Fant 9747 publikasjoner. Viser side 374 av 390:
Update on Polar Ozone: Past, Present, and Future. WMO Global Ozone Research and Monitoring Project, Report No. 55
2014
Updated trends for atmospheric mercury in the Arctic: 1995–2018
The Arctic region forms a unique environment with specific physical, chemical, and biological processes affecting mercury (Hg) cycles and limited anthropogenic Hg sources. However, historic global emissions and long range atmospheric transport has led to elevated Hg in Arctic wildlife and waterways. Continuous atmospheric Hg measurements, spanning 20 years, and increased monitoring sites has allowed a more comprehensive understanding of how Arctic atmospheric mercury is changing over time. Time-series trend analysis of TGM (Total Gaseous Mercury) in air was performed from 10 circumpolar air monitoring stations, comprising of high-Arctic, and sub-Arctic sites. GOM (gaseous oxidised mercury) and PHg (particulate bound mercury) measurements were also available at 2 high-Arctic sites. Seasonal mean TGM for sub-Arctic sites were lowest during fall ranging from 1.1 ng m−3 Hyytiälä to 1.3 ng m−3, Little Fox Lake. Mean TGM concentrations at high-Arctic sites showed the greatest variability, with highest daily means in spring ranging between 4.2 ng m−3 at Amderma and 2.4 ng m−3 at Zeppelin, largely driven by local chemistry. Annual TGM trend analysis was negative for 8 of the 10 sites. High-Arctic seasonal TGM trends saw smallest decline during summer. Fall trends ranged from −0.8% to −2.6% yr−1. Across the sub-Arctic sites spring showed the largest significant decreases, ranging between −7.7% to −0.36% yr−1, while fall generally had no significant trends. High-Arctic speciation of GOM and PHg at Alert and Zeppelin showed that the timing and composition of atmospheric mercury deposition events are shifting. Alert GOM trends are increasing throughout the year, while PHg trends decreased or not significant. Zeppelin saw the opposite, moving towards increasing PHg and decreasing GOM. Atmospheric mercury trends over the last 20 years indicate that Hg concentrations are decreasing across the Arctic, though not uniformly. This is potentially driven by environmental change, such as plant productivity and sea ice dynamics.
Elsevier
2022
Updating historical global inventories of anthropogenic mercury emissions to air. AMAP Technical Report, no. 3, 2010
2010
2022
Uptake and effects of 2, 4, 6 - trinitrotoluene (TNT) in juvenile Atlantic salmon (Salmo salar)
Elsevier
2018
2013
Uptake of organic contaminants from car tire microplastics in Arctic marine species
Car tire particles represent an important environmental challenge that is difficult to alleviate. The particles stem from abrasion during driving, so-called tire wear particles (TWPs), down-cycled end-oflife tire crumb rubber (CR) granulate that is used widely as low-cost infill on sports fields, or degradation products from discarded tires. The material contains a variety of additives and chemical residues from the manufacturing process, including metals, especially high concentrations of zinc, polycyclic aromatic hydrocarbons (PAHs), and benzothiazoles (Halsband et al., 2020), but also paraphenylenediaminesb (PPDs) and numerous other organic chemicals. In urbanized areas, TWPs arebemitted from vehicles, while CR is dispersed from artificial sports fields and other urban surfaces to the environment. This suggests that particulate and chemical runoff to coastal systems is likely and represents a route of exposure to marine organisms. In the Arctic, even small human settlements can represent local sources of TWPs and CR granulate emissions. Here, we summarize recent experimental studies examining the responses of different marine animals to tire rubber particle or leachate exposure, focusing on toxicity and the uptake kinetics of tire-related organic chemicals into organs and tissues. We present data for different ecological functional groups relevant to the Arctic, including copepods, shrimps, crabs, and fish, representing different body sizes, marine habitats, and feeding modes, and thus varying exposure scenarios. Our findings from GC-HRMS SIM chromatography demonstrate that several tire additives are taken up into tissues. Although the available data indicates many tire-derived organic chemicals do not seem to bioaccumulate, mapping of tire rubber particle and chemical distributions in Arctic coastal systems, dose-response toxicity testing and risk assessments of environmental concentrations are warranted, also with a view to potential trophic transfer within the Arctic marine food chain.
2023
2013
Urban air pollution 2000-2015. Results from monitoring and modeling in Oslo and Trondheim. NILU OR
Ecotraffic har på oppdrag fra Statoil undersøkt forventede endringer i utslipp fra vegtrafikk ved overgang til biodrivstoff. Denne rapporten oppsummerer trender fra måle- og modellresultater for luftkvalitet i Trondheim og Oslo fra 2000 til 2015, den siste tredjedelen av perioden bare med modellresultater. Noen mulige effekter ved introduksjon av biodrivstoff er undersøkt. For konsentrasjon av partikler vil introduksjon av biodrivstoff bidra til en reduksjon av nivået. For NOX og NO2 vil imidlertid biodrivstoff kunne ha en ugunstig effekt og føre til økt konsentrasjonsnivå.
2010
2004
2001
2017
2013
2023
2005