Residential Wood Burning and Vehicle Emissions as Major Sources of Environmentally Persistent Free Radicals in Fairbanks, Alaska.

Environmentally persistent free radicals (EPFRs) play an important role in aerosol effects on air quality and public health, but their atmospheric abundance and sources are poorly understood. We measured EPFRs contained in PM2.5 collected in Fairbanks, Alaska, in winter 2022. We find that EPFR concentrations were enhanced during surface-based inversion and correlate strongly with incomplete combustion markers, including carbon monoxide and elemental carbon (R2 > 0.75). EPFRs exhibit moderately good correlations with PAHs, biomass burning organic aerosols, and potassium (R2 > 0.4). We also observe strong correlations of EPFRs with hydrocarbon-like organic aerosols, Fe and Ti (R2 > 0.6), and single-particle mass spectrometry measurements reveal internal mixing of PAHs, with potassium and iron. These results suggest that residential wood burning and vehicle tailpipes are major sources of EPFRs and nontailpipe emissions, such as brake wear and road dust, may contribute to the stabilization of EPFRs. Exposure to the observed EPFR concentrations (18 ± 12 pmol m-3) would be equivalent to smoking ∼0.4-1 cigarette daily. Very strong correlations (R2 > 0.8) of EPFR with hydroxyl radical formation in surrogate lung fluid indicate that exposure to EPFRs may induce oxidative stress in the human respiratory tract.

Noninvasive Fuel Flow Monitoring System for Vented Fuel Oil Heaters.

In this work, we present hardware and firmware design and preliminary testing results for a noninvasive device for measuring fuel oil consumption in fuel oil vented heaters. Fuel oil vented heaters are a popular space heating method in northern climates. Monitoring fuel consumption is useful to understanding residential daily and seasonal heating patterns and understanding the thermal characteristics of buildings. The device is a pump monitoring apparatus (PuMA) that employs a magnetoresistive sensor to monitor the activity of solenoid driven positive displacement pumps, which are commonly used in fuel oil vented heaters. PuMA accuracy for calculating fuel oil consumption was evaluated in a lab setting and found to vary up to 7% from the measured consumption value during testing. This variance will be explored more in field testing.

Association between cooking fuel and folate insufficiency among pregnant women in Northern China.

This study explored whether using a coal or biomass stove for cooking was associated with a greater risk of red blood cell (RBC) folate insufficiency among pregnant women compared to using clean energy. A researcher-designed questionnaire was used to collect information on exposure-related factors and confounding factors. RBC folate concentrations were examined by microbiological assay. Binary logistic regression analysis was used to identify factors related to RBC folate insufficiency. The use of coal or firewood for cooking was associated with an increased risk of RBC folate insufficiency (<906 nmol/L) compared to gas. In subgroup analyses, associations between the use of polluting cooking fuels and folate insufficiency were positive for both urban and rural residents and statistically significant for rural women. Efforts to promote the use of clean energy and proper ventilation, especially in rural areas, are recommended to improve the health of pregnant women and their offspring.

Energy poverty influences urban outdoor air pollution levels during COVID-19 lockdown in south-central Chile.

The effect of COVID-19 lockdowns on ambient air pollution levels in urban south-central Chile, where outdoor air pollution primarily originates indoors from wood burning for heating, may differ from trends in cities where transportation and industrial emission sources dominate. This quasi-experimental study compared hourly fine (PM2.5) and coarse (PM10) particulate matter measurements from six air monitors (three beta attenuation monitors; three low-cost sensors) in commercial and low/middle-income residential areas of Temuco, Chile between 2019 and 2020. The potential impact of varying annual meterological conditions on air quality was also assessed. During COVID-19 lockdown, average monthly ambient PM2.5 concentrations in a commercial and middle-income residential neighborhood of Temuco were up to 50% higher (from 12 to 18 µg/m3) and 59% higher (from 22 to 35 µg/m3) than 2019 levels, respectively. Conversely, PM2.5 levels decreased by up to 52% (from 43 to 21 µg/m3) in low-income areas. The fine fraction of PM10 in April 2020 was 48% higher than in April 2017-2019 (from 50% to 74%) in a commercial area. These changes did not appear to result from meterological differences between years. During COVID-19 lockdown, higher outdoor PM2.5 pollution from wood heating existed in more affluent areas of Temuco, while PM2.5 concentrations declined among poorer households refraining from wood heating. To reduce air pollution and energy poverty in south-central Chile, affordability of clean heating fuels (e.g. electricity) should be a policy priority.

