Farm Worker Health

Ahman, M.; Holmstrom, M.; Kolmodin-Hedman, B.; Thelin, A. (2001). Nasal symptoms and pathophysiology in farmers. International Archives of Occupational and Environmental Health 74(4): 279-84, ISSN: 0340-0131.

Abstract: Increased morbidity and mortality in lower airway diseases have been reported among farmers. The aim of this study was to assess upper airway problems in farmers. Twenty-five dairy farmers, 20 pig farmers, 21 grain farmers and 19 control subjects were studied, by use of questionnaire, skin-prick test, dynamic spirometry, nasal inspection, acoustic rhinometry (before and after a decongestant) as well as by determinations of the olfactory threshold and nasal lavage (NAL) concentrations of eosinophil cationic protein (ECP), myeloperoxidase (MPO) and albumin. RESULTS: Compared with the control group, farmers had more complaints of work-related symptoms from the lower airways, and symptoms of smell impairment, and more often had nasal polyps and hyperaemia of the nasal mucosa. They also had higher levels of MPO in NAL (especially dairy farmers and pig farmers), and a tendency to more swollen nasal mucosa and lower olfactory threshold (especially grain farmers). CONCLUSIONS: The farmers had more pathological findings in their nasal mucosa, possibly indicating effects of allergens and irritants in their work environment.More studies are needed to evaluate work environment factors causing these pathological findings in farmers.

Keywords: farm workers, nasal polyps, diagnosis, respiratory hypersensitivity, etiology, age, questionnaires, respiratory function tests.

Asmar, S.; Pickrell, J.A.; Oehme, F.W. (2001). Pulmonary diseases caused by airborne contaminants in swine confinement buildings. Veterinary and Human Toxicology 43 (1): 48-53, ISSN: 0145-6296.

NAL Call No.: SF601 A47.

Abstract: Exposure to toxic gases and particles or dusts while working or living in confinement animal systems pose a pulmonary health hazard. The severity of lung impairment from exposure to such environment is investigated using intratracheal instillation, intratracheal nebulization, and inhalation procedures. Ability to deliver particles with intratracheal instillation that are evenly distributed throughout the lung depends on the material used for injection. Pulmonary histopathology reflects anatomic changes following inhalation or instillation of chemicals or particles. Endobronchial saline washings of bronchioles and alveoli allow measurement of markers of pulmonary inflammation such as total nucleated cell (leukocyte) counts and those of macrophages, neutrophils and lymphocytes; TNF-alpha, and collagen concentration are used to further evaluate pulmonary response to endotoxin or dust exposure. Alveolar epithelial cells have an important role in clearing pulmonary fluid and maintaining the structure of lung tissue. After repeated exposure, damage to epithelial cells may result in their death, causing edema and collagen deposition that may lead to fibrosis.

Keywords: swine health, farm worker health, air pollutants, environmental toxicity, dust, housing, lung diseases, pulmonary inflammation, macrophages, neutrophils, lymphocytes.

Chang, C.W.; Chung, H.; Huang, C.F.; Su, H.J.J. (2001). Exposure of workers to airborne microorganisms in open-air swine houses. Applied and Environmental Microbiology 67 (1) : 155-161, ISSN: 0099-2240.

NAL Call No.: 448.3 Ap5.

Keywords: housing, farrowing houses, human health, air microbiology, microbial flora, air spora, bacteria, fungi, gram negative bacteria, bacterial count, microbial contamination, pig farming, sanitation, hygiene, Taiwan.

Djuricic, S.; Zlatkovic, M.; Babic, D.D.; Gligorijevic, D.; Plamenac, P. (2001). Sputum cytopathological findings in pig farmers. Pathology, Research and Practice. 197(3):145-55, ISSN: 0344-0338.

Abstract: The purpose of this study is to compare the cytological changes in the respiratory tracts of pig farmers exposed to an environment of swine confinement buildings with control, non-exposed subjects living in the same geographical area. Spontaneously produced sputum specimens were obtained from 133 pig farmers and 120 control subjects, all clinically healthy, and grouped according to smoking habits and sex. The findings of siderophages, eosinophils, abnormal columnar cells and respiratory spirals were significantly more frequent in the pig farmers. Siderophages were noted in 25.6% of pig farmers and in 5% of control subjects. By logistic regression analysis, pig farming is the single predictive factor for siderophages and eosinophils. For other cytological abnormalities, except Creola bodies and granular debris, smoking is the most significant predictive variable, but pig farming, age and male sex also correlate with smoking. Atypical squamous metaplasia was observed in 11.3% of pig farmers and in 5.8% of control subjects. These findings are in concordance with previous epidemiological and clinical studies and also reveal a new aspect of the harmful effect of pig farming exposure to the vascular and epithelial structures of the respiratory tract. It also demonstrates the usefulness of the simple method of sputum cytological analysis.

Keywords: occupational health, pig farmers, smoking, non-smoking, confinement buildings, respiratory tract disorders, siderophages, eosinophils, atypical squamous metaplasia, sputum cytological analysis.

Drobeniuc, J.; Favorov, M.O.; Shapiro, C.N.; Bell, B.P.; Mast, E.E.; Dadu, A.; Culver, D.; Iarovoi, P.; Robertson, B.H.; Margolis, H.S. (2001). Hepatitis E virus antibody prevalence among persons who work with swine. Journal of Infectious Diseases 184(12):1594-7, ISSN: 0022-1899.

