Effect of Route of Breathing on Response to Exposure in a Swine Confinement Building

Abstract

Exposure of naive subjects to swine buildings results in acute nasal, lung, and peripheral blood inflammatory responses with an increase in nonallergic airway responsiveness. Because nasal passages filter large particles and soluble gases and because swine building exposure results in an acute inflammatory response at this level, we questioned what effect breathing through or avoiding this route would have on local and systemic inflammation. Nine normal young men 23 to 37 yr of age were exposed for 5 h to a swine building, once breathing normally and once with the mouth occluded (n = 8) (Protocol 1) or the nose occluded (n = 4) (Protocol 2); three subjects participated in both protocols. For each protocol each subject underwent a methacholine challenge for PC20 measurement, a nasal lavage, venous blood puncture, and a bronchoalveolor lavage (BAL) once before and once after each swine building exposure. Bronchial responsiveness as measured by PC20 decreased in most subjects after swine building exposure and was not influenced by the route of breathing. Nasal lavage neutrophils increased tenfold after each swine exposure, except when the nose was occluded where no alteration was observed. Total BAL cells significantly increased after each exposure to the swine building, this increase was not modified by the route of breathing. In Protocol 1, white blood cells increased from a baseline level of 7.0 to 10.5 x 10(9) cells/L after exposure with normal breathing and to 10.7 x 10(9) cells/L during nasal breathing exclusively. For Protocol 2, these respective values were: 5.6, 11.7 and 10.4 x 10(9)/L. Interleukins 6 and 8 levels in BAL, nasal washes, and serum were increased by swine building exposure, except in the nasal wash when the nose was occluded. In conclusion, the lung and blood responses to exposure in a swine confinement building are not modified by the route of breathing, suggesting that nasal inflammation and filtration are not important in the process and that small respirable particles and/or gases may be responsible for these responses.

Work-Related Health Effects in Swine Building Workers After Respiratory Protection Use

“…26 This study confirms that working in swine confinement buildings results in cross-shift decline in lung function and increases blood neutrophils and IL-6. In contrast to previous studies with subjects naive to the environment 10,12,27 (where circulating TNF levels either increased or remained constant at high concentrations), plasma TNF stayed at low concentrations and tended to decrease further during both visits. This could be an indication of a difference in the immune reactions between a first time exposure and repeated exposures.…”

“…10,11 Increases in tumor necrosis factor (TNF) have been found in some 4 but not in all studies, 12 but downstream effects of TNF release probably also depend on the concentration of its receptors. The TNF receptors have been shown to increase locally following bronchial endotoxin instillation in humans.…”

Farming practices and the respiratory health risks of swine confinement buildings

“…It is presently not clear which of these substances or if their combination is responsible for the health effects of SCB. It has recently been shown that nasal filtration did not prevent lung and systemic effects of swine confinement building air, suggesting that small respirable particles are involved [18]. Canola oil spray offers significant protection; the exact effect of spraying oil on the quality of the air in SCB has however not been determined [19].…”

The relationship between chronic rhinosinusitis and occupation: The 1998, 2001, and 2005 Korea National health and nutrition examination survey (KNHANES)

“…In the agricultural setting, inhalation exposure to high concentrations of mixed organic dusts, which contain bacteria, fungi, endotoxins, glucans, and mycotoxins, has been associated with organic toxic syndrome and acute febrile illness. Cormier et al [1988] showed increased interleukin-6 and -8 levels in nasal washes after exposure in a swine confinement building.…”