Lung function and respiratory symptoms among workers in a soft paper mill

Summary The aim of the present cross-sectional study was to investigate whether long-term exposure to soft paper dust causes impairment of lung function. Exposed workers (n = 287) and referents (n =79) were investigated, using spirometry and questionnaires. Personal samplings of total dust showed that the actual mean concentrations did not exceed 3 mg/m³. The exposed subjects were divided into three categories according to historical and present exposure to paper dust; low exposure, moderate exposure and high exposure. The study did not show any lung function impairment due to exposure to paper dust. However, the exposed subjects had a significantly increased prevalence of symptoms from both the upper and lower airways as well as an increased prevalence of reported asthma. On the basis of our study, we conclude that lung function impairment does not occur among workers exposed to mean levels of soft paper dust below 5 mg/m³.     

Prevalence of respiratory symptoms among wheat flour mill workers in Ibadan, Nigeria

BACKGROUND: While investigations into occupational health problems of various groups of workers have been conducted in Nigeria, so far, very little attention has been paid to the health status of workers in the grain industry. The prevalence of respiratory symptoms among wheat flour mill workers and control groups in a medium size industrial setting in Nigeria was studied. METHODS: The study employed a cross-sectional analytical design. Data were collected using structured interviews, work-site observations, and physical examination. Respondents consisted of 91 flour-millers, 30 matched internal controls from the maintenance unit of the same flour mill factory, and 121 matched external controls. RESULTS: Fifty-four percent of the flour-millers reported at least one respiratory symptom compared with 30% of the internal controls (P < 0.05) and 19% of the external controls (P < 0.001). Most symptoms were significantly more prevalent among the flour-millers compared with control subjects, and this trend was more evident amongst non-smokers than ex-smokers. CONCLUSIONS: The study concluded that wheat flour mill workers in Nigeria, like grain workers elsewhere, were at an increased risk of developing both pulmonary and non-pulmonary symptoms compared with control subjects. The result has implications for improved dust control measures in the grain industry in Nigeria.     

Chronic and acute respiratory effects among grain mill workers

Exposure to flour dust may induce chronic respiratory manifestations as well as acute ventilatory effects. We compared the prevalence of respiratory symptoms, ventilatory impairment, and variations in pulmonary function over the workshift in a group of mill workers exposed to wheat flour and in referent workers. One hundred and forty-two men exposed to flour in a mill and 37 referent workers were included in this study. Each subject completed a standardized questionnaire. Pulmonary function tests were performed before and after the workshift. The assessment of environmental exposure to flour showed high concentrations during some jobs with a high percentage of inhalable particles and a low concentration of respirable particles. The exposed workers had a significantly higher prevalence of usual cough and usual phlegm than the referents. The prevalence of asthma, based on the questionnaire, was similar. Before the workshift, the exposed workers had significantly lower mean lung function values for peak flow rate and forced expiratory flow rate at 75% of the vital capacity than the referents. After the workshift, all the lung function values showed a slight decrease, significant for forced vital capacity and forced expiratory volume during 1 s in both groups. Among the exposed workers, the asthmatic subjects had a significantly higher decrease across the shift than the nonasthmatic workers. This result is probably linked to bronchial hyperreactivity. Among nonasthmatic subjects, the decrease was larger in nonexposed workers than in exposed workers. A higher prevalence of respiratory symptoms and lower pulmonary function values were observed among mill workers by comparison with referents. Moreover, the data suggest that asthmatic status and the time of spirometric measurements need to be taken into account in epidemiological studies on exposure to airborne allergens. In addition, the study does not exclude a healthy worker effect with selection of dust-resistant subjects or better identification of asthmatic subjects among the workers exposed to an allergenic substance than among the nonexposed workers.     

