Recent trends in bagassosis in Japan.

The only workers presently exposed to bagasse dust in Japan are the employees of sugar refineries and lacquerware factories. A follow up study of six former cases of bagassosis from among the retired employees of a paper board factory, closed since 1973, showed that none of the subjects still had bagassosis. Examinations of 70 employees of a sugar refinery for allergic reactions also showed no case of bagassosis. Seven cases with suspicious shadows of bagassosis on chest radiographs and four cases with positive serum precipitin to stored bagasse were, however, found among those 70 subjects. The results show the disappearance of a past episode of bagassosis and the possibility of a new occurrence of bagassosis among the employees of sugar refineries and lacquerware factories in the near future in Japan.     

Immunological Aspects of Bagassosis

Immunological investigations of 37 patients with bagassosis, 92 unaffected bagasse workers, and 150 non-exposed controls showed that precipitins against extracts of bagasse could be demonstrated just as frequently in the unaffected and the non-exposed as in the affected. However, there was a general tendency for the precipitin levels of patients with bagassosis to fall slightly with increasing time after recovery from the clinical episode. The presence of the precipitins so far demonstrated in the sera of bagasse workers therefore appears to be of no clinical significance.

Inhalation tests with an extract of bagasse, in a group of 16 patients who had had bagassosis, produced late, systemic reactions in 15 similar to those described in farmer's lung and bird fancier's lung, so supporting the hypothesis that a similar type of hypersensitivity is the cause of bagassosis. Inhalation of extracts of Thermoactinomyces vulgaris also produced typical, late reactions in 12 out of 15 subjects, whereas extracts of Micropolyspora faeni failed to produce reactions in any of 16 subjects. The specific reactions to inhalation tests with Thermoactinomyces vulgaris were typical of a precipitin-mediated type of hypersensitivity reaction and support the view that this actinomycete may be important in the aetiology of bagassosis.

     

Bagassosis: An Epidemiological, Environmental, and Clinical Survey

An epidemiological and environmental survey of 170 bagasse workers employed by a raw sugar producing company in Trinidad was carried out in order to assess the prevalence of respiratory symptoms and to determine if exposure to bagasse was associated with alterations in ventilatory capacity.

The epidemiological survey failed to reveal a significantly increased prevalence of respiratory symptoms in the more exposed group but showed that the group of Indian workers who were regularly and continuously exposed to bagasse had a significantly lower ventilatory capacity than the control group. This diminished ventilatory capacity was demonstrated despite negligible dust concentrations in the plant. However, the possibility that persistent exposure to low concentrations of bagasse may be the cause must be considered.

During a five-year period, 17 patients with bagassosis were seen, the clinical picture being similar to that described in extrinsic allergic alveolitis from other causes.

The systematic variations demonstrated in some indices of ventilatory function in different racial groups are discussed.

     

Experimental bagassosis: role of infection

The pathological lesions of bagassosis have been reproduced in guinea pigs given bagasse fibers along with low doses of actinomycete spores. In the early stages, interstitial infiltration with lymphocytes and macrophages as seen in humans was noted. Later, small interstitial bagasse granulomas composed of foreign body giant cells, fibroblasts, and lymphocytes developed, some of which had a laminated appearance. Lymph node changes consistent with an immunological reaction were observed. Actinomycetes alone showed occasional areas of pneumonitis and bagasse alone small granulomas consisting of foreign body giant cells and bagasse fibers. Finally, the combined effect of dust and actinomycetes produced interstitial fibrosis composed of thick reticulin fibers and occasional collagen fibers, which persisted to the end of the experiment. Bagasse alone and actinomycetes alone produced only thin reticulin fibers. It has been suggested that bagassosis is due to the synergistic action of bagasse fibers and Micropolyspora faeni and that in the pathogenesis of the syndrome an immunological component may be involved.     

