Inhalation of swine dust induces cytokine release in the upper and lower airways

In healthy subjects, acute inhalation of swine dust causes an influx of inflammatory cells into the airways and increased bronchial responsiveness. The exposure may also cause fever and generalized symptoms. It seems likely that proinflammatory cytokines are involved in the response to inhaled swine dust. Nasal and bronchoalveolar lavage (BAL) were performed before, and 7 and 24 h after the start of 3 h exposure to swine dust, during a period of work in a swine confinement building, in 22 healthy subjects. Lavage fluids were analysed with regard to the cellular response and concentrations of interleukin (IL)-1 alpha, IL-1 beta, IL-6 and tumour necrosis factor-alpha (TNF-alpha). Each subject carried personal samplers for exposure measurements. Inhalable dust and airborne endotoxin, 3-hydroxylated (2-OH) fatty acid and muramic acid were measured. Bronchial responsiveness to methacholine was investigated 1-2 weeks before and 7 h after the start of the exposure. Exposure caused fever (> 38 degrees C) in three subjects, and approximately 25% of the subjects experienced symptoms. Bronchial responsiveness to methacholine increased by 3.5 (1.6-4.8) doubling doses (median (25th-75th percentile)). Following exposure, granulocytes increased more than 50 fold in BAL fluid and more than 40 fold in nasal lavage fluid. IL-1 alpha and IL-1 beta increased significantly in BAL fluid (p < 0.05) and nasal lavage fluid (p < 0.01). IL-6 increased 25 fold in BAL and 15 fold in nasal lavage fluid (p < 0.001). TNF-alpha was below detection limit (0.25 ng.L-1) in most subjects before exposure and increased following exposure to 3.8 (2.4-5.7) and 1.3 (0.6-2.3) ng.L-1 in BAL and nasal lavage fluid, respectively, (p < 0.001). Total inhalable dust was 20.5 (14.6-30.0) mg.m-3 and the concentrations of airborne endotoxin, 3-OH fatty acid and muramic acid were 1.2 (0.8-1.4), 3.5 (2.2-4.5) and 0.9 (0.3-1.9) microgram.m-3, respectively. There was a significant correlation between the IL-6 response in BAL fluid and exposure to dust endotoxin activity and 3-OH fatty acids (p < 0.05). Otherwise, no significant correlations were found between exposure and the cytokine response. We conclude that exposure to swine dust causes an intense upper and lower airway inflammation, which involves the proinflammatory cytokines interleukin-1, interleukin-6 and tumour necrosis factor-alpha.

Respiratory function in vineyard and orchard workers

A group of 174 male vineyard and orchard workers was studied for the prevalence of acute and chronic respiratory symptoms and lung function changes. In addition, 115 male control workers were studied for the prevalence of chronic respiratory symptoms. There was a significantly higher prevalence of dyspnea and chest tightness in exposed compared to control workers. In particular, exposed nonsmokers had significantly higher prevalences of dyspnea and chest tightness than controls this was found for exposed nonsmokers with both short (< or = 10 years) and long (> 10 years) exposure. Smokers exposed for more than 10 years had significantly higher prevalences of chronic cough, chronic phlegm, chronic bronchitis, and chest tightness than smokers with shorter exposures (p < 0.01 or p < 0.05). Workers employed for more than 10 years had higher prevalences of most of the acute (shipt-related) symptoms than those workers with shorter employment; however, the differences were significant only for cough in smokers (p < 0.05). Significantly lower than predicted FVC values were measured in smokers and nonsmokers after both short and long duration of employment. Differences between measured and predicted FEV1, FEF50, and FEF25 were significant for workers employed for more than 10 years. A separate analysis of individual data as a percent of predicted values demonstrated that many workers had FVC (5.2%), FEV1 (6.3%), FEF50 (27.6%), and FEF25 (40.2%) lower than 70% of predicted values. These data suggest that vineyard and orchard workers may develop acute and chronic respiratory symptoms and lung function changes which are, in part, related to environmental factors and to cigarette consumption.

