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Cyclic volatile methyl siloxanes (cVMS) are present in technical applications and personal care products.They are predicted to undergo long-range atmospheric transport, but measurements of cVMS in remote areas remain scarce. An active air sampling method for decamethylcyclopentasiloxane (D5) was further evaluated to include hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), and dodecamethylcyclohexasiloxane (D6). Air samples were collected at the Zeppelin observatory in the remote Arctic (79°N, 12°E) with an average sampling time of 81 ± 23 hours in late summer (AugustOctober) and 25 ± 10 hours in early winter (November -December) 2011. The average concentrations of D5 and D6 in late summer were 0.73 ± 0.31 ng/m 3 and 0.23 ± 0.17 ng/m 3 respectively, and 2.94 ± 0.46 ng/m 3 and 0.45 ± 0.18 ng/m 3 in early winter respectively. Detection of D5 and D6 in the Arctic atmosphere 2 confirms their long range atmospheric transport. The D5 measurements agreed well with predictions from an Eulerian atmospheric chemistry-transport model, and seasonal variability was explained by the seasonality in the OH radical concentrations. These results extend our understanding of the atmospheric fate of D5 to high latitudes, but question the levels of D3 and D4 that have previously been measured at Zeppelin with passive air samplers. IntroductionCyclic volatile methyl siloxanes (cVMS) are high-volume production chemicals used in the production of silicone polymers, in personal care products, and in a range of technical applications. cVMS have been found in both the physical environment and in biota, and have lately become subject to increasing scientific scrutiny by environmental scientists and regulators. 1-3The three congeners, and dodecamethylcyclohexasiloxane (D6) have specifically been the focus of the attention.e.g.1-3Hexamethylcyclotrisiloxane (D3) is an additional member of the group of cVMS. The physical-chemical properties of cVMS differ from many known organic pollutants, as they combine high volatility with extreme hydrophobicity and a considerable affinity for organic phases like octanol (Table S1). 4Volatilization to the atmosphere is the main emission pathway of cVMS to the environment. 1-3 Hence the atmosphere is a key compartment for understanding the environmental fate and behavior of cVMS. Once in the atmosphere, cVMS are predicted to be mainly present in the gas phase, and degradation by reaction with hydroxyl radicals is understood to be the main removal mechanism. 5 The atmospheric half-lives due to reaction with hydroxyl radicals are 20.0 days for D3, 10.3 days for D4, 6.7 days for D5, and 5.8 days for D6 (Table S1). The estimated levels of D5 from these models correspond well with observed atmospheric concentrations in the environment. 9, 11 The predicted seasonality of D5 was a consequence of the strong seasonality of the hydroxyl radical concentrations at high latitudes. During the polar night low levels of hydroxyl radicals slow down the atmospheric degradation of D5 and allow it to ...

In 2005, the European Commission funded the NORMAN project to promote a permanent network of reference laboratories and research centers, including academia, industry, standardization bodies, and NGOs. Since then, NORMAN has (i) facilitated a more rapid and wide-scope exchange of data on the occurrence and effects of contaminants of emerging concern (CECs), (ii) improved data quality and comparability via validation and harmonization of common sampling and measurement methods (chemical and biological), (iii) provided more transparent information and monitoring data on CECs, and (iv) established an independent and competent forum for the technical/scientific debate on issues related to emerging substances. NORMAN plays a significant role as an independent organization at the interface between science and policy, with the advantage of speaking to the European Commission and other public institutions with the “bigger voice” of more than 70 members from 20 countries. This article provides a summary of the first 10 years of the NORMAN network. It takes stock of the work done so far and outlines NORMAN’s vision for a Europe-wide collaboration on CECs and sustainable links from research to policy-making. It contains an overview of the state of play in prioritizing and monitoring emerging substances with reference to several innovative technologies and monitoring approaches. It provides the point of view of the NORMAN network on a burning issue—the regulation of CECs—and presents the positions of various stakeholders in the field (DG ENV, EEA, ECHA, and national agencies) who participated in the NORMAN workshop in October 2016. The main messages and conclusions from the round table discussions are briefly presented.

Passive air samplers (PAS) were deployed at 86 European background sites during summer 2006 in order (i) to gain further insight into spatial patterns of persistent organic pollutants (POPs) in European background air and, (ii) to evaluate PAS as an alternative sampling technique under EMEP (Co-operative programme for monitoring and evaluation of the long-range transmissions of air pollutants in Europe). The samples were analyzed for selected PCBs, HCHs, DDTs, HCB, PAHs and chlordanes, and air concentrations were calculated on the basis of losses of performance reference compounds. Air concentrations of PCBs were generally lowest in more remote areas of northern Europe with elevated levels in more densely populated areas. <i>γ</i>-HCH was found at elevated levels in more central parts of Europe, whereas <i>α</i>-HCH, <i>β</i>-HCH and DDTs showed higher concentrations in the south-eastern part. There was no clear spatial pattern in the concentrations for PAHs, indicative of influence by local sources, rather than long range atmospheric transport (LRAT). HCB was evenly distributed across Europe, while the concentrations of chlordanes were typically low or non-detectable. A comparison of results obtained on the basis of PAS and active air sampling (AAS) illustrated that coordinated PAS campaigns have the potential serve as useful inter-comparison exercises within and across existing monitoring networks. The results also highlighted limitations of the current EMEP measurement network with respect to spatial coverage. We finally adopted an existing Lagrangian transport model (FLEXPART) as recently modified to incorporate key processes relevant for POPs to evaluate potential source regions affecting observed concentrations at selected sites. Using PCB-28 as an example, the model predicted concentrations which agreed within a factor of 3 with PAS measurements for all except 1 out of the 17 sites selected for this analysis

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