Respiratory symptoms and lung function among workers in swine confinement buildings: a cross-sectional epidemiological study

To study possible chronic respiratory problems of people working in swine confinement buildings, a cross-sectional epidemiological study was initiated. A cohort of swine confinement workers was matched for age, sex, and smoking history with nonconfinement swine producers. Pulmonary function studies and a survey questionnaire for chronic respiratory disease symptoms (the American Thoracic Society, Epidemiologic Standardization Project Questionnaire) were performed on both groups. Compared to controls, the confinement workers experienced significantly higher prevalence of chronic bronchitis and wheezing, (odds ratio 7 and 4, respectively). There were, however, no significant differences in baseline pulmonary functions. Based on the high prevalence of chronic respiratory disease symptoms, this study emphasizes an emerging occupational concern in agriculture to the estimated 500,000 persons working in swine confinement operations and the estimated 500,000 additional persons who work in poultry, veal, beef, or dairy confinement operations. It is important to study a representative population of these workers prospectively to determine if a progressive loss in lung function is evident.     

Environmental and health studies of farm workers in Swedish swine confinement buildings.

The relation between the health of workers and the environment in swine confinement buildings was investigated in a study of 57 workers on 30 swine farms in southern Sweden and 55 matched controls. Swine workers reported significantly higher frequencies of respiratory symptoms, more frequent colds and absence due to chest illness, and a history of pneumonia. The increased frequency of symptoms of respiratory disease was related to the number of years and percent of the day spent working with swine. Symptoms were also associated with respirable dust, total dust, endotoxin in total dust, and number of microbes in the air of the work environment. In a multiple regression analysis of the relation between 16 different environmental parameters to work period shifts of five pulmonary function parameters, endotoxin was found to be significantly related to the FEV1 in a dose dependent way.     

Environmental and health studies of farm workers in Swedish swine confinement buildings

The relation between the health of workers and the environment in swine confinement buildings was investigated in a study of 57 workers on 30 swine farms in southern Sweden and 55 matched controls. Swine workers reported significantly higher frequencies of respiratory symptoms, more frequent colds and absence due to chest illness, and a history of pneumonia. The increased frequency of symptoms of respiratory disease was related to the number of years and percent of the day spent working with swine. Symptoms were also associated with respirable dust, total dust, endotoxin in total dust, and number of microbes in the air of the work environment. In a multiple regression analysis of the relation between 16 different environmental parameters to work period shifts of five pulmonary function parameters, endotoxin was found to be significantly related to the FEV1 in a dose dependent way.     

Prevalence of self-reported respiratory disease symptoms among veterinarians in the Southern Netherlands

In June 1991, 831 veterinarians registered in the Southern Netherlands were mailed a questionnaire to obtain details of work practice and health problems. One hundred fifty-two veterinarians were not eligible (retired or not working regularly), 497 practitioners returned a complete questionnaire (73% response rate). The purpose was to assess the prevalence of respiratory disease symptoms (RDS) and to compare the prevalence of RDS between occupational specialties and with a group of swine farmers. The professional specialty of each veterinarian was grouped as: small-animal practice (17%), large-animal practice (51%), mixed-animal practice (14%), and other practice (i.e., government, industry) (18%). Adjusted for age, gender, smoking, history of atopy, and use of respiratory protective devices, large-animal practitioners had a two times higher odds of chronic cough (OR = 1.8, 95% CI 1.1-2.8) or chronic phlegm production (OR = 2.1, 95% CI 1.1-3.7) and a three times higher odds of chest wheezing (OR = 2.8, 95% CI 1.3-6.3) than veterinarians with another specialty. Modelling the occurrence of RDS in veterinarians with exposure variables indicated that working more than 20 hr per week in swine confinement buildings increased the odds of occurrence of chronic cough and chronic phlegm production approximately three times, in addition to a significant effect of smoking. Besides a significant effect of smoking and history of atopy, no exposure variables other than occupation were associated with occurrence of asthmatic attacks in swine farmers and large-animal practitioners. Large-animal practitioners had a two times higher odds of asthmatic attacks (OR = 1.8, 95% CI 1.1-2.9) than swine farmers. Large-animal practitioners have a considerably higher proportion of symptoms like cough, phlegm production, a stuffed up nose, sneezing, and tearing eyes than small-animal practitioners during, and 4–8 hr after, working with animals. © 1996 Wiley-Liss, Inc.     

