM1 size range were measured by an Alkali aerosol mass spectrometer (Alkali-AMS) and a cluster analysis was conducted. Local meteorological conditions and trace gas and PM concentrations were also obtained for a nearby location. In addition, back trajectory analyses and chemical transport model (CTM) simulations were included for the evaluation. The Alkali-AMS cluster analysis indicated three major clusters: (1) biomass burning origin, (2) mixture of other combustion sources, and (3) marine origin. Low temperatures and low wind speed conditions correlated with high concentrations of K-containing particles, mainly owing to local and regional emissions from residential biomass combustion; transport of air masses from continental Europe also contribute to Cluster 1. The CTM results indicate that open biomass burning in the eastern parts of Europe may have contributed substantially to high PM2.5 concentrations (and to Cluster 1) during an episode in late March. According to the CTM results, the mixed cluster (2) is likely to include particles emitted from different source types and no single geographical source region seems to dominate for this cluster. The back trajectory analysis and meteorological conditions indicated that the marine origin cluster was correlated with westerly winds and high wind speed; this cluster had high concentrations of Na-containing particles, as expected for sea salt particles.

Two Inversion Layers and Their Impacts on PM2.5 Concentration over the Yangtze River Delta, China

AbstractAn integrated winter field campaign was conducted to investigate the atmospheric boundary layer structure and PM2.5 concentration at three sites over the Yangtze River delta (YRD) in China: Shouxian (a rural area), a site in a northern suburb of Nanjing, and Dongshan (a residential area). Two temperature inversion layers and air pollution events occurred simultaneously from 30 to 31 December 2016, local time, over the YRD. It was found that the two inversion layers were related to the presence of a high pressure system, resulting in divergence in the upper boundary layer and radiative cooling near the ground at night. Dominated by agricultural and residential biomass burning, the surface emission sources from the Shouxian rural area were moderately strong. After the formation of the two inversions, the vertical distribution of PM2.5 concentration below the upper inversion layer was uniform as a result of thorough boundary layer mixing in the earlier hours. During nighttime at the Nanjing site, air pollutant plumes from nearby elevated point sources could not easily diffuse downward/upward between the two inversion layers, which led to a distinct peak in the PM2.5 concentration. At the Dongshan site, the emission sources were weak and the nighttime PM2.5 concentration above 100 m was high. The surface PM2.5 concentration gradually increased from early morning to noon, which was attributed to emissions related to the local residents. The results indicated that the vertical distribution of pollutants was affected by a combination of local emissions, vertical boundary layer structure, and horizontal and vertical transports.

Measuring the spatial variability of black carbon in Athens during wintertime

A first assessment of the spatial variability of ambient black carbon (BC) concentrations in the Greater Area of Athens (GAA) was carried out during an intensive wintertime campaign, when ambient levels are exacerbated by increased biomass burning for residential heating. Short-term daytime BC measurements were conducted at 50 sites (traffic and urban/suburban/regional background) and on-road along 12 routes. Daytime measurements were adjusted based on BC concentrations continuously monitored at a reference site. Indicative nighttime BC ambient concentrations were also measured at several residences across the area. Daytime BC concentrations recorded an average of 2.3 μg m-3 with considerable between-site variability. Concentrations at traffic sites were significantly higher (43% on average), compared with the rest of the sites. Varying levels were observed between background site subtypes, with concentrations at urban background sites (located near the center of Athens and the port of Piraeus) being 34% and 114% higher, on average, than at suburban and regional background sites, respectively. The traffic intensity at the nearest road and the population and built density in the surrounding area of sites were recognized as important factors controlling BC levels. On-road concentration measurements (5.4 μg m-3 on average) enabled the identification of hot-spots in the road network, with peak levels encountered along motorways (13.5 μg m-3 on average). Nighttime measurements demonstrated that wintertime BC pollution, enhanced by residential biomass burning for heating, affects the entire Athens basin. The reference site in central Athens was found to be representative of the temporal variability for daytime and nighttime BC concentrations at background locations.

Ultrafine Particles from Residential Biomass Combustion: A Review on Experimental Data and Toxicological Response.

Biomass burning is considered an important source of indoor and outdoor air pollutants worldwide. Due to competitive costs and climate change sustainability compared to fossil fuels, biomass combustion for residential heating is increasing and expected to become the major source of primary particulate matter emission over the next 5–15 years. The understanding of health effects and measures necessary to reduce biomass emissions of harmful compounds is mandatory to protect public health. The intent of this review is to report available data on ultrafine particles (UFPs, i.e., particles with diameter smaller than 100 nm) emitted by residential biomass combustion and their effects on human health (in vitro and in vivo studies). Indeed, as far as we know, papers focusing specifically on UFPs originating from residential biomass combustion and their impact on human health are still lacking.

Mineralogical, chemical and leaching characteristics of ashes from residential biomass combustion.

