Airways inflammation after exposure in a swine confinement building during cleaning procedure

BACKGROUND: Healthy volunteers exposed for 3 hr during weighing of pigs develop an airway inflammation characterized by a massive influx of neutrophilic granulocytes in the upper and lower airways and increased bronchial responsiveness to methacholine. The purpose of the present study was to investigate health effects from exposure during cleaning of the swine confinement building and to evaluate the effect of a respiratory protection device. METHODS: Sixteen subjects were exposed for 3 hr during cleaning of a swine confinement room with a high-pressure cleaner. Seven out of sixteen subjects were equipped with a mask during exposure. RESULTS: The bronchial responsiveness increased in all subjects following exposure, significantly more in the group exposed without a mask (P < 0.05). The cell concentration (mainly neutrophilic granulocytes) in nasal lavage fluid as well as the concentration of interleukin-8, increased significantly only in those subjects exposed without a respiratory protection device. In peripheral blood, an increase of neutrophilic granulocytes was observed in both groups, although it was significantly higher in the group without mask (P < 0.05). The inhalable dust level was 0.94 (0.74 - 1.55) mg/m(3) and respirable dust 0.56 (0.51-0.63) mg/m(3). CONCLUSION: Exposure to dust aerosols during the cleaning of the interior of a swine confinement building induces increased bronchial responsiveness and an acute inflammatory reaction in the upper airways. The use of a mask attenuated but did not abolish the inflammatory response. This suggests that gases and/or ultrafine particles in this environment could be important factors in the development of increased bronchial responsiveness.     

Symptomatic effects of exposure to diluted air sampled from a swine confinement atmosphere on healthy human subjects

Aerial emissions from a swine house at North Carolina State University's field laboratory were diluted to a level that could occur at varying distances downwind from a confined animal feeding operation (CAFO) both within and beyond the property line, and these emissions were delivered to an environmental exposure chamber. The study design consisted of two 1-hr sessions, one in which 48 healthy human adult volunteers were exposed to diluted swine air and another in which they were exposed to clean air (control). Objective measures of blood pressure, temperature, heart rate, respiratory rate, lung function, nasal inflammation, secretory immunity, mood, attention, and memory were correlated with objective measures of air quality. Ratings of perceived (self-reported) health symptoms were also obtained. The mean levels of airborne constituents in the swine air condition were hydrogen sulfide (24 ppb), ammonia (817 ppb), total suspended particulates (0.0241 mg/m3), endotoxin (7.40 endotoxin units/m3), and odor (57 times above odor threshold). No statistical differences on objective measures of physical symptoms, mood, or attention resulted from the 1-hr exposure to swine emissions in the environmental chamber when compared with clean air for healthy human volunteers. However, subjects were 4.1 (p = 0.001) times more likely to report headaches, 6.1 (p = 0.004) times more likely to report eye irritation, and 7.8 (p = 0.014) times more likely to report nausea in the swine air (experimental) condition than in the control condition. These results indicate that short-term exposure in an environmental chamber to malodorous emissions from a swine house at levels expected downwind can induce clinically important symptoms in healthy human volunteers.     

Farmers' exposure to airborne microorganisms in composting swine confinement buildings

Farmers' exposure to airborne microorganisms was studied in 12 composting swine confinement buildings and in 7 buildings with traditional slatted-floor pit systems. Airborne cultivable mesophilic, xerophilic, and thermotolerant fungi, mesophilic bacteria, and thermophilic actinobacteria were determined with a six-stage impactor. Furthermore, the total concentrations of microorganisms were determined with filter sampling and direct count using a microscope. In swine confinement buildings where the composting system was functioning properly, the concentrations of microorganisms were 10-1000 times higher than in traditional swine buildings. High concentrations of thermotolerant fungi and thermophilic actinobacteria (up to 10(5) CFU/m(3)), which have been considered to be the main causative agents of farmer's lung, were found in the composting swine confinement buildings that were studied. The conclusion was reached that farmers are exposed to high concentrations of fungal and actinobacterial spores also in swineries, at least in composting confinement buildings. Therefore, personal protection is strongly recommended in composting swineries, especially during the turning of the compost bed.     

