J. McKernan, M. Toraason, J. Fernback, M. Petersen
In tungsten refining and manufacturing processes, a series of tungsten oxides are typically formed as intermediates in the production of tungsten powder. The present study was conducted to characterize airborne tungsten-containing fiber dimensions, elemental composition and concentrations in the US tungsten refining and manufacturing industry. During the course of normal employee work activities, seven personal breathing zone and 62 area air samples were collected and analyzed using National Institute for Occupational Safety and Health (NIOSH) fiber sampling and counting methods to determine dimensions, composition and airborne concentrations of fibers. Mixed models were used to identify relationships between potential determinants and airborne fiber concentrations. Results from transmission electron microscopy analyses indicated that airborne fibers with length >0.5 microm, diameter >0.01 microm and aspect ratios > or =3:1 were present on 35 of the 69 air samples collected. Overall, the airborne fibers detected had a geometric mean length approximately 3 microm and diameter approximately 0.3 microm. Ninety-seven percent of the airborne fibers identified were in the thoracic fraction (i.e. aerodynamic diameter < or = 10 microm). Energy dispersive X-ray spectrometry results indicated that airborne fibers prior to the carburization process consisted primarily of tungsten and oxygen, with other elements being detected in trace quantities. Based on NIOSH fiber counting 'B' rules (length > 5 microm, diameter < 3 microm and aspect ratio > or = 5:1), airborne fiber concentrations ranged from below the limit of detection to 0.085 fibers cm(-3), with calcining being associated with the highest airborne concentrations. The mixed model procedure indicated that process temperature had a marginally significant relationship to airborne fiber concentration. This finding was expected since heated processes such as calcining created the highest airborne fiber concentrations. The finding of airborne tungsten-containing fibers in this occupational setting needs to be confirmed in similar settings and demonstrates the need to obtain information on the durability and associated health effects of these fibers.
{"title":"Presence of tungsten-containing fibers in tungsten refining and manufacturing processes.","authors":"J. McKernan, M. Toraason, J. Fernback, M. Petersen","doi":"10.1093/annhyg/men078","DOIUrl":"https://doi.org/10.1093/annhyg/men078","url":null,"abstract":"In tungsten refining and manufacturing processes, a series of tungsten oxides are typically formed as intermediates in the production of tungsten powder. The present study was conducted to characterize airborne tungsten-containing fiber dimensions, elemental composition and concentrations in the US tungsten refining and manufacturing industry. During the course of normal employee work activities, seven personal breathing zone and 62 area air samples were collected and analyzed using National Institute for Occupational Safety and Health (NIOSH) fiber sampling and counting methods to determine dimensions, composition and airborne concentrations of fibers. Mixed models were used to identify relationships between potential determinants and airborne fiber concentrations. Results from transmission electron microscopy analyses indicated that airborne fibers with length >0.5 microm, diameter >0.01 microm and aspect ratios > or =3:1 were present on 35 of the 69 air samples collected. Overall, the airborne fibers detected had a geometric mean length approximately 3 microm and diameter approximately 0.3 microm. Ninety-seven percent of the airborne fibers identified were in the thoracic fraction (i.e. aerodynamic diameter < or = 10 microm). Energy dispersive X-ray spectrometry results indicated that airborne fibers prior to the carburization process consisted primarily of tungsten and oxygen, with other elements being detected in trace quantities. Based on NIOSH fiber counting 'B' rules (length > 5 microm, diameter < 3 microm and aspect ratio > or = 5:1), airborne fiber concentrations ranged from below the limit of detection to 0.085 fibers cm(-3), with calcining being associated with the highest airborne concentrations. The mixed model procedure indicated that process temperature had a marginally significant relationship to airborne fiber concentration. This finding was expected since heated processes such as calcining created the highest airborne fiber concentrations. The finding of airborne tungsten-containing fibers in this occupational setting needs to be confirmed in similar settings and demonstrates the need to obtain information on the durability and associated health effects of these fibers.","PeriodicalId":342592,"journal":{"name":"The Annals of occupational hygiene","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116753064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OBJECTIVES The aim of the study was to see if a cook could be exposed to mutagenic aldehydes in fumes from frying of beefsteak using margarine, rapeseed oil, soybean oil or virgin olive oil as frying fat. In addition, levels of particle exposure were measured to make the results comparable to other studies. METHODS The levels of higher aldehydes and total particles were measured in the breathing zone of the cook during the panfrying of beefsteak with the four different frying fats. In addition, the number of particles in the size intervals 0.3-0.5, 0.5-0.7 and 0.7-1.0 microm in the kitchen was registered. RESULTS Measured levels of mutagenic aldehydes were between non-detectable and 25.33 microg m(-3) air. The exposure level of total aerosol was between 1.0 and 11.6 mg m(-3). CONCLUSIONS Higher aldehydes were detected in all samples from this study, and mutagenic aldehydes were detected in most of the samples. Frying with margarine gave statistically significantly higher levels of mutagenic aldehydes and particles in all three size fractions than frying with the three different kinds of oil.
