Laaidi Mohamed, Laaidi Karine, Besancenot Jean-Pierre, Thibaudon Michel
Climat et Santé, Centre d'Epidémiologie de Populations, Faculté de Médecine, Dijon Cedex, France.
Ann Allergy Asthma Immunol. 2003 Aug;91(2):195-201. doi: 10.1016/S1081-1206(10)62177-1.
Ragweed is an annual, herbaceous, wind-pollinated plant that is responsible for strong allergies. In France, it is mainly present in the region of Lyon, where it threatens the health of the population.
To analyze annual, daily, and bihourly pollen concentrations in the air to determine the characteristics of ragweed pollination and in particular its diurnal rhythm.
Ragweed pollens were sampled from 1987 to 2001 by a Hirst volumetric trap calibrated to handle a flow of 10 L/min of air, which roughly corresponds to a human breathing rhythm. Pollen counts were performed on a daily and bihourly basis, which is of particular importance in allergologic practice.
Ragweed pollination occurs from the beginning of August to the end of September. Annual and daily levels of pollen have increased significantly since 1987. The pronounced diurnal periodicity shows a peak from 9 to 11 AM. Pollen counts increased from the early morning with temperature increase and relative humidity decrease.
Daily pollen counts of this strongly allergic plant are above the allergic thresholds commonly defined, limiting the interest of eradication campaigns. Thus, prevention of ragweed allergy depends on informing and educating the public through reports and updates. Diurnal variations seem to be the most crucial part of such a report, allowing allergy patients to adapt their daily outdoor activities in respect to the pollen peaks and off-peaks.
豚草是一种一年生草本风媒植物，会引发强烈过敏反应。在法国，它主要出现在里昂地区，对当地居民的健康构成威胁。
分析空气中豚草花粉的年度、每日和每两小时浓度，以确定豚草授粉的特征，尤其是其昼夜节律。
1987年至2001年期间，使用经校准可处理每分钟10升空气流量的赫斯特容量捕集器采集豚草花粉，该流量大致相当于人类的呼吸节奏。每天和每两小时进行一次花粉计数，这在变态反应学实践中尤为重要。
豚草授粉期为8月初至9月底。自1987年以来，花粉的年度和每日水平显著增加。明显的昼夜周期性显示上午9点至11点出现峰值。花粉计数从清晨开始随着温度升高和相对湿度降低而增加。
这种强致敏性植物的每日花粉计数高于通常定义的过敏阈值，这限制了根除运动的意义。因此，豚草过敏的预防依赖于通过报告和更新向公众宣传和教育。昼夜变化似乎是此类报告中最为关键的部分，能让过敏患者根据花粉峰值和低谷来调整日常户外活动。