Differences in cellular and inflammatory cytokine profiles in the bronchoalveolar lavage fluid in bagassosis and silicosis

BACKGROUND: Little is known about the crucial mediators involved in the inflammation and fibrogenesis in bagassosis. The aim of this study was to characterize the cellular and cytokine patterns in the airways of bagassosis and to compare these with silicosis subjects and controls. METHODS: Bronchoalveolar lavage (BAL) was performed in 11 patients with bagassosis, 16 cases with silicosis, and 8 controls. Differential cell counts, total protein concentration, TNF-alpha, IL-1beta, IL-5, IL-6, and IL-8 were analyzed in the bronchoalveolar lavage fluid (BALF). RESULTS: Bagassosis was characterized with hypercellularity with neutrophilia in BALF; while the predominant cell in the BALF in silicosis was macrophage. Compared with control subjects, increased TNF-alpha, IL-1beta, IL-8, and IL-6 levels were found in the BALFs in both bagassosis and silicosis. Furthermore, IL-6 levels in the BALF of silicosis subjects were significantly higher than that seen in bagassosis. In contrast, bagassosis had higher level of IL-8 in BALF than that in silicosis. Relationship among these parameters were found between IL-8 levels and neutrophils, lymphocytes and IL-1 beta in bagassosis, macrophages and IL-1beta in silicosis. No significant differences of total protein concentrations and IL-5 in BALF were found between controls or bagassosis, and silicosis. CONCLUSIONS: The findings of this study suggest that neutrophils, TNF-alpha, IL-1beta, IL-8, and IL-6 are involved in the pathogenesis in bagassosis. The mechanisms underline the different cellular and cytokine profiles in bagassosis and silicosis warrant further investigation.     

Pulmonary function at rest and during exercise following bagassosis

Miller, G. J., Hearn, C. E. D., and Edwards, R. H. T. (1971).Brit. J. industr. Med.,28, 152-158. Pulmonary function at rest and during exercise following bagassosis. Lung function and exercise responses were investigated in two groups of Indian bagasse workers to assess whether there were any permanent sequelae following regular exposure to bagasse dust in a group of 12 men who had developed bagassosis and a group of six who had not. Ventilatory capacity, lung volumes, single breath carbon monoxide transfer factor (TF), diffusion capacity of the alveolar-capillary membrane (Dm), and volume of blood in the pulmonary capillaries (Vc) were measured, and then exercise responses were investigated with a cycle ergometer. The ventilatory response to hypercapnia was assessed by a modified re-breathing method.

The group of 12 patients had small but significant reductions in lung volumes, TF, and Dm 7 to 10 years after the acute episode. The ventilatory responses to exercise and hypercapnia were increased but exercise capacity was normal and limited by the cardiovascular responses. Exercise hyperventilation was the likely explanation for the exertional dyspnoea in this group.

Six of a group of workers who had been regularly exposed to mouldy bagasse dust without developing bagassosis and had a significant reduction in ventilatory capacity during exposure were found to have normal lung function and exercise responses two years after withdrawal from bagasse.

Immunological reactivity to an extract of Thermoactinomycetes vulgaris was found to have subsided after withdrawal from bagasse dust, although it can persist for six years. In a single case, disodium cromoglycate failed to suppress the late systemic reaction provoked by the inhalation test.

     

炼化企业作业职工恶性肿瘤流行病学调查研究

对锦州、抚顺、兰州、大连、锦西、南京、上海、大庆、独山子和茂名等十三个炼油厂做了癌症死亡率回顾性队列研究。队列成员５１８８９人，失访１７１７人（３．３１％）。结果表明：页岩型炼油厂队列成员肺癌的ＳＭＲ显著增高，肺癌与暴露程度间存在着剂量－反应关系。对于煤合成油厂的高暴露区（１９７１～１９８８年）的肺癌，通过Ｌｏｇｉｓｔｉｃ回归分析，调整其他环境混淆效应后，其ＯＲ值为９．２５。石油型炼厂队列成员全癌死亡率增高，在观察期内表现出上升趋势，胃癌、肝癌的ＳＭＲ分别为１．４３和１．５１，存在着明显的统计学意义。     

Cluster cases of malignant pleural mesothelioma in an oil factory

BACKGROUND: The traditional occupational hazards of the productive cycle of oils are attributable to chemicals (use of solvents, pesticides and other agents), dusts, labour accidents (trauma, ignition, explosion), noise, manual lifting, work organization and hot-wet microclimate. The latest risk is due to the use of high temperatures (from 50 up to 250 degrees C) during the processes of extraction with solvent and refining. No cases are reported in literature of asbestos related disease in subjects who worked in oil factories. Nevertheless the structure and organization of the workplace, which is similar to that of sugar refineries, where cases of malignant mesothelioma have been described (moreover in workers employed in running and maintenance of the plants), led to the assumption that even in oil factories asbestos for the insulation of pipes and boilers could be present. OBJECTIVES: To describe 3 cases of Malignant Mesothelioma that occurred in workers of the same oil factory. METHODS: Since this occupational sector is not conventionally known for asbestos exposure the Local Health Unit and the Lombardy Mesothelioma Registry decided to investigate this industrial plant. RESULTS: Following examination of the archives of the Local Health Unit and inspection of the plant, an environmental asbestos contamination (pipes and boilers) was found. The 3 cases were defined as occupational disease and the required legal procedures were initiated. This underlines the importance of close cooperation with Local Health Units of occupational medicine and the Regional Mesothelioma Registry in the study and acknowledgment of cases which would otherwise not have been recognized, with consequent loss of precious information.     

