Effect of route of breathing on response to exposure in a swine confinement building

Control measures for airborne ammonia and respirable dust exposure in swine barns

Extended exposure to airborne contaminants such as ammonia (NH₃) and respirable dust in swine facilities has been associated with various health problems among swine barn workers. The overall goal of this study was to assess the impact of selected control measures, namely, canola oil sprinkling, low crude protein diet, high level of cleaning, and manure pH manipulation, on NH₃ and respirable dust concentrations in swine production rooms through area sampling and on worker exposure to these contaminants in accordance with National Institute of Occupational Safety and Health (NIOSH) methods for occupational exposure monitoring. Results from five trials showed that low crude protein diet can be used for reducing worker exposure to NH₃ while oil sprinkling can be used for controlling respirable dust levels in swine rooms. Reduction in airborne levels did not translate to reduction in occupational exposure. Commercial NH₃ monitors showed higher readings than the standard NIOSH 6015 method.

Comparative responses to nasal allergen challenge in allergic rhinitic subjects with or without asthma

BACKGROUND

Nasal allergen challenge (NAC) is useful to study the pathophysiology of rhinitis, and multiple challenges may more adequately approximate natural exposure.

OBJECTIVE

To determine the effect of 4 consecutive daily NAC, on clinical and inflammatory parameters in rhinitics with or without asthma.

METHODS

Rhinitic subjects were recruited: 19 with mild asthma and 13 without asthma. Subjects underwent a control challenge (normal saline) followed by 4 consecutive daily NAC. Allergen challenge consisted of spraying the chosen allergen extract into each nostril until a positive nasal response occurred. Symptoms were recorded on a Likert scale, and oral peak expiratory and nasal peak inspiratory flows allowed assessment of a nasal blockage index (NBI), for a period of 7 hours. Induced sputum and nasal lavage were performed on control day and after 1 and 4 days of NAC.

RESULTS

Compared with the control day, there was a significant increase in symptom scores and NBI 10 minutes after each last daily NAC in both groups (p < 0.05). Symptom scores and NBI were similar for the 2 groups, except for nasal obstruction and rhinorrhea, which were more marked in subjects with asthma and rhinitis, respectively. Nasal lavage eosinophils were increased after 4 days of challenges in both groups, but there was no change in sputum eosinophils. No cumulative effect or any late response were observed in any of the groups over the challenge period.

CONCLUSION

Multiple NAC may be a useful tool to study the pathophysiology of allergic rhinitis or its relationships with asthma.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01286129.

The relationship between chronic rhinosinusitis and occupation: the 1998, 2001, and 2005 Korea National health and nutrition examination survey (KNHANES)

OBJECTIVES

We examined the relationship between chronic rhinosinusitis and occupation.

METHODS

We analyzed data from the 1998, 2001, and 2005 Korea National Health and Nutrition Examination Survey (KNHANES). Men and women aged 20-59 who participated in the three KNHANES were included to analyze the relationship between chronic rhinosinusitis and occupation. Trained interviewers visited subjects' homes and administered a standardized questionnaire on diagnosed diseases. Subjects were asked if they had experienced chronic rhinosinusitis during the previous year or had had rhinosinusitis for three or more consecutive months. Occupational classification followed the major groups of the Korean Standard Classification of Occupations (KSCO). We calculated the prevalence ratios (PRs) of chronic rhinosinusitis by major groups compared with clerical workers in the three KNHANES. Poisson regression with robust standard error was conducted, adjusting for age in 10-year strata.

RESULTS

There were significantly increased PRs of chronic rhinosinusitis in plant and machinery operators and assemblers, elementary occupations, crafts and related trade workers, and the unemployed.

CONCLUSIONS

These results support the relationship between chronic rhinosinusitis and occupational exposure at the macro level.

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.

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.

Positive human health effects of wearing a respirator in a swine barn

STUDY OBJECTIVES

A study was conducted to evaluate the acute health effects of wearing an N-95 disposable respirator in a swine confinement facility.

DESIGN

A crossover trial design was used in the study.

SETTING

The study was carried out at the research facilities of the Centre for Agricultural Medicine, the Royal University Hospital, and the Prairie Swine Centre Inc, Saskatoon, Saskatchewan, Canada.

PARTICIPANTS

Twenty-one nonsmoking healthy male subjects with no previous swine barn exposure participated in the study.

INTERVENTIONS

The subjects participated in a laboratory session (baseline day), a 4-h exposure in a traditional swine room wearing the respirator (intervention day), and a 4-hour exposure in a traditional swine room without a respirator (nonintervention day).

MEASUREMENTS

Lung function, methacholine challenge tests, blood counts, nasal lavage, and cytokines in serum and nasal lavage fluid.

RESULTS

Mean (+/- SE) shift change in FEV(1), from preexposure to postexposure, was highest on nonintervention day (-8.1+/-1.01%) and was significantly different from intervention day (0.32+/-0.62%; p<0.0001) and baseline day (1.57+/-0.51%; p<0.0001). Similar patterns were observed in the mean values of the provocative concentration of a substance (methacholine) causing a 20% fall in FEV(1) (nonintervention day, 130.4+/-36.9 mg/mL; intervention day, 242.0+/-38.0 mg/mL; and baseline day, 328.0 mg/mL +/-34.1 mg/mL). Significant increases in serum neutrophil levels and nasal cell counts were observed on the nonintervention day in comparison to the baseline and intervention days. Significant increases also were found in the levels of cytokines interleukin (IL)-6 and IL-8 in nasal lavage fluid and in the levels of IL-6 in serum for the nonintervention day in comparison to the other 2 days.

CONCLUSIONS

The results demonstrate that an N-95 disposable respirator can help to significantly reduce acute negative health effects in subjects not previously exposed to a swine barn environment.