| 1. |
- Langer, Sarka, 1960, et al.
(författare)
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Impacts of fuel quality on indoor environment onboard a ship: From policy to practice
- 2020
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Ingår i: Transportation Research Part D-Transport and Environment. - : Elsevier BV. - 1361-9209 .- 1879-2340. ; 83
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Tidskriftsartikel (refereegranskat)abstract
- Environmental considerations, concerning the negative impacts of ship exhaust gases and particles on ambient air quality, are behind the requirements of cleaner marine fuels currently applied in designated emission control areas (ECAs). We investigated the impact of a ship operating on two types of fuel on the indoor air quality onboard. Gaseous and particulate air pollutants were measured in the engine room and the accommodation sections on-board an icebreaker operating first on Heavy Fuel Oil (HFO, 1%-S), and later Marine Diesel Oil (MDO, 0.1%-S). Statistically significant decrease of SO2, NOx, PM2.5 and particle number concentration were observed when the ship was operating on MDO. Due to the higher content of alkylated PAHs in MDO compared to HFO, the concentration of PAHs increased during operation on MDO. The particulate PAHs classified as carcinogens, were similar to or lower in the MDO campaign. Chemical analysis of PM2.5 revealed that the particles consisted mainly of organic carbon and sulfate, although the fraction of metals was quite large in particles from the engine room. Principal Component Analysis of all measured parameters showed a clear difference between HFO and MDO fuel on the indoor environmental quality on-board the ship. This empirical study poses a first example on how environmental policy-making impacts not only the primary target at a global level, but also brings unexpected localized benefits at workplace level. The study emphasizes the need of further investigations on the impact of new marine fuels and technologies on the indoor air environments on board.
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| 2. |
- 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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| 3. |
- Beko, G., et al.
(författare)
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The Indoor Chemical Human Emissions and Reactivity (ICHEAR) project: Overview of experimental methodology and preliminary results
- 2020
-
Ingår i: Indoor Air. - : Hindawi Limited. - 1600-0668 .- 0905-6947. ; 30:6, s. 1213-1228
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Tidskriftsartikel (refereegranskat)abstract
- With the gradual reduction of emissions from building products, emissions from human occupants become more dominant indoors. The impact of human emissions on indoor air quality is inadequately understood. The aim of the Indoor Chemical Human Emissions and Reactivity (ICHEAR) project was to examine the impact on indoor air chemistry of whole-body, exhaled, and dermally emitted human bioeffluents under different conditions comprising human factors (t-shirts/shorts vs long-sleeve shirts/pants; age: teenagers, young adults, and seniors) and a variety of environmental factors (moderate vs high air temperature; low vs high relative humidity; presence vs absence of ozone). A series of human subject experiments were performed in a well-controlled stainless steel climate chamber. State-of-the-art measurement technologies were used to quantify the volatile organic compounds emitted by humans and their total OH reactivity; ammonia, nanoparticle, fluorescent biological aerosol particle (FBAP), and microbial emissions; and skin surface chemistry. This paper presents the design of the project, its methodologies, and preliminary results, comparing identical measurements performed with five groups, each composed of 4 volunteers (2 males and 2 females). The volunteers wore identical laundered new clothes and were asked to use the same set of fragrance-free personal care products. They occupied the ozone-free (<2 ppb) chamber for 3 hours (morning) and then left for a 10-min lunch break. Ozone (target concentration in occupied chamber ~35 ppb) was introduced 10 minutes after the volunteers returned to the chamber, and the measurements continued for another 2.5 hours. Under a given ozone condition, relatively small differences were observed in the steady-state concentrations of geranyl acetone, 6MHO, and 4OPA between the five groups. Larger variability was observed for acetone and isoprene. The absence or presence of ozone significantly influenced the steady-state concentrations of acetone, geranyl acetone, 6MHO, and 4OPA. Results of replicate experiments demonstrate the robustness of the experiments. Higher repeatability was achieved for dermally emitted compounds and their reaction products than for constituents of exhaled breath.
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| 4. |
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| 5. |
- Cabovska, Blanka, 1990, et al.
(författare)
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A study on the relationship between energy performance and IEQ parameters in school buildings
- 2021
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Ingår i: E3S Web of Conferences. - : EDP Sciences. - 2555-0403 .- 2267-1242. ; 246
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Konferensbidrag (refereegranskat)abstract
- Over the last decades, strong focus has been placed on the energy efficiency of buildings; not least school buildings. Energy performance (EP) of buildings is nowadays in principle described by one single indicator based on purchased energy in kWh/year.m2. Another important building performance aspect is the indoor environmental quality. This study's overarching goal is to identify school buildings with a good balance between energy performance and indoor environment. Thus, this paper investigates possible correlations between information given in energy performance certificates (EPCs/e.g. energy use, year of construction, type of ventilation) and measured indoor environmental parameters. The work comprises investigation of approximately 20 school buildings with different ventilation systems in Gothenburg. In-situ investigations of the buildings' properties and ventilation systems were conducted. Indoor environmental parameters were recorded during one week in each classroom. In this paper, indoor temperature, absolute humidity added indoors and CO2 concentration data are compared with the corresponding school's energy performance data and ventilation type. Results suggest that mechanically ventilated buildings have clearer relationships between energy performance, building indicators and measured indoor environment. For buildings such as naturally ventilated, the relationships are usually weak, and the values spread over much wider ranges.
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| 6. |
- Cabovska, Blanka, 1990, et al.
(författare)
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Measured and perceived IEQ under different ventilation strategies in Swedish classrooms
- 2022
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Ingår i: 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022.
-
Konferensbidrag (refereegranskat)abstract
- Indoor environmental quality was assessed in Swedish primary school classrooms grouped into three categories based on the ventilation system: 1) natural or exhaust ventilation, 2) balanced mechanical ventilation systems with constant air volume (CAV), 3) balanced mechanical ventilation systems with variable air volume (VAV). Measurements of NO2, ozone, TVOC, formaldehyde, PM10, and PM2.5 and a questionnaire survey were conducted. The concentrations of pollutants were integrated into Indoor Air Pollution Index allowing the rank comparison of classrooms. Children’s perception scores were calculated based on the questionnaire responses. Naturally ventilated classrooms had higher level of air pollution. No significant differences in pollutant levels were observed between classrooms with CAV and VAV systems. The type of ventilation system affected the subjective assessment of indoor air quality; it was worst in naturally ventilated classrooms.
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| 7. |
- Dalenbäck, Jan-Olof, 1954, et al.
(författare)
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Låg luftfuktighet i svenska bostäder – ett problem?