{"title":"Exposure to mutagenic aldehydes and particulate matter during panfrying of beefsteak with margarine, rapeseed oil, olive oil or soybean oil.","authors":"A. Sjaastad, K. Svendsen","doi":"10.1093/annhyg/men060","DOIUrl":"https://doi.org/10.1093/annhyg/men060","url":null,"abstract":"OBJECTIVES\u0000The aim of the study was to see if a cook could be exposed to mutagenic aldehydes in fumes from frying of beefsteak using margarine, rapeseed oil, soybean oil or virgin olive oil as frying fat. In addition, levels of particle exposure were measured to make the results comparable to other studies.\u0000\u0000\u0000METHODS\u0000The levels of higher aldehydes and total particles were measured in the breathing zone of the cook during the panfrying of beefsteak with the four different frying fats. In addition, the number of particles in the size intervals 0.3-0.5, 0.5-0.7 and 0.7-1.0 microm in the kitchen was registered.\u0000\u0000\u0000RESULTS\u0000Measured levels of mutagenic aldehydes were between non-detectable and 25.33 microg m(-3) air. The exposure level of total aerosol was between 1.0 and 11.6 mg m(-3).\u0000\u0000\u0000CONCLUSIONS\u0000Higher aldehydes were detected in all samples from this study, and mutagenic aldehydes were detected in most of the samples. Frying with margarine gave statistically significantly higher levels of mutagenic aldehydes and particles in all three size fractions than frying with the three different kinds of oil.","PeriodicalId":342592,"journal":{"name":"The Annals of occupational hygiene","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127024797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-11-01DOI: 10.1097/00001648-200611001-00484
E. Sauleau, P. Wild, M. Hours, A. Leplay, A. Bergeret
In the context of a prospective assessment of exposure for epidemiology, our objective is to obtain an optimal group-based design of allocation of a fixed total number of measurements. Such a design has been described by Ashford [Ashford JR. (1958) The design of a long-term sampling programme to measure the hazard associated with an industrial environment. J R Statist Soc A; 121: 331-47]. As this strategy is not operational, we developed three series of strategies: the first based on simplifications of Ashford's strategy; the second based on a pilot study; and the third on an iterative assessment of the group specific standard deviation of exposure. These strategies are compared by simulating a day-to-day individual exposure in several industrial sites and the resulting health effect. Our criteria for comparing strategies are the mean squared error of the estimated exposure in each group weighted by the number of subjects and the mean squared error of the estimated linear regression coefficient in the dose-response relationship. Strategies relying on an iterative approach have been found to perform best whatever the circumstances, nearly as well as Ashford's optimal strategy.