Respiratory symptoms and pulmonary function in mill workers exposed to wood dust

This study surveyed wood dust exposure levels and pulmonary hazards among wood mill workers. Dust concentrations as measured by six-stage cascade impactors were high in work areas of grinding and screening. Total dust concentrations for these dusty activities ranged from 4.4 to 22.4 mg/m³, and the respirable proportions were between 2.4% and 50.2%. The dust level in the sawing work was 2.9 mg/m³. Although symptoms of cough and phlegm were higher in smoking workers than in nonsmoking workers, the prevalence of respiratory symptoms in the exposed workers was not significantly higher than in the controls. However, the incidence of symptoms such as chronic phlegm and chronic bronchitis in the nonsmoking high-exposure workers was significantly higher than in nonsmoking controls. The mean values of MMF, PEFR, and FEF25% were significantly lower in the exposed workers than in controls for both smokers and nonsmokers. The pulmonary function deficits, with the exception of FEV1.0/FVC, also showed a significant trend with increasing levels of wood dusts exposure classified by job titles for both smokers and nonsmokers. After adjustment for age, sex, height, and smoking status, all parameters of pulmonary function were significantly lower in exposed workers than in controls and showed a declining trend with increasing exposure levels classified by job titles. These results indicate that high level of wood dust exposure in the wood mill industries may lead to pulmonary hazards. Engineering control and industrial hygiene are mandatory for dusty activities. © 1996 Wiley-Liss, Inc.     

Airway responsiveness to methacholine,respiratory symptoms,and dust exposure levels in grain and flour mill workers in eastern france

Our goal was to assess the relation between dust exposure levels and the respiratory health status of workers in grain and flour mills in eastern France. We studied 118 male workers from 11 mills and 164 unexposed male controls. Dust concentration was measured by personal sampling methods. Outcome variables included respiratory symptoms, routine pulmonary function tests, and indices of airway responsiveness to methacholine. A great within- and between-area variability of inhalable dust concentration was found in all mills. A dose-response relationship was observed between dust exposure levels and chronic respiratory symptoms, suggesting that exposure to grain and flour dust may lead to chronic bronchitis. A significant relation was found between dust exposure and airway hyper-responsiveness; this finding is important since it has been hypothesized that the latter abnormality may lead to or be a predisposing factor in subsequent chronic, irreversible airflow obstruction.     

全国3876名沐浴场所从业人员呼吸系统自报症状及其影响因素

目的 了解沐浴场所从业人员呼吸系统健康状况,探讨其影响因素。方法 采用随机抽样的方法在2017年调查全国沐浴场所从业人员3 876人。收集从业人员基本情况呼吸系统健康状况等信息,用logistic回归分析沐浴场所从业人员呼吸系统症状的影响因素。结果 从业人员呼吸系统症状自报率为19.66%。不同性别、工龄、文化程度、工作时间和自评环境状况“空气干燥”、“有刺激性气味”对从业人员呼吸系统自报症状影响无统计学意义（P＞0.05）;Logisitic回归分析提示与年龄≥40岁相比,30～39岁（OR = 1.352,95%CI:1.074～1.703）,20～29岁（OR = 1.812,95%CI:1.46～2.247）,＜20岁（OR = 2.022,95%CI:1.482～2.759）年龄组有呼吸系统自报症状可能性增大,自评环境状况“环境潮湿”（OR = 1.913,95%CI:1.556～2.351）、“有霉味”（OR = 1.656,95%CI:1.143～2.399）和“通风不好”（OR = 2.425,95%CI:2.021～2.911）是从业人员有呼吸系统自报症状的危险因素,差异均有统计学意义。结论 我国沐浴场所从业人员呼吸系统症状自报率较高,从业人员的年龄、环境潮湿、有霉味以及通风不好都是其主要影响因素。     

铸造接尘女工肺功能与呼吸系统症状的配对研究

为了深入探讨铸造粉尘对接尘女工呼吸系统的损害，本文按配对设计原则，就１６２对不吸烟的铸造接尘女工与对照女工进行了肺功能和呼吸系统症状的配对研究。结果表明：接尘组ＦＶＣ、ＦＥＶ１、ＦＥＦ２５％～７５％、Ｖ７５、Ｖ５０等肺功能指标的实测值均较对照组显著降低，除Ｖ７５外，Ｐ值均小于０．０１；肺功能各项指标异常、呼吸系统症状呈阳性以及患慢性支气管炎的例数，接尘组则均较对照组明显增加，且均具有统计学意义。因此，对铸造接尘女工的职业性危害问题应给予足够的重视。     

Assessment of respiratory symptoms and lung function values among the brick field workers of West Bengal,India

Brick manufacturing process releases large amounts of silica dust into the work environment due to the use of silica-containing materials. The main aim of the study was to investigate the impairment of lung function and prevalence of respiratory symptoms among the different groups of brick field workers in comparison with control subjects. A total of 250 brick field workers and 130 unexposed control subjects were randomly selected in which demographic characteristics, respiratory symptoms, and lung function values were recorded. The result showed significantly lower p value (<.001) in lung function and respiratory symptoms among brick field workers when compared with control group. The prevalence of respiratory symptoms was dyspnea (46.8%), phlegm (39.2%), and chest tightness (27.6%). Dust exposure in working environment affected the lung function values and increased the respiratory symptoms among the brick field workers.     

