Biomass burning in eastern Europe during spring 2006 caused high deposition of ammonium in northern Fennoscandia

High air concentrations of ammonium were detected at low and high altitude sites in Sweden, Finland and Norway during the spring 2006, coinciding with polluted air from biomass burning in eastern Europe passing over central and northern Fennoscandia. Unusually high values for throughfall deposition of ammonium were detected at one low altitude site and several high altitude sites in north Sweden. The occurrence of the high ammonium in throughfall differed between the summer months 2006, most likely related to the timing of precipitation events. The ammonia dry deposition may have contributed to unusual visible injuries on the tree vegetation in northern Fennoscandia that occurred during 2006, in combination with high ozone concentrations. It is concluded that long-range transport of ammonium from large-scale biomass burning may contribute substantially to the nitrogen load at northern latitudes. (C) 2013 Elsevier Ltd. All rights reserved

Respiratory Health among Korean Pupils in Relation to Home, School and Outdoor Environment

There are few studies about school-environment in relation to pupils' respiratory health, and Korean school-environment has not been characterized. All pupils in 4th grade in 12 selected schools in three urban cities in Korea received a questionnaire (n = 2,453), 96% participated. Gaseous pollutants and ultrafine particles (UFPs) were measured indoors (n = 34) and outdoors (n = 12) during winter, 2004. Indoor dampness at home was investigated by the questionnaire. To evaluate associations between respiratory health and environment, multiple logistic- and multi-level regression models were applied adjusting for potential confounders. The mean age of pupils was 10 yr and 49% were boys. No school had mechanical ventilation and CO2-levels exceeded 1,000 ppm in all except one of the classrooms. The indoor mean concentrations of SO2, NO2, O3 and formaldehyde were 0.6 µg/m3, 19 µg/m3, 8 µg/m3 and 28 µg/m3, respectively. The average level of UFPs was 18,230 pt/cm3 in the classrooms and 16,480 pt/cm3 outdoors. There were positive associations between wheeze and outdoor NO2, and between current asthma and outdoor UFPs. With dampness at home, pupils had more wheeze. In conclusion, outdoor UFPs and even low levels of NO2 may adversely contribute to respiratory health in children. High CO2-levels in classrooms and indoor dampness/mold at home should be reduced

Pan-European rural monitoring network shows dominance of NH3 gas and NH4NO3 aerosol in inorganic atmospheric pollution load