Impact of heating season on the soil pollution in Kirklareli province of Turkey.

This study, conducted in Kirklareli city centre, aims to analyse heavy metal pollution in soil due to heating season (HS). For this purpose, 86 soil samples were taken from the identified locations with a depth of 0-10 cm before (43 samples in September 2015) and after (43 samples in April 2016) HS. Besides, 10 soil samples (5 samples before the HS and 5 samples after the HS) were collected to determine the contamination level from 50 cm deep soil as a reference value. Collected soil samples were tested for Zn, Cu, Co, Pb, Ni, Cr, Hg and Cd metal concentration as well as pH values. Both seasons showed similar results in the soil samples in terms of mean metal concentration levels in the following order: Zn > Cr > Ni > Cu > Co > Pb > Cd > Hg. The mean concentration values of all the metals were higher after the HS than the levels before the HS. The study also attempted to determine anthropogenic metal input. An increase was observed in anthropogenic metal input after the HS when compared with before HS. Geoaccumulation index (Igeo) was employed to determine the degree of metal pollution, while the contamination factor (Cf) was used to determine the level of contamination. The overall degree of pollution was identified using the degree of contamination (Cd) and modified degree of contamination (mCd). Besides, the positive matrix factorization (PMF) receptor model used to find the possible sources of heavy metals in soil samples.

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.

Comparison of organic compounds in char and soot from the combustion of biomass in boilers of various emission classes.

The combustion of biomass in boilers of emission classes 2 and 3 produces deposits in the form of char and soot inside the combustion chamber. Char and soot differ in content of elemental carbon (EC) and organic carbon (OC) as well as in the content of organic compounds. Deposits from boilers of emission class 2 contain higher amounts of OC and EC than those from boilers of emission class 3. The only exception is deposits formed by the combustion of briquettes from hardwood in boilers of emission class 3 that contained approximately by up to 60 percent higher amount of OC and by approx. 100% more EC than deposits from combustion in boilers of emission class 2. Deposits identified as char are characterized by dominant organic compounds derived from thermic degradation of cellulose, lignin, phytosterols, terpenes, their alteration products, and aromatic hydrocarbons. Deposits identified as soot have dominant PAHs, compounds containing oxygen (furans, benzofurans, phenols) and compounds containing aliphatic nitrogen (benzonitrile). Char from boilers of emission class 2 contains approx. by 80% more alkanes and cycloalkanes, by 80% more nitriles, by 50% more carboxyl acids, by 230% more anhydrosaccharides, phytosterols and by 180% more PAHs. These differences can be utilized for identification of burned fuel.

Inferring room-level use of domestic space heating from room temperature and humidity measurements using a deep, dilated convolutional network.

Time series data about when heating is on and off in homes can be useful for research on building energy use and occupant behaviours, particularly data at room level and at a granularity of minutes. Direct methods which measure the temperature of radiators and other heaters can be effective at producing such data, but are expensive. Indirect methods, which infer heating on- and off-times from ambient room temperature data, can be cheaper but produce more error-prone data. Existing indirect methods have however utilised relatively simple prediction algorithms based on changes in ambient temperature between closely adjacent time points. In the method presented here we have implemented several refinements to this approach:•An Artificial Neural Network algorithm is applied to the prediction task: a deep, dilated convolutional network.•A wider range of input features is utilised to base predictions upon: ambient room temperature and humidity, and external temperature and humidity.•Predictions for each time point are based on data from a wider, 600-minute, time window.•We evaluate model performance on a dataset with 10 min granularity and achieve mean precision and recall during the heating season of >=0.74 for individual time points, and >=0.82 for full heating events, outperforming comparator methods.

European residential wood pellet trade and prices dataset.