Byssinosis: environmental and respiratory symptoms among textile workers in Sudan

Summary This study has been carried out to investigate the prevalence of byssinosis and other respiratory symptoms among 311 Sudanese workers in different sections of the Khartoum Weaving and Spinning Company. The prevalence of byssinosis was 67% among blowers, 40% in carders and draw-frame workers, 42% in simplex workers and 37% in ring-frame workers. The prevalence of chronic bronchitis ranged between 29 to 47% in all groups. A significant fall in FEV₁ was recorded in carders and draw- and ring-frame workers. There was also a statistically significant decrease in FVC after shift in all groups except in the ring-frame group. The result of the present study revealed that the prevalence of byssinosis was very high in mills processing coarse cotton. Application of control measures and the early detection of exposure effects will reduce the prevalence of byssinosis and other respiratory impairments.     

Acute respiratory symptoms among sisal workers in Tanzania

Background Few studies have focused on respiratory health effectsamong sisal workers. Aim To report on the prevalence of acute respiratory symptomsamong sisal processors. Methods We interviewed 163 dust-exposed brushing and decorticationworkers and 31 low-exposed security workers from six sisal estatesin Tanzania using a modified symptom score questionnaire todetermine the prevalence of acute respiratory symptoms duringwork. Groups were compared using chi-square tests, Fisher'sexact tests, t-tests and logistic regression, adjusting forconfounding factors. Results After the first working day of the week, 73% of thebrushing workers reported dry cough, 66% sneezing, 65% productivecough, 63% running nose and 34% stuffy nose. Brushing workershad a significantly higher prevalence of these symptoms thandecortication workers. Brushing and decortication workers hadsignificantly more dry cough and sneezing than the control groupof security workers, when adjusting for age, smoking, past respiratorydiseases and residence. Conclusion Processors of sisal fibre have a high prevalenceof acute respiratory symptoms. More detailed studies on workand health in sisal estates are needed, including exposure studies.     

Respiratory symptoms and ventilatory capacity in workers in a vegetable pickling and mustard production facility

Summary A group of 117 women occupationally exposed in a pickling factory were studied for the prevalence of acute and chronic respiratory symptoms and lung function changes. Workers were studied by task which included (1) pickling, (2) mustard making, and (3) packing. Similar prevalences for all respiratory symptoms were seen for the three worker groups, with all groups having significantly higher prevalences of chronic cough (P < 0.05), chest tightness, nasal catarrh, and sinusitis (P < 0.01) than a nonexposed control group from a bottling plant. Prevalences of acute symptoms were greater for pickling than for mustard or packing workers. Measured forced expiratory volume in 1 s and maximum flow rates at 50% and the last 25% of the control vital capacity were in general significantly lower than predicted values for the worker subgroups. Pickling workers exposed for more than 1 year in the industry had greater across-shift reductions for all spirometric parameters tested than those workers exposed for 1 year or less. Our data suggest that extended occupational exposure in the pickling industry results in acute exposure-related respiratory effects and ultimately may lead to the development of chronic respiratory symptoms and changes in baseline lung function.     

