Sudre B, Vacheyrou M, Braun-Fahrländer C, Normand A-C, Waser M, Reboux G, Ruffaldi P, von Mutius E, Piarroux R
CNRS-Université de Franche-Comté/UMR 6249 Laboratoire Chrono-environnement, Parasitology-Mycology departement, University Hospital of Besançon, France.
Allergy. 2009 Jul;64(7):1068-73. doi: 10.1111/j.1398-9995.2009.01958.x. Epub 2009 Feb 13.
There is evidence of an allergy protective effect in children raised on farm. It has been assumed that microbial exposure may confer this protection. However in farm, little attention has been given to the pollen level and to concomitant microbiological exposure, and indoor pollen concentrations have never been precisely quantified.
The kinetics of pollen in dairy farms have been studied in a pilot study (n = 9), and exposure in a sub-sample of the ongoing European birth cohort PASTURE (n = 106). Measurements of viable microorganisms and pollen were performed in air samples. To identify factors that modulate the pollen concentration multivariate regression analyses were run.
Indoor pollen (95% of Poaceae fragments and grains) were significantly higher in winter than in summer (P = 0.001) and ranged between 858 to 11 265 counts/m(3) during feeding in winter, thus exceeding typical outdoor levels during the pollen season. Geometric mean in French farms was significantly higher than in German and Swiss farms (7 534, 992 and 1 079 count/m(3), respectively). The presence of a ventilation system and loose housing systems significantly reduced indoor pollen levels. This pollen concentration rise after feeding was accompanied by an increase in fungal and actinomycetal levels, whereas the concentration of bacteria was not associated with feeding.
Farmers and their children who attend cowsheds during the feeding sessions are exposed perennially to high pollen concentrations. It might be speculated that the combined permanent exposure to microbes from livestock and grass pollen may initiate tolerance in children living on a farm.
有证据表明在农场长大的儿童具有过敏保护作用。据推测，接触微生物可能赋予这种保护。然而，在农场中，花粉水平和伴随的微生物接触很少受到关注，室内花粉浓度从未被精确量化。
在一项试点研究（n = 9）中研究了奶牛场花粉的动态变化，并在正在进行的欧洲出生队列PASTURE的一个子样本（n = 106）中进行了接触情况研究。对空气样本中的活菌和花粉进行了测量。为了确定调节花粉浓度的因素，进行了多变量回归分析。
室内花粉（95%为禾本科碎片和颗粒）在冬季显著高于夏季（P = 0.001），冬季喂食期间浓度范围为858至11265个/立方米，超过了花粉季节典型的室外水平。法国农场的几何平均数显著高于德国和瑞士农场（分别为7534、992和1079个/立方米）。通风系统和开放式畜舍系统的存在显著降低了室内花粉水平。喂食后花粉浓度的升高伴随着真菌和放线菌水平的增加，而细菌浓度与喂食无关。
在喂食期间进入牛棚的农民及其子女常年暴露于高花粉浓度中。可以推测，长期同时接触来自家畜的微生物和草花粉可能会使农场儿童产生耐受性。
