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.     

Prevalence of respiratory symptoms and disorders among rice mill workers in India

Objectives

Lung function tests have become an integral part of assessment of pulmonary disease. Diseases of the respiratory system induced by occupational dusts are influenced by the duration of exposure. The aim of the study is to investigate the impairment of lung function and prevalence of respiratory symptoms among the rice mill workers.

Methods

A total of 120 rice mill workers from three districts of Karnataka were included in this study. Fifty urban dwellers from the same socio-economic level were selected as controls. The study included clinical examination, assessment of respiratory symptoms, pulmonary function test, measurement of peak expiratory flow rate, absolute eosinophil count, ESR estimation, total IgE estimation and radiographic test.

Results

The present study has shown that the rice mill workers complained of several types of respiratory disorders like phlegm (40.8 %), dyspnea (44.2 %), chest tightness (26.7 %), cough (21.7 %), and nose irritation (27.5 %). Rice mill workers exposed to dust presented significantly (p < 0.05) lower levels of FVC (3.44 ± 0.11), FEV₁ (2.73 ± 0.15) and PEFR (304.95 ± 28.79) than the controls. The rice mill workers are having significantly higher absolute eosinophil counts, total IgE and ESR than control groups. The hematological findings suggest that the harmful effects may be linked to both non-specific irritation and allergic responses to rice husk dust among rice mill workers.

Conclusion

Dust exposure in the working environment affects the lung function values and increased the respiratory symptoms among the rice mill workers.     

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.     

Respiratory function and bronchial reactivity in mill workers

Professional exposure to vegetable dusts affect the respiratory function of the exposed subjects. A previous survey conducted in an industrial flour-mill demonstrated a higher frequency of respiratory symptoms in workers compared to a control group. Ten subjects employed in a work site particularly exposed to dust were studied. Each subject answered a questionnaire and performed on Mondays and Fridays, at the begenning and end of his work shift, a flow volume curve and an isocapnic hyperventilation test. The aerobiology of the professional environment was also measured. We noted: 1) in the flow volume curves: a drop in the FEV₁ during the Monday morning shift, a significant difference between the FEV₁ (p<0.05) and the MMEFR 25–75 (p<0.05) measured at 6 am on Monday and Friday, and between the MMEFR 25–75 values obtained at 12 noon on Monday and Friday (p<0.05). 2) after isocapnic hyperventilation, a significant drop in the MMEFR 25–75 at 6 am on Monday (p<0.01) and in the FEV₁ and MMEFR 25–75 at 12 noon on Mondays (p<0.05), a significant drop in the FEV₁ at 1 pm on Monday (p<0.01).     

Work-related respiratory symptoms and lung function among solderers in the electronics industry: a meta-analysis

Objective

Research on the respiratory effect of exposure to solder fumes in electronics workers has been conducted since the 1970s, but has yielded inconsistent results. The aim of this meta-analysis was to clarify the potential association.

Methods

Effect sizes with corresponding 95% confidence intervals (CIs) for odds of respiratory symptoms related to soldering and spirometric parameters of solderers were extracted from seven studies and pooled to generate summary estimates and standardized mean differences in lung function measures between exposed persons and controls.

Results

Soldering was positively associated with wheeze after controlling for smoking (meta-odds ratio: 2.60, 95% CI: 1.46, 4.63) and with statistically significant reductions in forced expiratory volume in 1 s (FEV1) (−0.88%, 95% CI: −1.51, −0.26), forced vital capacity (FVC) (−0.64%, 95% CI: −1.18, −0.10), and FEV1/FVC (−0.35%, 95% CI: −0.65, −0.05). However, lung function parameters of solderers were within normal ranges [pooled mean FEV1: 97.85 (as percent of predicted), 95% CI: 94.70, 100.95, pooled mean FVC: 94.92 (as percent of predicted), 95% CI: 81.21, 108.64, and pooled mean FEV1/FVC: 86.5 (as percent), 95% CI: 78.01, 94.98].

Conclusions

Soldering may be a risk factor for wheeze, but may not be associated with a clinically significant impairment of lung function among electronics workers.     

