BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Authors: Philipp M Hagemann; Stephanie Nsiah-Dosu; Jennifer Elisabeth Hundt; Karin Hartmann; Zane Orinska Journal: Front Immunol Date: 2019-05-29 Impact factor: 7.561
Authors: Linda Tizek; Elisa Redlinger; Johannes Ring; Kilian Eyerich; Tilo Biedermann; Alexander Zink Journal: World Allergy Organ J Date: 2022-01-27 Impact factor: 4.084
Authors: Jenni M Mäki; Pirkka V Kirjavainen; Martin Täubel; Eija Piippo-Savolainen; Katri Backman; Anne Hyvärinen; Pauli Tuoresmäki; Balamuralikrishna Jayaprakash; Joachim Heinrich; Gunda Herberth; Marie Standl; Juha Pekkanen; Anne M Karvonen Journal: Sci Rep Date: 2021-03-05 Impact factor: 4.379