title: [Associations between bioaerosols coming from livestock facilities and asthmatic symptoms in children].
abstract: Although health effects of occupational exposures to livestock emissions are known, potential associations between living in the neighbourhood of intensive livestock facilities and the risk of developing respiratory or allergic diseases are still under discussion. During routine school entry examinations in selected rural districts in Lower Saxony we asked parents about respiratory and allergic symptoms of their 5-6 year old children. A questionnaire with standardised questions of the ISAAC-Studies for respiratory and allergic symptoms and corresponding risk factors was used. Complementarily the children were examined for visible signs of flexural dermatitis and in a subsample the SX1-test was used as an in vitro test for inhalative IgE mediated sensibilisations in capillary blood. Individual exposure to bioaerosols (endotoxin, fungi, bacteria and total dust) coming from livestock facilities was estimated using a Lagrange dispersion model based on the emission rates and locations of the lifestock facilities. A total of 7943 questionnaires (response rate over 85%) were analysed, of which 3867 could be used for the correlation analyses between exposition to endotoxin and asthmatic symptoms. Multivariate logistic regression models were analyzed, considering an atopic disease of the parents as a potential effect modifier and not as a confounder. The prevalence of allergic and asthmatic symptoms is similar to the results of other comparable studies, e. g. "wheezing in the last 12 months" 15.9% for boys and 12.9% for girls. An increase in the prevalence of asthmatic symptoms for higher endotoxin levels was observed only for children of atopic parents. The multivariate controlled odds ratio for one unit logarithm endotoxin concentrations is 1.15, p-value 0.016. Similar effects were observed for other asthma indicators, but not for subjective criteria of the exposition, e. g. the distance to the next large livestock facility guesstimated by parents. Among the overall analysed potential associations between exposition to bioaerosols and asthmatic and allergic symptoms only a few were statistically significant. The discussed association between endotoxin and asthmatic symptoms in predisposed children needs further investigation.
authors.affiliation: Niedersächsisches Landesgesundheitsamt, Hannover. Michael.Hoopmann@nlga.niedersachsen.de
authors.forename: M
authors.initials: M
authors.lastname: Hoopmann
authors.forename: O
authors.initials: O
authors.lastname: Hehl
authors.forename: F
authors.initials: F
authors.lastname: Neisel
authors.forename: T
authors.initials: T
authors.lastname: Werfel
mesh_terms: D000367:Age Factors; D000485:Allergens / Q000276:immunology; D000818:Animals; D000829:Animals, Domestic / Q000276:immunology; D001249:Asthma / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004731:Endotoxins / Q000009:adverse effects / Q000276:immunology*; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006799:Housing, Animal; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D015995:Prevalence; D012135:Respiratory Sounds / Q000175:diagnosis; D012307:Risk Factors; D012424:Rural Population; D011795:Surveys and Questionnaires
chemical_list: D000485:Allergens; D004731:Endotoxins; D007073:Immunoglobulin E