- 2021
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Ingår i: Energi & miljö. ; 10
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Låg relativ luftfuktighet inomhus är ett problem i många svenska bostäder under uppvärmningssäsongen, mera i lägenheter än i småhus, i hus byggda efter 1985 och i de norra delarna av landet. Ventilation av nya bostäder blir en allt viktigare faktor med avseende på luftfuktigheten inomhus.
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| 8. |
- Domhagen, Fredrik, 1987, et al.
(författare)
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Modelling VOC levels in a new office building using passive sampling, humidity, temperature, and ventilation measurements
- 2023
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Ingår i: Building and Environment. - 0360-1323. ; 238
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Tidskriftsartikel (refereegranskat)abstract
- New buildings often have high initial concentrations of VOCs that, although not necessarily harmful, may be disturbing and cause discomfort among occupants. In new buildings, running the ventilation system continuously and at full rate during the first year is common practice to reduce VOC levels. However, the drawback of such an arbitrary strategy is the risk of over-ventilating with unnecessary heat losses as a consequence. In this article, a new approach, a VOC-passport, is developed where early measurements of VOCs together with a calculation model are used to find an optimized ventilation strategy. The proposed calculation model is tested on two newly built office rooms where VOCs were measured using passive samplers, together with temperature, humidity and ventilation rates, and it shows good agreement with measurements. An example of how a daily ventilation schedule may look like if optimized with the prosed model is presented. The example illustrates that in buildings where VOC levels are allowed to increase periodically, VOC levels can be kept at acceptable levels during occupancy hours if the effective storage capacity is known. The proposed method has a potential to improve the indoor air quality in new buildings without compromising energy efficiency.
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| 9. |
- Domhagen, Fredrik, 1987, et al.
(författare)
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Theoretical Threshold for Estimating the Impact of Ventilation on Materials’ Emissions
- 2024
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Ingår i: Journal of Environmental Science and Technology. - 0013-936X .- 1520-5851. ; 58:11, s. 5058-5067
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Tidskriftsartikel (refereegranskat)abstract
- In new buildings, nonoccupant VOC emissions are initially high but typically decrease within months. Increased ventilation is commonly used to improve indoor air quality, assuming it speeds up VOC off-gassing from materials. However, previous research presents inconsistent results. This review introduces a simplified analytical model to understand the ventilation-emission relationship. By combining factors such as diffusivity, emitting area, and time, the model suggests the existence of a theoretical ventilation threshold beyond which enhanced ventilation has no further influence on emission rates. A threshold of approximately 0.13 L s-1 m-2 emitting area has been found for various VOCs documented in the existing literature, with which the conflicting results are explained. It is also shown that the threshold remains notably consistent across different boundary conditions and model resolutions, indicating its suitability for real-world applications.
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| 10. |
- Fischer, Andreas, et al.
(författare)
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Chemistry and indoor air quality in a multi-storey wooden passive (low energy) building : Formation of peroxyacetyl nitrate
- 2014
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Ingår i: Indoor + Built Environment. - : SAGE Publications Ltd. - 1420-326X .- 1423-0070. ; 23:3, s. 485-496
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Tidskriftsartikel (refereegranskat)abstract
- Indoor air measurements were conducted in one unoccupied apartment of a 'near-zero-energy' residential building with a unique, wooden construction. Ozone, NO2, fine particles and volatile organic compounds, formaldehyde, acetaldehyde and peroxyacetyl nitrate (PAN) were measured under 'as is' conditions and after intentional intervention by adding ozone to simulate an ambient air ozone episode. Undisturbed concentrations were: O 3 5-10 ppb, NO2 5-8 ppb, fine particles 2000-5000 cm -3, formaldehyde 35 ± 5 μg/m3, PAN 0.3 ppb. During intervention, O3 was 50-60 ppb, NO2 15-20 ppb, fine particles 20,000-25,000 cm-3, formaldehyde 44 ± 2 μg/m3 and PAN 0.7-1 ppb. It was shown that chemical reactions had taken place in the indoor air. Ozone-initiated chemistry produced various aldehydes, PAN and, as a direct response to increased ozone concentrations, also fine particles. Calculations made by a simple model of PAN formation showed that an air change rate of around 0.2 h-1 would provide optimum conditions for PAN formation in a setting comparable to that of the investigated apartment. This air change rate is well below the Swedish national minimum of 0.5 h-1. Further, the calculations show that the non-photochemical PAN formation could be a consequence of mixing ozone and nitrogen dioxide with terpenes and acetaldehyde.
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| 11. |
- Fischer, Andreas, et al.
(författare)
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Ozone removal by occupants in a classroom
- 2013
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 81, s. 11-17
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Tidskriftsartikel (refereegranskat)abstract
- Ozone concentrations were measured in a classroom with and without occupants, with the purpose to quantify effects on indoor O3 concentrations. The teacher and 24 11-year old pupils each removed O3 at a rate, first order in O3, corresponding to a rate constant of (2.5±0.6)×10-5s-1 in the present locality and to a deposition velocity of 0.45cms-1. The O3-removal caused by the occupants was approximately 2.6 times larger than that of the available surfaces belonging to the classroom and its furniture. Observation of 6-methyl-5-hepten-2-one and 4-oxopentanal at maximum concentrations of 0.2ppb and 0.7ppb, respectively, suggested squalene from human skin oil as a reactive, ozone-consuming substance. There are indications of a source of 4-oxopentanal in the classroom, even some time after the pupils left for the day. The work presented is important for a proper description of indoor exposure, both to ozone itself and some of its reaction products when trying to quantify relations between exposure and health effects.
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| 12. |
- 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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| 13. |
- Giorgi, R., et al.
(författare)
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Nanoparticles of calcium hydroxide for wood deacidification: Decreasing the emissions of organic acid vapors in church organ environments
- 2009
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Ingår i: Journal of Cultural Heritage. - : Elsevier BV. - 1296-2074 .- 1778-3674. ; 10:2, s. 206-213
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Tidskriftsartikel (refereegranskat)abstract
- Acetic and formic acid vapors emitted from woodwork in historical organs are very important corrosive agents for lead pipes. These acids are slowly released from the wood both during playing and when the pipes are silent. To inhibit this emission process. the wood surface can be modified, by creating a protective layer with alkaline features. However, a coating of wood is not recommended since this could modify the appearance and create a layer not perfectly compatible with the substrate. For this reason, we propose to use some innovative nanotechnology that has been successfully applied for the deacidification of wood samples coming from the Vasa shipwreck. Application of calcium (or magnesium) hydroxide nanoparticles, with sizes ranging from 30-150 nm, allowed a homogeneous distribution of particles through the surface layer of wood simply by soaking (or spraying) it in a alcohohc (or mixed with less polar solvents) dispersion of nanoparticies. Nanoparticles do not modify the wood appearance and distribute randomly within the first layers of wood. The small size of particles accounts for the high reactivity with CO2 from the air, to give the alkaline reserve of carbonates that provide high efficacy in the neutralization of gaseous acids. The emission of volatile organic compounds (VOC) from the treated wood was determined by using an emission test cell, Field and Laboratory Emission Cell (FLEC). The results show that the emissions of acetic acid vapor from nanoparticles treated wood was very low (
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| 14. |
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| 15. |
- 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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| 16. |
- Langer, Sarka, 1960, et al.