{"title":"Comparison of measurement strategies for prospective occupational epidemiology.","authors":"E. Sauleau, P. Wild, M. Hours, A. Leplay, A. Bergeret","doi":"10.1097/00001648-200611001-00484","DOIUrl":"https://doi.org/10.1097/00001648-200611001-00484","url":null,"abstract":"In the context of a prospective assessment of exposure for epidemiology, our objective is to obtain an optimal group-based design of allocation of a fixed total number of measurements. Such a design has been described by Ashford [Ashford JR. (1958) The design of a long-term sampling programme to measure the hazard associated with an industrial environment. J R Statist Soc A; 121: 331-47]. As this strategy is not operational, we developed three series of strategies: the first based on simplifications of Ashford's strategy; the second based on a pilot study; and the third on an iterative assessment of the group specific standard deviation of exposure. These strategies are compared by simulating a day-to-day individual exposure in several industrial sites and the resulting health effect. Our criteria for comparing strategies are the mean squared error of the estimated exposure in each group weighted by the number of subjects and the mean squared error of the estimated linear regression coefficient in the dose-response relationship. Strategies relying on an iterative approach have been found to perform best whatever the circumstances, nearly as well as Ashford's optimal strategy.","PeriodicalId":342592,"journal":{"name":"The Annals of occupational hygiene","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2006-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127974557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although it is well known that both cigarette smoke and microscopic airborne asbestos fibres can cause lung cancer, evidence as to how these two agents combine is nebulous. Many workers have believed in the multiplicative theory, whereby asbestos increases the risk in proportion to the risk from other causes. However, evidence against this theory is mounting: a recent review concluded that the multiplicative hypothesis was untenable, and that the relative risk of lung cancer from asbestos exposure was about twice as high in non-smokers as in smokers, a finding largely independent of type of asbestos fibre. The criteria for entry to the current study were met by 7279 men in the 1891-1920 birth cohort of Quebec chrysotile miners and millers. The data consisted of date of birth, place of employment, smoking habit, asbestos exposure accumulated to age 55 and, for those 5527 who died between 1950 and June 1992, date and cause of death; 533 of the deaths were from lung cancer. For the principal analyses, ex-smokers were excluded from the study cohort, which comprised 5888 men, of whom 473 died of lung cancer. The conventional form of analysis is simply of the double dichotomy: non-smokers of cigarettes, 'unexposed' and exposed; all others, 'unexposed' and exposed. The respective standardized lung cancer mortality ratios (SMRs) were 0.29 and 0.62; and 1.37 and 1.72. Thus, the differences in relative risk, due to exposure, were closely similar, 0.33 and 0.35. On the other hand, the effects of asbestos measured by the corresponding ratios, 2.12 and 1.25, did differ, being 1.7 times as high in non-smokers as in others. The principal analysis was much more penetrating: the method was to fit models to a 'disaggregated' 6 x 10 array, by smoking habit (excluding ex-smokers) and asbestos exposure, of lung cancer SMRs. Both linear and log-linear models were fitted: the former included the additive and linear-multiplicative; the latter embraced the more conventional multiplicative form. The additive model fitted much the best. The fit of each multiplicative model was improved by the introduction of an interaction term that implied a less than multiplicative relationship. Thus smoking and exposure to chrysotile appear to have acted independently in causing lung cancer, with 10 cigarettes a day having an effect roughly equivalent to exposure amounting to 700 million particles per cubic foot x years. The refutation of the multiplicative hypothesis in these data reinforces its inapplicability in general; but the additive hypothesis is not generally applicable either. Indeed, there seems to be no good reason to believe that interactions conform to any simple theory. The implications are important.
虽然众所周知，香烟烟雾和空气中微小的石棉纤维都能导致肺癌，但关于这两种物质如何结合的证据还很模糊。许多工人相信乘法理论，即石棉增加的风险与其他原因的风险成正比。然而，反对这一理论的证据越来越多:最近的一项综述得出结论，乘法假设是站不住脚的，非吸烟者因接触石棉而患肺癌的相对风险大约是吸烟者的两倍，这一发现在很大程度上与石棉纤维的类型无关。符合本研究标准的是1891-1920年魁北克温石棉矿工和磨坊主出生队列中的7279名男性。数据包括出生日期、工作地点、吸烟习惯、55岁前累积的石棉接触，以及1950年至1992年6月期间死亡的5527人的死亡日期和死因;其中533人死于肺癌。在主要分析中，戒烟者被排除在研究队列之外，该队列包括5888名男性，其中473人死于肺癌。传统的分析形式是简单的双重二分法:不吸烟的人，“未暴露”和暴露;所有其他的，“未暴露”和暴露。标准化肺癌死亡率(SMRs)分别为0.29和0.62;1.37和1.72。因此，由于暴露导致的相对风险差异非常相似，分别为0.33和0.35。另一方面，用相应的比值(2.12和1.25)测量石棉的影响确实有所不同，非吸烟者的影响是其他人的1.7倍。主要分析更为深入:该方法是根据吸烟习惯(不包括前吸烟者)和石棉暴露，将模型拟合到肺癌smr的“分解”6 x 10数组。拟合线性模型和对数线性模型:前者包括加性模型和线性乘法模型;后者采用了更传统的乘法形式。加性模型拟合得最好。每个乘法模型的拟合通过引入一个隐含小于乘法关系的交互项得到改善。因此，吸烟和接触温石棉在导致肺癌方面似乎是独立的，每天10支烟的影响大致相当于每立方英尺x年接触7亿个颗粒。这些数据中对乘法假设的反驳强化了它在一般情况下的不适用性;但加性假设也不是普遍适用的。事实上，似乎没有充分的理由相信相互作用符合任何简单的理论。这其中的含义很重要。
