Article Text
Abstract
Objectives Exposure to farm environments during childhood and adult life seems to reduce the risk of atopic sensitisation. Most studies have been conducted among farmers, but people living in rural areas may have similar protective effects for atopy. This study aims to investigate the association between residential proximity to livestock farms and atopy among non-farming adults living in a rural area in the Netherlands.
Methods We conducted a cross-sectional study among 2443 adults (20–72 years). Atopy was defined as specific IgE to common allergens and/or total IgE ≥100 IU/mL. Residential proximity to livestock farms was assessed as 1) distance to the nearest pig, poultry, cattle or any farm, 2) number of farms within 500 m and 1000 m, and 3) modelled annual average fine dust emissions from farms within 500 m and 1000 m. Data were analysed with multiple logistic regression and generalised additive models.
Results The prevalence of atopy was 29.8%. Subjects living at short distances from farms (<327 m, first tertile) had a lower odds for atopy compared with subjects living further away (>527 m, third tertile) (OR 0.79, 95% CI 0.63 to 0.98). Significant associations in the same direction were found with distance to the nearest pig or cattle farm. The associations between atopy and livestock farm exposure were somewhat stronger in subjects who grew up on a farm.
Conclusions Living in close proximity to livestock farms seems to protect against atopy. This study provides evidence that protective effects of early-life and adult farm exposures may extend beyond farming populations.
- atopy
- livestock farm exposure
- allergy
- residential proximity
- cross-sectional study
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Footnotes
Contributors FB, LAMS, DJJH, CJY and CBMM contributed to the study concept and design. FB and EJMK coordinated and conducted the medical examination. FB performed analysis and drafted the manuscript. All authors contributed to the interpretation of the results and performed critical revision of the manuscript, and all approved the final version before submission.
Funding The Livestock Farming and Neighbouring Residents’ Health (VGO) study was funded by the Ministry of Health, Welfare and Sports and the Ministry of Economic Affairs of the Netherlands, and supported by a grant from the Lung Foundation Netherlands (Grant number: 3.2.11.022).
Competing interests None declared.
Patient consent Obtained.
Ethics approval Medical Ethical Committee of the University Medical Centre Utrecht.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement In consultation with the Medical Ethical Committee that approved the study protocol, data from the VGO study are not publicly available due to privacy protection ofparticipants. The study’s privacy regulations statedthat only researchers from NIVEL, IRAS, and RIVM(consortium partners) have access to the studydatabase. Sharing an anonymized and de-identifieddataset is not possible as it would still containElectronical Medical Records and the personal dataof participants, which could potentially lead to theidentification of subjects. Researchers may reach aprivacy agreement to access the data by contacting DJJH (d.heederik@uu.nl) or LAMS (l.a.smit@uu.nl).