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[Concentration of airborne pollen in Beijing city with burkard sampler].

OBJECTIVE
To investigate the airborne pollen concentration in Beijing city during autumn and to grade the Artemisia pollen concentration.


METHOD
Burkard volumetric trap was used to sample the airborne pollen in Beijing city from August 1st 2007 to October 10th 2007. Patients only allergic to mugwort pollen were followed up, and their symptom scores and the mugwort pollen concentration were analyzed statistically.


RESULT
1) Mugwort and Humulus (including Cannabis Sativa L) were the main airborne pollen during August and September in Beijing city, accounting for 31% and 51%, respectively; 2) Mugwort pollen season was from 8th August to 8th October; 3) The daily peak concentration of Mugwort pollen was 267 g/m3, with an average of 71 g/m3, the daily peak concentration of Humulus pollen was 672 g/m3, with an average of 124 g/m3; 4) 88.5% out-patients suffering from hay fever or asthma during Autumn were allergic to mugwort, 28.2% allergic to Humulus; 5) the grading of airborne Mugwort pollen concentration: 0-14 g/m3 as grade 0, 15-40 g/m3 as grade I, 41-116 g/m3 as grade II, more than 117 g/m3 as grade III.


CONCLUSION
It was the first time that Burkard volumetric sampler was employed in monitoring Mugwort and Humulus concentration in Beijing city. Average concentration of mugwort pollen was about 100 g/m3, and concentration grade III of mugwort pollen was distributed during the last ten days of August and the beginning of September.