(författare)
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I-CUB: 'Indoor Climate-Users-Buildings': Relationship between measured and perceived indoor air quality in dwellings
- 2021
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 2069:1
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Konferensbidrag (refereegranskat)abstract
- Assessment of indoor environmental quality has recently moved to a combined methodology of both measurements and questionnaire surveys. In this study, we have used data from the national survey of the Swedish housing stock, BETSI, conducted in 2007/2008, during the heating season. The study included, among others, measurement of selected indoor air pollutants and an extensive questionnaire survey on the occupants' perception of their dwellings. Measured concentrations of the air pollutants NO2, TVOCs and formaldehyde were aggregated into one Indoor Air Pollution Index (IAPI) on a continuous scale between 0 (excellent Indoor Air Quality; IAQ) and 10 (poor IAQ). The perceived IAQ was assessed by the occupants on a 5-point category scale from very good to very poor. On the entire scale of IAPIs, 92% of the respondents in single-family houses perceived the IAQ as very good or good and 8% as acceptable, while in the apartments, the ratings 'very good' and 'good' accounted for 58%, acceptable for 33% and 9 % for 'poor' and 'very poor', respectively. In both building types, the tendency of IAPIs was shifted to lower values (good IAQ). Analysis of IAPI-medians showed no statistically significant differences between and among the air quality perception ratings.
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| 17. |
- 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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| 18. |
- 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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| 19. |
- 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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| 20. |
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| 21. |
- Langer, Sarka, 1960, et al.
(författare)
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Squalene Depletion in Skin Following Human Exposure to Ozone under Controlled Chamber Conditions
- 2024
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Ingår i: Environmental Science & Technology. - 0013-936X .- 1520-5851. ; 58:15, s. 6693-6703
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Tidskriftsartikel (refereegranskat)abstract
- A major component of human skin oil is squalene, a highly unsaturated hydrocarbon that protects the skin from atmospheric oxidants. Skin oil, and thus squalene, is continuously replenished on the skin surface. Squalene is also quickly consumed through reactions with ozone and other oxidants. This study examined the extent of squalene depletion in the skin oils of the forearm of human volunteers after exposure to ozone in a climate chamber. Temperature, relative humidity (RH), skin coverage by clothing, and participants’ age were varied in a controlled manner. Concentrations of squalene were determined in skin wipe samples collected before and after ozone exposure. Exposures to ozone resulted in statistically significant decreases in post-exposure squalene concentrations compared to pre-exposure squalene concentrations in the skin wipes when squalene concentrations were normalized by concentrations of co-occurring cholesterol but not by co-occurring pyroglutamic acid (PGA). The rate of squalene loss due to ozonolysis was lower than its replenishment on the skin surface. Within the ranges examined, temperature and RH did not significantly affect the difference between normalized squalene levels in post-samples versus pre-samples. Although not statistically significant, skin coverage and age of the volunteers (three young adults, three seniors, and three teenagers) did appear to impact squalene depletion on the skin surfaces.
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| 22. |
- Langer, Sarka, 1960, et al.
(författare)
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Study of the measured and perceived indoor air quality in Swedish school classrooms
- 2020
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 588:3
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Konferensbidrag (refereegranskat)abstract
- The influence of a classroom's indoor environment on children's health, performance and comfort is a concern that receives increasing attention. Many schools experience problems with inadequate indoor air quality and climate. Investigations of the indoor air quality (IAQ) in schools have been often non-systematic, which can lead to costly ad-hoc remediation actions. It is therefore important to develop a holistic approach to the assessment of IAQ in schools. This paper presents a field study on the indoor air quality and thermal environment conditions of elementary schools in Gothenburg, Sweden. The focus of the paper is on the methodology to investigate the IAQ using both objective measurements and subjective assessment of the perceived IAQ. The indoor environmental measurements include indoor air quality and thermal comfort parameters for which guideline values exist. Finally, a questionnaire was developed to evaluate the perception of the classroom's thermal environment and air quality by young children. The paper presents the study protocol and diagnostics approach for IAQ in classrooms. Examples of results from the first 10 investigated classrooms are presented.
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| 23. |
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| 24. |
- Lundgren, Björn, 1941, et al.
(författare)
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Air quality in offices, impact of ventilation rate, ozone and limonene
- 2003
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Ingår i: The 4th international conference on Cold Climat HVAC.
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Konferensbidrag (refereegranskat)abstract
- The objective of this study has been to clarify to what extent ozone (O3) and O3 /limonene in interaction with surface materials has an impact on the indoor air quality in typical low-polluting offices at realistic outdoor air change rates. Three similar offices furnished with the same materials and ventilated with charcoal filtered outdoor air were used in the study. Eight environmental conditions with different realistic combinations of air change rate, O3 and limonene levels were studied. Changes of environmental conditions were performed seven days before the first chemical sampling was performed at set conditions. Decreasing the air change rate from 1.0 to 0.3 h-1 increased the levels of volatile organic compounds in the indoor air. The presence of ozone affected the level and fraction of aldehydes proposing chemical transformations. Adding new materials to the offices at a low air change rate of 0.3 h-1 demonstrated a variable effect depending on the specific air quality in the room. Normal concentration of O3 in indoor environment contributes to chemical transformations even in low-polluted offices.
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| 25. |
- Nerentorp, Michelle, 1986, et al.
(författare)
-
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
-
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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| 26. |
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| 27. |
- 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
-
Ingår i: Marine Chemistry. - : Elsevier BV. - 0304-4203 .- 1872-7581. ; 193, s. 20-33
-
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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| 28. |
- Niklasson, Annika, 1977, et al.