职业司机慢性疾病发病危险因素的调查

目的探讨职业司机慢性疾病发病率的危险因素,做好健康监护,减少交通事故。方法采用余善法推荐的NIOSH职业紧张测量工具对调查对象进行测试,每一因素都按照Likert s 5点法和7点法赋分予以数量化,按照量表赋分方法计算各因素得分。随机抽查504名职业司机慢性疾病患病情况及其危险因素,将有、无慢性疾病者进行分组对照分析。结果504名职业司机中有377名曾患有慢性疾病,患病率为74.80%。其中患病率较高的有慢性胃炎,消化性溃疡最多(占26.16%),其他依次为痔疮、慢性泌尿系统疾病、高血压、慢性关节炎、椎间盘突出等。结论影响职业司机慢性疾病患病率的危险因素主要有司机的文化程度、经济状况、生活方式、医疗保障、慢性疾病家族史、从事司机作业工龄等;其次,倒班方式、发生过交通事故、司机平时危险感、紧张感以及对职业态度等也是慢性疾病发病率的危险因素。     

Respiratory symptoms among Swedish swine producers

Two hundred nine male farmers engaged in swine production, born in 1913 or later, and alive in 1985 received mailed questionnaires on respiratory symptoms, medical history, and exposure to contaminated air in swine confinement buildings. The response rate was 76%. The prevalence of three or more symptoms of bronchitis was higher than that in welders who had completed the same questionnaire--Mantel-Haenszel odds ratio 5.26 (1.9-14.8) for smoking subjects. The number of reported symptoms was strongly influenced by smoking habits (p less than .01) and by exposure (p less than .01), and by a positive interaction between these (p less than .01, two-way analysis of covariance). Air in swine confinement buildings is contaminated with bacterial endotoxins and organic dust, and it is concluded that it may pose a risk for airways diseases such as chronic bronchitis.     

Bronchial reactivity and work-related symptoms in farmers

Work-related respiratory symptoms and bronchial reactivity were studied in 76 never-smoking farmers and in a control group not exposed to organic dusts. The farmers were divided into those working with vegetables/grain crops, animals but not swine, and with swine. The extent of symptoms was evaluated using a specific organic dust questionnaire. Bronchial reactivity was assessed with the methacholine challenge test. An increased incidence of organic dust toxic syndrome (ODTS), mucous membrane irritation (MMI), and chronic bronchitis (CB) was found among farmers working with swine or other animals. Pulmonary function baseline values were normal. Bronchial reactivity was increased and related to subjective symptoms of MMI and CB. There was also a relation between fatigue at work and bronchial reactivity.     

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.     

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.     

Self reported respiratory symptoms and diseases among hairdressers.

