Release behavior of small sized daughter allergens from Cryptomeria japonica pollen grains during urban rainfall event
Release behavior of small sized daughter allergens from Cryptomeria japonica pollen grains during urban rainfall event
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DOI：
10.1007/s10453-011-9212-4
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发表时间：
2012-03-01
期刊：
影响因子：
2
通讯作者：
Miwa, M.
中科院分区：
文献类型：
--
作者：
Wang, Q.;Nakamura, S.;Miwa, M.
在日本，柳杉花粉(直径约30亩)在每年春季散布。子代致敏颗粒比其亲本花粉粒小，并含有丰富的细颗粒(颗粒大小为1.1微米，PM(1.1))，释放到大气中。花粉的女儿变应原颗粒释放后，可以在城市大气中长时间运输。特别是在降雨后1~2个晴天，变应原Cry j 1浓度峰值与空气中亲本花粉计数峰值的日变化延迟时间较高。此外，在日本的散粉季节，还发现了来自东亚大陆的亚洲沙尘(ADS)的长距离输送。因此，花粉与包括ADS在内的空气污染物之间的相互作用应该引起关注。因此，本研究对柳杉花粉的形态变化及其致敏物质(Cry J1)的洗脱行为进行了研究。我们的结果证实了细小的子代变应原颗粒的存在，这种颗粒在大小上明显不同于亲本花粉颗粒。降雨后晴天，大气中细致敏颗粒物增多，粗致敏颗粒物减少。而细颗粒物的质量浓度与粗颗粒物中Cry j-1的质量水平之间的相关性较差。可能的原因可能是降雨前高湿度条件下花粉爆裂。此外，当花粉与降雨接触时，所谓的乌比希小体会释放出大量的Cry j1，其中含有大量的过敏原Cry j1。特别是，我们发现空气污染降雨中释放的致敏Cry j1含量中有60%含有来自道路粉尘和ADS的Ca(2+)离子。因此，降雨应是导致花粉致敏物质向细小颗粒转变的主要因素。总而言之，细小的致敏颗粒被雨水转化为细小的颗粒，可以被吸入下呼吸道，导致哮喘的过敏反应。
In Japan, Cryptomeria japonica pollen (with diameter similar to 30 mu m) is scattered during each spring season. Daughter allergenic particles, which are smaller in size than their parent pollen grain and are abundant in fine particles (the particle sizes < 1.1 mu m, PM(1.1)), are released in the atmosphere. The daughter allergenic particles of pollen can be transported in the urban atmosphere for a long period of time after their release. In particular, the daily variation delays in the peaks of allergenic Cry j 1 concentrations compared with the peaks of airborne parent pollen counts were observed in high levels during 1 or 2 sunny days after rainfall. In addition, long range transportation of Asian dusts (ADS) from the East Asian continent was also found during the pollen scattering seasons in Japan. Therefore, the interaction between pollen and air pollutants, including ADS, should be of concern. Thus, in this study, the morphological change of Cryptomeria japonica pollen and the elution behavior of its allergenic contents (Cry j 1) were investigated. Our results confirmed the existence of fine daughter allergen particles, which are clearly differ from the parent pollen grains in size. Fine allergenic particles in atmosphere were increased, while coarse allergenic particles were decreased on sunny days after rainfall. However, the correlation between the mass concentrations of fine particles and mass levels of Cry j 1 in coarse particles (the particle sizes > 7.0 mu m) was poor. The possible reason may be pollen burst at high humidity before rainfall. Additionally, Cry j 1 contents were emitted from the so-called Ubisch body, which contains allergenic Cry j 1 abundantly when pollen was in contact with rainfall. In particular, we found that 60% of allergenic Cry j 1 contents released in air polluted rainfall contained Ca(2+) ion derived from road dust and ADS. Therefore, rainfall should be a main factor to induce transition of pollen allergenic contents to fine particles. In conclusion, allergenic particles which are small sized and translated into fine particles by rainfall can be inhaled into the lower respiratory tract and contribute to the hypersensitivity of asthma.