A comprehensive European dataset on monthly atmospheric NH3, acid gases (HNO3, SO2, HCl), and aerosols (NH4+, NO3-, SO42-, Cl−, Na+, Ca2+, Mg2+) is presented and analysed. Speciated measurements were made with a low-volume denuder and filter pack method (DEnuder for Long-Term Atmospheric sampling, DELTA®) as part of the EU NitroEurope (NEU) integrated project. Altogether, there were 64 sites in 20 countries (2006–2010), coordinated between seven European laboratories. Bulk wet-deposition measurements were carried out at 16 co-located sites (2008–2010). Inter-comparisons of chemical analysis and DELTA® measurements allowed an assessment of comparability between laboratories. The form and concentrations of the different gas and aerosol components measured varied between individual sites and grouped sites according to country, European regions, and four main ecosystem types (crops, grassland, forests, and semi-natural). The smallest concentrations (with the exception of SO42- and Na+) were in northern Europe (Scandinavia), with broad elevations of all components across other regions. SO2 concentrations were highest in central and eastern Europe, with larger SO2 emissions, but particulate SO42- concentrations were more homogeneous between regions. Gas-phase NH3 was the most abundant single measured component at the majority of sites, with the largest variability in concentrations across the network. The largest concentrations of NH3, NH4+ and NO-3 were at cropland sites in intensively managed agricultural areas (e.g. Borgo Cioffi in Italy), and the smallest were at remote semi-natural and forest sites (e.g. Lompolojänkkä, Finland), highlighting the potential for NH3 to drive the formation of both NH4+ and NO3- aerosol. In the aerosol phase, NH4+ was highly correlated with both NO3- and SO42-, with a near-1:1 relationship between the equivalent concentrations of NH4+ and sum(NO3- + SO42-) of which around 60 % was as NH4NO3. Distinct seasonality was also observed in the data, influenced by changes in emissions, chemical interactions, and the influence of meteorology on partitioning between the main inorganic gases and aerosol species. Springtime maxima in NH3 were attributed to the main period of manure spreading, while the peak in summer and trough in winter were linked to the influence of temperature and rainfall on emissions, deposition, and gas–aerosol-phase equilibrium. Seasonality in SO2 was mainly driven by emissions (combustion), with concentrations peaking in winter, except in southern Europe, where the peak occurred in summer. Particulate SO42− showed large peaks in concentrations in summer in southern and eastern Europe, contrasting with much smaller peaks occurring in early spring in other regions. The peaks in particulate SO42- coincided with peaks in NH3 concentrations, attributed to the formation of the stable (NH4)2SO4. HNO3 concentrations were more complex, related to traffic and industrial emissions, photochemistry, and HNO3:NH4NO3 partitioning. While HNO3 concentrations were seen to peak in the summer in eastern and southern Europe (increased photochemistry), the absence of a spring peak in HNO3 in all regions may be explained by the depletion of HNO3 through reaction with surplus NH3 to form the semi-volatile aerosol NH4NO3. Cooler, wetter conditions in early spring favour the formation and persistence of NH4NO3 in the aerosol phase, consistent with the higher springtime concentrations of NH4+ and NO3−. The seasonal profile of NO3- was mirrored by NH4+, illustrating the influence of gas–aerosol partitioning of NH4NO3 in the seasonality of these components. Gas-phase NH3 and aerosol NH4NO3 were the dominant species in the total inorganic gas and aerosol species measured in the NEU network. With the current and projected trends in SO2, NOx , and NH3 emissions, concentrations of NH3 and NH4NO3 can be expected to continue to dominate the inorganic pollution load over the next decades, especially NH3, which is linked to substantial exceedances of ecological thresholds across Europe. The shift from (NH4)2SO4 to an atmosphere more abundant in NH4NO3 is expected to maintain a larger fraction of reactive N in the gas phase by partitioning to NH3 and HNO3 in warm weather, while NH4NO3 continues to contribute to exceedances of air quality limits for PM2.5

Air pollution trends in the EMEP region between 1990 and 2012

The present report synthesises the main features of the evolution over the 1990-2012 time period of the concentration and deposition of air pollutants relevant in the context of the Convention on Long-range Transboundary Air Pollution: (i) ozone, (ii) sulfur and nitrogen compounds and particulate matter, (iii) heavy metals and persistent organic pollutants. It is based on observations gathered in State Parties to the Convention within the EMEP monitoring network of regional background stations, as well as relevant modelling initiatives. Joint Report of: EMEP Task Force on Measurements and Modelling (TFMM), Chemical Co-ordinating Centre (CCC), Meteorological Synthesizing Centre-East (MSC-E), Meteorological Synthesizing Centre-West (MSC-W)