(författare)
-
Air Pollutant Concentrations and Atmospheric Corrosion of Organ Pipes in European Church Environments
- 2008
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Ingår i: Studies in Conservation. - 0039-3630 .- 2047-0584. ; 53:1, s. 24-40
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract: The atmospheric environment inside and outside historical organs in several European regions is reported. In each region, comparisons were made between an instrument suffering organ pipe corrosion and an organ without corrosion problems. Concentrations of acetic acid (ethanoic acid), formic acid (methanoic acid), acetaldehyde (ethanal), formaldehyde (methanal) and other volatile organic compounds in the organ environment were determined using active sampling. Temperature and relative humidity were recorded. In addition, polished metal samples that mimic the material used in the historical organ pipes have been exposed in the organ wind systems for up to 22 months. High concentrations of acetic acid and formic acid vapours are present in the wind system of the corroded organs. Acetaldehyde and formaldehyde are also present in smaller amounts. The main source of acetic acid is the wood from which the wind system is built. In contrast, formic acid is generated in the chruch environment outside the wind system. The results show that the two organic acids play an important role in the atmospheric corrosion of organ pipes. It is suggested that the corrosion of lead pipes in historical organs can be effectively reduced by removing the sources of gaseous acetic acid and formic acid in the wind system and in the chruch environment.
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| 29. |
- Olofsson, Marcus, 1968, et al.
(författare)
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The flux of isoprene from a willow coppice plantation and the effect on local air quality
- 2005
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 39:11, s. 2061-2070
-
Tidskriftsartikel (refereegranskat)abstract
- Isoprene fluxes from a Salix viminalis (willow) plantation in western Sweden were measured using the relaxed eddy accumulation (REA) technique. Fluxes of up to 0.23 mu g m(-2) s(-1) could be observed. A standard emission factor at 303 K and a PAR flux of 1000 mu mol m(-2) s(-1) was estimated to 0.98 mu g m(-2) s(-1) by using the G93 algorithm. The chemistry of an air parcel passing over a willow coppice plantation was investigated utilising a Lagrangian box model in which the measured isoprene fluxes were used as input data. Dispersion after the field was accounted for by a procedure based on the Gaussian plume model. The calculations indicate that, in most cases, the isoprene emissions have a small effect on the local air quality.
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| 30. |
- Psomas, Theofanis, 1983, et al.
(författare)
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Association of Perceived Thermal Comfort and Air Quality with Building- and Occupant-Related Characteristics and Environmental Parameters in Sweden
- 2024
-
Ingår i: Energies. - 1996-1073 .- 1996-1073. ; 17:6
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the article is to analyze the perceived thermal comfort and indoor air quality of occupants and establish associations between these responses and the building-related, occupant-related characteristics, and environmental parameters of residential buildings (a total of 38 variables). The analysis is focused on the Swedish building stock as investigated during the latest national survey in 2008. The analysis covers 1035 residential buildings (multifamily and single-family dwellings). Analytical statistical analysis has been conducted, and logistic regression models have also been developed for the identification of statistically significant covariates. The analysis showed that users in this study demonstrated a significantly positive response to perceived thermal comfort and indoor air quality conditions. Perceived ratings were also highly correlated with each other. As the regression models indicated, the majority of the significant variables were related to the buildings. Nevertheless, this study also underscores the significance of contextual occupant attributes and behaviors as a crucial element influencing the subjective perception of indoor environments. Policymakers, guided by these insights, are encouraged to integrate considerations of occupant attributes into design and urban planning.
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| 31. |
- Psomas, Theofanis, 1983, et al.
(författare)
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Does Gender Matter in Perception of Indoor Environmental Quality? Findings From A Swedish National Survey
- 2022
-
Ingår i: Proceedings of Indoor Air 2022.
-
Konferensbidrag (refereegranskat)abstract
- Individuals perceive indoor spaces differently, and their requirements are subjectively defined. An analysis of the latest national survey of the stock in Sweden is conducted to describe particular aspects of indoor space in relation to gender. The objective of this study is to provide additional evidence to the existing body of knowledge concerning the existence and potential significance of gender differences on indoor environmental quality factors and overall satisfaction. The analysis is conducted in 80 apartments and 296 single-family buildings, both of which are occupied by males and females. The analysis makes use of 5 indoor environmental quality factors, which are quantified using a five-point ordinal scale. For both genders and all factors and variables evaluated, descriptive and advanced statistical analysis is performed. Different confounding variables were also investigated. The findings indicate that different genders evaluate spaces equally in the majority of cases. Additionally, an adaptation mechanism is highlighted.
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| 32. |
- Psomas, Theofanis, 1983, et al.
(författare)
-
Does Gender Matters in Perception of Indoor Environmental Quality? Findings From A Swedish National Survey
- 2022
-
Ingår i: 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022.
-
Konferensbidrag (refereegranskat)abstract
- Individuals perceive indoor spaces differently, and their requirements are subjectively defined. An analysis of the latest national survey of the stock in Sweden was conducted to describe particular aspects of perception of different parameters of indoor space in relation to gender. The objective of this study was to provide additional inputs to the existing body of knowledge concerning the existence or not and potential significance of gender differences on the perception of four different indoor environmental quality factors and overall satisfaction (five-point ordinal scale). The analysis was conducted in 80 apartments and 295 single-family buildings, both of which were occupied by males and females. For both genders and all factors and confounding variables evaluated, descriptive and advanced statistical analysis was performed. The findings indicate that different genders evaluate spaces equally in the majority of cases.
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| 33. |
- Psomas, Theofanis, 1983, et al.
(författare)
-
Indoor humidity of dwellings and association with building characteristics, behaviors and health in a northern climate
- 2021
-
Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323 .- 1873-684X. ; 198
-
Tidskriftsartikel (refereegranskat)abstract
- Data from a nationwide survey on the status of the Swedish residential building stock and indoor air quality was placed in the public domain by the National Board of Housing, Building and Planning of Sweden. The current research investigates the indoor humidity conditions in Swedish residential buildings, single-family houses and apartments, assessing the measurements from the extensive BETSI-survey against adjusted relative humidity levels based on existing norms and Standards. The aim of this study is to investigate associations and correlations between relative humidity levels and multiple building and system characteristics, occupancy patterns and behaviors and health symptoms-complaints. The analysis uses 13 categorical and 9 continuous variables-parameters of the examined dwellings. Analysis shows that low indoor relative humidity is a realistic issue in Swedish dwellings during the heating season. The issue is more prevalent in apartments than single-family houses. In addition, low indoor relative humidity seems to be more extensive in dwellings with higher indoor temperature, smaller volume, higher ventilation rate and frequent airing practices, lower number of occupants, constructed mainly after 1985, in city suburbs and in the northern parts of the country. The developed multinomial logistic regression model may predict very accurately the relative humidity level of the Swedish dwellings, during heating season. This analysis offers additional evidence to the scientific literature for possible correlation of low relative humidity with specific health symptoms, complaints and disturbances.