广西蔗渣尘所致职业性变应性肺泡炎调查报告

本文报告了广西七糖厂职业性变应性肺泡炎(OEAA)的流行病学调查结果。本结果首次证实广西糖业生产工人中有蔗渣尘所致的OEAA急、慢性病例存在。急性OEAA发病率约7.18%。这些病例都发生在接触受放线菌污染严重的蔗渣尘工人中。然而,这些病例过去全部被误诊,因此广西当前防治OEAA最重要的工作是提高接触者及医师对本病的认识。     

Influence of processed sugarcane bagasse on the microbial,nutritional, rheological and quality characteristics of biscuits

Sugarcane bagasse, a dietary fiber-rich by-product of the sugar industry (70–75%) and having negligible protein and fat content, was treated with acid, alkali and steaming to reduce the microbial load. Steaming was effective in making the bagasse microbiologically safe. The processed bagasse (5–15%) was used in the rheological studies and in the preparation of soft dough biscuits. Glucose (hexose), arabinose and xylose (pentose) were present, whereas rhamnose, mannose and galctose were not traced in all of the bagasse samples. Farinograph characteristics of wheat flour–bagasse blends showed that the mixing profile weakened with addition of bagasse. Processed bagasse also affected the pasting characteristics indicating starch dilution on incorporation of bagasse, as indicated by sensory characteristics. Biscuits prepared from steamed bagasse (10%) along with additives were highly acceptable. Results indicated that high-fiber biscuits can be prepared by replacing wheat flour with steamed bagasse at a 10% level.     

Influence of processed sugarcane bagasse on the microbial, nutritional, rheological and quality characteristics of biscuits

Sugarcane bagasse, a dietary fiber-rich by-product of the sugar industry (70-75%) and having negligible protein and fat content, was treated with acid, alkali and steaming to reduce the microbial load. Steaming was effective in making the bagasse microbiologically safe. The processed bagasse (5-15%) was used in the rheological studies and in the preparation of soft dough biscuits. Glucose (hexose), arabinose and xylose (pentose) were present, whereas rhamnose, mannose and galctose were not traced in all of the bagasse samples. Farinograph characteristics of wheat flour-bagasse blends showed that the mixing profile weakened with addition of bagasse. Processed bagasse also affected the pasting characteristics indicating starch dilution on incorporation of bagasse, as indicated by sensory characteristics. Biscuits prepared from steamed bagasse (10%) along with additives were highly acceptable. Results indicated that high-fiber biscuits can be prepared by replacing wheat flour with steamed bagasse at a 10% level.     

Investigation of a cluster of pituitary adenomas in workers in the aluminum industry.

OBJECTIVE: Four cases of pituitary adenoma among employees at a primary aluminum production factory were identified over a five year period by a community physician. The objective of this investigation was to determine whether there has been a comparable high incidence in other aluminum factories, and if particular jobs, departments, or activities in the industry are associated with higher rates of the disease. METHOD: Pituitary adenoma in employees at all United States factories of the company for the years 1989-94 was assessed by a search of a health data information bank and an insurance data base covering present and past employees of the corporation. The incidence in the aluminum workers was estimated and compared with the workers in the index plant. A nested case control study was conducted to compare employment histories of identified cases with those of age and sex matched controls selected from the health information data base. RESULTS: 25 cases, including the index cases, were identified which had been diagnosed during the period 1989-94. The resulting rate of 10.4/100,000 person-years was much lower than that at the index plant. Case-control analysis showed no coherent pattern of location, department, or job significantly associated with risk. In particular, jobs and departments associated with exposures common to aluminum smelting-such as coal tar pitch volatiles and fluorides-were shown to be uncommon among cases compared with age and sex matched controls. CONCLUSION: Overall, despite the unprecedented cluster at a single plant, no strong evidence was found that the rate of pituitary adenoma is increased in aluminum workers generally. We found no association with any work activity or location in the industry to suggest a work related or exposure related cause for the disease.     