OBJECTIVES: Hairdressers are exposed to many irritative and allergenic substances capable of causing occupational respiratory symptoms and diseases. The self reported prevalence of respiratory symptoms and diseases was studied, and the risks among hairdressers compared with saleswomen was estimated. METHODS: A cross sectional prevalence study of respiratory symptoms and diseases was carried out among hairdressers and supermarket saleswomen, with a computer assisted telephone interview method (CATI). The study population comprised all the female hairdressers and supermarket saleswomen aged 15-54 years in the Helsinki metropolitan area, Finland. Disproportionate random samples of female hairdressers and sales-women were drawn from the trade union membership registers. The interviews were carried out between February and April 1994. A response rate of 80.5% (355/440) was obtained for hairdressers and 82.2% (583/709) for saleswomen. Atopy, smoking, chronic illnesses, type of work, working hours, working conditions, personal and professional use of hair products, and the use of personal protective devices were assessed. The outcome variables were self reported symptoms of the upper and lower respiratory tract. These were used to define chronic bronchitis, and asthma, laryngitis, and allergic rhinitis diagnosed by a physician. RESULTS: There was a considerable difference in the prevalence of chronic bronchitis; 6.8% in hairdressers versus 1.9% in saleswomen. The odds ratio (OR) adjusted for age, smoking, and atopy for chronic bronchitis indicated an increased risk of chronic bronchitis (OR 4.8, 95% confidence interval (95% CI) 2.2 to 10.1). No association was found between work as a hairdresser and asthma, laryngitis, and allergic rhinitis. Also the prevalence of rhinitis, rhinitis with eye symptoms, cough with phlegm, dyspnoea, and dyspnoea accompanied by cough was increased among hairdressers. The corresponding adjusted risk ORs were 1.7 (95% CI 1.3 to 2.3) for rhinitis, 1.9 (95% CI 1.4 to 2.6) for rhinitis with eye symptoms, 1.4 (CI 1.1 to 1.9) for cough with phlegm, 1.5 (95% CI 1.0 to 2.2) for dyspnoea, and 1.6 (95% CI 1.0 to 2.7) for dyspnoea with cough. CONCLUSIONS: Our results indicate an increased prevalence of upper and lower respiratory symptoms among hairdressers. Allergenic and irritative chemicals in hairdressing are likely candidates explaining the difference found between the hairdressers and controls. Work related reasons should be considered when a hairdresser presents with airway symptoms. Preventive actions are needed to improve the working conditions and personal protection.     

A comparative study of morbidity with temporary disability and hygienic assessment of working conditions of workers engaged in major occupations at the Dneproshina tire-manufacturing plant

Comparative study (1979-81, 1965-67) of temporary disability showed its upward trend in tire vulcanizers by 20%. This fact was associated with unfavourable working conditions, workers' stability and aging, elevated physical work load. In the disease structure there occurred some changes: the share of osteomuscular diseases showed a rise and that of nervous and digestive diseases declined. All the studied professional groups (assemblers, millers, vulcanizers) experienced a rise in osteomuscular morbidity and only vulcanizers had higher rates of respiratory, skin and subcutaneous diseases.     

Respiratory symptoms and airway obstruction in swine veterinarians: a persistent problem

OBJECTIVE: There are many occupational hazards associated with the practice of swine veterinarians. To reassess the prevalence of respiratory complaints and pulmonary function abnormalities in this group. METHODS: This was a cross-sectional study conducted during the American Association of Swine Veterinarians annual meeting. Subjects completed a respiratory symptom/work history questionnaire and performed spirometry. RESULTS: Participants included 122 veterinarians (median age=42.5 years). Work-related symptoms included rhinitis symptoms (69%), cough and chest tightness (53%), wheezing (31%). Airway obstruction was seen in 24% of participants. Veterinarians with airway obstruction reported working more hours per week in hog barns than did practitioners with normal pulmonary function (P=0.009). CONCLUSIONS: Respiratory symptoms were common in the swine veterinarians tested as was airway obstruction. The association with these findings and hog barn exposure suggests that working in these facilities is still a risk factor for airway disease.     

Work related distal airway obstruction in an agricultural population.

OBJECTIVE--To assess the prevalence of distal airway obstruction and its risk factors in agricultural areas. METHODS--A cross sectional study of respiratory symptoms and lung function was performed among French farmers and their spouses (1122 subjects) who came for preventive medicine examinations. They answered a respiratory questionnaire and performed pulmonary function tests on a portable spirometer. Diagnoses of chronic bronchitis were made on the basis of reported chronic respiratory symptoms. Airway obstruction was determined from predicted values. Odds ratio (OR) and linear regression coefficients were calculated after stratification by smoking and history of cardiac and other respiratory diseases. RESULTS--Of respiratory symptoms prevalence of chronic cough was 8.47%, and chronic bronchitis 7.66%. Prevalence of distal airway obstruction was 11.4%, and overall airflow obstruction 3.2%. Smokers were 20.2% men, and 5.7% women. Linear regressions showed high association between pack-years in smokers or exsmokers and forced expiratory volume in one second/forced vital capacity (FEV1/VC) and forced expiratory flow between 25% and 75% of vital capacity (FEF25-75). In non-smokers without any history of cardiac or respiratory diseases, age and the size of farms had the highest correlations with these variables. OR for distal airway obstruction was 2.1 in subjects > 50 years old v the younger ones and 3.02 in the smaller farms v the larger ones. CONCLUSION--After stratification by smoking and history of cardiac and respiratory diseases, distal airway obstruction is present in agricultural areas. The age, and the size of farm are the highest respiratory risk factors in non-smokers.     

