北京城区气传花粉季节特征及与气象条件关系

Seasonal Dynamics of Airborne Pollens and Its Relationship with Meteorological Factors in Beijing Urban Area

研究北京城区气传花粉季节特征及其与气象条件关系,为本地区防治花粉症及建设合理城市绿地提供有效资料.研究应用Burkard采样器于2011年12月31日至2012年12月31日对北京城区气传花粉含量进行监测,并对花粉含量及气象因素进行统计学分析.结果表明,2012年北京城区的花粉季节起始时间为3月17日~11月10日,持续238 d,占全年天数的65%;全年花粉含量月分布呈现两个高峰,第一个高峰为3~5月,主要花粉为木犀科、杨属、柳属等树木花粉,占全年花粉总量的53%;第二个高峰为8~10月,主要花粉为菊科、藜科及苋科等莠草花粉,占全年花粉总量的26%;2012年度北京城区最具代表性的气传花粉来自于菊科、木犀科及杨柳科,比重之和为40%.结果还表明,秋季气传花粉以致敏性较强的莠草花粉为主,所以北京花粉症的高发季节主要集中在秋季.北京城区气传花粉含量受气象因素影响较明显,影响最明显的是风速、温度、湿度及降水等气象要素.研究表明,在0~15℃的温度区间内,花粉含量随温度的升高而升高;当温度大于15℃,即在18~30℃的范围内时,花粉含量随温度的升高而降低.北京城区2012年春秋季的平均温度为17℃,且这两个季节的花粉量占全年的79%,因此春秋季的温度是北京最适宜花粉的散播;根据研究数据分析,当相对湿度在20%~50%或大于70%的时候,气传花粉含量随相对湿度的增大而减小,而相对湿度在50%~60%时,气传花粉含量随相对湿度的增大而增加;研究还表明风速在1~3 m·s-1时,易于花粉粒飘散,气传花粉含量较大,但风速超过3 m·s-1时或持续时间较长时,空气中花粉含量值反而较小;雨水会影响花粉的产量和释放,易致空中飘散花粉粒减少.通过研究已经探明了北京城区气传花粉的种类及飘散规律,以及花粉含量和气象条件之间的关系,为进行气传花粉预报提供了参考.

The seasonal dynamics of airborne pollens and their relationship with meteorological conditions,which are considered to be important factors for appropriate construction of urban green system and reliable prevention of tropic pollinosis,were investigated in Beijing urban area. The airborne pollens were monitored from December 31 st 2011 to December 31 st 2012 by Burkard volumetric trap,and the data were analyzed. The results revealed that： 1 In 2012 the pollen dispersion period lasted 238 days from March 17 thto November 18 th,accounting for 65% of the year. There were two peaks of pollen amount in air,which occurred from March to May and from August to October,respectively. In the spring peak,tree pollens such as Oleaceae,Populus and Salix pollens were the dominant,accounting for 53% of the total annual pollens,while in the autumn period,weed pollens such as Compositae,Chenopodiaceae and Amaranthaceae pollens made up about 40% of the annual total value; 2 The highly allergenic weeds pollens dominated in autumn,which caused a high incidence of tropic pollinosis; 3The airborne pollen amount of Beijing urban area was significantly affected by meteorological condition like the wind speed,temperature,humidity,precipitation and so on; 4 When temperature ranged from 0℃ to15℃,the pollen amount showed positive relation with temperature; while in the temperature range of 18℃ to 30℃,it showed negative relation; 5 The average temperature of spring and autumn season in 2012 was 17℃,and 79% of airborne pollens were detected in these two seasons. This temperature condition was conducive to the pollen dispersion.; 6The pollen amount showed negative relation with relative moisture between 20% and 50% and larger than 70%,while in the moisture range of 50% to 60%,it showed positive relation; 7The wind speed smaller than 3 m·s- 1was good to pollen distribution,when it was larger than 4 m·s- 1or the wind lasted for a long time,the pollen amount in the air would decrease; 8 The pollen release was decreased by the rain. The above results can be helpful to forecast the pollen amount in the air.