Occupational exposure to dust in quartz manufacturing industry.
(25/1312)
Owing to the abundance of a sedimentary rock, 65 small-scale quartz manufacturing enterprises, employing 650 workers, have been established in the region studied. Quartz powder manufacturing involves various processes and operations, such as manual handling of quartz stones, crushing, grinding, sieving, screening, mixing, storing and bagging. Results demonstrate that each of these operations generates high concentrations of airborne 'total' dust and respirable dust, which contain a very high percentage (> 75%) free silica. The estimated average exposure to airborne 'total' dust was 22.5 mg m-3 (Permissible Limit of Exposure 1.08 mg m-3), and respirable dust 2.93 mg m-3 (PLE 0.36 mg m-3). This shows that 'total' dust exposure was 7.7 times higher than respirable dust. Since the present work systems and practices may pose a serious health risk to the workers, public and the environment, suitable preventive and control measures have been suggested for improvement in the workplace. (+info)
Environmental measurements of total dust and fiber concentration in manufacturer and user of man-made mineral fibers.
(26/1312)
Man-made mineral fibers (MMMF), most of which are referred to as man-made vitreous fibers (MMVF), are mostly amorphous silicates manufactured from glass, rock, or other minerals. Analysis for MMMF have been restricted largely to the measurement of total airborne mass concentrations, but more recently to the determination of airborne fiber levels by phase contrast optical microscopy. In Korea, many small factories are related with manufacturing and using MMMF without any special evaluation of environmental measurements. Though MMMF are known as the substitute of asbestos and their toxicity are regarded as very low, MMMF do not totally excluded from the respiratory and/or skin diseases now. Therefore, we evaluated the environments of many workplaces with total dust and fiber concentration. Most dust and fiber concentrations were below threshold limit value (TLV) at various industries and working processes. However, these data showed a slight relationship between total dust and fiber concentration. (+info)
Workers' right-to-know legislation: does it work?
(27/1312)
Workers' right-to-know (WRTK) laws and regulations were established to empower workers to protect their health by providing them with information about the hazards to which they are exposed while at work. The present study was conducted to examine the implementation of WRTK regulations in Israel. We interviewed 552 workers and 33 safety officers from a random sample employed at 50 industrial plants. The workers' questionnaire included items on awareness and self-management of workplace hazards, and the safety officers answered questions about job experience and hazards communications to workers. In 36% of cases workers and their safety officers disagreed about the existence of hazards in the workplace (p < 0.001). Most (78%) of the workers' knowledge about work hazards was based on informal sources, i.e., not those stipulated by the regulations. There were also discrepancies between worker and safety officer reports regarding the provision of safety training upon employment (p < 0.001), recent instructions about special risks and distribution of relevant printed material. We found that more than 5% of workers were unable to read the language in which the hazards material was written and 22% had levels of education below that required to comprehend the technical terms used. There are serious problems in the implementation of WRTK regulations in Israel. We recommend that employers be made aware of the importance of these laws and of their proactive duty to comply with them and that the material distributed to workers be written in simpler terms and/or explained orally in a language they understand. These findings have important implications for all countries with similar legislation and should form the basis for further and more comprehensive studies world-wide. (+info)
Shrinking membership in the American Society of Animal Science: does the discipline of poultry science give us some clues?
(28/1312)
Concerns have been expressed by the American Society of Animal Science (ASAS) leadership about the declining membership in ASAS. I present the viewpoint that the history of the Poultry Science Association (PSA) membership and the elimination of poultry science departments from many land grant universities could be an indication of what the future holds for animal science. I suggest that the industrialization of poultry production has led to a decline in the demand for traditionally trained poultry scientists. Industrialization of swine production is proceeding rapidly, with other animal-based industries showing the same trend. If maintaining a large ASAS membership is indeed a priority, new opportunities must be developed. Equine and companion animal programs offer such possibilities, tapping into a high level of student interest. (+info)
Global climate change.