Multivariate analysis of risk factors for stroke eight-year follow-up study of farming villages in Akita, Japan

Akita Prefecture has an especially high mortality rate from stroke, and its age-adjusted death rate from stroke is the highest in Japan. We have carried out an epidemiological survey of cardio- and cerebrovascular diseases (CVD) in farming villages in this prefecture since 1963, with a response rate of 84%. During our 8-year follow-up, 94 new stroke cases were observed among 1,814 subjects. Multiple logistic function analysis was carried out on nonstroke and stroke cases from subjects aged 40 to 69 years at time of initial examination, in order to clarify the risk factors for stroke. The analysis used eight variables: age, sex, systolic blood pressure, obesity index, urinary sugar, urinary protein, serum total cholesterol, and total protein. The results showed that hypertension was the most important risk factor for stroke. However, regarding cholesterol, multivariate analysis showed that among men and women aged 40 to 69 years at entry, subjects with low serum total cholesterol levels were more prone to cerebral hemorrhage, but that serum cholesterol level had no weight as a risk factor for cerebral infarction. These results correspond well with the observed fact that stroke incidence or death rate in Japan is higher in populations with high prevalence of hypertension and low concentration of cholesterol, and also with the fact that death rate from hemorrhage declines with the increment of serum total cholesterol and the westernization of diet.     

Lung disorders of workers exposed to rush smear dust in China

The aim of this study was to evaluate the lung disorders of the workers exposed to rush smear dust. A cross sectional study was carried out on 1,709 current workers (788 male, 921 female) in 80 factories. All subjects were asked by questionnaire, and health examination including chest X-ray was conducted for 661 workers in 35 factories. Lung function test was also examined for 119 non-smoking males among 661 subjects. Dust samplings were collected and total and respirable dust concentrations at 127 spots in 35 factories were measured. The geometric mean dust concentration in the workshops was up to 20.00 mg/m(3), and the geometric mean respirable dust concentration reached 8.22 mg/m(3). The mean quartz concentration of accumulated dust was 29.2%. The prevalence of radiographic small opacities profusion category > or = 1/0, according to the ILO 1980 Classification System, was 2.6% among 661 employees. One worker was found to have pneumoconiotic findings of 2/2 profusion accompanied with large opacity. The prevalence of pneumoconiosis (1/0 or more) correlated with cumulative dust exposure (r=0.192, p<0.0001). The similar relationship was found between the prevalence rate of cough or sputa and worksite dust concentration. In non-smokers, a positive association was found between the prevalence of cough and occupational exposure duration (r=0.080, p=0.004). Approximately 19.3% and 34.5% of employees suffered from respiratory impairment for FVC and FEV1.0, respectively. This is the first report of "rush" pneumoconiosis in China. Rush mat workers were found to be at high risk for pneumoconiosis, a preventable disease. Our results showed a dose-response relationship between rush-mat dust level and the prevalence of pneumoconiosis. Similar relationship between the prevalence of cough and sputum and the work duration was found for non-smoking workers but not for smoking workers.     

阳西县厂矿企业职工乙肝病毒感染现况调查

[目的]探讨厂矿企业职工近期乙肝痫毒（HBV）感染状况，以使加强厂矿企业职工的健康管理。[方法]2005年8月至2004年7月，对阳西县88家厂矿企业的职工4442人进行血清HIV感染指标的检测。[结果]检测4442人，HBsAg阳性率为11．5％，男性为13．6％，女性为10．2％（P〈0．01）；抗-HBs阳性率为24．4％，HBeAg阳性率为4．3％，抗-HBe阳性率为4．2％，抗-HBc阳性率为8．6%。不同年龄与厂矿职工的HBsAg阳性率的差异均无统计学意义。[结论]目前阳西县厂矿企业职工的HBsAg阳性率不太高。     

Asbestos-related mesothelioma: factors discriminating between pleural and peritoneal sites.

Up to the end of 1980, 144 confirmed cases of mesothelioma were identified among employees of an organisation using asbestos in manufacturing and insulation. The primary site was peritoneal in 74 cases, pleural in 66, and undetermined in four. All employees had been exposed to amphibole asbestos, and evidence from different factories confirmed the predominant role of crocidolite in the production of mesothelioma. The ratio of pleural to peritoneal sites showed a continuous change when related to the year of first exposure, varying from 5:1 pleural to peritoneal before 1921 to 1:3 after 1950. The strong temporal relationship appeared to reflect progressive dust suppression, including the non-fibrous dusts present in insulation materials and perhaps also the degree to which the fibres had been opened. Other predisposing factors were related to the degree of individual exposure, the peritoneal site being associated preferentially with longer and heavier exposures.     