The European market for wood pellets used in small-scale heating systems has been expanding significantly over the past decade. For an analysis of market efficiency in the Journal Energy with the title "The European wood pellets for heating market - price developments, trade and market efficiency" wood pellet prices have been collected as well as trade flows downloaded for the trade relations between Austria, Germany, Italy and France. Only since January 2012 monthly wood pellet trade data is published by Eurostat. This, now monthly expanding data-set provides new opportunities for analysing the development of this important renewable energy commodity. Furthermore, national wood pellet prices published by national authorities and interest groups are improving in quality in the recent years. The collection and combination of these data-sets are a chance for novel econometric analysis. This paper presents valuable tools and processes to acquire and prepare this data and connects to a data and code repository for downloading the resources described in this and the related Journal Energy publication.

A comparative life cycle assessment of centralised and decentralised wood pellets production for residential heating.

Recently, wood pellets have become a reliable and clean renewable fuel for residential heating, replacing fossil fuels and reducing greenhouse gas emissions. Wood pellets are normally produced in industrial pellet plants (centralised production), but decentralised small-scale local production also occurs. This study applies Life Cycle Assessment (LCA) to quantify and compare the environmental profile of one centralised and two decentralised alternatives for wood pellet production for residential heating in Portugal: (1) industrial wood pellets production (centralised), (2) wood pellets production at sawmills (decentralised) and (3) wood pellets production at households (decentralised). System boundaries include the stages of forest management, wood pellet production, wood pellet distribution and wood pellet energetic conversion. The impact results show that industrial pellet production ranks as the worst alternative, while pellet production at households has the best environmental profile for all the impact categories under study. However, the environmental impacts of pellet production at the sawmill do not differ greatly from those of the pellet production at households; they are 14 to 16% higher for global warming and fossil resources scarcity and 0.3 to 3% higher for the remaining impact categories. The worst environmental performance of the industrial pellet production alternative is mainly due to high electricity and diesel consumption during wood pellet production and the use of logging residues to generate heat for drying biomass feedstock. A sensitivity analysis was performed to evaluate the influence of changing the distance travelled during the transport of packed pellets to stores and sawdust to households. The results show changes in the environmental performance ranking, highlighting that for short distances, both decentralised alternatives can be more sustainable from an environmental perspective than the centralised alternative, but for larger distances, the pellet production at households should be avoided.

Life cycle assessment of wood pellets and wood split logs for residential heating.

Wood-fuelled systems are commonly used all over the world for residential heating, and recently wood pellets have been replacing traditional firewood. This article presents an environmental life cycle assessment of five wood-based combustion systems for residential heating: i) a pellet stove using maritime pine pellets; a wood stove using ii) eucalyptus (Eucalyptus globulus Labill.) and iii) maritime pine (Pinus pinaster Ait.) split logs; and a fireplace using iv) eucalyptus and v) maritime pine split logs. The functional unit is 1 MJ of thermal energy for residential heating. System boundaries include four stages: (1) forest management; (2) pellet and wood split log production; (3) distribution; and (4) thermal energy generation. Environmental impacts were calculated for seven impact categories from the ReCiPe 2016 midpoint method, and a sensitivity analysis was performed using the Product Environmental Footprint (PEF) life cycle impact assessment method and modifying the distances travelled. Of the five heating systems analysed, the fireplace presents the worst performance for all the impact categories with the exception of freshwater eutrophication and marine eutrophication, when maritime pine split logs are burned in the fireplace. Comparing the pellet stove with the wood stove, neither system is better for all the impact categories analysed. Regarding sensitivity analysis, the use of an alternative characterisation method leads to similar trends in the results in comparison with those obtained from the ReCiPe method, while changes in transport distances do not affect the total impacts to a large extent.

Evaluation of impact of residential heating on air quality of megacity Istanbul by CMAQ.

Residential heating is one of the major sectors that contribute to emissions of harmful air pollutants in urban areas. In Istanbul, local sources are the main contributors of particulate matter levels. To quantify the contributions of residential heating sector to ambient particulate matter concentrations, we have developed an up to date spatially distributed high-resolution emissions inventory based on local activity data. The air quality simulations were conducted using the CMAQ (version 5.2). Our study results showed that our high-resolution emissions of the residential heating sector significantly improve the spatial distribution and concentration of air pollutants (SO2, PM10, PM2.5) for Istanbul. Air quality model simulations with our high-resolution emissions underestimated PM10 concentrations throughout the study episode on average by only 4.16% with a mean bias of 2.23 µg/m-3 while base inventory underestimated PM10 concentrations on average by 35.1% with a mean bias of 18.91 µg/m-3. Results show that our spatially distributed high-resolution emissions inventory produces more realistic results for Istanbul during wintertime when residential heating has the most influence on local air pollution.