NAL Call No.: 448.8 J821.

Abstract: Prevalence of antibody and risk factors to hepatitis E virus (HEV) infection were determined in a cross-sectional study of 2 group-matched populations: swine farmers (n=264) and persons without occupational exposure to swine (n=255) in Moldova, a country without reported cases of hepatitis E. The prevalence of HEV infection was higher among swine farmers than among the comparison group (51.1% vs. 24.7%; prevalence ratio, 2.07; 95% confidence interval [CI], 1.62-2.64). In multivariate analysis, HEV infection was associated with an occupational history of cleaning barns or assisting sows at birth (odds ratio [OR], 2.46; 95% CI, 1.52-4.01), years of occupational exposure (OR, 1.04 per year; 95% CI, 1.01-1.07), and a history of drinking raw milk (OR, 1.61; 95% CI, 1.08-2.40). HEV infection was not associated with civilian travel abroad or having piped water in the household. The increased prevalence of HEV infection among persons with occupational exposure to swine suggests animal-to-human transmission of this infection.

Keywords: occupational health, pig farmers, hepatitis E virus, zoonosis, cleaning barns, assisting with farrowing, Moldova.

Muller-Suur, C.; Larsson, P.H.; Larsson, K.; Grunewald, J. (2002). Lymphocyte activation after exposure to swine dust: a role of humoral mediators and phagocytic cells. European Respiratory Journal 19 (1): 104-7, ISSN: 0903-1936.

Abstract: Exposure to swine dust causes intense airway inflammation with multifold increase in inflammatory cells and secretion of pro-inflammatory cytokines. This in vitro study focuses on the swine-dust activation of lymphocytes in whole blood, in phagocyte-depleted whole blood and in peripheral blood mononuclear cells (PBMC), in order to investigate whether phagocytic cells and/or soluble mediators are involved in the activation of T-cells following exposure to organic dust from a swine confinement house. T-cell activation was analysed by flow cytometry with double staining for CD3 and the activation marker CD69. Swine dust (50 microg) incubated (24 h) with heparinized whole blood was shown to activate 27.6% of the T-cells, while swine dust incubated with whole blood depleted from phagocytic cells or PBMC only activated 4.5%, and 4.8% of the T-cells, respectively. Plasma separated from whole blood preincubated with swine dust for 24 h stimulated as much as 32.4% of PBMC T-cells and contained high levels of interleukin (IL)-12 (14 pg x mL) and interferon (IFN)-gamma (2284 pg x mL(-1)), while plasma from PBMC incubated with swine dust contained low levels of IL-12 (2 pg x mL(-1)) and IFN-gamma (196 pg x mL(-1)). This study demonstrates that activation of T-cells by organic dust from a swine confinement building seems to require phagocytic cells, most likely acting through the release of soluble mediators. Also, conditioned plasma from swine-dust exposed whole blood, which was capable of activating T-cells, contained high concentrations of interleukin-12 and interferon-y.

Keywords: farm workers, exposure to swine dust, swine confinement house, airway inflammation, cytokines, phagocytic cells, T-cell activation.

Radon, K.; Danuser, B.; Iversen, M.; Jorres, R.; Monso, E.; Opravil, U.; Weber, C.; Donham, K.J.; Nowak, D. (2001). Respiratory symptoms in European animal farmers. European Respiratory Journal 17 (4): 747-54, ISSN: 0903-1936.

Keywords: pig farmers, occupational airway disease, respiratory hypersensitivity, dose-response relationship, hours worked, etiology, wheezing, shortness of breath, asthma, nasal allergies, chronic phlegm, questionnaire, European Community Respiratory Health Survey (ECRHS), Denmark, Germany, Switzerland, Spain.

Withers, M.R.; Correa, M.T.; Morrow, M.; Stebbins, M.E., Seriwatana, J.; Webster, W.D.; Boak, M.B.; Vaughn, D.W. (2002). Antibody levels to hepatitis E virus in North Carolina swine workers, non-swine workers, swine, and murids. American Journal of Tropical Medicine and Hygiene 66(4):384-8, ISSN: 0002-9637.

NAL Call No.: 448.8 Am326.

Abstract: In a cross-sectional serosurvey, eastern North Carolina swine workers (n = 165) were compared with non-swine workers (127) for the presence of antibodies to hepatitis E virus as measured by a quantitative immunoglobulin enzyme-linked immunosorbent assay. Using a cutoff of 20 Walter Reed U/ml, swine-exposed subjects had a 4.5-fold higher antibody prevalence (10.9%) than unexposed subjects (2.4%). No evidence of past clinical hepatitis E or unexplained jaundice could be elicited. Swine (84) and mice (61), from farm sites in the same region as exposed subjects, were also tested. Antibody prevalence in swine (overall = 34.5%) varied widely (10.0-91.7%) according to site, but no antibody was detected in mice. Our data contribute to the accumulating evidence that hepatitis E may be a zoonosis and specifically to the concept of it as an occupational infection of livestock workers.

Keywords: occupational health, pig farmers, hepatitis E virus, zoonosis, antibody prevalence, serosurvey, North Carolina.

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