Respiratory symptoms: associations with pesticides, silos, and animal confinement in the Iowa Farm Family Health and Hazard Surveillance Project.

BACKGROUND: Farmers are at risk for airways diseases resulting from exposures which include organic agents and chemicals on the farm. Few data on airways disease and farm exposures are available from population-based studies. The Iowa Farm Family Health and Hazard Surveillance Project provided the opportunity to assess associations between symptoms of airway disease and several farm exposures, including pesticides, grain dust, animal confinement, and exposures from silos, in a population-based study.
METHODS: A stratified two-stage cluster sample was used to provide a representative farmer sample from the state. Participants provided questionnaire responses concerning demographic, respiratory symptoms, smoking, and exposure information. Associations between farm exposures and airways disease symptoms were assessed in the 385 farmer participants using chi(2) analysis and logistic regression analysis adjusting for age and smoking.
RESULTS: The most frequently reported respiratory symptoms were flu-like symptoms in connection with dusty work (22%), dyspnea (21%), and phlegm (15%). Current smoking was uncommon (13%). Among farmers, applying pesticides to livestock was associated with significantly increased odds of phlegm (OR = 1.91, 95% CI 1.02-3.57), chest ever wheezy (OR = 3.92, 95% CI 1.76-8.72), and flu-like symptoms (OR = 2.93, 95% CI 1.69-5.12) in models adjusting for age and smoking. Conventional vertical silos were significantly associated with increased odds of chest ever wheezy (OR = 2.75, 95% CI 1.23-6.12) and flu-like symptoms (OR = 2.40, 95% CI 1.31-4.37). There were also significant associations between several respiratory symptoms and the presence of animal confinement facilities on the farm.
CONCLUSIONS: The association between insecticide application to livestock and symptoms of airways disease is a new finding that could lead to further study of specific airway responses and exposures associated with this practice. Results confirming associations between respiratory symptoms and conventional vertical silos may be important in future studies aimed at prevention and control of exposures in those farm buildings. Copyright 2000 Wiley-Liss, Inc.