The long distance transport of airborne Ambrosia pollen to the UK and the Netherlands from Central and south Europe.

Letty A De Weger,Branko Šikoparija,Donat Magyar,Idalia Kasprzyk,Matt Smith,Catherine H Pashley,Łukasz Grewling,Michel Thibaudon,Carsten A Skjøth

doi:10.1007/s00484-016-1170-7

Abstract

The invasive alien species Ambrosia artemisiifolia (common or short ragweed) is increasing its range in Europe. In the UK and the Netherlands, airborne concentrations of Ambrosia pollen are usually low. However, more than 30 Ambrosia pollen grains per cubic metre of air (above the level capable to trigger allergic symptoms) were recorded in Leicester (UK) and Leiden (NL) on 4 and 5 September 2014. The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the episode could be the result of long distance transport, to identify the potential sources of these pollen grains and to describe the conditions that facilitated this possible long distance transport. Airborne Ambrosia pollen data were collected at 10 sites in Europe. Back trajectory and atmospheric dispersion calculations were performed using HYSPLIT_4. Back trajectories calculated at Leicester and Leiden show that higher altitude air masses (1500 m) originated from source areas on the Pannonian Plain and Ukraine. During the episode, air masses veered to the west and passed over the Rhône Valley. Dispersion calculations showed that the atmospheric conditions were suitable for Ambrosia pollen released from the Pannonian Plain and the Rhône Valley to reach the higher levels and enter the airstream moving to northwest Europe where they were deposited at ground level and recorded by monitoring sites. The study indicates that the Ambrosia pollen grains recorded during the episode in Leicester and Leiden were probably not produced by local sources but transported long distances from potential source regions in east Europe, i.e. the Pannonian Plain and Ukraine, as well as the Rhône Valley in France.Electronic supplementary materialThe online version of this article (doi:10.1007/s00484-016-1170-7) contains supplementary material, which is available to authorized users.

Highlights

Allergic sensitization can result in disorders of the airways such as allergic rhinitis, conjunctivitis and allergic asthma (Zheng et al 2011)
These diurnal patterns suggested that the pollen grains did not originate from local sources, since studies have shown that Ambrosia pollen from local plants is usually recorded in the air from about 6.30 am to around midday (Ogden et al 1969)
This study indicates that the Ambrosia pollen grains recorded at the beginning of September 2014 in Leicester and Leiden were probably not produced by local sources in response to range expansion due to climate change, but transported long distances from potential source regions in east Europe, i.e. the Pannonian Plain and Ukraine, as well as the Rhône Valley in France

Summary

Introduction

Allergic sensitization can result in disorders of the airways such as allergic rhinitis, conjunctivitis and allergic asthma (Zheng et al 2011). Pollen grains from wind-pollinating (anemophilous) plants are often the causative agents of sensitization (Bousquet et al 2007). The most infested areas of Europe are currently the Rhône Valley in France, northern Italy, the Pannonian Plain, and large areas in Ukraine and western Russia (Skjøth et al 2010; Smith et al 2013; Thibaudon et al 2014; Prank et al 2013; Podberezko et al 2013; Reznik 2009). With the increase in plant abundance, there has been an increase in the number of patients sensitized to Ambrosia: ~60 % in Hungary (Makra et al 2004); ~ 47 % in France, mainly the Rhône Valley (Thibaudon et al 2010); and an increase from 24 % in 1989 to 70 % in 2008 was witnessed in northern Italy (Tosi et al 2011). In countries like Spain and the UK, the Ambrosia sensitization rate is still low (Bousquet et al 2007), corresponding with the scarcity of the plant in these areas

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