Immunological findings and respiratory function in cotton textile workers

Summary Immunological parameters were studied in a group of 24 cotton textile workers. These were volunteers from a cohort of 106 (83 women and 23 men) previously studied textile workers. A group of 30 employees from a bottle packing plant served as a control for the immunologic studies. The subgroup of volunteers undergoing immunologic testing did not differ from the original cohort of textile workers in age, sex, smoking history, or prevalence of most chronic respiratory symptoms, nor were there any significant differences in baseline lung function or across-shift changes. The 24 cotton worker volunteers underwent skin testing with extracts of cotton dust and cotton seed. Eight of these 24 (33.3%) had positive tests, and 5 of the 8 had elevated serum immunoglobulin E (IgE) levels. Only one of the 8 skin-test-positive workers had symptoms of byssinosis. Only 1 of 30 control workers' skin tested with cotton extract reacted, and none had an increased serum IgE level (P < 0.01). Both baseline lung function and across-shift changes did not differ between workers with positive and negative skin test reactions or between workers with normal and elevated IgE levels. Additionally, we studied the response in vitro of nonsensitized guinea pig trachea to cotton bract extract and demonstrated a dose-dependent contractile response. These data suggest that while immunological findings are frequent in textile workers, they correlate poorly with respiratory symptoms and function and may not be the basis for the airway obstruction seen in this disease.Supported in part by grant no. YF 733 from the National Institutes of Health, Bethesda, Maryland, USA, grant no. R01 OHO 2593-01A1 from the National Institute of Occupational Safety and Health, Centers for Disease Control, Atlanta, Georgia, USA, and the Henry and Catherine Gaissman Fund, New York, NY, USA     

Respiratory symptoms and pulmonary function among wood dust-exposed joss stick workers

Health hazards associated with wood dust exposure have been investigated in various industries. This study surveyed wood dust exposure levels and pulmonary effects among joss stick workers. Greater dust concentrations, as measured by six-stage cascade impactors, were observed in work areas where joss sticks were produced and incense was mixed than in other work areas. Total dust concentrations for these two high dust activities ranged from 9.9 to 42.7 mg/m³, and respirable proportions were between 2.0% and 54.6%. Higher dust levels were observed for dry joss stick production methods than for wet production methods. Dust levels for all other performance areas were lower than the permissible exposure level of 10 mg/m³. Although symptoms of cough and phlegm were higher in smoking workers than in nonsmoking workers, the prevalence of respiratory symptoms for exposed workers was not significantly higher than for the controls. The prevalence of pulmonary function deficits and the values of FEF_25% and FEF_75% in the exposed workers were significantly worse than those in the controls. But no difference was found between the male controls and the male exposed workers, the high-exposure group. Respiratory symptoms and pulmonary function also did not show a dose-response trend with the exposure levels estimated by correlation with worker job titles and duration of employment. No suspected case of pneumoconiosis was found from the chest radiographs. These results suggest that wood dust exposure in the joss stick industries might not lead to significant pulmonary damage.     

Relationship of airborne endotoxin and bacteria levels in pig farms with the lung function and respiratory symptoms of farmers

Summary Previous studies have demonstrated a high prevalence of respiratory and other symptoms and a decrement in lung function among pig farm workers, although the relationships with specific agents present in the work environment remain obscure. This study was therefore undertaken to investigate the relationship between symptoms, lung function and airborne endotoxin, ammonia and dust levels in piggeries. Information on symptoms, lung function, endotoxin, ammonia and dust levels was available for 183 pig farmers who worked in 136 farms. For 62 farms information was present on the levels of bacteria and gram-negative bacteria. For these 62 farms, endotoxin exposure measurements were taken in more than one stable. In general, no significant correlations were found between lung function and chronic respiratory symptoms, or dust and ammonia levels. The endotoxin concentration in stables was negatively related to most lung function variables, but only for the subgroup of 62 farmers was a statistically significant relationship found between endoxtoxin exposure and FEV₁. A borderline statistically significant and negative relationship was found between the endotoxin concentration and the FVC. Symptoms experienced during or shortly after work showed odds ratios larger than one with the levels of bacteria, gram-negative bacteria and endotoxin, indicating a positive relationship. No consistency in the relationship between symptoms and dust levels was found. The results suggest that endotoxins and (gram-negative) bacteria probably play an important role in the development of symptoms and lung function changes among pig farmers.     

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.     

