A Cross Sectional Study of Respiratory and Allergy Status in Dairy Workers

ABSTRACT

Introduction

Workers on dairy farms face exposures to organic dusts and endotoxin. At the same time, a number of studies of farmers have reported a lower prevalence of asthma in farmworkers compared to persons without farm contact. The “hygiene hypothesis” suggests that early life exposures on farms could be protective against allergic disease and asthma. Such protective relationships are less well studied in adult farm workers.

Methods

A cross-sectional analysis of respiratory function and allergy status was performed in a sample of dairy farm workers (n = 42) and community controls (n = 40). Measures of respiratory status (spirometry, exhaled nitric oxide FeNO, self-reported symptoms) and levels of total and bovine-specific IgE were compared between the groups.

Results

Prevalence of self-reported asthma and most respiratory symptoms was similar in the two groups, with the exception of increased report of dyspnea among dairy workers. In the dairy workers, level of lung function was not reduced and FeNO was not increased. In unadjusted and adjusted models, dairy work was not associated with reduced lung function or increased airway inflammation. Mean IgE levels did not differ significantly between workers and controls, but elevated bovine-specific IgE was detected only among dairy workers, with an apparent association between elevated bovine IgE and increased FeNO.

Conclusion

While dairy workers did not demonstrate increased asthma prevalence compared to controls, sensitization to bovine antigen in several workers appeared to be associated with airway inflammation. Occupational health programs for dairy workers should consider the risk of animal allergy as part of respiratory health protection efforts.

KEYWORDS:

• Dairy workers
• occupational allergy
• occupational asthma

Acknowledgments

The authors sincerely thank the participating dairy workers and community controls and express their appreciation to Gemina Garland-Lewis, Erica Grant, Tino Alonso, Eric Gambino, Sally Trufan, the COHR team, and the PNASH faculty and staff for their support of this work.

The authors would like to acknowledge the study participants for their involvement in the study, as well as the owners and management of the dairy farms where workers were recruited.

Disclosure statement

The authors declare that they have no relevant or material financial interests that relate to the research described in this paper.

Additional information

Funding

Research reported in this manuscript was supported by the National Institute for Occupational Safety and Health (CDC/NIOSH) under Federal Training Grant T42OH008433 as well as CDC/NIOSH grant U54 OH 007544. The content is solely the responsibility of the authors and does not necessarily represent the official views of NIOSH