Mortality from asthma, chronic obstructive pulmonary disease, respiratory system cancer, and stomach cancer among paper mill workers: a case-referent study

In an earlier case-referent study from a soft-paper mill with levels of paper dust exceeding 5 mg/m3, an increased mortality was found (OR = 3.8, p less than 0.05) from asthma and chronic obstructive pulmonary disease (COPD) among the employed. Furthermore, other studies on paper mill workers have also indicated an increased mortality from lung cancer. The main objectives of the present case-referent study were to investigate the mortality from asthma. COPD, and lung cancer in two other Swedish paper mills. In these mills, the levels of paper dust have been below 3 mg/m3. The subjects for the study were all men who died between 1961 and 1985 from asthma and COPD (n = 31), respiratory cancer (n = 27), and stomach cancer (n = 33) selected in three parishes surrounding two paper mills. As referents we randomly selected about six times as many men who had died from nonmalignant nonrespiratory diseases in these parishes (n = 550). On the basis of information found in the personnel records in the mills, the men were classified into different occupational categories or as unexposed. No increased risk of asthma or COPD was found among the workers exposed to paper dust. However, it was found that there was significantly increased mortality (OR = 5.7, p less than 0.05) for asthma and COPD among workers in a previous log sorting department. The study also showed a significantly increased risk of lung cancer (OR = 2.1, p less than 0.05) among maintenance workers. There was no increased risk of stomach cancer in the study.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immunological and respiratory changes in tobacco workers

BACKGROUND: Tobacco workers develop respiratory changes following occupational exposure to tobacco dust. METHODS: This study investigated 102 tobacco workers as well as a group of 30 matched control workers. Immunological testing, symptom questionnaire, and lung function measurements were performed in all workers. RESULTS: Increased total IgE was found in 12.7% of tobacco workers but in none of the controls (P < 0.05). Increased specific IgE (tobacco allergen) was recorded in 26.7% of tobacco workers with positive skin tests to tobacco extract but in none of the controls (P < 0.05). Regression analysis of ventilatory tests in female tobacco workers indicated a significant association of FEF75 to employment and smoking among workers with positive skin tests to tobacco. There were, however, no other associations between positive immunologic findings and lung function abnormalities and symptoms. CONCLUSIONS: Our study found increased immunological reactions in the tobacco workers. However, with the possible exception of lung function at low lung volume in female workers, these reactions do not appear to contribute significantly to the symptoms and lung function abnormalities seen in these workers. Am. J. Ind. Med. 45:76-83, 2004.     

布地奈德对哮喘急性发作期患儿血清炎性因子及肺功能的影响

目的探讨布地奈德雾化吸入对哮喘急性发作期患儿血清炎性因子及肺功能的影响。方法将我院收治的317例哮喘急性发作期患儿按照随机分层分组法分为观察组和对照组,对照组给予常规治疗,观察组在对照组基础上给予小剂量布地奈德粉雾化吸入,观察患儿临床症状、血清炎性因子及肺功能改善情况。结果观察组临床症状积分、无症状天数比例及急性发作次数均显著优于对照组（P〈0.05）;观察组血清炎性因子水平及肺功能改善情况均显著优于对照组（P〈0.05）。结论小剂量布地奈德粉雾化吸入能显著改善患儿的临床症状和肺功能,长期使用不会引起下丘脑-垂体-肾上腺轴功能抑制。     

稻谷尘对退休粮工呼吸功能影响的调查

本文报道了130例退休粮工及373例无粉尘接触史的退休工人的呼吸道疾患及肺功能检查的结果,显示接触组的慢性呼吸道疾病症状和体征较对照组有显著意义的升高。肺功能的检查结果表明,接触组的FVC、FEV_1、PEF、V_(75)、V_(50)、V_(25)等指标较对照组有显著的下降,两组的差别有显著及极显著意义。对男粮工与对照组进行了肺功能与接尘、吸烟两因素方差分析,结果表明粉尘和吸烟对V_(50)、V_(250及FEF_(25～75)三项指标有显著的交互作用,即吸烟可以加重粉尘对工人肺功能的影响。     

Follow-up study of respiratory function in Hemp workers

A 3-year follow-up study was performed on 38 women and 28 men from the originally studied textile workers employed in a soft hemp processing mill. Acute and chronic respiratory symptoms and ventilatory capacity were recorded during the cross-sectional and the follow-up studies. Maximum expiratory flow-volume (MEFV) curves were obtained on these workers, and forced vital capacity (FVC), 1-second forced expiratory volume (FEV₁) and flow rates at 50% and at 25% of the VC (FEF₅₀, FEF₂₅) were measured. High prevalences of acute and chronic respiratory symptoms persisted at the follow-up study. In particular, high prevalences of byssinosis were documented at both studies (women: 47.4% and 47.4%; men: 64.3% and 67.9%, respectively). Statistically significant mean across-shift reductions were recorded for all ventilatory capacity tests at the initial study. A large mean annual decline was calculated for FEV₁ in women and for all ventilatory capacity parameters in men; these declines were greater for workers with symptoms of byssinosis than for those without. The accelerated decline in FEV₁ noted in the women workers, who were predominantly nonsmokers, suggests an independent hemp effect. Exposures in the work environment were measured with Hexhlet filters and revealed very high dust concentrations (mean total: 21.4 mg/m³, 22.4 mg/m³; respirable: 8.4 mg/m³, 9.9 mg/m³) at both initial and follow-up studies. These levels are much higher than those found in mills processing organic materials in North America. Our data demonstrate that work in the hemp industry, particularly in small poorly regulated mills, continues to have deleterious effects on respiratory function.     

