Seasonal variation of airborne pollen grains in the atmosphere of Zarqa area, Jordan

Airborne pollen grains are responsible for pollinosis in susceptible people. This study provides aerobiological baseline information about Zarqa area, Jordan, for the first time using the Burkard seven-day volumetric spore trap. The study period was from December 2008 to November 2009. Pollen grains were found to be belonging to 51 flowering plant families in addition to a group of fern spores. The highest abundance was attributed to Oleaceae (20 %) followed by Euphorbiaceae (14.4 %), Poaceae (10 %), Pinaceae (7.11 %), Fabaceae (6.94 %), Asteraceae (5.17 %), Brassicaceae (3.6 %), Rosaceae (3.3 %), Solanaceae (3.07 %), Mytraceae (2.2 %), 22.61 % corresponded to other families, and 0.35 % for fern spores, and 1.6 % was attributed to unknowns. May was the month of maximum pollen grains with a total count of 7,779, while November was the month of the least total count (128 pollen grains). Oleaceae showed a sharp peak in May, while Euphorbiaceae did not show a clear peak. A sharp peak of Pinaceae occurred in April; however, Fabaceae, Asteraceae, and Brassicaeae peaked between March and May. In December, February and/or March, monthly indices of total pollen counts showed positive correlations with maximum temperature and wind speed and negative correlations with rainfall and relative humidity. From March to June, the airborne pollen count was significantly greater in the air during day hours than night hours. However, the results were reversed from July to October. Monthly indices for total pollen taxa and pollen grains of the most abundant species were provided for the first time in Zarqa to help researchers and allergy specialists to conduct further research and/or to do better diagnosis for pollinosis in susceptible people.