(29/1312)
Most of the last 100,000 years or longer has been characterized by large, abrupt, regional-to-global climate changes. Agriculture and industry have developed during anomalously stable climatic conditions. New, high-resolution analyses of sediment cores using multiproxy and physically based transfer functions allow increasingly confident interpretation of these past changes as having been caused by "band jumps" between modes of operation of the climate system. Recurrence of such band jumps is possible and might be affected by human activities. (+info)
An isotopic approach for understanding the CH(3)Br budget of the atmosphere.
(30/1312)
The atmospheric budget of methyl bromide (CH(3)Br), an ozone-depleting gas, is highly uncertain, because it has complex sources and sinks. Although oceans, biomass burning, and industrial production are identified as the major sources, the fraction of CH(3)Br that is contributed by each source is not well known. A mass-balance approach that exploits differences in the carbon isotopic signature (delta(13)C) of CH(3)Br sources and sinks may provide a means of reducing uncertainties in the atmospheric budget. This approach depends on the distinctiveness of industrially produced methyl bromide. Our delta(13)C measurements of industrial CH(3)Br from the three largest manufacturers worldwide yield a weighted average of -54.4 per thousand relative to the Peedee Belemnite standard. This result suggests that industrial CH(3)Br is isotopically distinct and that the carbon isotopic composition of atmospheric CH(3)Br may indicate what fraction of atmospheric CH(3)Br is anthropogenic. (+info)
Occupational risk factors of lung cancer: a hospital based case-control study.
(31/1312)
OBJECTIVES: To investigate the relation between lung cancer and exposure to occupational carcinogens in a highly industrialised region in western Europe. METHODS: In a case-control study 478 cases and 536 controls, recruited from 10 hospitals in the Antwerp region, were interviewed. Cases were male patients with histologically confirmed lung cancer; controls were male patients without cancer or primary lung diseases. Data were collected by questionnaires to obtain information on occupations, exposures, and smoking history. Job titles were coded with the Office of Populations, Censuses and Surveys industrial classification. Exposure was assessed by self report and by job-task exposure matrix. Exposure odds ratios were calculated with logistic regression analysis adjusted for age, smoking history, and marital and socio-economic status. RESULTS: A job history in the categories manufacturing of transport equipment other than automobiles (for example, shipyard workers), transport support services (for example, dockers), and manufacturing of metal goods (for example, welders) was significantly associated with lung cancer (odds ratios (ORs) 2.3, 1.6, and 1.6 respectively). These associations were independent of smoking, education, civil, and economic status. Self reported exposure to potential carcinogens did not show significant associations with lung cancer, probably due to nondifferential misclassification. When assessed by job-task exposure matrix, exposure to molybdenum, mineral oils, and chromium were significantly associated with lung cancer. A strong association existed between smoking and lung cancer: OR of ex-smokers 4.2, OR of current smokers 14.5 v non-smokers. However, smoking did not confound the relation between occupational exposure and lung cancer. CONCLUSIONS: The study has shown a significant excess risk of lung cancer among workers in manufacturing of metal goods, manufacturing of transport equipment (other than automobiles), and transport support services. Assessment of exposure to specific carcinogens resulted in significant associations of chromium, mineral oils, and molybdenum with lung cancer. This study is, to our knowledge, the first study reporting a significant association between occupational exposure to molybdenum and lung cancer. (+info)
Health effects among workers in sewage treatment plants.
(32/1312)
OBJECTIVES: To further assess the presence of fatigue, symptoms of diarrhoea, and inflammation of airways among people working in sewage plants and the relation to airborne bacterial endotoxin at the workplace. METHODS: 34 Employees in sewage treatment plants and 35 controls were selected. They underwent a questionnaire investigation, and spirometry and airway responsiveness were measured. Measurements were made of airborne endotoxin at different workplaces. RESULTS: The amount of airborne endotoxin varied between 3.8 and 32,170 ng/m3. Workers reported significantly higher nose irritation, tiredness, and diarrhoea. Airway responsiveness was increased among sewage workers, but no differences between the groups were found for spirometry. CONCLUSIONS: The results confirm previous studies on the presence of airways and intestinal inflammation among workers in sewage treatment plants. The most likely causative agent is endotoxin, and at 14 of 23 workplaces, concentrations exceeded recommended guidelines. (+info)