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| 34. |
- Psomas, Theofanis, 1983, et al.
(författare)
-
Indoor humidity of dwellings in a northern climate
- 2021
-
Ingår i: REHVA Journal. ; 06/2021, s. 37-40
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Low indoor relative humidity has been shown to be an issue in Swedish dwellings and mostly apartments, during the heating season. Present analysis adds to the scientific literature by demonstrating a possible association between low relative humidity and particular health symptoms and complaints.
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| 35. |
- Psomas, Theofanis, 1983, et al.
(författare)
-
Influence of indoor environmental quality and dwelling satisfaction aspects on overall satisfaction: Findings from a Swedish national survey
- 2023
-
Ingår i: E3S Web of Conferences. - 2555-0403 .- 2267-1242. ; 396
-
Konferensbidrag (refereegranskat)abstract
- The objective of this study is to contribute to the discussion on the impact of dwelling satisfaction aspects (size, standard, layout, appearance/aesthetics, well-being, cost and area/neighbourhood) and perceived indoor environmental quality (thermal comfort, air quality, satisfaction with daylight and acoustic comfort) on occupants' overall satisfaction. This article uses data from the Swedish National Survey, BETSI (2007/08). The results are representative of adults living in multi-family and single-family buildings (1597 responses/955 buildings). Linear regression models are developed with overall satisfaction as the dependent variable and independent variables: seven satisfaction aspects, four indoor environmental quality factors and all combined (eleven). An all-model explained 54.7% of the results (best performed). All the retained variables (except satisfaction with daylight) are statistically significant predictors. Satisfaction with well-being (b = 0.286) and satisfaction with dwellings' standard (b = 0.188) have the greatest effect on overall satisfaction. The model with the IEQ aspects explained only 35.5% of the results. Reliability statistics (Cronbach's alpha) and confirmatory factor analysis have been implemented in the dataset. The responses can be categorized into two clusters. The two clusters were significantly different across living duration, dwelling type, age category and tenure status.
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| 36. |
- Psomas, Theofanis, 1983, et al.
(författare)
-
Low Relative Humidity, a Problem or Not in Swedish Dwellings?
- 2021
-
Ingår i: INDOOR ENVIRONMENTAL QUALITY PERFORMANCE APPROACHES (IAQ 2020), PT 1. - 9781955516013
-
Konferensbidrag (refereegranskat)abstract
- The current research investigates the relative humidity conditions in Swedish dwellings (678 apartments and single-family houses), comparing measurements from the 2007/2008 BETSI-survey (heating season), with the recommendations of the EN 16798:2019. Analysis shows that 61.4% of the apartments and 29.8% of the single-family houses belong to Cats. 3 and 4, which correspond to moderate and low level of expectation, respectively (mainly due to low relative humidity). The problem is bigger for dwellings with smaller volume, higher ventilation rate and indoor temperature, constructed mainly after 1985.
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| 37. |
- Salvador, Christian Mark, 1989, et al.
(författare)
-
Indoor ozone/human chemistry and ventilation strategies
- 2019
-
Ingår i: Indoor Air. - : Hindawi Limited. - 1600-0668 .- 0905-6947. ; 29:6, s. 913-925
-
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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| 38. |
- Sasic Kalagasidis, Angela, 1968, et al.
(författare)
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Early-stage concentrations of formaldehydes and TVOCs in a new low-energy building
- 2020
-
Ingår i: E3S Web of Conferences. - : EDP Sciences. - 2555-0403 .- 2267-1242. ; 172
-
Konferensbidrag (refereegranskat)abstract
- This paper deals with temporary discomfort caused by characteristic odours from new objects and materials in office buildings. Earlier investigations have shown that increased ventilation rates in residential buildings decrease the indoor concentrations of non-occupant-related indoor air pollutants such as aldehydes and total volatile organic compounds (TVOCs). To study how this basic principle for the control of indoor air pollutants complies with a demand-controlled ventilation, which is an important energy efficiency measure in modern office buildings, the authors have designed and conducted a serial of field tests. Concentrations of aldehydes and TVOCs have been measured in two newly built and identical meeting rooms under different ventilation strategies. By overruling the existing demand control ventilation and increasing gradually but differently the air change rates in the rooms over a course of five weeks, the concentration of formaldehyde and TVOCs decreased for about 75 % from the initial values of ca. 45 μg/m3 and ca. 400 μg/m3 respectively. Impact of door openings on instantaneous indoor air quality has been studied in parallel by combining CO2 measurements and numerical simulations. Good agreement was found between the simulated and measured CO2 concentrations and thereby the door opening model was verified.
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| 39. |
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| 40. |
- Shannigrahi, Ardhendu Sekhar, 1965, et al.
(författare)
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n-Alkanoic monocarboxylic acid concentrations in urban and rural aerosols : Seasonal dependence and major sources
- 2014
-
Ingår i: Atmospheric research. - : Elsevier BV. - 0169-8095 .- 1873-2895. ; 143, s. 228-237
-
Tidskriftsartikel (refereegranskat)abstract
- We report new data on the abundance and distribution of n-monocarboxylic acids (n-MCAs) in fine- and coarse-mode aerosols in rural and urban areas of Sweden, and determine their possible sources. Overall, C6–C16n-MCAs accounted for ~ 0.5–1.2% of the total PM10 (particulate matter ≤ 10 μm) mass. In general, the C12–C16 fraction was the most abundant (> 75%), with the exception of wintertime samples from a rural site, where C6–C11 acids accounted for 65% of the total C6–C16n-MCA mass. Positive matrix factorization analysis revealed four major sources of n-MCAs: traffic emissions, wood combustion, microbial activity, and a fourth factor that was dominated by semi-volatile n-MCAs.Traffic emissions were important in the urban environment in both seasons and at the rural site during winters, and were a major source of C9–C11 acids. Wood combustion was a significant source at urban sites during the winter and also to some extent at the rural site in both seasons. This is consistent with the use of wood for domestic heating but may also be related to meat cooking. Thus, during the winter, traffic, wood combustion and microbial activity were all important sources in the urban environment, while traffic was the dominant source at the rural site. During the summer, there was considerable day-to-day variation in n-MCA concentrations but microbial activity was the dominant source. The semi-volatile low molecular weight C6–C8 acids accounted for a small (~ 5–10%) fraction of the total mass of n-MCAs. This factor is unlikely to be linked to a single source and its influence instead reflects the partitioning of these compounds between the gas and particle phases. This would explain their greater contribution during the winter.