{"title":"The combination of effects on lung cancer of cigarette smoking and exposure in quebec chrysotile miners and millers.","authors":"F. Liddell, B. Armstrong","doi":"10.1093/ANNHYG/MEF008","DOIUrl":"https://doi.org/10.1093/ANNHYG/MEF008","url":null,"abstract":"Although it is well known that both cigarette smoke and microscopic airborne asbestos fibres can cause lung cancer, evidence as to how these two agents combine is nebulous. Many workers have believed in the multiplicative theory, whereby asbestos increases the risk in proportion to the risk from other causes. However, evidence against this theory is mounting: a recent review concluded that the multiplicative hypothesis was untenable, and that the relative risk of lung cancer from asbestos exposure was about twice as high in non-smokers as in smokers, a finding largely independent of type of asbestos fibre. The criteria for entry to the current study were met by 7279 men in the 1891-1920 birth cohort of Quebec chrysotile miners and millers. The data consisted of date of birth, place of employment, smoking habit, asbestos exposure accumulated to age 55 and, for those 5527 who died between 1950 and June 1992, date and cause of death; 533 of the deaths were from lung cancer. For the principal analyses, ex-smokers were excluded from the study cohort, which comprised 5888 men, of whom 473 died of lung cancer. The conventional form of analysis is simply of the double dichotomy: non-smokers of cigarettes, 'unexposed' and exposed; all others, 'unexposed' and exposed. The respective standardized lung cancer mortality ratios (SMRs) were 0.29 and 0.62; and 1.37 and 1.72. Thus, the differences in relative risk, due to exposure, were closely similar, 0.33 and 0.35. On the other hand, the effects of asbestos measured by the corresponding ratios, 2.12 and 1.25, did differ, being 1.7 times as high in non-smokers as in others. The principal analysis was much more penetrating: the method was to fit models to a 'disaggregated' 6 x 10 array, by smoking habit (excluding ex-smokers) and asbestos exposure, of lung cancer SMRs. Both linear and log-linear models were fitted: the former included the additive and linear-multiplicative; the latter embraced the more conventional multiplicative form. The additive model fitted much the best. The fit of each multiplicative model was improved by the introduction of an interaction term that implied a less than multiplicative relationship. Thus smoking and exposure to chrysotile appear to have acted independently in causing lung cancer, with 10 cigarettes a day having an effect roughly equivalent to exposure amounting to 700 million particles per cubic foot x years. The refutation of the multiplicative hypothesis in these data reinforces its inapplicability in general; but the additive hypothesis is not generally applicable either. Indeed, there seems to be no good reason to believe that interactions conform to any simple theory. The implications are important.","PeriodicalId":342592,"journal":{"name":"The Annals of occupational hygiene","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130964319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The British Standards Institution 'Guide to implementing an effective respiratory protective device programme' (BS 4275) lists assigned protection factors (APFs) for various types of respiratory protective equipment (RPE). The APFs were allocated either on the basis of available workplace studies data which met set criteria or on the basis of professional judgement that there is equivalence between its operation and that of a device for which an APF is derived from workplace data. However, in many cases no workplace study information exists to support this professional judgement. As an interim measure, pending information based on workplace measurements, the breathing resistance of a range of tight-fitting RPE from negative pressure filtering devices through to self-contained positive pressure breathing apparatus was measured at various breathing rates. The relative inhalation resistances were then compared on the assumption that similar breathing resistance performance is likely to give similar inward leakage on a facepiece and hence similar protection if all other factors, such as fit, etc., are equal. This work indicates that for most devices the allocation of APFs by analogy to other devices seems to be acceptable. However, there appears to be no justification for the allocation of an APF value of 100 to continuous flow compressed air line breathing apparatus. It is recommended that it should be lowered to 40 until there is valid workplace study data to support the current APF of 100. The work provides an informative insight into the relative performance of devices.