Agricultural lung diseases

Agriculture is considered one of the most hazardous occupations. Organic dusts and toxic gases constitute some of the most common and potentially disabling occupational and environmental hazards. The changing patterns of agriculture have paradoxically contributed to both improved working conditions and increased exposure to respiratory hazards. Animal confinement operations with increasing animal density, particularly swine confinement, have contributed significantly to increased intensity and duration of exposure to indoor air toxins. Ongoing research has implicated bacterial endotoxins, fungal spores, and the inherent toxicity of grain dusts as causes of upper and lower airway inflammation and as immunologic agents in both grain and animal production. Animal confinement gases, particularly ammonia and hydrogen sulfide, have been implicated as additional sources of respiratory irritants. It has become evident that a significant percentage of agricultural workers have clinical symptoms associated with long-term exposure to organic dusts and animal confinement gases. Respiratory diseases and syndromes, including hypersensitivity pneumonitis, organic dust toxic syndrome, chronic bronchitis, mucous membrane inflammation syndrome, and asthmalike syndrome, result from ongoing acute and chronic exposures. In this review we focus upon the emerging respiratory health issues in a changing agricultural economic and technologic environment. Environmental and occupational hazards and exposures will be emphasized rather than clinical diagnosis and treatment. Methods of prevention, from both engineering controls and personal respiratory perspectives, are also addressed.     

Prevalence of respiratory symptoms, reduction in lung function and allergic sensitization in a group of traffic police officers exposed to urban pollution

BACKGROUND: Environmental factors are believed to play a critical role in the development of allergic respiratory diseases, such as asthma and rhinitis. Particularly, the role of urban pollution in the pathogenesis of these diseases is debated. OBJECTIVES: The aim of the study was to investigate whether subjects with a well-defined occupational history of exposure to road traffic fumes presented an increased prevalence of respiratory symptoms of chronic bronchitis (cough), asthma (wheeze), and allergic sensitisation to the most common allergens and reduced lung function compared with an unexposed control group. METHODS: The study was conducted on 484 traffic police in Catania (465 men and 19 women), with a mean age of 45 +/- 7.9 years, who were subdivided into three groups. The first group included traffic police assigned to traffic direction, the second group included traffic police working in administrative offices, the third group included all traffic police who did not fall into the previous groups. In the first group, "truly exposed" subjects were identifed as police officers assigned to traffic direction in the last 8 years. Similarly, in the second group, "truly non-exposed" subjects were identified as police officers working in offices in the last 8 years. RESULTS: Statistical analysis showed a significant difference in mean age between the truly exposed group and the truly non-exposed group (p < 0.01). The truly exposed group showed a greater prevalence of symptoms (cough, wheeze and dyspnoea), and positive reaction to skin allergy tests compared with the "truly non-exposed group", but this increase did not reach statistical significance. Alterations of the respiratory function tests were more frequent in the non-exposed (14.3%) compared to the exposed group (9.6%). The highest prevalence of cough, dyspnoea and wheezing was detected in smokers compared to non-smokers and to ex-smokers within each group. CONCLUSIONS: Our results show a major prevalence of respiratory symptoms and allergic sensitisation in exposed traffic police compared with non-exposed police, although this did not reach statistical significance. Further epidemiological studies conducted on larger samples are required to better understand the role of road traffic pollution in inducing allergic respiratory diseases.     