Effects of exposure to dust in swine confinement buildings--a working group report

Pulmonary and other symptoms among workers in swine confinement buildings were evaluated by an international working group. In several studies in five different countries a total of about 2000 workers has been studied in clinical and epidemiologic investigations. Symptoms indicative of acute and chronic airway inflammation were widespread, as were systemic reactions of organic dust toxic syndrome. The base-line, and across workshift, pulmonary function changes were moderate. There was no evidence that antigen-antibody reactions are important in the pathogenesis. Longitudinal studies are recommended to establish the relationship between acute and chronic symptoms and end stage disease.     

Urinary and hand wipe pesticide levels among farmers and nonfarmers in Iowa

In the spring and summer of 2001, as part of a larger study investigating farm family pesticide exposure and home contamination in Iowa, urine and hand wipe samples were collected from 24 male farmers and 23 male nonfarmer controls. On two occasions approximately 1 month apart, one hand wipe sample and an evening and morning urine sample were collected from each participant. The samples were analyzed for the parent compound or metabolites of six commonly used agricultural pesticides: alachlor, atrazine, acetochlor, metolachlor, 2,4-dichlorophenoxyacetic acid (2,4-D) and chlorpyrifos. For atrazine, acetochlor, metolachlor and 2,4-D, farmers who reported applying the pesticide had significantly higher urinary metabolite levels than nonfarmers, farmers who did not apply the pesticide, and farmers who had the pesticide commercially applied (P-value <0.05). Generally, there were no differences in urinary pesticide metabolite levels between nonfarmers, farmers who did not apply the pesticide, and farmers who had the pesticide commercially applied. Among farmers who reported applying 2,4-D themselves, time since application, amount of pesticide applied, and the number of acres to which the pesticide was applied were marginally associated with 2,4-D urine levels. Among farmers who reported applying atrazine themselves, time since application and farm size were marginally associated with atrazine mercapturate urine levels. Farmers who reported using a closed cab to apply these pesticides had higher urinary pesticide metabolite levels, although the difference was not statistically significant. Farmers who reported using closed cabs tended to use more pesticides. The majority of the hand wipe samples were nondetectable. However, detection of atrazine in the hand wipes was significantly associated with urinary levels of atrazine above the median (P-value <0.01).     

Occupational exposure and lung function measurements among workers in swine confinement buildings

Previous studies have demonstrated that air in swine confinement buildings contains large amounts of dusts, highly contaminated with microorganisms and bacterial endotoxin. A study was undertaken to investigate the respiratory function of workers before and after the work shift in swine confinement buildings. Questionnaires were mailed to workers on swine farms. Dust levels were measured by personal sampling, and the micro-flora in the dust was determined. Work-related symptoms from the lung were frequent. Several workers who were smokers had forced expiratory volume in 1 second (FEV1) values lower than expected when they started work. Among a group of life-long nonsmoking workers the baseline forced vital capacity and FEV1 were not decreased. Changes in the FEV1 over the working shift were generally not found. It is suggested that exposure to dust in swine confinement buildings may lead to respiratory impairment but further studies on larger population samples and different exposure conditions are required.     

Exposure of farmers to phosmet, a swine insecticide

OBJECTIVES: The goal of this study was to measure dermal and inhalation exposures to phosmet during application to animals and to identify what determinants of exposure influence the exposure levels. METHODS: Ten farmers were monitored using dermal patches, gloves, and air sampling media during normal activities of applying phosmet to pigs for insect control. Exposures were measured on the clothing (outer), under the clothing (inner), on the hands, and in the air. Possible exposure determinants were identified, and a questionnaire on work practices was administered. RESULTS: The geometric mean of the outer exposure measurements was 79 microg/h, whereas the geometric mean of the inner exposure measurements was 6 microg/h. The geometric mean for hand exposure was 534 microg/h, and the mean air concentration was 0.2 microg/m3. Glove use was associated with the hand and total dermal exposure levels, but no other determinant was associated with any of the exposure measures. The average penetration through the clothing was 54%, which dropped to 8% when the farmers wearing short sleeves were excluded. The farmers reported an average of 40 hours a year performing insecticide-related tasks. CONCLUSIONS: Farmers who applied phosmet to animals had measurable exposures, but the levels were lower than what has been seen in other pesticide applications. Inhalation exposures were insignificant when compared with dermal exposures, which came primarily from the hands. Clothing, particularly gloves, provided substantial protection from exposures. No other exposure determinant was identified.     

