The Global Monitoring Plan (GMP) according to article 16 of the Stockholm Convention on Persistent Organic Pollutants (POPs) requires that POP laboratories must be capable – at any time – to analyse ...samples for POPs within a variation of ±25%. Based on this target error of 25%, a statistical model using z-scores was applied to assess the performance of analytical laboratories for POPs and a number of matrices. Since the second round of these ‘Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants (POPs)’, carried out in 2012/2013, perfluoroalkyl substances (PFASs) have been included into the proficiency tests. The third round was carried out in 2016/2017. The test materials included test solutions of PFASs analytical standards, the abiotic matrices sediment, air (extract) and water and the biotic matrices fish, human milk and human plasma. The number of laboratories submitting results for PFASs remained quite stable (IL2 = 27 laboratories; IL3 = 29), but there was broader geographic distribution observed in IL3: in addition to the laboratories from Asia and the Western Europe/other groups, two laboratories from Africa participated, two from Central-Eastern Europe and one from the Latin American/Caribbean region.
Considering that PFASs were introduced for the first time in round 2, the results were good to reasonable compared to those of a number of other POPs included in the same study. However, it shall also be mentioned that for some matrices and PFASs, the number of laboratories submitting results was too small and the results too scattered to derive a consensus value. This was especially true for the PFOS precursor compounds and the air matrix. Also, laboratories struggle with the analysis of the branched PFOS isomers.
These interlaboratory assessments on PFASs gave promising results and demonstrated the importance of proficiency tests in an international environment to generate trust in laboratory results. The need to participate regularly in such intercomparison assessments is highlighted. The results show the current level of PFAS analysis, which varies by laboratory and by matrix rather than per geographic region.
•Two rounds of interlaboratory assessments for PFASs gave excellent to reasonable performance.•Worldwide, almost 30 PFASs laboratories regularly participate in proficiency tests.•Excellent results for L-PFOS in test solutions, sediment and human milk.•Not much experience recognized on determination of branched PFOS.•Air samples still a problem for PFOS precursors.
Soils contaminated with per- and polyfluoroalkyl substances (PFASs) are an important source for impacting drinking water delivery systems and surface water bodies world-wide, posing an urgent risk to ...human health and environmental quality. However, few treatment techniques have been tested for PFAS-contaminated soil hotspots. This study investigated the possibility of thermal desorption as a possible technique to remediate soils contaminated with multiple PFASs. Two fortified soils (summation.sub.9 PFAS almost equal to 4 mg kg.sup.-1) and one field-contaminated soil (summation.sub.9 PFAS almost equal to 0.025 mg kg.sup.-1) were subjected to a 75-min thermal treatment at temperatures ranging from 150 to 550#176;C. Soil concentrations of PFASs showed a significant decrease at 350#176;C, with the summation.sub.9 PFAS concentration decreasing by, on average, 43% and 79% in the fortified and field contaminated soils, respectively. At 450#176;C, >99% of PFASs were removed from the fortified soils, while at 550#176;C the fraction removed ranged between 71 and 99% for the field contaminated soil. In the field contaminated soil, PFAS classes with functional groups of sulfonates (PFSAs) and sulfonamides (FOSAs) showed higher removal than the perfluoroalkyl carboxylates (PFCAs). Thus thermal desorption has the potential to remove a wide variety of PFASs from soil, although more studies are needed to investigate the cost-effectiveness, creation of transformation products, and air-phase vacuum filtration techniques.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The long-term time trends of atmospheric pollutants at eight Arctic monitoring stations are reported. The work was conducted under the Arctic Monitoring and Assessment Programme (AMAP) of the Arctic ...Council. The monitoring stations were: Alert, Canada; Zeppelin, Svalbard; Stórhöfði, Iceland; Pallas, Finland; Andøya, Norway; Villum Research Station, Greenland; Tiksi and Amderma, Russia. Persistent organic pollutants (POPs) such as α- and γ-hexachlorocyclohexane (HCH), polychlorinated biphenyls (PCBs), α-endosulfan, chlordane, dichlorodiphenyltrichloroethane (DDT) and polybrominated diphenyl ethers (PBDEs) showed declining trends in air at all stations. However, hexachlorobenzene (HCB), one of the initial twelve POPs listed in the Stockholm Convention in 2004, showed either increasing or non-changing trends at the stations. Many POPs demonstrated seasonality but the patterns were not consistent among the chemicals and stations. Some chemicals showed winter minimum and summer maximum concentrations at one station but not another, and vice versa. The ratios of chlordane isomers and DDT species showed that they were aged residues. Time trends of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) were showing decreasing concentrations at Alert, Zeppelin and Andøya. The Chemicals of Emerging Arctic Concern (CEAC) were either showing stable or increasing trends. These include methoxychlor, perfluorohexane sulfonic acid (PFHxS), 6:2 fluorotelomer alcohol, and C9-C11 perfluorocarboxylic acids (PFCAs). We have demonstrated the importance of monitoring CEAC before they are being regulated because model calculations to predict their transport mechanisms and fate cannot be made due to the lack of emission inventories. We should maintain long-term monitoring programmes with consistent data quality in order to evaluate the effectiveness of chemical control efforts taken by countries worldwide.
