Determinants of longitudinal changes in spirometric function among swine confinement operators and farmers.
Schwartz-DA; Donham-KJ; Olenchock-SA; Popendorf-WJ; Fossen-DS; Burmeister-LF; Merchant-JA
Am J Respir Crit Care Med 1995 Jan; 151(1):47-53
A population based study was conducted to evaluate the determinants of longitudinal changes in airflow in a population of swine operators, and to determine whether specific elements of the agricultural aerosol or cross shift changes in airflow were related to longitudinal decrements in lung function. The sample consisted of 168 swine confinement operators and 127 neighborhood farmer control subjects. Spirometric measurements such as forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and mid expiratory flow (FEF(25-75)) were taken. Field visits and environmental evaluations were also conducted. The average follow up time was approximately 2 years. Regression models were developed for the evaluation of the association between longitudinal changes in lung function and a set of confounders/covariates. The swine confinement operators were found to have less farming experience when compared to farmer control subjects, and were found to be exposed to higher environmental dust concentrations and other irritants. The cohort was exposed to slightly lower measures of airflow and exhibited greater declines in FEV1, FVC, and FEF(25-75). Independent relations between longitudinal declines in spirometric measures of lung function and cross shift declines in spirometric measures of lung function, higher levels of endotoxin in bioaerosols, and working in the swine confinement setting were observed after controlling for confounding factors. Cross shift declines in lung function and higher levels of endotoxin appeared to be important determinants of accelerated declines in airflow among agricultural workers. Given the independent association between endotoxin concentration in bioaerosols and accelerated longitudinal declines in lung function, the authors suggest that minimizing exposure to agricultural aerosols may decrease the incidence of chronic pulmonary disease among agricultural workers.
NIOSH-Author; NIOSH-Grant; Pulmonary-system-disorders; Lung-function; Long-term-study; Pulmonary-function-tests; Lung-irritants; Airborne-particles; Epidemiology; Animal-husbandry-workers
Internal Medicine University of Iowa Pulmonary Disease Division Iowa City, IA 52242
Pulmonary System Disorders
American Journal of Respiratory and Critical Care Medicine
University of Iowa, Iowa City, Iowa