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| 41. |
- Shi, Bingbing, 1983, et al.
(författare)
-
Intermediate air filters for general ventilation applications: An experimental evaluation of various filtration efficiency expressions
- 2013
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Ingår i: Aerosol Science and Technology. - : Informa UK Limited. - 0278-6826 .- 1521-7388. ; 47:5, s. 488-498
-
Tidskriftsartikel (refereegranskat)abstract
- Neither the European standard nor the US standard for classification of intermediate class filters comprises testing of filter performance with respect to ultrafine particles (UFPs) or particles of the most penetrating size (MPPS). This could turn out to be a major lack in classification standards since UFPs have been pointed out as a serious health hazard. In this study, fractional efficiencies of eight new full-scale bag filters and twenty-three new filter medium samples were determined. The influence of air velocity and aerosol type was investigated, and correlations between efficiencies for UFPs (EFUFPs), MPPS-sized particles (EFMPPS) and 0.4 μm-sized particles (EF0.4μm) were established. The tested bag filters were challenged by four aerosol types: a neutralized atomized oil aerosol, the same oil aerosol but non-neutralized, a non-neutralized thermally generated oil smoke, and a “natural” indoor aerosol. The tests were carried out at different air velocities through the filter medium, ranging between 0.08 m/s and 0.22 m/s. The relationships that were observed between EFUFPs, EFMPPS, and EF0.4μm appeared to be linear within the observed filtration efficiency ranges. These relationships were similar regardless of the test aerosol type used, but somewhat different for glass fiber filters than for charged synthetic filters. Generally, EFMPPS was 10–20% lower than EF0.4μm. The influence of air velocity variations on the size resolved efficiency was determined. The glass fiber filters showed practically the same fractional efficiencies regardless of whether the test aerosol was neutralized or not. However, the charged synthetic filters showed substantially lower efficiencies when tested with the non-neutralized aerosol compared to the case when the aerosol was neutralized.
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| 42. |
- Shi, Bingbing, 1983, et al.
(författare)
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Removal of ultrafine particles and particles of the most penetrating size by new intermediate class filters
- 2011
-
Ingår i: Proceedings of the Indoor Air 2011 Conference, Austin, TX, USA, 6 pages.
-
Konferensbidrag (refereegranskat)abstract
- Twenty-three new filter samples, including three different medium types, were tested in a small scale test-rig using a Scanning Mobility Particle Sizer (SMPS). The filtration efficiencies for ultrafine particles (UFPs) and particles of the most penetrating particle size (MPPS) were determined. The filters were of class F5-F9 according to the European filter standard, which roughly corresponds to MERV9-MERV15 according to the US-standard. The filters were challenged by the indoor aerosol prevailing in the laboratory. Additional tests were made using an oil aerosol. With the indoor aerosol, charged synthetic filters showed substantially higher MPPS efficiencies than glass fiber and uncharged synthetic filters of the same class did. With the oil aerosol, the different filter media types, belonging to the same filter class, showed similar efficiencies. The oil aerosol drastically reduced, or eliminated, the electrostatic filtration mechanism. For example F7 and F8 filters not influenced by electrostatic mechanisms typically showed 40% and 50% removal of MPPS particles respectively.
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| 43. |
- Strandberg, Bo, 1960, et al.
(författare)
-
The Use of Polyurethane Foam (PUF) Passive Air Samplers in Exposure Studies to PAHs in Swedish Seafarers
- 2022
-
Ingår i: Polycyclic Aromatic Compounds. - : Informa UK Limited. - 1040-6638 .- 1563-5333. ; 42:2, s. 448-459
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to test the usefulness of polyurethane foam (PUF) passive air samplers as stationary, and, for the first time, as personal samplers for one week's sampling period of polycyclic aromatic hydrocarbons (PAHs) in occupational air. Routine monitoring of workplace exposure is commonly performed with active sampling. However, active samplers can sometimes be unsuitable; e.g., it is difficult to make time-integrated measurements, longer than one day, and they can be noisy and obstructive. Indoor air quality on ships is an important aspect of the environment which has not been studied extensively on ships. For seafarers, good indoor air quality becomes particularly important as the ship represents both a working and living environment. In this study, measurements were carried out on two occasions on two different ships, at different workplaces, and for various personnel categories. On each ship, measurements were performed before and after a change of the type of fuel that the ships were operating on. We found a considerable wide range of PAHs exposure levels for the various workplaces and personnel categories on the ships. The stationary measurements, sum 32 PAHs, ranged from 33-39,000 ng m(-3) and the personal exposure measurements ranged from 61-8,400 ng m(-3). The results point to that the content of PAHs in the fuel can affect the indoor air environment on the entire ship. Further, the results demonstrate that the PUF sampler can serve as a simple and usable screening tool for estimating and tracking point sources of PAHs in micro-environments. Moreover, this study contributes to increased knowledge of exposure to and sources of PAHs for seafarers.
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| 44. |
- Teli, Despoina, 1980, et al.
(författare)
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Drivers of winter indoor temperatures in Swedish dwellings: Investigating the tails of the distribution
- 2021
-
Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323 .- 1873-684X. ; 202
-
Tidskriftsartikel (refereegranskat)abstract
- Residential indoor climate is a key factor for occupant comfort, health and wellbeing, while also affecting the buildings' energy demand. A strong focus has been traditionally placed on low winter indoor temperatures in dwellings due to their considerable health impacts. However, there is a trend towards high and stable indoor temperatures, which also have significant implications. This paper investigates the drivers of winter indoor temperatures by analysing the following three metrics of measured temperatures in a sample of 1039 Swedish dwellings: a) level, through the sample dwellings’ standardised indoor temperatures at 5 °C outdoor temperature, b) daily variation, through the standard deviation of the indoor temperature and c) shape, using daily indoor temperature profiles derived from cluster analysis. The study explores the association of these metrics to building-, dwelling- and occupant-related parameters. The analysis shows that 80% of the standardised indoor temperatures were above 21 °C, with one third of the latter being above 23 °C, while 82% of dwellings had constant temperatures throughout the day. High winter indoor temperatures were more evident in middle-placed apartments in multi-family buildings connected to district heating and in better insulated single-family houses. High temperatures were also associated with experiencing draft from windows, too warm conditions in winter and difficulty to control the indoor temperature, but not with the overall thermal comfort assessment which was very positive in both the high and low temperature tails. Long-term adaptation effects, established norms and comfort expectations are discussed as important confounding factors in the development of residential indoor temperatures.