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•Time trends of organic pollutants in air were analyzed at eight Arctic sites.•Many Stockholm Convention-regulated chemicals are decreasing or not changing in air.•Seasonal cycles of pollutants showed variability with location of the sampling site.•Levels of emerging chemicals were scattered with non-changing or increasing trends.
•A two-part train traffic emission factors model is built.•The model could predict the PM10 level at a railway station platform in a tunnel.•The two terms in this model are brake effect term and ...accumulative effect term.•The relationship between PM10 and train frequency in both terms is linear.•The two terms equally affect the PM10 level at train station platforms.
In 2017 a new railway tunnel containing two stations opened in Stockholm, Sweden. A series of field measurements were carried out on the platforms in this tunnel before and after it was opened for normal traffic. These measurements were used to investigate the contribution of airborne particle emissions from wear processes to total train emissions. This field data was used to develop a two-part train traffic emission factor model for PM10. The two parts are the accumulative effect term (relating to operating distance such as wheel-rail contact and overhead electric line sliding contact) and a brake effect term (relating to the number of braking operations such as brake disc and brake pad contact). The results show that operating a single trial train at a higher than normal frequency on an otherwise empty platform increases the platform particulate concentration until the concentration reaches a steady value. The model suggests that brake emissions account for about 50% of the total emissions measured in the tunnels.
This timely book, which is based on the results of the Integration of the Second Generation in Europe survey, presents the disturbing results of a recent study in Stockholm that examines the ...experiences of residents descended from Turkish migrants. Focusing on three different ethno-national groups—Turks, Kurds, and Syriacs—the contributors explore issues such as identity, family situation, language use, education, labor market experiences, and employment. The essays highlight the varying degrees of success each group has achieved in the process of trying to integrate into Stockholm society. The book also examines the widespread discrimination and exclusion the descendants of migrants experience. As a whole, this volume shows a troubling picture of the obstacles faced by immigrant new societies.
Urban geography could be characterized by analysing the patterns that describe the flows of people and goods. Measuring urban structures is essential for supporting an evidence-based spatial planning ...policy. The objective of this study is to examine how the spatial–temporal distribution of public transport passenger flow could be used to reveal urban structure dynamics. A methodology to identify and classify centres based on mobility data was applied to Metropolitan Stockholm in Sweden using multi-modal public transport passenger flows. Stockholm is known for its long-term monocentric planning with a dominant central core and radial public transport system. Strategic nodes along its radial public transport system have been a focus for development of sub-centres. Although the regional planning policy embraces a shift towards a polycentric planning policy, the results indicate that this has not been realized insofar.
•A methodology for identifying urban clusters based on public transport flows•A methodology for classifying urban clusters based on temporal mobility profiles•Unravelling the urban structure dynamics of metropolitan Stockholm•Stockholm has not yet transformed into a polycentric or multi-centric structure.
Persistent organic pollutants (POPs) are of global concern due to their negative effects on humans and the environment, and globally are regulated in the Stockholm Convention on POPs. The present ...study had Mongolia as a partner in a multinational project funded and coordinated by the United Nations Environment Programme with the aim to monitor POPs in core media, including air (with passive samplers), water, and a pooled human milk sample. Project implementation and all sampling were undertaken by the Institute of Chemistry and Chemical Technology whereas POPs analysis was performed in laboratories abroad. Brominated and chlorinated POPs were analyzed by gas chromatography/mass spectrometry, perfluorinated compounds (PFAS) and isomers of hexabromocyclododecane (HBCD) by liquid chromatography/mass spectrometry. The monitoring results found very low concentrations of PFAS in river water. Toxic equivalents (TEQs) for PCDD/PCDF were low in air and in human samples but had a relatively higher presence of TEQ from dioxin-like PCB than in other countries. With respect to chlorinated POPs, drins, chlordanes, DDTs, heptachlors, and mirex were very low in air and human milk. Elevated levels were found for polychlorinated biphenyls (PCB), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), pentachlorobenzene (PeCBz), and HBCD in air with extreme values for hexachlorobutadiene. The abundance of HCHs and HCB was confirmed in the human milk sample but not for PCB, PeCBz or HBCD. Short-chain chlorinated paraffins (170 ng/g lipid) were the highest among all human milk pools. It is recommended to continue POPs monitoring in the future, especially for those where high concentrations were found.