Four types of pellets and three agro-fuels were chemically characterised and burned in a pellet stove. To assess the influence of the material composing the firebox and the combustion efficiency of distinct biomass heating devices in the composition of the bottom ashes, three of the pellets were also burned in a conventional woodstove and in a fireplace. Ashes were analysed for their C, H and N contents by an elemental analyser, whilst major and trace elements were quantified by inductively coupled plasma atomic-emission spectrometry and inductively coupled plasma mass spectrometry, respectively. The mineralogy of ashes was determined by X-ray powder diffraction. The European standard test was applied to samples to determine the leaching potential of major, minor and trace elements. The contents of major and trace elements in the different types of biomass presented enormous variations, which are reflected in dissimilar mineralogical and chemical compositions of the respective ashes. The leachable potential of several elements of environmental concern present in oxy-anionic form at the alkaline pH of biomass ashes were generally high in all samples. Concentrations of some elements in the leachates were in the range of values with classification of "hazardous materials" by the European legislation in what respects the acceptance of these wastes at landfills. Pellets made up of wood wastes and containing preservatives (chromated copper arsenate and ammoniacal copper arsenate) are of concern. Due to lower combustion efficiencies, the leachable potential for most of the trace elements in ashes from the woodstove, and especially from the fireplace, was lower than that of the pellet stove.

Monitoring polycyclic aromatic hydrocarbon concentrations and distributions in rice paddy soils from Gyeonggi-do, Ulsan, and Pohang

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants that are released by incomplete combustion of carbon-containing materials. The top soils of rice paddies were collected from Gyeonggi-do (18 sites), Ulsan (20 sites), and Pohang (19 sites) in Korea to assess the spatial distribution and potential sources of PAHs. The total concentrations of 15 PAHs in the soils were 19.53–672.93, 125.01–3106.27, and 51.94–8106.21 mg/kg in Gyeonggi province, Ulsan, and Pohang, respectively. The concentration of 7 key carcinogenic PAHs were followed the order: Pohang (38.54–4826.63 ng/g) > Ulsan (28.54–1561.39 ng/g) > Gyeonggi province (19.53–206.51 ng/g). Three-ring PAHs were predominant in the soils from Gyeonggi-do while 3–5 ring compounds were abundant in the agricultural soils from the two industrial regions (Ulsan and Pohang). The PAH isomeric diagnostic ratios indicated that PAH contamination in the two cities mainly originated from pyrogenic sources. The principal component analysis indicated that pyrogenic coal burning and residential biomass combustion were major contributors to the soil contamination in the two cities. The transportation of PAHs through the air from industrial complexes and high volume of traffic may influence the PAHs distribution in the soils of the two cities in Korea.

Monitoring and modeling of household air quality related to use of different Cookfuels in Paraguay

In Paraguay, 49% of the population depends on biomass (wood and charcoal) for cooking. Residential biomass burning is a major source of fine particulate matter (PM 2.5) and carbon monoxide (CO) in and around the household environment. In July 2016, cross‐sectional household air pollution sampling was conducted in 80 households in rural Paraguay. Time‐integrated samples (24 hours) of PM 2.5 and continuous CO concentrations were measured in kitchens that used wood, charcoal, liquefied petroleum gas (LPG), or electricity to cook. Qualitative and quantitative household‐level variables were captured using questionnaires. The average PM 2.5 concentration (μg/m3) was higher in kitchens that burned wood (741.7 ± 546.4) and charcoal (107.0 ± 68.6) than in kitchens where LPG (52.3 ± 18.9) or electricity (52.0 ± 14.8) was used. Likewise, the average CO concentration (ppm) was higher in kitchens that used wood (19.4 ± 12.6) and charcoal (7.6 ± 6.5) than in those that used LPG (0.5 ± 0.6) or electricity (0.4 ± 0.6). Multivariable linear regression was conducted to generate predictive models for indoor PM 2.5 and CO concentrations (predicted R 2 = 0.837 and 0.822, respectively). This study provides baseline indoor air quality data for Paraguay and presents a multivariate statistical approach that could be used in future research and intervention programs.

Effect of Stove Technology and Combustion Conditions on Gas and Particulate Emissions from Residential Biomass Combustion.

We have systematically examined the gas and particle phase emissions from seven wood combustion devices. Among total carbon mass emitted (excluding CO2), CO emissions were dominant, together with nonmethane volatile organic compounds (NMVOCs) (10-40%). Automated devices emitted 1-3 orders of magnitude lower CH4 (0.002-0.60 g kg-1 of wood) and NMVOCs (0.01-1 g kg-1 of wood) compared to batch-operated devices (CH4: 0.25-2.80 g kg-1 of wood; NMVOCs: 2.5-19 g kg-1 of wood). 60-90% of the total NMVOCs were emitted in the starting phase of batch-operated devices, except for the first load cycles. Partial-load conditions or deviations from the normal recommended operating conditions, such as use of wet wood/wheat pellets, oxygen rich or deficit conditions, significantly enhanced the emissions. NMVOCs were largely dominated by small carboxylic acids and alcohols, and furans. Despite the large variability in NMVOCs emission strengths, the relative contribution of different classes showed large similarities among different devices and combustion phases. We show that specific improper operating conditions may even for advanced technology not result in the emission reduction of secondary organic aerosol (SOA) forming compounds and thus not reduce the impact of wood combustion on climate and health.