[Chronic obstructive bronchitis in a fodder farming setting]

Respiratory disease in agricultural workers are dominated both in terms of frequency and severity by chronic obstructive long disease. In the Doubs, in dairy cereal farmers, the prevalence of chronic bronchitis in active farm workers is around 10 per cent, and 6 per cent are non-smokers. It is twice the level of the control population of non-exposed subjects. The frequency is most elevated in the men and increases both with age and with altitude. A longitudinal study of male farm workers aged more than 45 has shown that there is an abnormally rapid loss of forced expired volume in one second (FEV1). Two different studies carried out in the Doubs have revealed epidemiological, respiratory function and immunological arguments in favour of immuno-allergic mechanisms. Notably, obstructive chronic bronchitis (OCB) occurs more frequently in agricultural workers with a previous history of farmer's lung or previous sub-acute delayed symptoms in relation to exposure. On the other hand, there are no close links between OCB and the intensity of antigenic exposure (the total quantity of fodder handled). By contrast, there is a relationship between exposure to thermophillic actinomycetes (antigen of farmer's lung) and OCB. The frequency of serum precipitins is most elevated in farm workers with OCB than in asymptomatic agricultural workers. Finally, non-smokers who are suffering from OCB without evidence of farmer's lung, have a respiratory function profile and also alveolar lavage cell pattern characteristic of extrinsic allergic alveolitis after provocation tests to mouldy hay. These arguments are in favour of immuno-allergic mechanisms in the pathogenesis of chronic bronchitis in farm workers which seems to be well differentiated from chronic bronchitis due to smoking.

Olaquindox-induced airborne photoallergic contact dermatitis followed by transient or persistent light reactions in 15 pig breeders

There have been no previous reports of photosensitivity following photoallergy to airborne olaquindox in a large group. 15 pig breeders, with photo-distributed dermatitis related to olaquindox dust, were investigated to study the nature, promoting factors, and course of this disease. Minimal erythema doses for UVA and UVB were established before photopatch testing and at intervals thereafter. All patients presented with olaquindox-induced photoallergy. In 14 cases, this was followed by prolonged increased sensitivity to UVA. 7 patients also displayed an increased sensitivity to UVB. 13 farmers came into contact with olaquindox in mineral feed (1000 mg/kg) and only 2 in final feed (50 mg/kg). 8 patients avoided further contact with olaquindox because of warnings in the media. Allergies and photoallergies to other occupational substances preceded or followed olaquindox (photo)allergy. Because of their increased sensitivity to light, most of these farmers used sunscreens, and 2 of them developed (photo)allergy to UV-absorbers. As a result of our studies, we recommend photopatch testing for olaquindox in pig breeders with photo-distributed dermatitis. This would enable the early recognition of photoallergy to olaquindox and the prevention of persistent light reaction.

Clinical and biochemical changes in greenhouse sprayers chronically exposed to pesticides

1 This study was conducted with the aim of evaluating the impact on health produced by the use of different types of pesticides in greenhouses. It is based on the need to practice and develop biological monitoring techniques to assess exposure and predict health risk in workers occupationally exposed to pesticides. 2 Two groups of greenhouse workers with either high or low exposure to a combination of pesticides was taken in Almería, a Spanish province where cultures under plastic are very extended. 3 One hundred and five sprayers were interviewed to collect information about symptoms and signs related to past exposures. Each pesticide sprayer was examined by a physician, and a blood sample was drawn for plasma and red blood cell cholinesterases, complete blood count, and liver and renal function tests. 4 Exposure of workers to a combination of pesticides resulted in 37% of the workers showing toxic signs and symptoms. The main toxic effect observed were a high incidence of spontaneous abortion, depression, and certain neurologic disorders like headache, tremor and paraesthesia. 5 The major analytical change was a decrease of the mean corpuscular haemoglobin concentration in 38% of the cases. However, no significant decrease in both serum and erythrocyte cholinesterase activities was observed. 6 The sprayers were not usually aware of the potential hazards of pesticides and did not try their best to maintain personal hygiene.

Epidemiology of Lyme disease in France: Lyme borreliosis in the region of Berry sud: a six year retrospective

The purpose of this epidemiologic retrospective is to recognize the endemic nature of Lyme borreliosis in 'Berry', region of France. Fifty-nine cases have been reported here during the past six years (1988-1994). An erythema migrans (EM), or a late manifestation concurrent with positive ELISA-test represents the main inclusion criterion (case definition used by the CDC). The results reveal a high incidence considering the limited information available in France. The farmer has been found to be mainly at risk, with EM being observed in 49% of cases. In general, late manifestations are rarely described. Peripheral neurological manifestations occur more frequently than those reported in the USA. The steps taken as a result of our study of Lyme disease are in accordance with the recommendations of the World Health Organization.