Respiratory health of workers exposed to swine confinement buildings only or to both swine confinement buildings and dairy barns

Swine building workers (N = 488) and nonfarming neighborhood referents (N = 216) were enrolled in this study. There was a slight but significant increase in the prevalence of chronic bronchitis (17.49 versus 11.57%) and more evidence of airflow obstruction (forced expiratory volume in 1 s/forced vital capacity 0.75 versus 0.78) among the swine workers when they were compared with the referents. The subjects who spent more than 3 h/d in the swine buildings had a higher prevalence of chronic bronchitis (21.94 versus 13.25%) and airflow obstruction (forced expiratory volume in 1 s/forced vital capacity 0.75 versus 0.76) than those with shorter daily contact. Swine building only workers had no precipitins to antigens found in their environment and no clinical evidence of extrinsic allergic alveolitis. The number of years on the farm, dual exposure with dairy cattle, positive skin prick tests, type of piggery, and type of feeding did not add to the respiratory health impact of swine buildings.     

A prospective study of morbidity and mortality rates among farmers and rural and urban nonfarmers

Farmers are known to have lower morbidity and mortality rates than the mean for other occupational groups in the general population. Whether this is due to the urban-rural health gradient or to occupational factors related to farming is not clear. To explore this issue, we conducted a prospective study of farmers and matched rural and urban referents. Official hospital admission and mortality data for the years 1989-1996 were obtained. The relative risk of being admitted to hospital were 10% higher among rural and urban referents than among the farmers. The biggest differences were seen for mental and cardiovascular disorders. The odds of dying during follow-up did not differ between the two rural groups but were doubled among urban referents. In conclusion, the lower morbidity and mortality rates among farmers are partly due to the urban-rural health gradient but in addition salutogenic factors linked to farming seem to be active.     

Effect of respirators equipped with particle or particle-and-gas filters during exposure in a pig confinement building

OBJECTIVES: This study compared the protective effect of two respiratory protection devices during exposure in a pig confinement building. METHODS: Thirty-six healthy persons were exposed for 3 hours in the building, 12 without any protection, 12 with a particle-filter mask, and 12 with a mask filtering both particles and gases. Symptoms, body temperature, nasal lavage fluid, exhaled nitric oxide, and bronchial responsiveness to methacholine were assessed before and after the exposure. Pre- and postexposure urine and blood samples were collected. RESULTS: After the exposure, the participants with respirators reported fewer symptoms than those without. Wearing a mask also reduced the inflammatory response assessed with nasal lavage (cell concentration, interleukins 6 and 8) and peripheral blood (cell number). Lung function was significantly impaired only in the unprotected group; postexposure vital capacity and forced expiratory volume in 1 second showed a decrease of 3-4% from the preexposure levels (P=0.006 and P=0.002, respectively). Bronchial responsiveness (P<0.01) and body temperature (P<0.001) increased similarly in the three groups. Bronchial responsiveness to methacholine increased 2.7, 2.4, and 2.1 doubling concentration steps for those unprotected, those using a particle-filter mask, and those using a mask with particle and gas filters, respectively. The prostaglandin D2 metabolite, 9a, 11b-PGF2 increased significantly (P=0.003) only in those unprotected. CONCLUSIONS: Wearing a respirator in a pig confinement building reduces the inflammatory reaction but does not influence the increase in bronchial responsiveness, with no difference between the use of a particle-filter mask or a mask with a particle-gas filter combination.     

Partial protection by respirators on airways responses following exposure in a swine house

BACKGROUND: Exposure to swine dust leads to an intense airway inflammation and increased bronchial responsiveness. The purpose of the present study was to evaluate the effect of a respiratory protection device during exposure in a swine house. METHODS: Twenty-two subjects, 11 with a respirator, were exposed. Symptoms, body temperature, nasal lavage, and a bronchial metacholine challenge were performed before and 7 hr after exposure. For exposure assessment a nasal sampler was evaluated. RESULTS: The subjects with a respirator showed an attenuated inflammatory nasal response. An increase in bronchial responsiveness was observed in both groups, significantly greater in the unprotected group. The use of respirators reduced endotoxin exposure by more than 90% (assessed by nasal samplers). CONCLUSION: The use of a respirator attenuated the inflammatory response compared with an unprotected group. The minor effect on bronchial responsiveness suggests that gases and/or ultrafine particles may also be important factors.     

