Found 9895 publications. Showing page 199 of 396:
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2005
The aim of this pilot-study was to use silicone rubber-based passive samplers to measure novel brominated flame retardants (nBFRs), polybrominated diphenyl ethers (PBDEs) and dechlorane plus (DP) in seawater and air around Longyearbyen as well as investigate the presence of those compounds in sediment and biota (amphipods, Gammarus spp.) nearby Longyearbyen. Passive samplers require no electricity and provide an integrated picture of the levels of the targeted compounds over time. The results were combined with the sampled sediment and Gammarus spp. to assess concentrations in the environment. Out of all substances under study, PBDE-47 and -99, α- and β- tetrabromoethylcyclohexane (TBECH), syn- and anti-DP were detected in all investigated matrices. Freely dissolved water concentrations of ΣDPs (3 pg/L) were in line with recent Arctic studies, while ΣPBDEs (3 pg/L) were comparable to urban rivers in southern Norway. Nevertheless, for some compounds, especially the lighter and most volatile ones, long-range transport is most likely a more important contribution to observed levels than local sources. For other compounds, e.g. PBDEs, local sources might still play a role for the load of contaminants into the surrounding environment. The present study is the first to report a suit of nBFRs and DPs in Arctic benthic fauna. Many of the nBFRs and DPs were detected in sediment and in the amphipods. We recommend further studies with respect to measurements of concentrations over time, and in other species as well, to better understand whether the nBFRs and DPs are common in the marine environment on Svalbard. We recommend that local sources of flame retardants in remote areas receive more attention in the future.
Norsk institutt for vannforskning
2018
NILU has on behalf of the Norwegian Environment Agency determined the concentration of ionic perfluorinated substances (PFASs), including PFOA, in outdoor gear.
Of the investigated 18 items, no PFAS could be detected at all in nine of them. Two samples contained PFOA exceeding the limit of 1 µg/m2. The quality assurance where three replicates of one sample were extracted had a relative standard deviation (RSD) less than 10% for all detected substances except one (PFTrDA). Other quality measures such as recovery calculations and blanks shows that the method used for extraction is suitable for these types of matrices and substances. PFOS was not present in the items investigated, indicating that the textile industry manages to effectively avoid PFOS in their production processes.
2015
NILU has on behalf of the Norwegian Environment Agency determined the concentration of ionic perfluorinated substances (PFASs), including PFOA, in outdoor clothing. Of the investigated 12 items, no PFAS could be detected at all in only 2 of them (sample 8 and 12). Four samples contained PFOA exceeding the limit of 1 µg/m2. The quality assurance where three replicates of one sample were extracted had a relative standard deviation (RSD) less than 10% for all detected substances except one (PFTrDA). Other quality measures such as recovery calculations and blanks shows that the method used for extraction is suitable for these types of matrices and substances. PFOS was not present in the items investigated, indicating that the textile industry manages to effectively avoid PFOS in their production processes.
2014
2007
Understanding the global distribution of atmospheric black carbon (BC) is essential for unveiling its climatic effect. However, there are still large uncertainties regarding the simulation of BC transport due to inadequate information about the removal process. We accessed the wet removal rate of BC in East Asia based on long-term measurements over the 2010–2016 period at three representative background sites (Baengnyeong and Gosan in South Korea and Noto in Japan). The average wet removal rate, represented by transport efficiency (TE), i.e., the fraction of undeposited BC particles during transport, was estimated to be 0.73 in East Asia from 2010 to 2016. According to the relationship between accumulated precipitation along trajectory and TE, the wet removal efficiency was lower in East and North China but higher in South Korea and Japan, implying the importance of the aging process and frequency of exposure to below- and in-cloud scavenging conditions during air mass transport. Moreover, the wet scavenging in winter and summer showed the highest and lowest efficiency, respectively, although the lowest removal efficiency in summer was primarily associated with a reduced BC aging process because the in-cloud scavenging condition was dominant. The average half-life and e-folding lifetime of BC were 2.8 and 7.1 d, respectively, which is similar to previous studies, but those values differed according to the geographical location and meteorological conditions of each site. Next, by comparing TE from the FLEXible PARTicle (FLEXPART) Lagrangian transport model (version 10.4), we diagnosed the scavenging coefficients (s−1) of the below- and in-cloud scavenging scheme implemented in FLEXPART. The overall median TE from FLEXPART (0.91) was overestimated compared to the measured value, implying the underestimation of wet scavenging coefficients in the model simulation. The median of the measured below-cloud scavenging coefficient showed a lower value than that calculated according to FLEXPART scheme by a factor of 1.7. On the other hand, the overall median of the calculated in-cloud scavenging coefficients from the FLEXPART scheme was highly underestimated by 1 order of magnitude, compared to the measured value. From an analysis of artificial neural networks, the convective available potential energy, which is well known as an indicator of vertical instability, should be considered in the in-cloud scavenging process to improve the representative regional difference in BC wet scavenging over East Asia. For the first time, this study suggests an effective and straightforward evaluation method for wet scavenging schemes (both below and in cloud), by introducing TE along with excluding effects from the inaccurate emission inventories.
2020
Investigation of work environment indoor air quality at Invitrogen Dynal AS, Lillestrøm, Norway. NILU OR
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