High incidence of Coxiella burnetii markers in a rural population in France

Since Coxiella burnetii, the causative agent of Q fever, is often transmitted from goats and sheep to humans through aerosols, we examined the sera from 168 persons involved in goat breeding in the Centre region of France and 40 members of veterinary and medical staff from the same region for the presence of antibodies against C. burnetii. An immunofluorescence assay was used to detect the presence of antibodies of the IgG isotope against epitopes from phase II of C. burnetii, which are the first antibodies to appear in infected people, and from phase I, which reflect more chronic stages of the infection. Our serological survey showed that most of the tested sera were positive for C. burnetii markers, indicating at least an encounter with the bacterium. In the overall population of 208 subjects, 71% of the sera had antibodies against phase II epitopes (titres > or = 1:40). Among the goat farmers and their immediate families, 78% had antibodies against phase II and 33% against phase I (titres > or = 1:40). Considering only high titres (> or = 1:320), though, only 37% of the farmers had antibodies against phase II and 15% against phase I. Only 3 out of 12 veterinarians working in the field had high titres of antibodies against phase II and phase I, while none of 28 members of veterinary and medical laboratories had significant levels of antibodies. These results emphasize the need for closer surveillance of populations at risk for Q fever, to prevent the infection by C. burnetii from reaching chronic stages of the disease.

Effect of ambient ozone exposure on lung function in farm workers

Effects of ozone exposure on outdoor farm workers in the Fraser Valley of British Columbia, Canada, were investigated. Fifty-eight workers underwent spirometry daily before and after each 8- to 14-h workday from June 23 to August 26, 1993. The mean daily maximum (1 h) ambient ozone concentration was 40 ppb (range: 13 to 84 ppb). Concentrations of acid aerosols and fine particulates, potential confounders of ozone effects, were very low. In individual regressions of evening FEV1 and FVC on maximum daily ozone concentration, 47 of 53 workers with valid data (46 of 53 for FVC) had negative slopes. The average slopes (weighted by the inverse SE of the regression coefficients) were -3.3 and -4.7 ml for FEV1 and FVC, respectively, for each ppb increase in ozone (p < 0.001). Following correction for an individual's mean lung function level, date, and temperature, regression of either the afternoon or the daily change (afternoon-morning) corrected for the morning measurement of FEV1 and FVC on ozone showed similar magnitudes of effect. These associations were still apparent on the following morning, suggesting a persistent ozone effect. These results indicate that exposure of a population of outdoor workers to ambient ozone concentrations below 85 ppb is associated with decreased lung function over the day, which persists to the following day.

A population based case-control study of agricultural injuries in children

OBJECTIVES

To identify preventable risk factors related to agricultural injuries occurring to children on family farms.

SETTING

A geographically defined central region of Wisconsin, USA with nearly 1800 family dairy farms.

METHODS

A two year, population based incidence study of occupational injuries among farm residents was conducted. For cases, trained staff abstracted information on the nature, severity, and treatment of the injury from the patient's medical record. Staff also administered a telephone questionnaire to cases and controls, usually answered by parents.

RESULTS

There were 60 cases of farm residents younger than 18 years who sought care for acute agriculture related injuries. Farms on which uninjured children lived served as controls (n = 102). Multivariate analyses of 16 different variables revealed three significantly related to injuries to children: hours worked per week (odds ratio (OR) = 1.05; 95% confidence interval (CI) = 1.01 to 1.08); presence of disabled safety device (OR = 2.64; 95% CI = 1.10 to 6.35); and feeding cows by grazing (OR = 0.22; 95% CI = 0.06 to 8.83).

CONCLUSIONS

Interventions designed to reduce the risk of agricultural injuries to farm children should acknowledge the participation of children as productive workers on the farm. Although education has been the standard method for encouraging safe practices in farm work, additional approaches, such as limiting the number of hours a child works, avoiding the disabling of safety devices, and using specific methods of managing cows, should also be adopted to minimize injury risks to farm children.

ABC of work related disorders. Occupational infections

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[Allergies in agriculture]

Thanks to enormous progress in industrial medicine, life expectancy of workers in dust-polluted (dust-burdened) jobs has massively improved; however, farmers, gained too little interest of industrial medicine so far and thus show one of the highest mortality rates from pulmonary diseases. Today the farmer's exposure to dust and respective allergens is often extremely high; however, the composition of the inhaled dust varies extremely, depending on the type of work. Particularly organic dusts are inhaled that are known as common and frequent allergy inducers in the normal population. In spite of the increased exposure to the common airborne allergens, children of farmers rarely develop allergies, obviously due to an increased tolerance to common allergens. The high mortality rate from pulmonary diseases, including asthma, in farmers seems therefore less a question of profession-specific allergens than of decompensated adaptation phenomena. Thus an optimized dust prevention seems important. Dermatologic diseases: Farmers are exposed to many irritative and potentially sensitizing contact allergens including those from natural sources (plants) and diverse fungicides, pesticides as well as chemicals used in mechanical professions. The risk of phototoxic and photoallergic reactions is increased by profession-related exposure to sun. This also concerns related reactions to medical drugs. The best preventive measure for contact sensitization is an optimized skin protection, particularly of the hands.