Persistence of respiratory symptoms in ex-underground iron ore miners

AIMS: To assess the persistence of respiratory symptoms in ex-miners after cessation of mining exposure. METHODS: Population-based cross-sectional study using a postal questionnaire comparing prevalence of symptoms between ex-miners who had stopped mining at least 1 year before the study and referents not occupationally exposed to irritants or dust. Age, smoking and a family history of asthma were considered as possible confounders in the analysis. RESULTS: A total of 206 ex-miners and 4,560 referents participated. Ex-miners had on average been working as miners for 13 years and had stopped mining 16 years before the study. Chronic productive cough and physician-diagnosed chronic bronchitis were significantly more common among ex-miners (P < 0.05 and <0.01, respectively). Furthermore, there was a trend that other respiratory symptoms were more common in ex-miners. CONCLUSION: Ex-miners had an increased risk of chronic productive cough and physician-diagnosed chronic bronchitis many years after they had stopped working as a miner.     

Respiratory history during infancy and childhood, and respiratory conditions in adulthood

The aim of this paper was to study respiratory disorders in infancy and childhood as a risk factor for respiratory conditions in adulthood. During the first part of the survey 15,247 adolescents in the Bordeaux area (average age: 16.5 years, boys = 46.6%) filled in a self-administered questionnaire concerning their respiratory history during infancy and childhood, their present symptoms and their smoking habits. Each subject with chronic cough (n = 538) was then matched with two controls (n = 1094) and the parents of these subjects and of their controls were sent a complementary questionnaire. During the second part, 1807 adults (average age: 39.3 years; men = 49.7%) working at Bordeaux University filled in a self-administered questionnaire about their present respiratory symptoms, smoking habits and respiratory symptoms during adolescence. Spirometry was performed in 172 adolescents and 1665 adults. The results of the first part showed a very significant relationship in adolescents between respiratory history during infancy and childhood and current chronic cough even in non-smokers, non-wheezers and non-asthmatics. The second part showed a very significant relationship in adults between respiratory symptoms during adolescence and present respiratory symptoms on the one hand, and a lower pulmonary function on the other, taking wheezing, smoking and asthma into account. In common with many similar studies, we conclude that respiratory disorders in young children may predispose to later disease, and that consequently it might be important to determine appropriate measures to prevent respiratory illness in childhood.     

Acute effects of the work environment on pulmonary functions of swine confinement workers

A sample population of owner/operators of swine confinement production facilities (21 subjects in 21 different facilities) were tested by spirometry immediately before and after a 4-hr work period. These confinement workers had statistically significant decrements in flow rates ranging from 3.3% (mean FVC) to 11.9% (mean FEF25-75). The air within the work environment was sampled for particulates and gases during the exposure period. There was suggestive evidence for a dose-response association between environmental exposures to carbon dioxide (CO2) and hydrogen sulfide (H2S). There was also some evidence for an additive relationship between smoking and work environment exposure on decline in lung function. The results of this study indicate that those working in swine confinement buildings experience irritation to the respiratory tract which is manifest by decreased flow rates. These findings suggest this exposure represents an emerging occupational health hazard. Further studies are warranted to assess the potential for chronic or irreversible damage to the respiratory tract.     

From sneezes to adieux: stages of health for American men and women

This article traces health from daily symptoms to death for American (U.S.) men and women in three age groups 17-44, 45-64, 65+. How do leading problems change as our perspective shifts from daily symptoms to annual incidence and prevalence rates of diseases and injuries; then to problems that induce long term limitations; to conditions brought to physicians for care; to diagnoses for hospital stays; and finally to causes of death? We study the top 15 conditions in each of these stages of health. Young adults are bothered most by acute and chronic respiratory diseases, but deaths among them are due to diseases and violent injuries that seldom figure in daily life. Fatal chronic diseases becomes more prevalent in middle ages and spur professional care, but they rarely cause daily symptoms. For older people, life threatening chronic conditions stretch through all stages of health. Arthritis also becomes a dominant facet of symptoms, social limitations and ambulatory care. Men's and women's leading daily symptoms are very similar; so are their leading acute and chronic conditions, limiting conditions, diagnoses for health care and causes of death. What distinguishes the sexes is the rate, not the ranks, of health problems they suffer. We elaborate the iceberg of morbidity metaphor, as a device to highlight stage, age and sex differences in health.