| 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. |
- 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
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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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| 3. |
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| 4. |
- 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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| 5. |
- 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.
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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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| 6. |
- 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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| 7. |
- 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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| 8. |
- 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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| 9. |
- 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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| 10. |
- 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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