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| 45. |
- Teli, Despoina, 1980, et al.
(författare)
-
Indoor climate and air quality: does occupants’ assessment reflect the measured conditions?
- 2022
-
Ingår i: 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022.
-
Konferensbidrag (refereegranskat)abstract
- The analysis in this paper is based on data from a building stock investigation conducted in the winter season of 2007/2008. The study focused on the technical status, indoor environmental quality and energy use in the Swedish housing stock. A sub-sample of 86 single-family houses with matching pairs of indoor climate and air quality measurements and questionnaire responses are examined in more detail, to investigate the relationship between indoor climate and air quality with occupants’ perception. The results show that indoor air temperatures outside the recommended values are still perceived positively by the occupants. Perception of dryness was assessed by the occupants positively, regardless the measured relative humidity in their homes. Perception of air quality overall agreed with measured conditions, although this may be related to the investigated sample. The paper discusses methodological and substantive limitations that may have led to these findings and aspects to consider when dealing with survey design and data.
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| 46. |
- Teli, Despoina, 1980, et al.
(författare)
-
Indoor Temperature Variations in Swedish Households: Implications for Thermal Comfort
- 2018
-
Ingår i: Cold Climate HVAC 2018. CCC 2018. Springer Proceedings in Energy. - Cham : Springer International Publishing. - 9783030006617 ; , s. 835-845
-
Konferensbidrag (refereegranskat)abstract
- Everyday thermal environments affect people’s comfort and wellbeing, with extreme conditions affecting human health. A strong focus on avoiding the extremes along with the introduction of tight thermal comfort criteria over the years has led to design strategies and behaviors that promote thermally stable indoor environments. However, recent research has shown that indoor temperature variation has significant health benefits, e.g. it could help tackle diabetes and obesity. These findings suggest that it is important to investigate not just the average temperature levels in households but also their distribution and variation over different periods. In Sweden, indoor temperatures are considered to be on average high and constant due to a combination of the heating provision mechanism and the high building standards compared to other countries. This paper investigates the temperature distributions in Swedish households using detailed 15-minute indoor air temperature measurements from the 2008 BETSI-survey, provided by the Swedish National Board of Housing, Building and Planning (Boverket). Approximately two million measurements from 1306 households taken during two-week periods in winter 2007/08 are used in this investigation. Indoor temperature variation is investigated in two levels: (i) over the 2-week monitoring period and (ii) within-day. Results showed a considerable range in average dwelling temperatures of 9 K, highlighting a substantial variability between homes in heating temperature and most likely in thermal comfort preferences. Regardless the different temperature levels, the majority of dwellings maintain stable thermal conditions, as demonstrated from the very low temperature variations found. Differences in daily temperature patterns were also observed.
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| 47. |
- Teli, Despoina, 1980, et al.
(författare)
-
Using data-driven indoor temperature setpoints in energy simulations of existing buildings: A Swedish case study
- 2023
-
Ingår i: IOP Conference Series: Earth and Environmental Science. - 1755-1307 .- 1755-1315. ; 1196:1
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Konferensbidrag (refereegranskat)abstract
- Building energy analyses of large samples or building stocks commonly use National building stock temperature averages in their calculations. However, such averages may not be representative of the conditions in a specific building type and may mask meaningful information found at building or dwelling level. Analysis of indoor temperature data from the Swedish housing stock showed that 25% out of approximately 1000 dwellings were heated at a temperature ≥23°C in wintertime. If indoor temperature management is considered as a potential energy saving measure for the building stock it may be more effective to explore implementation in these specific dwellings, than considering average temperature reduction across the entire building stock. This however would require more detailed input data on indoor temperatures. Would such an approach be worthwhile? To answer this question, two types of Swedish multifamily buildings were simulated with i) business-as-usual scenarios and ii) setpoints based on indoor temperature data from the last Swedish National Survey. The study shows that using data-driven, dwelling-specific indoor temperatures could lead to more effective decision making on indoor temperature management, targeting buildings and dwellings where temperature reduction would most likely cause the least compromise on comfort. Such a strategy however should be complementary to a wider plan of improved energy efficiency measures across the building stock.
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| 48. |
- Vasquez, Natalia Giraldo, et al.
(författare)
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Ventilation strategies and children's perception of the indoor environment in Swedish primary school classrooms
- 2023
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Ingår i: Building and Environment. - 0360-1323. ; 240
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Tidskriftsartikel (refereegranskat)abstract
- This study explored the relationship between children's subjective perception of indoor environmental quality in classrooms, measured thermal and air quality factors, and the type of ventilation. Environmental data were collected in 45 classrooms in 23 primary schools in Sweden during the heating season. Schools with three types of ventilation were recruited: natural or exhaust ventilation (category A), balanced supply-exhaust with constant air volume (category B), and balanced supply-exhaust with variable air volume or demand-controlled ventilation (category C). 796 children (8–14 years of age) answered a questionnaire about their perception of the classroom's indoor environment. Based on ten dichotomous questions, the children's overall perceptions and subjective well-being was scored (“Individual score”) from worst (0) to best (10) perception. A Perception Index (PI) was calculated as the arithmetic mean of the Individual scores from all children in a given classroom. We did not find statistically significant differences in the Individual scores or PI between the three ventilation categories. However, the PI of classrooms with ventilation category A, which also had lower ventilation rates and higher concentrations of pollutants, was noticeably lower than that in classrooms with ventilation category B or C. Correlations between the PI and most of the measured environmental parameters or the individual questions about perception were weak and not significant. The PI may be improved by including factors not considered in this study, such as those related to acoustic and lighting conditions.
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| 49. |
- Örtengren, Ulf, 1959, et al.
(författare)
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Influence of pH and time on organic substance release from a model dental composite: a fluorescence spectrophotometry and gas chromatography/mass spectrometry analysis.