Respiratory morbidity in relationship to farm characteristics in swine confinement work: possible preventive measures

Swine confinement farming is associated with an increased risk of respiratory morbidity. Adverse health effects have been shown in association with levels of dust, endotoxins, and ammonia. This study was conducted to evaluate characteristics of confinement farms associated with respiratory morbidity in order to establish priorities for preventive measures. A questionnaire on symptoms and farm characteristics was completed by 1,432 male swine confinement farmers. Of these, 200 with and 200 without chronic respiratory symptoms were randomly selected for lung function testing. A significantly increased risk for chronic respiratory symptoms was shown if farmers used wood-shavings as bedding (prevalent odds ratio [POR]2.2), used disinfectants (POR 1.7), used natural ventilation (POR 2.6), had floor types other than slatted or half-slatted (POR 2.1), or used a mechanical feeding system (POR 1.4). Lung function (FEV1) was significantly lower with increasing numbers of years worked (51 ml/10 years), with smaller numbers of pigs (8.5 ml/100 pigs), and when the air outlet of the ventilation system was via the pit (248 ml). To decrease the risk of respiratory morbidity the following preventive measures are proposed: discouragement of the use of disinfectants and of wood-shavings as bedding, and promotion of the use of mechanical ventilation systems.

The role of atopy in grain dust-induced airway disease

To determine whether atopy influences the physiologic or inflammatory response to grain dust, we compared spirometric measures of airflow and bronchoalveolar lavage (BAL) measures of lower respiratory tract inflammation between demographically similar nonatopic (n = 10) and atopic (n = 10) study subjects after each of two inhalation exposures: Hanks' balanced salt solution (HBSS) and corn dust extract (CDE; 0.4 microgram of endotoxin/kg body weight). Subjects were healthy nonsmokers with similar baseline pulmonary function, without bronchial hyperreactivity, and had not participated in agriculture. Atopic subjects had two or more positive skin responses to 10 common environmental allergens. Both groups developed significant airflow obstruction and lower airway inflammation after CDE inhalation. Importantly, the magnitude of the post-CDE exposure airflow decrements, BAL cellularity, and BAL concentration of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), IL-6, and IL-8 did not significantly differ between atopics and nonatopics. The concentrations of histamine and eosinophils in the BAL fluid were unaffected by CDE inhalation and did not significantly differ between atopics and nonatopics. Atopic status does not appear to be a significant determinant of airflow obstruction or lower airway inflammation following CDE inhalation. Our findings suggest that atopy may play, at most, a minor role in the development of grain dust-induced airway disease.

[Sugar beet pollen allergy as a rare occupational disease]

Although there are a few isolated reports in the literature suggesting that sugar beet pollen is highly antigenic, hypersensitivity to components of sugar beet is not a common disease. We report a 29-year-old man with a history of atopic dermatitis who developed both contact dermatitis and allergic rhinitis from sugar beet pollen through his job in a seed nursery.

Occupational allergic contact dermatitis and airborne contact dermatitis from 5 fungicides in a vineyard worker. Cross-reactions between fungicides of the dithiocarbamate group?

We report a patient with occupational contact dermatitis due to sensitization to mancozeb and perhaps metiram used in a vineyard. Patch testing showed strong allergic patch test reactions to 2 of the commercially available preparations used (Dithane Ultra and Polyram WG). Further patch tests showed allergic patch test reactions to mancozeb (0.5 and 1% pet.), a weak reaction to metiram (1% pet.) as well as to 4 other fungicides of the dithiocarbamate group (maneb, nabam, propineb and zineb), which had never been used in the vineyard.

Occupational allergic contact dermatitis caused by decorative plants

12 cases of occupational allergic contact dermatitis caused by decorative plants were diagnosed in a 14-year period. The patients were middle-aged, and their average exposure time was 13 years. The plant families and plants causing occupational contact dermatitis were Compositae (5 patients; chrysanthemum, elecampane, gerbera, feverfew), Alstroemeriaceae (5 patients, Alstroemeria), Liliaceae (4 patients; tulip, hyacinth), Amaryllidaceae (2 patients; narcissus) and Caryophyllaceae (2 patients; carnation, cauzeflower). The known chemical allergens causing dermatitis were tuliposide-A and sesquiterpene lactones, such as alantolactones and parthenolide, in the Liliaceae and Compositae families. 7 of the 12 patients were able to continue their work; 5 were not because of severe relapses of skin symptoms. The plant allergen and extract series currently available are of great help in the diagnosis.