Grain Harvesting as a Local Source of Cladosporium 1 spp. in Denmark

Cladosporium spp. are omnipresent moulds that grow on multiple substrates. Their spores possess a high allergenic potential. Currently, little is known about the incidence and the sources of airborne Cladosporium spores in Denmark. Air samples were collected between 31 May and 22 September 2015 in Viborg (Jutland, western Denmark). Eighteen out of 21 days with daily average concentrations exceeding the health relevant threshold of 3,000 Spores m-3, including the day with peak daily (13,553 Spores m-3) and 3-h concentrations (35,662 Spores m-3), occurred in August. The air masses that approached Viborg during the longest episode of elevated spore concentrations originated from northern Poland, the Baltics, passing over southern Sweden and the eastern Danish island of Zealand. The Cladosporium spore concentrations from Viborg were compared with the Cladosporium spore concentrations from the operational monitoring station in Copenhagen (Zealand, eastern Denmark). During the episode concentrations in Viborg were on average 2,268 spores m-3 higher than in Copenhagen. On the peak day between 8:00-15:00 concentrations in Viborg were 4-7 times higher than in Copenhagen, which we associated with grain crop harvesting in eastern Jutland. Elevated day time concentrations in Viborg on the days with daily average concentrations exceeding the threshold also indicate the local character of the sources

Airborne Cladosporium and Alternaria spore concentrations through 26 years in Copenhagen, Denmark

Cladosporium spp. and Alternaria spp. spores are dominating the airspora of Denmark. Currently, little is known about the influence of climate change on the fungal spore abundance in the air. The aim of this study was to examine temporal changes in airborne Alternaria and Cladosporium spores over 26 years. This is the first report of long-term airborne Cladosporium spore occurrence in Denmark. Air spore concentrations were obtained with a Burkard volumetric spore sampler placed in Copenhagen, Denmark, during June–September, 1990–2015. The highest monthly Spore integrals (SIn) for Alternaria were measured in August, whereas for Cladosporium July SIn was nearly as high as August SIn. Average Alternaria seasonal spore integral (SSIn) was 8615 Spores day m−3, while average 3-month (July–September) Cladosporium SIn was 375,533 Spores day m−3. Despite increasing annual temperature and decreasing relative humidity, we found a decreasing trend for Alternaria seasonal SIn (Slope = − 277, R2 = 0.38, p < 0.05), Alternaria (Slope = − 31, R2 = 0.27, p < 0.05) and Cladosporium (Slope = − 440, R2 = 0.23, p < 0.05) annual peak concentrations. We did not find any statistically significant trends for airborne Alternaria seasonal characteristics and duration, and likewise for Cladosporium 3-month SIn and peak concentration dates. Mean temperature was the main meteorological factor affecting daily spore concentrations. However, effect of meteorological parameters on daily spore concentrations was stronger for Cladosporium (R2 = 0.41) than for Alternaria (R2 = 0.21). Both genera had diurnal peaks during the day hours, earlier for Cladosporium (11:30–14:30) and later for Alternaria (15:00–19:00). Although Alternaria and Cladosporium daily concentrations were moderately correlated (Spearman’s correlation coefficient: rs = 0.55, p < 0.05), their overall annual indices were different, which indicates different sources and different factors determining spore release. We explain temporal decreasing trends in Alternaria SSIn by growing urbanisation around Copenhagen and by changes in agricultural practices

Crop harvest in Denmark and Central Europe contributes to the local load of airborne <i>Alternaria</i> spore concentrations in Copenhagen

This study examines the hypothesis that Danish agricultural areas are the main source of airborne Alternaria spores in Copenhagen, Denmark. We suggest that the contribution to the overall load is mainly local or regional, but with intermittent long distance transport (LDT) from more remote agricultural areas. This hypothesis is supported by investigating a 10 yr bi-hourly record of Alternaria spores in the air from Copenhagen. This record shows 232 clinically relevant episodes (daily average spore concentration above 100 m−3) with a distinct daily profile. The data analysis also revealed potential LDT episodes almost every year. A source map and analysis of atmospheric transport suggest that LDT always originates from the main agricultural areas in Central Europe. A dedicated emission study in cereal crops under harvest during 2010 also supports our hypothesis. The emission study showed that although the fields had been treated against fungal infections, harvesting still produced large amounts of airborne fungal spores. It is likely that such harvesting periods can cause clinically relevant levels of fungal spores in the atmosphere. Our findings suggest that crop harvest in Central Europe causes episodes of high airborne Alternaria spore concentrations in Copenhagen as well as other urban areas in this region. It is likely that such episodes could be simulated using atmospheric transport models

Regional Variation in Airborne Alternaria Spore Concentrations in Denmark Through 2012-2015 Seasons: The Influence of Meteorology and Grain Harvesting

High airborne Alternaria spore concentrations measured in eastern Denmark have been associated with local agricultural sources. However, the density of agricultural areas is highest in western Denmark. This is the first report of airborne Alternaria spore concentrations obtained with Burkard volumetric spore sampler in western Denmark, Viborg. We compared the concentrations of airborne Alternaria spores and the patterns of air mass transport using HYSPLIT model between Copenhagen and Viborg for the seasons 2012-2015, with the main focus on the days with daily average Alternaria spore concentrations ≥ 100 s m-3 (high concentration days). Except for 2012, Annual Spore Integrals (ASIns) were on average 3,335 s day m-3 higher in Viborg than in Copenhagen. The high concentration days during 2012-2015 occurred more frequently and with higher values in Viborg (96 days; mean=381 s m-3) than in Copenhagen (79 days; mean=270 s m-3). We found increased shares of trajectories coming from South-East on the high concentration days and increased shares of trajectories coming from the West and North-West on the days with concentrations below 100 s m-3 for both stations. July and August had the highest spore integrals matching the periods of grain harvesting in Denmark. The absence of the concurrent grain harvesting in Denmark was associated with the lowest ASIns in 2012. The results of this study support the hypothesis that local sources cause the main load of airborne Alternaria spore concentrations in Denmark, however, the contribution from the remote source areas in northern Germany, Poland and southern Sweden remains unquantified

Migrations et identités

L’Allemagne a tardé à se considérer comme territoire d’immigration bien qu’elle le fût devenue depuis longtemps pour des raisons économiques. Depuis quelques années elle s’intéresse à ce problème au présent, mais également aux migrations intérieures et extérieures qu’elle a connues par le passé. Elle se replonge ainsi dans les mouvements humains dramatiques des 19e et 20e siècles. À partir des contributions de germanistes, d’historiens, d’un psychanalyste, d’un magistrat, d’un politologue, le présent ouvrage jette sur le phénomène migratoire des éclairages complémentaires, centrés sur l’Allemagne du point de vue thématique, mais qui atteignent une dimension beaucoup plus large. Volontaires ou contraintes, individuelles où en groupe, les migrations étudiées apparaissent comme des ruptures qui conduisent, selon les cas, à des déracinements complets ou à des réenracinements effectifs qui ne dépendent pas de la seule capacité du migrant, mais aussi de l’attitude du pays d’accueil