Potassium : a neglected nutrient in global change

L'article inclou sis apèndixsAim: Potassium (K) is the second most abundant nutrient after nitrogen (N) in plant photosynthetic tissues. Thousands of physiological and metabolic studies in recent decades have established the fundamental role of K in plant function, especially in water use efficiency and economy, and yet macroecological studies have mostly overlooked this nutrient.- Methods: We have reviewed available studies on the contents, stoichiometries and roles of potassium in the soil-plant system and in terrestrial ecosystems. We have also reviewed the impacts of global change drivers on K contents, stoichiometries, and roles. - Conclusions: The current literature indicates that K, at a global level, is as limiting as N and phosphorus (P) for plant productivity in terrestrial ecosystems. K limitation has been seen up to some degree in 70% of all studied terrestrial ecosystems. However, atmospheric K deposition from human activities represents higher amounts than that from natural sources in some areas. We are far from understanding the K fluxes between the atmosphere and land, and the role of anthropogenic activities in these fluxes. The increasing aridity expected in wide areas of the world makes K more critical through its role in water use efficiency. N deposition exerts a strong impact on the ecosystem K-cycle, decreasing K availability and increasing K limitation. Plant invasive success is enhanced by higher soil K availability, especially in environments without strong abiotic stresses. The impacts of other global change drivers, such as increasing atmospheric CO² or changes in land use remain to be elucidated. Current models of the responses of ecosystems and carbon storage to projected global climatic and atmospheric changes are now starting to consider N and P, but they should also consider K, mostly in arid and semiarid ecosystems

Testing and development of new precipitation gauge for chemical analysis

Representative sampling of precipitation above ground is very difficult because the sampler itself affects the trajectory of the meteor. If chemical analysis of the precipitation is of interest, the sampling has to be made well above the ground. Samplers made of suitable material but not of optimal aerodynamical shape are traditionally used for collecting precipitation for chemical analysis by environmentalists worldwide. The obtained concentration is multiplied by the precipitation amount to obtain the wet deposition. Sometimes the precipitation amount from the same sampler that collects precipitation for chemical analysis is used and sometimes it is obtained from a standard gauge or from model calculations. Even if the material in the sampler is inert with respect to the ions analysed, the concentration can be wrong. If the sampling efficiency varies with time (due to changes in wind speed or droplet size), the precipitation weighted average concentration will not be correct. A sampler consisting of a snow sack in a wind protective tube has been modified in several steps to resemble a sampler used by meteorologist for measuring the precipitation amount on a daily basis. The two samplers measured similar precipitation amounts when a thinner rim was introduced on top of the tube containing the snow sack.Representative sampling of precipitation above ground is very difficult because the sampler itself affects the trajectory of the meteor. If chemical analysis of the precipitation is of interest, the sampling has to be made well above the ground. Samplers made of suitable material but not of optimal aerodynamical shape are traditionally used for collecting precipitation for chemical analysis by environmentalists worldwide. The obtained concentration is multiplied by the precipitation amount to obtain the wet deposition. Sometimes the precipitation amount from the same sampler that collects precipitation for chemical analysis is used and sometimes it is obtained from a standard gauge or from model calculations. Even if the material in the sampler is inert with respect to the ions analysed, the concentration can be wrong. If the sampling efficiency varies with time (due to changes in wind speed or droplet size), the precipitation weighted average concentration will not be correct. A sampler consisting of a snow sack in a wind protective tube has been modified in several steps to resemble a sampler used by meteorologist for measuring the precipitation amount on a daily basis. The two samplers measured similar precipitation amounts when a thinner rim was introduced on top of the tube containing the snow sack

Air pollution trends in the EMEP region between 1990 and 2012

In the late 1960s, early warnings were issued that air pollution could go beyond the limits of urban areas and industrial facilities, potentially affecting the acidity of precipitations at the scale of the whole European Continent. After a pioneer monitoring network was set up under the auspices of OECD (Organisation for Economic Co-operation and Development) a political consensus emerged for the need to elaborate a specific Convention on Long-range Transboundary Air Pollution (CLRTAP) that was signed in 1979 and entered into force in 1983. The present report synthetises the main features of the evolution over the 1990-2012 time period of the concentration and deposition of air pollutants relevant in the context of the Convention on Long-range Transboundary Air Pollution: (i) ozone, (ii) sulfur and nitrogen compounds and particulate matter, (iii) heavy metals and persistent organic pollutants. It is based on observations gathered in State Parties to the Convention within the EMEP monitoring network of regional background stations, as well as relevant modelling initiatives.The present report synthetises the main features of the evolution over the 1990-2012 time period of the concentration and deposition of air pollutants relevant in the context of the Convention on Long-range Transboundary Air Pollution