Occupational exposure of grain farmers to carbofuran

Six prairie grain farmers were monitored for pesticide exposure and related adverse effects while they mixed and/or sprayed carbofuran (Furadan^® 480F) with ground rig application equipment to control grasshoppers in southern Alberta, Canada. Dermal exposure was estimated with Tegaderm patches placed at seventeen locations on the skin beneath the work clothes. Hand and wrist exposure was determined by the amount of chemical found in hand rinses and on wrist patches. Potential inhalation exposure was measured with an air sampler using polyurethane foam as the adsorbent. Urine samples were collected at 24-hr intervals after exposure and monitored for carbofuran. Blood samples were analyzed for acetylcholinesterase (AChE), pseudocholinesterase (ChE) and several other blood parameters. The results indicated that during the mixing and/or spraying operation, a farmer could potentially be exposed to a total of 1,264 g carbofuran per kg of active ingredient (a.i.) used. Of this amount, 1,262 g/kg (or 99.8%) was dermal and 2 g/kg (or 0.2%) could be through the inhalation route. Hand and wrist exposure was about 1,100 g/kg a.i. (or 87% of total exposure). Excretion of the chemical in the urine amounted to 28 g/kg a.i. No ChE inhibition was observed. Other blood measurements were within normal ranges. The farmers showed no acute adverse effects during exposure and for four days after exposure. These results are discussed in relation to the mammalian toxicity of carbofuran.     

Immunological and respiratory findings in swine farmers.

The prevalence of respiratory symptoms and ventilatory capacity abnormalities in relation to immunological status was studied in 32 swine farmers and in 39 controls. A large number of swine farmers reacted to swine confinement building antigens (swine hair, 34%, swine confinement agents, 28%) but also to other extracts such as animal food (78%) and corn flour (37%). Control workers also reacted to these antigens in similar frequencies. Increased serum IgE levels were found in 3 swine farmers (9.4%) and all 3 had positive skin tests to at least one of the swine antigens. Among control workers one (2.6%) had an increased serum IgE level; this worker exhibited a positive skin reaction to swine food antigen. Swine farmers with positive skin reactions had across-shift reductions of FEF50 and FEF25 significantly larger than those with negative skin tests (P less than 0.01). Preshift measured ventilatory capacity data (FEV1, FEF50, FEF25) in swine farmers with positive skin tests were significantly lower (compared to predicted) than in those with negative skin tests. Additionally, we showed that a water-soluble swine confinement building antigen causes a dose-related contraction of nonsensitized guinea pig trachea smooth muscle studied in vitro. Our data indicate significant differences in lung function between swine workers with positive and negative skin tests. We suggest that skin testing may be helpful in identifying workers at risk for developing lung disease.     

A task-based assessment of noise levels at a swine confinement

This study describes a task-based noise evaluation conducted at a community college that operated a small swine confinement for training and profit. Seven full-shift dosimeter samples and area noise data were collected during the evaluation. The time weighted average noise levels were all well below the Occupational Safety and Health Administration's (OSHA) Permissible Exposure Limit, but exceeded the National Institute for Occupational Safety and Health's Recommended Exposure Limit on three of seven occasions. The potential for high noise exposures is evidenced in the noise dose measured for specific activities such as power washing, ear clipping, and snout snaring. When the data were extrapolated to depict exposures where specific tasks were carried out over a full shift, tasks such as power washing and snout snaring would exceed the OSHA Action Level (AL). Employees who exceed the OSHA AL are required to be enrolled in a hearing conservation program.     

Health effects from work in swine confinement buildings

A total of 14 epidemiologic studies from four countries, involving 2,786 workers is reviewed for respiratory symptoms, pulmonary function, antibodies to swine house allergens, and exposure-response variables. Cough and phlegm were the most common symptoms (ranging from 12 to 55%). Tightness of chest and wheezing were frequently reported (12 to 33%) as well as episodes of organic dust toxic syndrome. Acute symptoms, directly associated with work, were from 1.5 to 2 times more prevalent than chronic symptoms. Baseline pulmonary function generally revealed decrements in flow rates, but not volumes; over-shift changes showed small decrements in both flows and volumes. IgG antibodies to swine house antigens were common; no relation to symptoms could be found. Exposure response studies were limited, but relationships were seen between endotoxin and pulmonary function decrements, or respiratory symptoms.     

