Airborne Dust, Ammonia, Microorganisms, and Antigens in Pig Confinement Houses and the Respiratory Health of Exposed Farm Workers

Abstract

This study investigated the environmental conditions on pig farms and the respiratory health of pig farmers and their immunological response to airborne contaminants. Airborne concentrations of dust and ammonia were measured in 20 pig houses; viable microorganisms, endotoxins, and aeroallergens were measured in 6 of these houses, chosen to represent the range in dustiness. The 29 farmers employed on the farms completed a questionnaire and underwent lung function tests; 24 of them provided blood samples for the measurement of specific IgE and IgG antibody to extracts of pig squames and urine, feed components, and bacterial isolates. Mean airborne dust and ammonia concentrations in the pig houses ranged from 1.66 to 21.04 mg/m3 and from 1.50 to 13.23 ppm, respectively. Factors affecting these concentrations include time of year, feed systems used, and levels of ventilation. There was no direct relationship between airborne dust and ammonia concentrations. Airborne microorganisms ranged from 10(5) to more than 10(7) colony-forming units (cfu)/m3; most were bacteria, with few fungi or thermophilic actinomycetes isolated. Gram-positive bacterial genera (Staphylococcus, Micrococcus, and Bacillus spp.) predominated. Concentrations of endotoxin in collected airborne dust were low. Work-related respiratory symptoms, typically chest tightness/wheeze and nasal and eye irritation, were reported by 23 of the 29 workers. Three farmers had specific IgE to pig squames or urine and eight to feed components but none to the microbial extracts. Specific IgG to pig squames or urine and to feed components was demonstrated in 14 and 9 workers, respectively. Specific IgE responses occurred mainly in subjects with chest tightness or wheeze, although specific IgG responses were not related to symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Shotgun Pyrosequencing Metagenomic Analyses of Dusts from Swine Confinement and Grain Facilities

“…Prior efforts to measure the presence and significance of different microbial taxa in these dusts have primarily focused on traditional culture-dependent techniques [16]–[18], [31]–[33]. Total bacterial concentrations in swine confinement facility dust-laden ambient air have been estimated from as low as 10 4 cfu/m 3 to as high as 10 8 cfu/m 3 [18], [23], [31], [32], [34], [35].…”

“…Though there is a paucity of data, the most commonly cultured microorganisms in swine dust are gram (+) bacteria dominated by Staphylococcus, Micrococcus, and Bacillus sp . [16]. Many fungal species have also been detected; these include Acremonium, Aspergillus, Penicillium, and Cladosporium [17]–[20].…”

Culturable Airborne Bacteria in Outdoor Poultry-Slaughtering Facility

“…It was reported that airborne bacteria in pig confinement buildings in the United States, Canada, The Netherlands, Sweden, and Poland reach levels of 10 5 to 10 6 CFU m −3 (1, 3, 4, 6, 8, 11) and up to 10 7 CFU m −3 in the United Kingdom (5). Gram-positive bacteria are the predominant bacteria present (1, 3, 5–7, 11, 16) and microbial genera have been identified in many swine confinement units (3–5, 7, 8). Some organisms are recognized as potential agents inducing extrinsic allergic alveolitis and causing pathogenic infection (4).…”

Airborne Multidrug-Resistant Bacteria Isolated from a Concentrated Swine Feeding Operation

“…Mean total bacterial concentrations can range from 10 4 to 10 7 colony forming units (CFU)/m 3 (Clark et al 1983; Cormier et al 1990; Crook et al 1991; Predicala et al 2002). Specific bacteria detected in the air of swine CAFOs have included the following potential human pathogens: Enterococcus , Staphylococcus , Pseudomonas , Bacillus , Listeria , and Escherichia coli (Cormier et al 1990; Crook et al 1991; Predicala et al 2002). Yet, to date, these airborne pathogens have not been assessed for resistance to antibiotics that are commonly used in both swine production and clinical medicine.…”