| 1. |
- Angot, H., et al.
(författare)
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Chemical cycling and deposition of atmospheric mercury in polar regions: review of recent measurements and comparison with models
- 2016
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 16:16, s. 10735-10763
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Tidskriftsartikel (refereegranskat)abstract
- Mercury (Hg) is a worldwide contaminant that can cause adverse health effects to wildlife and humans. While atmospheric modeling traces the link from emissions to deposition of Hg onto environmental surfaces, large uncertainties arise from our incomplete understanding of atmospheric processes (oxidation pathways, deposition, and re-emission). Atmospheric Hg reactivity is exacerbated in high latitudes and there is still much to be learned from polar regions in terms of atmospheric processes. This paper provides a synthesis of the atmospheric Hg monitoring data available in recent years (2011-2015) in the Arctic and in Antarctica along with a comparison of these observations with numerical simulations using four cutting-edge global models. The cycle of atmospheric Hg in the Arctic and in Antarctica presents both similarities and differences. Coastal sites in the two regions are both influenced by springtime atmospheric Hg depletion events and by summertime snowpack re-emission and oceanic evasion of Hg. The cycle of atmospheric Hg differs between the two regions primarily because of their different geography. While Arctic sites are significantly influenced by northern hemispheric Hg emissions especially in winter, coastal Antarctic sites are significantly influenced by the reactivity observed on the East Antarctic ice sheet due to katabatic winds. Based on the comparison of multi-model simulations with observations, this paper discusses whether the processes that affect atmospheric Hg seasonality and inter-annual variability are appropriately represented in the models and identifies research gaps in our understanding of the atmospheric Hg cycling in high latitudes.
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| 2. |
- Földváry, Veronika, et al.
(författare)
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Effect of energy renovation on indoor air quality in multifamily residential buildings in Slovakia
- 2017
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Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323 .- 1873-684X. ; 122, s. 363-372
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Tidskriftsartikel (refereegranskat)abstract
- Buildings are responsible for a substantial portion of the global energy consumption. Most of the multifamily residential buildings built in the 20th century in Central and Eastern Europe do not satisfy the current requirements on energy efficiency. Nationwide measures taken to improve the energy efficiency of these buildings rarely consider their impact on the indoor air quality (IAQ). The objective of the present study was to evaluate the impact of simple energy renovation on IAQ, air exchange rates (AER) and occupant satisfaction in Slovak residential buildings. Three pairs of identical naturally ventilated multifamily residential buildings were examined. One building in each pair was newly renovated, the other was in its original condition. Temperature, relative humidity (RH) and the concentration of carbon dioxide (CO2) were measured in 94 apartments (57%) during one week in the winter. A questionnaire related to perceived air quality, sick building syndrome symptoms and airing habits was filled by the occupants. In a companion experiment, the IAQ was investigated in 20 apartments (50%) of a single residential building before and after its renovation. In this experiment, concentrations of nitrogen dioxide (NO2), formaldehyde and total and individual volatile organic compounds (VOC) were also measured. CO2 concentrations were significantly higher and AERs were lower in the renovated buildings. Formaldehyde concentrations increased after renovation and were positively correlated with CO2 and RH. Energy renovation was associated with lower occupant satisfaction with IAQ. Energy retrofitting efforts should be complemented with improved ventilation in order to avoid adverse effects on IAQ.
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| 3. |
- Langer, Sarka, 1960-, et al.
