Assesment of seasonal and annual allergenic type of pollen in North Lebanon in 2008 and 2009

Abstract

The identification of the type and concentrations of pollen grains will be very efficient and helpful for patients suffering from allergic diseases. An agreement between the Institute of Environment at the University of Balamand (IOE-UOB) and the Lebanese Society of Allergy and Immunology (LSAI) was signed in 2007 in order to design and test the mechanisms, methods and procedures to establish datasets for airborne pollen type and concentration in North Lebanon. The pollen project in which the IOE-UOB was responsible for the North Lebanon station was funded by Schering Plough Laboratory. In this study, the variation in airborne pollen concentration in North Lebanon is studied for the two consecutive years 2008-2009 using a VPPS 2000 Lanzoni trap (Hirst type) located at the roof of Zakhem Building at the University of Balamand. A total of 45,998 pollen grains belonging to 99 taxa were recorded. Of these taxa, 43 pollen taxa belonged to the allergenic type. The top 13 pollen were selected, which include Cupressaceae, Rosacea, Urticaceae, Poaceae, Quercus sp., Olea sp., Populus sp., Fraxinus sp., Ginkgo sp., Platanus sp., Castaneae sp., Fagus sp. and Corylus sp. The Spearman statistical test was used in order to correlate meteorological parameters (temperature, humidity, rainfall and wind velocity) with the pollen concentration during their main pollination season (MPS). The correlation was performed with a confidence interval between 95% and 99%. Temperature and humidity had the greatest negative influence on the majority of the pollen taxa. Cupressaceae, Rosacea, Urticaceae, Poaceae, Quercus sp., Olea sp., Populus sp., Fraxinus sp., Ginkgo sp., Platanus sp., Castaneae sp., Fagus sp. and Corylus sp. correlated with temperature, while Rosacea, Urticaceae, Poaceae, Quercus sp., Olea sp., Populus sp., Fraxinus sp., Ginkgo sp., Platanus sp., Castaneae sp., Fagus sp. and Corylus sp. correlated with humidity. Rainfall and wind velocity had the least effect on the concentration of the pollen taxa studied. Rainfall correlated with Rosaceae, Fraxinus sp. and Platanus sp., while wind velocity correlated with Cupressaceae, Fraxinus sp. Ginkgo and Castanea sp. After calculating the MPS of each of the 13 pollen taxa, a preliminary pollen calendar was produced. Afterward, a field survey was carried out to identify the source of the 13 allergenic pollen. Eight plants out of 13 were identified during the field survey. The remaining five, which comprise Fraxinus sp., Ginkgo sp., Castaneae sp., Fagus sp. and Corylus sp., were linked with wind direction, showing that their main source is from a western direction.