Testing and development of a new precipitation gauge for chemical analysis

Representative sampling of precipitation above ground is very difficult because the sampler itself affects the trajectory of the meteor. If chemical analysis of the precipitation is of interest, the sampling has to be made well above the ground. Samplers made of suitable material but not of optimal aerodynamical shape are traditionally used for collecting precipitation for chemical analysis by environmentalists worldwide. The obtained concentration is multiplied by the precipitation amount to obtain the wet deposition. Sometimes the precipitation amount from the same sampler that collects precipitation for chemical analysis is used and sometimes it is obtained from a standard gauge or from model calculations. Even if the material in the sampler is inert with respect to the ions analysed, the concentration can be wrong. If the sampling efficiency varies with time (due to changes in wind speed or droplet size), the precipitation weighted average concentration will not be correct. A sampler consisting of a snow sack in a wind protective tube has been modified in several steps to resemble a sampler used by meteorologist for measuring the precipitation amount on a daily basis. The two samplers measured similar precipitation amounts when a thinner rim was introduced on top of the tube containing the snow sack.Representative sampling of precipitation above ground is very difficult because the sampler itself affects the trajectory of the meteor. If chemical analysis of the precipitation is of interest, the sampling has to be made well above the ground. Samplers made of suitable material but not of optimal aerodynamical shape are traditionally used for collecting precipitation for chemical analysis by environmentalists worldwide. The obtained concentration is multiplied by the precipitation amount to obtain the wet deposition. Sometimes the precipitation amount from the same sampler that collects precipitation for chemical analysis is used and sometimes it is obtained from a standard gauge or from model calculations. Even if the material in the sampler is inert with respect to the ions analysed, the concentration can be wrong. If the sampling efficiency varies with time (due to changes in wind speed or droplet size), the precipitation weighted average concentration will not be correct. A sampler consisting of a snow sack in a wind protective tube has been modified in several steps to resemble a sampler used by meteorologist for measuring the precipitation amount on a daily basis. The two samplers measured similar precipitation amounts when a thinner rim was introduced on top of the tube containing the snow sack

Metod för bestämning av gasformig salpetersyra och partikulär nitrat i atmosfären.

En metod för analys av gasformig salpetersyra och nitrathalt i partiklar beskrivs. De separerades under provtagningen genom att salpetersyra först avlägsnas i en denuder belagd med natriumkarbonat. Partiklarna samlas därefter upp på ett natriumkarbonat-impregnerat filter. Nitrathalten i denuder och filter analyseras med jonkromatografi. Detektionsgränsen är ungefär 2 nmol/m3 för 24 timmars provtagning. Försök har visat att salpetersyra sorberas på praktiskt taget alla fasta material. Det medför att stora förluster av salpetersyra görs när luften kommer i kontakt med en sond eller filterhållare. Partiklar som innehåller nitrat avger salpetersyra under en filtrering. Stora analysfel kan därför göras när partikulär nitrathalt bestäms genom konventionell partikelprovtagning.En metod för analys av gasformig salpetersyra och nitrathalt i partiklar beskrivs. De separerades under provtagningen genom att salpetersyra först avlägsnas i en denuder belagd med natriumkarbonat. Partiklarna samlas därefter upp på ett natriumkarbonat-impregnerat filter. Nitrathalten i denuder och filter analyseras med jonkromatografi. Detektionsgränsen är ungefär 2 nmol/m3 för 24 timmars provtagning. Försök har visat att salpetersyra sorberas på praktiskt taget alla fasta material. Det medför att stora förluster av salpetersyra görs när luften kommer i kontakt med en sond eller filterhållare. Partiklar som innehåller nitrat avger salpetersyra under en filtrering. Stora analysfel kan därför göras när partikulär nitrathalt bestäms genom konventionell partikelprovtagning