Bronchial hyperresponsiveness and exposure in pig farmers

Objective: To study the effect of exposure on bronchial responsiveness in pig farmers. Method: A group of 196 pig farmers were tested for lung function and bronchial responsiveness to histamine in the summer of 1992. To achieve sufficient contrast in respiratory morbidity and exposure, 96 of the farmers were selected because they had chronic respiratory symptoms and the remaining 100 because they were free from any respiratory symptoms. Personal exposure to dust, endotoxins and ammonia was measured during 1 working day in the summer of 1991 and 1 day in the winter of 1992. Data on farm characteristics were gathered in the same period. Results: After adjusting for age and smoking behaviour, mild bronchial responsiveness, defined as PC₁₀≤ 16 mg/ml, was associated with the use of quaternary ammonium compounds as disinfectant [prevalence odds ratio (POR) 6.7, 95% confidence interval (CI) 1.4–32.8], use of wood-shavings as bedding (POR 13.3, CI 1.3–136.7), use of automated dry feeding (POR 2.8, CI 1.0–7.8), use of pellets as feeding material (POR 4.8, CI 1.1–21.1) and location of air exhaust via pit or roof in the confinement units (POR 2.7, CI 1.2–6.3). The association with the use of disinfectants other than quaternary ammonium compounds was not significant (POR 2.4, CI 0.7–8.4). No associations between bronchial responsiveness and measured exposure to dust, endotoxins or ammonia were discernible. Conclusion: Protective measures, designed to prevent airway disease in confinement farming, should be based on information about the operational and other characteristics of farms that are related to high exposure and health effects. Specifically, the use of quaternary ammonium compounds as disinfectant, the use of wood-shavings as bedding and the use of automated dry feeding should be discouraged. Received: 7 December 1996 / Accepted: 10 April 1997     

Developing a national approach to building healthy and sustainable cities

Effective strategies to build a national approach to the integration of health and urban planning at all levels of government is essential if the health problems of urban Australians, such as obesity and respiratory illnesses, are to improve. This paper examines some policies and initiatives that could facilitate intergovernment cooperation on health and sustainability within the constraints of Australia's federal government system. These include recommendations for an Australian Sustainability Commission and Charter of Sustainability, evaluations of the Better Cities Program of the 1990s, and current proposals for improving urban governance to enable the implementation of a healthy and sustainable cities agenda.     

Respiratory symptoms and ventilatory capacity in swine confinement workers.

A group of 59 workers (41 men and 18 women) employed in swine confinement areas was studied to assess the presence of acute and chronic respiratory symptoms and the prevalence of abnormalities in ventilatory function. A control group of 46 (31 men and 15 women) unexposed workers was studied for the prevalence of chronic respiratory symptoms. For both male and female swine confinement workers complaints of chronic cough, dyspnoea, and chest tightness were significantly more frequent than among control workers. Male workers also complained more of chronic phlegm. Male swine confinement workers who were smokers had significantly higher prevalences of chronic cough, chronic phlegm, and chronic bronchitis than male non-smoking swine confinement workers. The frequency of acute symptoms associated with the workshift was high among the swine confinement workers with more than half of the workers complaining of cough and dyspnoea associated with work. Significant acute across shift reductions in lung function occurred in swine confinement workers, being largest for FEF25. All Monday preshift ventilatory capacity measurements in male confinement workers were significantly lower than predicted values; FVC and FEV1 were found to be lower than predicted values for women. The data indicate that exposure in swine confinement buildings is associated with the development of acute and chronic respiratory symptoms and impairment of lung function. Smoking appears to aggravate these changes.     

Respiratory symptoms and ventilatory capacity in swine confinement workers.

A group of 59 workers (41 men and 18 women) employed in swine confinement areas was studied to assess the presence of acute and chronic respiratory symptoms and the prevalence of abnormalities in ventilatory function. A control group of 46 (31 men and 15 women) unexposed workers was studied for the prevalence of chronic respiratory symptoms. For both male and female swine confinement workers complaints of chronic cough, dyspnoea, and chest tightness were significantly more frequent than among control workers. Male workers also complained more of chronic phlegm. Male swine confinement workers who were smokers had significantly higher prevalences of chronic cough, chronic phlegm, and chronic bronchitis than male non-smoking swine confinement workers. The frequency of acute symptoms associated with the workshift was high among the swine confinement workers with more than half of the workers complaining of cough and dyspnoea associated with work. Significant acute across shift reductions in lung function occurred in swine confinement workers, being largest for FEF25. All Monday preshift ventilatory capacity measurements in male confinement workers were significantly lower than predicted values; FVC and FEV1 were found to be lower than predicted values for women. The data indicate that exposure in swine confinement buildings is associated with the development of acute and chronic respiratory symptoms and impairment of lung function. Smoking appears to aggravate these changes.