Towards the next generation of air quality monitoring: Persistent organic pollutants (POPs)

Hung, H.; MacLeod, M.; Guardans, R.; Scheringer, M.; Barra, R.; Harner, T.; Zhang, G.
1970 | Atmos Environ | (in press)

Persistent Organic Pollutants (POPs) are global pollutants that can migrate over long distances and bioaccumulate through food webs, posing health risks to wildlife and humans. Multilateral environmental agreements, such as the Stockholm Convention on POPs, were enacted to identify POPs and establish the conditions to control their release, production and use. A Global Monitoring Plan was initiated under the Stockholm Convention calling for POP monitoring in air as a core medium; however long temporal trends (>10 years) of atmospheric POPs are only available at a few selected sites. Spatial coverage of air monitoring for POPs has recently significantly improved with the introduction and advancement of passive air samplers. Here, we review the status of air monitoring and modeling activities and note major uncertainties in data comparability, deficiencies of air monitoring and modeling in urban and alpine areas, and lack of emission inventories for most POPs. A vision for an internationally-integrated strategic monitoring plan is proposed which could provide consistent and comparable monitoring data for POPs supported and supplemented by global and regional transport models. Key recommendations include developing expertise in all aspects of air monitoring to ensure data comparability and consistency; partnering with existing air quality and meteorological networks to leverage synergies; facilitating data sharing with international data archives; and expanding spatial coverage with passive air samplers. Enhancing research on the stability of particle-bound chemicals is needed to assess exposure and deposition in urban areas, and to elucidate long-range transport. Conducting targeted measurement campaigns in specific source areas would enhance regional models which can be extrapolated to similar regions to estimate emissions. Ultimately, reverse-modeling combined with air measurements can be used to derive “emission” as an indicator to assess environmental performance with respect to POPs on the country, region, or global level.

Response of Gammarus pulex and Baetis rhodani to springtime acidepisodes in humic brooks

1970 | Sci. Total Environ. | 463-464 (690-699)

While chronic acidification of water bodies has been steadily decreasing, episodic acidification continues to affect stream biology by temporarily decreasing pH and mobilizing aluminum. These events are becoming more common as climate change renders more frequent and intense storms and flooding. Throughout Scandinavia the effects of acidification have been mitigated by liming since the 1980ies, but remediation efforts can now be reduced. While transient acidity may reduce fish populations, also other species in streams are affected. In this in-stream study, two macro-invertebrates (Gammarus pulex and Baetis rhodani), both known as salmonid prey organisms, were exposed to snowmelt in six humic brooks with a natural gradient of pH and inorganic monomeric Al (Ali). We hypothesize that acid toxicity thresholds can be defined using lethal (mortality) and sublethal (changes in body elemental content) metrics. Periodic observations were made of mortality and whole body concentrations of base cations (BC: Ca, Mg, Na and K) and metals (Al, Fe, Zn and Mn). Mortality increased dramatically at pH<6.0 and Ali >15 µg/L for G. pulex and at pH<5.7 and Ali >20 µg/L for B. rhodani. No accumulation of Al was found. The invertebrate body Na concentration decreased when pH dropped, suggesting that osmoregulation in both species was affected. In contrast to general BC pattern, Ca concentration in G. pulex and Mg concentration in B. rhodani increased when pH decreased. Although Ali strongly correlates to pH, the Al composition of soil and bedrock also influences Al availability, potentially contributing to toxic Ali episodes. The estimated values calculated in this study can be used to improve water quality criteria and as thresholds to adjust doses of lime compared to old recommendations in ongoing liming programs. Such adjustments may be critical since both Ali and pH levels have to be balanced to mitigate damage to recovering stream ecosystems.