Asbestos-related mesothelioma: factors discriminating between pleural and peritoneal sites

Up to the end of 1980, 144 confirmed cases of mesothelioma were identified among employees of an organisation using asbestos in manufacturing and insulation. The primary site was peritoneal in 74 cases, pleural in 66, and undetermined in four. All employees had been exposed to amphibole asbestos, and evidence from different factories confirmed the predominant role of crocidolite in the production of mesothelioma. The ratio of pleural to peritoneal sites showed a continuous change when related to the year of first exposure, varying from 5:1 pleural to peritoneal before 1921 to 1:3 after 1950. The strong temporal relationship appeared to reflect progressive dust suppression, including the non-fibrous dusts present in insulation materials and perhaps also the degree to which the fibres had been opened. Other predisposing factors were related to the degree of individual exposure, the peritoneal site being associated preferentially with longer and heavier exposures.     

Concentrations and size distribution of inhalable and respirable dust among sugar industry workers: a pilot study in Khon Kaen, Thailand

There has been very limited information regarding bagasse exposure among workers in sugar industries as well as on health outcomes. The authors determined the occupational exposure of sugar industry workers in Khon Kaen to airborne bagasse dust. The size of the bagasse dust ranged from 0.08 to 9 μm with the highest size concentration of 2.1 to 4.7 μm. The most common size had a geometric mean diameter of 5.2 μm, with a mass concentration of 6.89 mg/m(3)/log μm. The highest mean values of inhalable and respirable dust were found to be 9.29 mg/m(3) from February to April in bagasse storage, 5.12 mg/m(3) from May to September, and 4.12 mg/m(3) from October to January. Inhalable dust concentrations were 0.33, 0.47, and 0.41 mg/m(3), respectively. Workers are likely to be exposed to high concentrations of bagasse dust and are at risk of respiratory diseases. Preventive measures, both in the form of engineering designs and personal protective devices, should be implemented.     

Tuberculosis among garment workers in an Arabian developing country: State of Qatar

Tuberculosis (TB) continues to be a leading infectious cause of death worldwide, and it remains a serious public health problem in developing countries. To determine the prevalence of tuberculosis infection among garment workers, the authors conducted a retrospective prevalence survey of employees working in garment factories in Qatar from January 2000 to June 2003. A mass screening of garment factory workers was carried out by chest X-ray and Mantoux skin test at the Rumailah Hospital, Hamad Medical Corporation. The authors considered those workers with a purified protein derivative (tuberculin) reaction of > or = 15 mm to be infected with TB, or to have a latent TB infection. Workers with active TB diseases were confirmed by histopathological and mycobacteriological examinations. The authors studied a total of 2,774 garment factory workers, and they found 43% of them to be infected (reaction > or = 15 mm). The mean age of the infected subjects was significantly higher than that of the noninfected subjects (p < .001); 53% of the infected subjects were between 30 and 40 years of age. Indians and Pakistanis made up the most frequent nationalities among the infected subjects (50.0%), followed by Nepalis (44.1%). The prevalence rate of tuberculosis infection in garment workers was high. Overcrowding in factories and residential facilities increases the risk of TB transmission.     

Inequality in the health status of workers in small-scale enterprises

BACKGROUND: Small-scale enterprises (SSEs) usually share poorer resources for promoting occupational health. AIM: To investigate inequality of health status among SSEs in Japan. METHOD: A cross-sectional, multiple-centred study was carried out using the periodical health check-up data for the fiscal year 2000 to compare the age-adjusted proportions of workers with hypertension (HT), hyperlipidaemia, impaired glucose tolerance (IGT) and obesity and of current smokers by size of enterprise, i.e. or=1000 employees in Japan. RESULTS: From five leading occupational health organizations, data were collected for 9833 enterprises with a total of 436 729 subjects, 302 383 males and 134 346 females. The proportions of workers in SSEs with or=50 male employees. The prevalence of smokers in SSEs with or=50 male employees. These proportions showed a significantly increasing tendency with decreasing size of male workforce. CONCLUSION: Despite the cross-sectional design and only adjusting age as a potential confounder, higher proportions of HT, IGT, obesity and smoking in male workers were found in SSEs compared to larger organizations.