(författare)
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God innemiljö på svenska fartyg : Kartläggning av innemiljön och förslag på förbättringsåtgärder
- 2015
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Rapport (refereegranskat)abstract
- Miljön ombord på fartyg är viktig för besättningens välbefinnande hälsa ocharbetseffektivitet. Inomhusluftens kvalitet och termisk komfort är viktiga delar avinnemiljön som inte har studerats så mycket på fartyg. Vid långa resor som vararveckor eller månader och kan passera flera klimatzoner finns inget sätt att byta miljöoch ingen utväg från fartyget, och då blir god innemiljön extra viktig eftersom denutgör både arbetsmiljö och boendemiljö (innemiljö). Syftet med denna studie var attkartlägga hur innemiljön på svenska fartyg ser ut, föreslå en enkel övervakningsmetodikför innemiljö samt föreslå förbättringsåtgärder där det behövs.Inom projektet har mätningar gjorts på nio fartyg under elva mätomgångar; ettfartyg undersöktes både vinter och sommar och ett annat fartyg före och efter byte avbränsle. Temperatur och relativ luftfuktighet som beskriver inneklimat, halterna avgasformiga luftföroreningarna koldioxid, kväveoxider, svaveldioxid, flyktiga organiskaämnen, polycykliska aromatiska kolväten, formaldehyd och partiklar (PM10, PM2.5 ochnanopartiklar) mättes i både maskinutrymmen och innemiljöer med diffusiva (passiva)provtagare och direktvisande instrument.Innemiljö och luftkvalitet på de undersökta fartygen var överlag god. Halter avluftföroreningar var under och mycket under både de hygieniska gränsvärdena förarbetsmiljö och rekommenderade riktvärden för god innemiljö. Även om det inteförekom hälsofarliga halter av luftföroreningarna, förekom stora skillnaderna i halterbåde inom och mellan fartyg. Principalkomponentanalys utpekade typ av bränsle somfrämsta indikator för luftkvalitet i maskinutrymmen samt bränslet och fartygensframdrivningssätt för andra innemiljöer på fartyget. Inom projektet har ”Indoor AirPollution Index” för fartyg utvecklats och använts för att rangordna fartygen medavseende på kvalitet av innemiljö.För att ytterligare höja kvaliteten på fartygens innemiljö, arbets- och boendemiljöhar följande förslag på tekniska och organisatoriska åtgärder för befintliga fartyg ochvid nybyggnation identifierats. För befintliga fartyg gäller framförallt kontroll ochunderhåll av ventilationssystem, ordning och reda särskilt i maskinutrymmen samt vidbehov användning av lämplig skyddsutrustning. Vid planering och design av nya fartygbör främst fartygets framdrivningssätt med tillhörande bränsle beaktas, eftersomanvändning av bränslen med bättre kvalitet än tjockolja också innebär förbättringar försåväl luftkvalitet som arbetsmiljö. Andra viktiga aspekter för upprätthållande av godinnemiljö är ventilationsanordning där man effektivt separerar avluftningar frånmaskinutrymmen från friskluftsintag till andra inneutrymmen samt utformning avarbetsplatser och innemiljöer med särskilt tonvikt på ett separat rengöringsrum imaskinutrymmen.
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| 4. |
- Langer, Sarka, 1960, et al.
(författare)
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Indoor Air Quality in energy-efficient buildings in Sweden: comparison with the Swedish residential housing stock and new conventional buildings
- 2018
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Ingår i: Proceedings Indoor Air 2018.
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Konferensbidrag (refereegranskat)abstract
- The aim of this study was to compare the indoor air quality in newly built energy-efficient (passive) buildings in Sweden with the Swedish residential housing stock and new conventional buildings. We have used data from our previous publications to calculate Indoor Environmental Index (IEI), which is an average of Indoor Discomfort Index (IDI) that regards temperature and relative humidity, and Indoor Air Pollution Index (IAPI) that regards concentrations of indoor air pollutants. The passive building had significantly worse IEQ than the housing stock (p <0.05). Further disentangling of the partial indexes revealed that the difference was almost entirely caused by low to very low relative humidity in the passive buildings which affected the IDI. It could be speculated that the low relative humidity is coupled to operation of the ventilation systems and air exchange rates. It might be of importance to review the ventilation requirements in the energy-efficient buildings
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| 5. |
- Langer, Sarka, 1960, et al.