Temperature-dependent accumulation mode particle and cloud nuclei concentrations from biogenic sources during WACS 2010

Ahlm, L.; Shakya, K.M.; Russell, L.M.; Schroder, J.C.; Wong, J.P.S.; Sjostedt, S.J.; Hayden, K.L.; Liggio, J.; Wentzell, J.J.B.; Wiebe, H.A.; Mihele, C., Leaitch, W.R.; Macdonald, A.M.
1970 | Atmos. Chem. Phys. | 13 (3393-3407)

Submicron aerosol particles collected simultaneously at the mountain peak (2182 m a.s.l.) and at a forested mid-mountain site (1300 m a.s.l.) on Whistler Mountain,
British Columbia, Canada, during June and July 2010 were analyzed by Fourier transform infrared (FTIR) spectroscopy for quantification of organic functional groups. Positive matrix factorization (PMF) was applied to the FTIR spectra. Three PMF factors associated with (1) combustion, (2) biogenics, and (3) vegetative detritus were identified at both sites. The biogenic factor was correlated with both temperature and several volatile organic compounds (VOCs). The combustion factor dominated the submicron particle mass during the beginning of the campaign, when the temperature was lower and advection was from the Vancouver area, but as the temperature started to rise in early July, the biogenic factor came to dominate as a result of increased emissions of biogenic VOCs, and thereby increased formation of secondary organic aerosol (SOA). On average, the biogenic factor represented 69 % and 49 % of the submicron organic particle mass at Whistler Peak and at the mid-mountain site, respectively. The lower fraction at the mid-mountain site was a result of more vegetative detritus there, and also higher influence from local combustion sources.
The biogenic factor was strongly correlated (r∼0.9) to number concentration of particles with diameter (Dp)>100 nm, whereas the combustion factor was better correlated to number concentration of particles with Dp<100 nm (r∼0.4). The number concentration of cloud condensation nuclei (CCN) was correlated (r∼0.7) to the biogenic factor for supersaturations (S) of 0.2 % or higher, which indicates that particle condensational growth from biogenic vapors was an important factor in controlling the CCN concentration for clouds where S≥0.2 %. Both the number concentration of particles with Dp>100 nm and numbers of CCN for S≥0.2 % were correlated to temperature. Considering the biogenic influence, these results indicate that temperature was a primary factor controlling these CCN concentrations at 0.2 % supersaturation.

Modelling of pH and inorganic aluminium after termination of liming in 3000 Swedish lakes

Sjöstedt, C.; Andrén, C.; Fölster, J.; Gustafsson, J.-P.
1970 | Appl. Geochem. | 35 (221-229)

Significant resources are spent on counteracting the effects of acidification, mainly by liming. Due to lower S and N deposition in Europe and North America, authorities are changing directives and strategies for remediation and reducing liming. However, as the acid–base buffer capacity differs in different water bodies, the desirable reduction of the lime dose is variable. In this study, a geochemical model is used to predict pH and inorganic monomeric Al (Ali) when liming is reduced and finally terminated in the 3000 Swedish lakes currently treated with lime. To estimate Ca and Mg concentrations not affected by liming for use in the model, the Ca/Mg ratio in nearby unlimed reference lakes was used. For the modelling of pH and inorganic Al the Visual MINTEQ program including the Stockholm Humic Model recently calibrated for Swedish fresh water was used. The predictions were validated with modelling results from six monitored lakes, in which liming had been terminated. The use of geochemical modelling appeared to be a promising tool for the calculation of accurate lime requirements in acid waters. For simulations in which liming was completely terminated, the pH value decreased by, on average, 1 pH unit to pH 5.7, whereas Ali increased by 17 μg L−1 to 32 μg L−1. If liming was reduced by half, the pH would drop only 0.3 pH units and Ali would increase by 2 μg L−1. Lakes in the south-western part of Sweden were predicted to reach a lower pH and higher Ali, which would be expected due to their greater historical S deposition. The results indicate that liming can be terminated in certain areas and in other areas be reduced without increases in the lake acidity.

A High-Volume Cryosampler and Sample Purification System for Bromine Isotope Studies of Methyl Bromide

B.F. Thornton; A. Horst; D. Carrizo; H. Holmstrand; P. Andersson; P.M. Crill; Ö. Gustafsson
1970 | J. Atmos. Ocean. Technol. | 30 (2095-2107)