•Mongolia's first contribution to the global monitoring plan of POPs.•Legacy industrial POPs (PCB, HCB, HCH) were more abundant than organochlorine pesticides.•Perfluorinated POPs were very low in water, and comparatively low in air and humans.•High concentrations of SCCP in human milk and HCBD in air need confirmation.
•Sweden has a great biogas potential that could contribute to replacement of fossil fuels.•Signs of a stagnating development after 15 years of stable expansion.•Biogas actors in Stockholm County ...provide insights regarding the development.•Uncertainties about demand and policy cause hesitation, public organizations key actors.•Will electricity complement or replace biogas?
Sweden has ambitions to phase out fossil fuels and significantly increase the share of biofuels it uses. This article focuses on Stockholm County and biogas, with the aim to increase the knowledge about regional preconditions. Biogas-related actors have been interviewed, focusing on the demand side. Biogas solutions play an essential role, especially regarding bus transports and taxis. Long-term development has created well-functioning socio-technical systems involving collaboration. However, uncertainties about demand and policy cause hesitation and signs of stagnating development.
Public organizations are key actors regarding renewables. For example, Stockholm Public Transport procures biogas matching the production at municipal wastewater treatment plants, the state-owned company Swedavia steers via a queuing system for taxis, and the municipalities have shifted to “environmental cars”.
There is a large interest in electric vehicles, which is expected to increase significantly, partially due to suggested national policy support. The future role of biogas will be affected by how such an expansion comes about. There might be a risk of electricity replacing biogas, making it more challenging to reach a fossil-free vehicle fleet. Policy issues strongly influence the development. The environmental car definition is of importance, but its limited focus fails to account for several different types of relevant effects. The dynamic policy landscape with uncertainties about decision makers’ views on biogas seems to be one important reason behind the decreased pace of development. A national, long-term strategy is missing. Both the European Union and Sweden have high ambitions regarding a bio-based and circular economy, which should favor biogas solutions.
Ongoing urban expansion may degrade natural resources, ecosystems, and the services they provide to human societies, e.g., through land use and water changes and feedbacks. In order to control and ...minimize such negative impacts of urbanization, best practices for sustainable urban development must be identified, supported, and reinforced. To accomplish this, assessment methods and tools need to consider the couplings and feedbacks between social and ecological systems, as the basis for improving the planning and management of urban development. Collaborative efforts by academics, urban planners, and other relevant actors are also essential in this context. This will require relevant methods and tools for testing and projecting scenarios of coupled social-ecological system (CSES) behavior, changes, and feedbacks, in support of sustainable development of growing cities. This paper presents a CSES modeling approach that can provide such support, by coupling socio-economically driven land use changes and associated hydrological changes. The paper exemplifies and tests the applicability of this approach for a concrete case study with relevant data availability, the Tyresån catchment in Stockholm County, Sweden. Results show that model integration in the approach can reveal impacts of urbanization on hydrological and water resource, and the implications and feedbacks for urban societies and ecosystems. The CSES approach introduces new model challenges, but holds promise for improved model support towards sustainable urban development.
•We present a tool for planning support by coupling social-ecological systems.•The tool helps identify and understand change drivers and feedbacks.•The tool was successfully tested in an urban-hydrological system in Sweden.•Model coupling can support better decisions for sustainable development.
This article probes the duality of marginalisation yet omnipresence of walking in cities. Using innovation in traffic light technology in Stockholm as a case study, it seeks to understand the ...attempts to regulate and safeguard pedestrians in the first decade after the Second World War. The article argues that traffic lights and other technologies were part of experts’ efforts to make urban mobility “systemic”, linking streets with vehicles and road users with the aim to optimize traffic. In doing so, their approach to pedestrian control was ambiguous. On the one hand, experts wanted to fit pedestrians into the emerging city traffic system: make them predictable, while also seeing to their safety. On the other hand, their designs and corresponding legislation often accepted pedestrian sovereignty, and walking was not systemised in Stockholm during the period studied here.
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