(författare)
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Indoor air quality in passive and conventional new houses in Sweden
- 2015
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Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323 .- 1873-684X. ; 93:P1, s. 92-100
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Tidskriftsartikel (refereegranskat)abstract
- The indoor environment was evaluated in 20 new passive houses and 21 new conventionally built houses during the 2012/2013 and 2013/2014 heating seasons. Temperature, relative humidity (RH), the concentrations of NO2, ozone, formaldehyde, volatile organic compounds (VOC) and viable microbiological flora were measured. Air exchange rates (AER) were estimated from the CO2 concentrations measured in the bedrooms. The median AER was slightly higher in the passive houses than in the conventional ones (0.68 h-1 vs. 0.60 h-1). The median concentrations in the passive and the conventional buildings were 10 and 12μg/m3 for NO2, 9.7 and 11 μg/m3 for ozone, 11 and 16μg/m3 for formaldehyde, and 270 and 150 μg/m3 for TVOC, respectively. Significant differences in the TVOC and formaldehyde concentrations between the two groups of buildings indicated substantial sources of TVOC present in the passive houses, while sources of formaldehyde may have been more pronounced in the conventional houses. In contrast to the passive houses, the indoor microbiological flora indicated possible mould or moisture problems in six (29%) of the conventionally built houses. When compared with the results previously reported for the Swedish housing stock, AERs and NO2 concentrations were significantly higher in both groups of newly built buildings, while formaldehyde concentrations were significantly lower in the passive houses. TVOC concentrations were not significantly different from those reported for the housing stock, although the most abundant individual VOCs were present mostly at higher concentrations in the new buildings.
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| 6. |
- Langer, Sarka, 1960-, et al.
(författare)
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Influence of fuel change on indoor environmental quality on-board a passenger ferry
- 2016
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Ingår i: Proceedings of Indoor Air 2016. - : International Society of Indoor Air Quality and Climate - ISIAQ.
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Konferensbidrag (refereegranskat)abstract
- This study intends to investigate how a change of fuel type from Heavy Fuel Oil to a ultra-low sulphur hybrid oil affects the indoor air quality on board a passenger ferry. The indoor air quality was assessed with respect to the concentration of NO2, SO2 and TVOC, temperature and relative humidity. The efficiency of the ventilation system on the ferry was estimated by measurements of the levels of CO2. The air on-board the ferry was rather dry and in the engine space also warm. CO2 levels exceeded 1 000 ppm extremely seldom, thus indicating well designed and functioning ventilation. The concentrations of the air pollutants were below the guidelines values for good IAQ. They were also much below the occupational limit values. Living and working on-board this ship is comparable to any other indoor environment. The change of the fuel influenced only the concentrations of SO2.
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| 7. |
- Nerentorp, Michelle, 1986, et al.
(författare)
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Mercury flux over West Antarctic Seas during winter, spring and summer
- 2017
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Ingår i: Marine Chemistry. - : Elsevier BV. - 0304-4203 .- 1872-7581. ; 193, s. 44-54
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Tidskriftsartikel (refereegranskat)abstract
- For the first time elemental mercury in air and surface seawater was measured continuously in the remote seas of western Antarctica. A major contributor to atmospheric emissions of the toxic and globally dispersed pollutant mercury is the re-evasion from water surfaces, due to a supersaturation of dissolved gaseous mercury (DGM) in surface water. In this study the degree of saturation and mercury flux at the air-sea surface interface have been estimated from continuous measurements of gaseous elemental mercury (GEM) or total gaseous mercury (TGM) in air, DGM in surface water and meteorological parameters. The measurements were performed during winter and spring (2013) in the Weddell Sea and during summer (2010/2011) in the Bellingshausen, Amundsen and Ross Seas, and show spatial and seasonal variations. The average DGM concentration in surface water in open sea was highest during spring (12 +/- 7pg L-1) and lowest during summer (7 +/- 6.8 pg L-1), resulting in a net evasion of mercury during spring (1.1 +/- 1.6 ng m(-2)h(-1)) and a net deposition during summer (-0.2 +/- 1.3 ng m(-2)h(-1)). In open sea, higher average concentrations of GEM (or TGM) and DGM were found close to the Drake Passage compared to in the Bellingshausen and Weddell Seas. Emission sources from the South American continent, identified with back trajectories, were suggested to explain the observed variations. The yearly mercury evasion from open sea surfaces in the Southern Ocean was estimated to 30 ( -450-1700) tons, using the average (and min and max) flux rates obtained in this study. Higher DGM was measured under sea ice (19-62 pg L-1 compared to in open sea due to a capsuling effect, resulting in a theoretical prevented evasion of 520 (0-3400) tons per year. Diminishing sea ice and higher water temperatures in polar regions could result in increased mercury evasion to the atmosphere. However, the contribution of the Southern Ocean to the global modeled annual emissions of mercury from sea surfaces would probably only be a few percent.
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| 8. |
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| 9. |
- Nerentorp, Michelle, 1986, et al.
