Organic dust disease of airways

Abstract

Exposure to aerosols of organic dusts such as coffee, tea, spices, soy, fur, and animal food in an occupational setting can affect the respiratory health of industrial workers. Based on our experience with workers from many small industries processing organic materials, we discuss the clinical features and possible mechanisms responsible for the respiratory impairment associated with these types of dust exposure. Significantly higher prevalences for most chronic respiratory symptoms were found among exposed workers than among control workers. Smoking appears to aggravate these symptoms. A large number of exposed workers complained of acute symptoms which developed during the work shift. In exposed workers, significant across-shift reductions in lung function were recorded for all spirometric tests, but particularly for the flow rates at 50% and 25% of vital capacity on maximum expiratory flow-volume curves. Comparison of preshift measured ventilatory capacity tests with predicted normal values indicates that these workers demonstrate obstructive changes affecting primarily flow rate at low lung volumes. The data suggest that exposure to organic aerosols in industrial settings, particularly in conjunction with smoking, may be associated with the development of chronic obstructive lung disease.

Respiratory Effects of Chronic Animal Feed Dust Exposure

“…There is increasing evidence of the deleterious effects of organic dust on respiratory functions in exposed workers [1][2][3][4][5] . Animal feed dust is a complex organic dust composed mainly of grain (corn, wheat, barley, rye, oats), residues of crushed seeds, waste products from the food industry (corn bran, wheat bran), fats, molasses, vitamins and minerals.…”

“…Numerous studies 1,[6][7][8][9][10] have demonstrated that grain dust is a biological active dust capable of inducing respiratory tract irritation and inflammation, and increases airways reactivity with temporary or permanent persistent functional changes.…”

“…Hypersensitivity pneumonitis is rare 15) . Reactions of the respiratory system to organic dust may potentially be caused or aggravated by a number of different mechanisms including nonspecific airway irritation, allergic reactions to antigens in dust, inflammatory reactions to various agents widely distributed in organic dust such as endotoxins 1) . Organic dusts are frequently contaminated by endotoxins and endotoxin exposure can be an important factor in the development of respiratory impairment 9,[16][17][18] .…”

“…Organic dusts are frequently contaminated by endotoxins and endotoxin exposure can be an important factor in the development of respiratory impairment 9,[16][17][18] . Also organic dust causes changes in the clearance of particles from the lungs leading to deposition 1) . The inflammatory effects of organic aerosols also have been explained by nonspecific or specific release of mediators in the airway or by the presence of histamine or other mediators in these organic dusts which may directly constrict airway smooth muscle and activate cells and chemotoxins 1) .…”

“…Also organic dust causes changes in the clearance of particles from the lungs leading to deposition 1) . The inflammatory effects of organic aerosols also have been explained by nonspecific or specific release of mediators in the airway or by the presence of histamine or other mediators in these organic dusts which may directly constrict airway smooth muscle and activate cells and chemotoxins 1) . Some investigators 1) have suggested that bronchial hyperresponsiveness may be due to increased permeability of the airway mucosa to irritants secondary to epithelial damage, resulting in a direct effect on airway smooth muscle contraction.…”