Association Between Health Symptoms and Particulate Matter from Traffic and Residential Heating - Results from RHINE III in Tartu.

BACKGROUND: Traffic and residential heating are the main sources of particulate matter (PM) in Northern Europe. Wood is widely used for residential heating and vehicle numbers are increasing. Besides traffic exhaust, studded tires produce road dust that is the main source of traffic-related PM10. Several studies have associated total PM mass with health symptoms; however there has been little research on the effects of PM from specific sources. OBJECTIVE: To study the health effects resulting from traffic and local heating PM. METHODS: Data on respiratory and cardiac diseases were collected within the framework of RHINE III (2011/2012) in Tartu, Estonia. Respondents' geocoded home addresses were mapped in ArcGIS and linked with local heating-related PM2.5, traffic-related PM10 and total PM2.5 concentrations. Association between self-reported health and PM was assessed using multiple logistic regression analysis. RESULTS: The annual mean modelled exposure for local heating PM2.5 was 2.3 µg/m3, for traffic PM10 3.3 µg/m3 and for all sources PM2.5 5.6 µg/m3. We found relationship between traffic induced PM10 as well as all sources induced PM2.5 with cardiac disease, OR=1.45 (95% CI 1.06-1.93) and 1.42 (95% CI 1.02-1.95), respectively. However, we did not find any significant association between residential heating induced particles and self-reported health symptoms. People with longer and better confirmed exposure period were also significantly associated with traffic induced PM10, all sources induced PM2.5 and cardiac diseases. CONCLUSION: Traffic-related PM10 and all sources induced PM2.5 associated with cardiac disease; whereas residential heating induced particles did not.

The determination of polycyclic aromatic hydrocarbons in the urine of non-smoking Polish pregnant women.

The aim of this study was to characterize the PAH exposure level among the non-smoking Polish pregnant women and to identify the minimal set of PAH metabolites that specifically reflect environmental PAH exposure. The study population consisted of 210 non-smoking pregnant women. The urine sample was used for analysis of the following PAH metabolites: 1-, 2-, 3-, 4-, 9-hydroxyphenanthrene (1-, 2-, 3-, 4-, 9-OH-PHE), 1-hydroxypyrene (1-OH-PYR), 1,6+1,8-dihydroxypyrene (DI-OH-PYR), phenanthrene trans-1,2-dihydrodiol (PHE-1,2-diol) and phenanthrene trans-9,10-dihydrodiol (PHE-9,10-diol). The analysis of all the biomarkers was performed by gas chromatography-mass spectrometry after their derivatization. The mean PAH metabolite concentrations were in the range of 0.15 (± 0.2) µg/g creatinine for 9-OH-PHE to 5.9 (± 10.6) µg/g creatinine for PHE-9,10-diol. Women living in the city center had higher concentrations of 1-OH-PHE (ß=0.6; p=0.04), 3-OH-PHE (ß=0.8; p=0.02), 9-OH-PHE (ß=0.9; p=0.02), and DI-OH-PYR (ß=1.0; p=0.006) than those living outside the city center. The usage of coal for residential heating was a significant predictor of all PAH metabolites except for 9-OH-PHE (p=0.1) and PHE-9,10-diol (p=0.08). With the increasing cotinine levels we observed a significant increase in the concentrations of the following PAH metabolites: 3-OH-PHE (ß=0.2; p=0.007), 4-OH-PHE (ß=0.3; p=0.002), PHE-1,2-diol (ß=0.3; p<0.001), 1-OH-PYR (ß=0.2; p=0.01). High-density housing, usage of coal for residential heating, cotinine level in saliva, season of urine collection and distance from the place of residence to the main road explained 26% of the variance of 3-OH-PHE and 21% of the variance of 1-OH-PHE. 2-OH-PHE, 3-OH-PHE, 9-OH-PHE and PHE-9,10-diol are sufficient to predict environmental PAH exposure. The urinary PAH biomarker levels found in this study indicate that non-smoking Polish pregnant women suffer from a higher PAH exposure than those in other western countries. This higher PAH exposure level probably poses a significant health risk for the newborns and young children and will require further attention in the future.