- 2004
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Ingår i: European journal of oral sciences. - : Wiley. - 0909-8836 .- 1600-0722. ; 112:6, s. 530-7
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Tidskriftsartikel (refereegranskat)abstract
- In this study we assessed the influence of pH and time on the degradation and elution of organic substances from the composite resin material, Z-100. To accomplish this, fluorescence spectrophotometry was evaluated as an appropriate technique for the identification of six organic substances (methacrylic acid, methyl methacrylate, hydroquinone, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate and 4,4'-isopropylidenediphenol) that were eluted from resin composite material stored for 24 h or 6 months at pH 4.0, 6.0 or 8.0. In addition, complementary analyses (solid-phase microextraction/gas chromatography/mass spectrometry) were carried out to identify and quantify the substances. The main substances leached from the resin composite were methacrylic acid, triethylene glycol dimethacrylate and hydroquinone. It was concluded that fluorescence spectrophotometry seems to be a suitable, non-destructive technique for the qualitative analysis of eluted organic components. Critical combinations of time and pH allowed the elution of several organic substances, predominantly methacrylic acid, triethylene glycol dimethacrylate and hydroquinone, from the model resin composite, Z-100.
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| 50. |
- Österman, Cecilia, 1971-, et al.
(författare)
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Bedömning av arbetsmiljö och säkerhet vid val av fartygsbränslen
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Sjöfarten genomgår för närvarande en omfattande omställning för att minska miljöstörande utsläpp från fartyg. Det sker i huvudsak genom tre olika strategier: konvertering av fartygets motorer för att kunna köra på renare bränsle; helt eller delvis övergång till alternativa energibärare, exempelvis genom elektrifiering; eller genom att installera utrustning för rening av avgaserna, exempelvis skrubbersystem. Dessa åtgärder har minskat utsläppen av försurande svavelutsläpp till omgivningsluften men också av andra luftföroreningar, som partiklar, sot och polyaromatiska kolväten (PAH). Men även om fokus för sjöfartens energiomställning huvudsakligen syftar till att minska utsläppen av luftföroreningar till omgivningsluften, har tidigare studier indikerat att fartygsbränslet även kan ha inverkan på fartygens innemiljö och arbetsmiljö och därmed sjöpersonalens hälsa, säkerhet och välbefinnande.I korthet har syftet med detta projekt varit att systematiskt och ur ett helhetsperspektiv undersöka hur olika driftsalternativ påverkar fartygs innemiljö, arbetsmiljö och säkerhet. Bedömningen omfattar även besättningens personliga exponering för farliga luftföroreningar, i vilken utsträckning deras arbetsuppgifter förändras, samt hur denna påverkan kan beskrivas i arbetsmiljöekonomiska termer. Undersökningar har genomförts på sex olika fartyg.Fartygens innemiljö har undersökts med stationära mätningar av temperatur, luftfuktighet (RF) och koldioxid (CO2), samt halten av luftföroreningarna svaveldioxid (SO2), kväveoxider (NOx = NO + NO2), totalhalt flyktiga organiska ämnen (TVOC) och polycykliska aromatiska kolväten (PAH). Besättningens personliga exponering undersöktes för NO2, TVOC och PAH. Provtagningen gjordes med passiva diffusionsprovtagare som burits i andningszonen av totalt 50 personer på fem av fartygen. En enkät med frågor om upplevd luftkvalitet på arbetsplatsen och i hytten har besvarats av 94 personer. Resultaten har jämförts med relevanta lagstadgade gränsvärden, hälsobaserade riktlinjer, samt med resultat från tidigare mätkampanjer.Resultaten visar att samtliga halter från såväl stationära mätningar som personburen exponering låg mycket under Arbetsmiljöverkets hygieniska gränsvärden. De flesta halter var även lägre än de hälsobaserade riktlinjer som används som jämförelse.3Maskinutrymmen var ofta mera kontaminerade än andra utrymmen ombord, särskilt med avseende på ämnen avdunstade från bränslen och smörjmedel, eller ämnen från motoravgaser. En förhöjd exponering observerades för maskinmanskap i samband med arbetsuppgifter kopplade till fartygens bränslesystem. I övrigt sågs ingen skillnad i personlig exponering mellan befäl och manskap. Resultaten från enkätundersökningen av personalens upplevelse av arbetsmiljö och innemiljö visar att luftkvaliteten ombord generellt upplevdes som god, både vad gäller arbetsplatserna och i de egna hytterna. Hälsorelaterat kumulativt riskindex kunde inte särskilja de primära bränsletypen. Bedömningen av hälsoaspekten i fartygens innemiljö blir otydlig framför allt på grund av användningen av sekundära bränslen. För fartygen med samma eller liknande funktion var batteridrift, lågsvavligt bränslet och LNG bättre alternativ än tjockolja och MDO. En mycket klar förbättring av innemiljön och besättningens exponering, utifrån det hälsorelaterade indexet, kunde påvisas för de fartyg som bytt bränsle till ett renare alternativ. Alla driftalternativ har egenskaper och risker som kräver särskild hänsyn vid utformning av system, rutiner för drift och underhåll, utbildning och träning, samt nödrutiner. Riskbedömningar behöver därför omfatta både risker för allvarlig skada, ohälsa och att arbetsuppgifter kan utföras på ett tillfredsställande sätt. Samtliga flytande bränslen är att betrakta som giftiga utom naturgas. Metanol är akut giftigt, både vid förtäring och hudexponering. Däremot är det inte cancerframkallande.Eftersom samtliga fartyg i undersökningen fortsatt har system för att köra på petroleum-baserade bränslen har få arbetsuppgifter försvunnit helt och inget av driftalternativen innebär minskade direkta kostnader för personal. Däremot ses skillnader i hur ofta olika arbetsmoment behöver utföras och under vilka förhållanden. Med renare bränslen följer ett minskat behov av rengöring av komponenter och maskinutrymmen. Det innebär i sin tur en minskad exponering för farliga ämnen och att arbetstid kan läggas på andra uppgifter som upplevs mer värdeskapande. Eftersom många arbeten ombord innebär en samtidig exponering för flera kända riskfaktorer krävs en helhetssyn som omfattar preventiva åtgärder och ett långsiktigt hälsofrämjande arbete. Det är inte tillräckligt att rikta åtgärder endast mot de värsta exponeringarna. Sammanfattningsvis visar resultaten av denna kartläggning att det inte finns en enda bästa lösning som passar alla fartyg, oavsett typ, last eller trad. Oavsett vilket driftsalternativ som väljs innebär det högre kostnader än den konventionella lösningen med förbränningsmotorer på tung brännolja. Troligen kommer sjöfartens energiomställning att behöva ekonomiska incitament och harmoniserade regelverk för att påskynda utvecklingen av lösningar som är hållbara ur ett livscykelperspektiv och samtidigt kommersiellt gångbara. För ett hållbart och attraktivt arbetsliv i en hållbar sjöfart behöver framtidens lösningar även säkerställa att drift och underhåll kan utföras på ett tillfredsställande sätt med så liten risk för ohälsa och olycksfall som möjligt.
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