(författare)
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Speciation of mercury in the waters of the Weddell, Amundsen and Ross Seas (Southern Ocean)
- 2017
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Ingår i: Marine Chemistry. - : Elsevier BV. - 0304-4203 .- 1872-7581. ; 193, s. 20-33
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Tidskriftsartikel (refereegranskat)abstract
- Despite the distance from large anthropogenic emission sources, toxic mercury is transported via the atmosphere and oceans to the Southern Ocean. Seawater samples were collected at selected stations and were analysed for total mercury (HgT) (8 stations), dissolved gaseous mercury (DGM) (62 stations) and methylmercury (12 stations) during winter (Weddell Sea), spring (Weddell Sea) and summer (Amundsen and Ross Seas) in the Southern Ocean. The HgT distribution in water columns was found to not vary significantly with depth. In the Weddell Sea the average column concentration was higher in spring (2.6 +/- 1.3 pM, 2 stations) than in winter (2.0 +/- 1.0 pM, 6 stations). We hypothesize that the seasonal HgT increase is due to atmospheric deposition of particulate Hg(II) formed during atmospheric mercury depletion events (AMDEs), as well as the addition of inorganic mercury species from melting sea ice and snow. Furthermore, HgT concentrations found in this study were significantly higher than previously measured in the Southern Ocean (Cossa et al., 2011), which was hypothesized to be due to seasonal variations in atmospheric deposition. The average water column DGM concentration in the Weddell Sea was 454 +/- 254 fM in winter and 384 +/- 239 fM in spring. The lowest average DGM concentration was found in summer in the Amundsen and Ross Seas (299 +/- 137 fM). The highest observed concentration in winter was hypothesized to be caused by the larger sea ice coverage, which is known to reduce the evasion of Hg(0) from the sea surface. The average monomethylmercury (MMHg) concentration in the Weddell Sea was 60 +/- 30 fM in winter (6 stations) and 95 +/- 85 fM in spring (2 stations), showing no significant seasonal difference. In the Amundsen and Ross Seas the summer average concentration of MeHg (MMHg and dimethylmercury; DMHg) was 135 +/- 189 fM (4 stations). The highest MeHg concentration was found in modified circumpolar deep water, which is known to have high primary production. 2017 Elsevier B.V. All rights reserved.
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| 10. |
- Salvador, Christian Mark, 1989, et al.
(författare)
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Indoor ozone/human chemistry and ventilation strategies
- 2019
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Ingår i: Indoor Air. - : Hindawi Limited. - 1600-0668 .- 0905-6947. ; 29:6, s. 913-925
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to better understand and quantify the influence of ventilation strategies on occupant-related indoor air chemistry. The oxidation of human skin oil constituents was studied in a continuously ventilated climate chamber at two air exchange rates (1 h-1 and 3 h-1 ) and two initial ozone mixing ratios (30 and 60 ppb). Additional measurements were performed to investigate the effect of intermittent ventilation ("off" followed by "on"). Soiled t-shirts were used to simulate the presence of occupants. A time-of-flight-chemical ionization mass spectrometer (ToF-CIMS) in positive mode using protonated water clusters was used to measure the oxygenated reaction products geranyl acetone, 6-methyl-5-hepten-2-one (6-MHO) and 4-oxopentanal (4-OPA). The measurement data were used in a series of mass balance models accounting for formation and removal processes. Reactions of ozone with squalene occurring on the surface of the t-shirts are mass transport limited; ventilation rate has only a small effect on this surface chemistry. Ozone-squalene reactions on the t-shirts produced gas-phase geranyl acetone, which was subsequently removed almost equally by ventilation and further reaction with ozone. About 70% of gas-phase 6-MHO was produced in surface reactions on the t-shirts, the remainder in secondary gas-phase reactions of ozone with geranyl acetone. 6-MHO was primarily removed by ventilation, while further reaction with ozone was responsible for about a third of its removal. 4-OPA was formed primarily on the surfaces of the shirts (~60%); gas-phase reactions of ozone with geranyl acetone and 6-MHO accounted for ~30% and ~10%, respectively. 4-OPA was removed entirely by ventilation. The results from the intermittent ventilation scenarios showed delayed formation of the reaction products and lower product concentrations compared to continuous ventilation.
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