A system was developed for collecting from the ambient atmosphere the methyl halides CH3Cl and CH3Br in quantities sufficient for chlorine and bromine isotope analysis. The construction and operation of the novel cryogenic collection system (cryosampler) and sample purification system developed for this task are described. This study demonstrates the capability of the cryosampler by quantifying the CH3Cl and CH3Br collected from atmospheric samples and the nonfractionating bromine isotope fingerprint of CH3Br from synthetic air samples of controlled composition. An optimized cryosampler operation time of 4 h at a flow rate of 15 L min−1 is applied to yield the nearly 40 ng required for subsequent δ81Br-CH3Br analyses. The sample purification system is designed around a packed column gas chromatography–quadropole–mass spectrometry (GCqMS) system with three additional cryotraps and backflushing capacity. The system's suitability was tested by observing both the mass recovery and the lack of Δ81Br isotope fractionation induced during sample purification under varying flow rates and loading scenarios. To demonstrate that the entire system samples and dependably delivers CH3Br to the isotope analysis system without inducing isotope fractionation, diluted synthetic air mixtures prepared from standard gases were processed through the entire system, yielding a Δ81Br-CH3Br of +0.03‰ ± 0.10‰ relative to their starting composition. Finally, the combined cryosampler–purification and analysis system was applied to demonstrate the first-ever δ81Br-CH3Br in the ambient atmosphere with two samples collected in the autumn of 2011, yielding −0.08‰ ± 0.43‰ and +1.75‰ ± 0.13‰ versus standard mean ocean bromide for samples collected at a suburban Stockholm, Sweden, site.

Five critical questions of scale for the coastal zone

Swaney, D.P.; Humborg, C.; Emeis, K.; Kannen, A.; Silvert, W.; Tett, P.; Pastres, R.; Solidoro, C.; Yamamuro, M.; Hénocque, Y.; Nicholls, R.
1970 | Estuar Coast Shelf Sci | 96 (9-21)

Riverine nitrogen export in Swedish catchments dominated by atmospheric inputs

Eriksson Hägg, H; Humborg, C.; Swaney, D.P.; Mörth, C.-M.
1970 | Biogeochemistry

Aqueous and biotic mercury concentrations in boreal lakes: model predictions and observations. — In: Mercury Pollution: Integration and Synthesis (eds. Watras, C.J. & Huckabee, J.W.). CRC Press, Lewis Publishers Inc., Boca Raton FL, Chapter I.8, pp. 99-106.

1970 | CRC Press, Lewis Publishers, New York | ISBN: 1-56670-066-3
hg , mercury

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An innovative integrated system of models and databases in support to the prioritisation of emerging contaminants on a European scale

| Society of Environmental Toxicology and Chemistry (SETAC)

SETAC Europe, 25th Annual Meeting | March 21, 2019 | Barcelona, Spain

The significance of land-atmosphere interactions in the Earth system—iLEAPS achievements and perspectives

| Antropocene | In press

The integrated land ecosystem-atmosphere processes study (iLEAPS) is an international research project focussing on the fundamental processes that link land-atmosphere exchange, climate, the water cycle, and tropospheric chemistry. The project, iLEAPS, was established 2004 within the International Geosphere-Biosphere Programme (IGBP). During its first decade, iLEAPS has proven to be a vital project, well equipped to build a community to address the challenges involved in understanding the complex Earth system: multidisciplinary, integrative approaches for both observations and modeling. The iLEAPS community has made major advances in process understanding, land-surface modeling, and observation techniques and networks. The modes of iLEAPS operation include elucidating specific iLEAPS scientific questions through networks of process studies, field campaigns, modeling, long-term integrated field studies, international interdisciplinary mega-campaigns, synthesis studies, databases, as well as conferences on specific scientific questions and synthesis meetings. Another essential component of iLEAPS is knowledge transfer and it also encourages community- and policy-related outreach activities associated with the regional integrative projects. As a result of its first decade of work, iLEAPS is now setting the agenda for its next phase (2014–2024) under the new international initiative, future Earth. Human influence has always been an important part of land-atmosphere science but in order to respond to the new challenges of global sustainability, closer ties with social science and economics groups will be necessary to produce realistic estimates of land use and anthropogenic emissions by analysing future population increase, migration patterns, food production allocation, land management practices, energy production, industrial development, and urbanization.

Erratum to ‘Biomagnification of Organic Pollutants in Benthic and Pelagic Marine Food Chains from the Baltic Sea.’

| Sci. Total Environ. | 407 (21) (5803-5804)

Estimating the major sources of PFOS and PFOA to the Danube River catchment

| Society of Environmental Toxicology and Chemistry (SETAC)

SETAC Europe, 25th Annual Meeting | March 21, 2019 | Barcelona, Spain

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