A study of noise-induced hearing loss and blood pressure in steel mill workers

Summary A cross-sectional study on noise-induced hearing loss and blood pressure was conducted in a steel mill company. Three hundred testees were selected by cluster sampling. They were physically examined and an audiometry was done. Only 151 workers, who had the highest hearing threshold at 4000 Hz and without any family history of hypertension or treatment of drugs on cardiovascular troubles, were selected as subjects in this study. Multiple regression analyses revealed that body mass index, employment duration, age and hearing loss explained a significant amount of variation in systolic and diastolic blood pressure (R ² = 0.16 and 0.12, respectively). There was no significant relationship between hearing loss and blood pressure. In order to adjust confounding factors, analyses of covariances were used and the results suggest that hearing loss is unrelated to blood pressure. It seems that hearing loss is not appropriate as a noise exposure index to measure the relationship between noise exposure and blood pressure.     

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.     

Longitudinal study of respiratory findings in rubber workers

A cross-sectional assessment of respiratory function and symptoms was performed in 1985 on 409 male rubber workers and 172 unexposed control workers. A follow-up study in 311 of the original rubber workers was performed 6 years later. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. At the time of the initial study, significantly higher prevalences of all chronic respiratory symptoms, except for asthma, were found among the rubber workers compared to controls. Smokers had a significantly higher prevalence of most of the chronic respiratory symptoms compared with nonsmokers. A high prevalence of acute symptoms during the workshift was recorded among the rubber workers at both surveys. Rubber workers demonstrated significantly lower ventilatory capacity measurements compared to predicted. Ventilatory capacity measurements diminished significantly across the workshift, particularly FEF50 and FEF25. Metaproterenol inhaled at the end of the workshift significantly improved lung function in a small group of sensitive rubber workers. Annual lung function loss among both smokers and nonsmokers was in excess of predicted. Our data suggest that exposure to noxious agents in the rubber industry are associated with the development of acute and chronic respiratory impairment. © 1996 Wiley-Liss, Inc.     

Effects of bioaerosol exposure on work-related symptoms among Swiss sawmill workers

Objective Exposure to bioaerosols in the occupational environment of sawmills could be associated with a wide range of health effects, in particular respiratory impairment, allergy and organic dust toxic syndrome. The objective of the study was to assess the frequency of medical respiratory and general symptoms and their relation to bioaerosol exposure. Method Twelve sawmills in the French part of Switzerland were investigated and the relationship between levels of bioaerosols (wood dust, airborne bacteria, airborne fungi and endotoxins), medical symptoms and impaired lung function was explored. A health questionnaire was distributed to 111 sawmill workers. Results The concentration of airborne fungi exceeded the limit recommended by the Swiss National Insurance (SUVA) in the twelve sawmills. This elevated fungi level significantly influenced the occurrence of bronchial syndrome (defined by cough and expectorations). No other health effects (irritations or respiratory effects) could be associated to the measured exposures. We observed that junior workers showed significantly more irritation syndrome (defined by itching/running nose, snoring and itching/red eyes) than senior workers. Lung function tests were not influenced by bioaerosol levels nor dust exposure levels. Conclusion Results suggest that occupational exposure to wood dust in a Swiss sawmill does not promote a clinically relevant decline in lung function. However, the occurrence of bronchial syndrome is strongly influenced by airborne fungi levels.     

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     

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.     

An environmental and respiratory health survey of workers in a grain mill in the Johannesburg area,South Africa

A respiratory health survey was conducted in a grain mill and the relationship of health indicators to quantitative measures of airborne dust, fungal, and bacterial contamination was examined. Respiratory symptoms were more prevalent in the high dust exposure categories; lung function levels were also higher in the high dust exposure categories, consistent with a “healthy” worker effect. Workers in the three higher dust exposure categories showed either no change or a decrease in lung function over the working week, while workers in the low exposure category demonstrated an improvement in lung function over the working week. Total dust and microbiological (fungal and bacterial) load were found to be significantly related to each other, and the relationship of microbiological load to lung function level and changes over the working week were similar to those found for total dust © 1993 Wiley-Liss, Inc.