Immunological and respiratory reactions in workers exposed to organic dusts

The relationship of skin reactivity and serum immunoglobulin E (IgE) levels to the prevalence of chronic respiratory symptoms and to ventilatory capacity is examined in workers exposed to different organic aerosols. The results from group of control workers similarly tested are also presented. Workers exposed to occupational allergens had positive skin tests more frequently than did controls, except for soy bean workers. Workers with positive skin tests to occupational allergens had a higher prevalence of almost all symptoms than those with negative skin tests although the differences did not always reach statistical significance. Workers with positive skin reactions in general had significantly higher serum IgE levels than did workers with negative skin reactions. There were across-shift reductions of ventilatory capacity in all groups of exposed workers, varying for forced vital capacity from 1.7% to 13.3%, for forced expiratory volume from 0.4%–21.9%, for maximum flow rates at 50% from 1.5% to 16.1% and for maximum flow rates at the last 25% of control vital capacity from 0% to 24.9%. There was, however, no correlation between acute and chronic lung function changes and skin reactivity or IgE values. Our data suggest that although exposure to organic aerosols may be associated with frequent immunologic reactions, these findings do not predict objective respiratory impairment.The research was supported in part by grant no. JBP 733 from the National Institutes of Health, Bethesda, Md., USA, and by grant no. RO1 OHO-2593-04 from the National Institutes of Occupational Safety and Health, Centers for Disease Control, Atlanta, Ga., USA     

A follow-up study of respiratory function in workers exposed to acid aerosols in a food-processing industry

A follow-up investigation was performed on 49 female workers studied 2 years earlier in a vegetable-pickling plant. Acute and chronic respiratory symptoms and ventilatory capacity measurements were recorded during the original and the follow-up studies. Maximal expiratory flow-volume (MEFV) curves were recorded during the Monday morning work shift. The forced vital capacity (FVC), 1-s forced expiratory volume (FEV1), and flow rates at 50% and the last 25% of the FVC (FEF50, FEF25) were measured. There were small increases in the prevalence of chronic symptoms between the two studies for both smokers and nonsmokers, but these did not reach statistical significance. Five workers at the time of the initial study had a diagnosis of occupational asthma; only one of these was still working at the time of follow-up. Workers lost to the follow-up had lower lung function than those seen at follow-up. In workers who were followed, larger than expected mean annual declines were noted for all ventilatory capacity parameters in both smokers (FVC 0.070 l, FEV1 0.070 l; FEF50 0.355 l/s, FEF25 0.270 l/s) and nonsmokers (FVC 0.045 l, FEV1 0.045 l, FEF50 0.285 l/s; FEF25 0.130 l/s). The decrease was particularly pronounced for FEF50 and FEF25. The accelerated decline in ventilatory capacity tests noted in the female nonsmokers suggests an independent effect on lung function of work exposure in this environment. Our data confirm that work in the pickling industry, particularly in small, poorly regulated plants, has deleterious effects on respiratory function. Received: 24 September 1996 / Accepted: 19 June 1997     

Indoor nitrogen dioxide pollution and respiratory symptoms of schoolchildren

Summary The influence of indoor nitrogen-dioxide exposure on respiratory symptoms of schoolchildren was investigated in a case-control study. The election method used was useful in obtaining symptomatic children, but insufficient in defining cases and controls without additional information. No relationship between indoor NO₂ and respiratory symptoms was found. Bias may have been present, especially because of the high mobility of the study population. Attempts to estimate historical exposure were inaccurate. Therefore the results do not exclude that an association between indoor NO₂ and respiratory symptoms exists.     

Production of silicon alloys is associated with respiratory symptoms among employees in Norwegian smelters

Objectives To develop a qualitative exposure classification of employees in Norwegian smelters and to investigate the relationship between respiratory symptoms and occupational exposure using this classification. Methods The 3,924 participants completed a standardised questionnaire including questions of respiratory symptoms, familial asthma, allergy, doctor-diagnosed asthma, smoking habits, previous exposure and occupation. The employees were classified according to their current job function: (1) line operators were employed full time on the production line, (2) non-exposed employees did not work in production, (3) the remaining employees were classified as non-line operators. The association between the prevalence of respiratory symptoms and job category was examined using multivariate logistic regression. Results The mean age of the participants was 38.6 years (standard deviation 9.2 years), 88.5% were males. The odds ratios (OR) (95% confidence intervals in parenthesis) for dyspnoea, cough and phlegm regarding previous exposure compared with no previous exposure were 1.4 (1.1–1.7), 1.4 (1.2–1.8) and 1.3 (1.0–1.7), respectively. The OR in line operators compared with non-exposed employees was 1.2 (0.9–1.7) for dyspnoea, 1.3 (1.0–1.8) for cough and 1.9 (1.4–2.7) for phlegm. The OR for respiratory symptoms was higher in relation to previous exposure than current job function except for phlegm. Conclusion In Norwegian smelters respiratory symptoms appear to be positively related to both current job function and previous exposure. Previous exposure appears to be more important than current job function.