{"title":"A review of assigned protection factors of various types and classes of respiratory protective equipment with reference to their measured breathing resistances.","authors":"M. Clayton, B. Bancroft, B. Rajan","doi":"10.1093/ANNHYG/MEF071","DOIUrl":"https://doi.org/10.1093/ANNHYG/MEF071","url":null,"abstract":"The British Standards Institution 'Guide to implementing an effective respiratory protective device programme' (BS 4275) lists assigned protection factors (APFs) for various types of respiratory protective equipment (RPE). The APFs were allocated either on the basis of available workplace studies data which met set criteria or on the basis of professional judgement that there is equivalence between its operation and that of a device for which an APF is derived from workplace data. However, in many cases no workplace study information exists to support this professional judgement. As an interim measure, pending information based on workplace measurements, the breathing resistance of a range of tight-fitting RPE from negative pressure filtering devices through to self-contained positive pressure breathing apparatus was measured at various breathing rates. The relative inhalation resistances were then compared on the assumption that similar breathing resistance performance is likely to give similar inward leakage on a facepiece and hence similar protection if all other factors, such as fit, etc., are equal. This work indicates that for most devices the allocation of APFs by analogy to other devices seems to be acceptable. However, there appears to be no justification for the allocation of an APF value of 100 to continuous flow compressed air line breathing apparatus. It is recommended that it should be lowered to 40 until there is valid workplace study data to support the current APF of 100. The work provides an informative insight into the relative performance of devices.","PeriodicalId":342592,"journal":{"name":"The Annals of occupational hygiene","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121585066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OBJECTIVES To summarize data on changes in lung contents of asbestos types between 1976-77 and 1990-96 for mesotheliomas and controls in the UK. METHODS Data were extracted from published studies of the years 1976, 1977 and 1990-96. RESULTS Between 1976-77 and 1990-96 there was a large reduction in the amount of crocidolite in the lungs of both mesotheliomas and controls. CONCLUSION The results are consistent with the use of the different asbestos types in the UK, after taking into account the period of exposure and elimination of fibres from the lung in the time elapsed since exposure.
{"title":"Asbestos lung fibre analysis in the United Kingdom, 1976-96.","authors":"G. Berry","doi":"10.1093/ANNHYG/MEF066","DOIUrl":"https://doi.org/10.1093/ANNHYG/MEF066","url":null,"abstract":"OBJECTIVES\u0000To summarize data on changes in lung contents of asbestos types between 1976-77 and 1990-96 for mesotheliomas and controls in the UK.\u0000\u0000\u0000METHODS\u0000Data were extracted from published studies of the years 1976, 1977 and 1990-96.\u0000\u0000\u0000RESULTS\u0000Between 1976-77 and 1990-96 there was a large reduction in the amount of crocidolite in the lungs of both mesotheliomas and controls.\u0000\u0000\u0000CONCLUSION\u0000The results are consistent with the use of the different asbestos types in the UK, after taking into account the period of exposure and elimination of fibres from the lung in the time elapsed since exposure.","PeriodicalId":342592,"journal":{"name":"The Annals of occupational hygiene","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127998492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
OBJECTIVES Although hearing protectors must be used as a temporary solution, their choice should take into account several aspects, such as ergonomic features, associated with this device. The present study aims to analyse the relationship between the acoustical attenuation efficiency and other aspects related to the comfort afforded by hearing protectors and, consequently, their acceptability when used in industrial noisy environments. METHODS An evaluation of comfort was performed using a questionnaire, completed by 20 workers. Several scales related to the subjective feeling of comfort were used to quantify the comfort index of a given protector. Simultaneously, the time of usage of each protector was self-recorded by each subject. To test the relationship between the comfort index and the time during which protectors were used, a two-way analysis of variance (two-way ANOVA) was applied. RESULTS AND CONCLUSIONS The results obtained seem to demonstrate that there are significant differences between catalogued and effective attenuation. Protectors with less catalogued attenuation, but with higher acceptability, i.e. which were more comfortable, tended to be more efficient than protectors with a higher catalogued attenuation, but which were less comfortable. Finally, it must be emphasized that high efficiency can only be achieved through the attainment of an adequate balance between the range of parameters likely to determine its usage.
{"title":"Hearing protectors acceptability in noisy environments.","authors":"P. Arezes, A. Miguel","doi":"10.1093/ANNHYG/MEF067","DOIUrl":"https://doi.org/10.1093/ANNHYG/MEF067","url":null,"abstract":"OBJECTIVES\u0000Although hearing protectors must be used as a temporary solution, their choice should take into account several aspects, such as ergonomic features, associated with this device. The present study aims to analyse the relationship between the acoustical attenuation efficiency and other aspects related to the comfort afforded by hearing protectors and, consequently, their acceptability when used in industrial noisy environments.\u0000\u0000\u0000METHODS\u0000An evaluation of comfort was performed using a questionnaire, completed by 20 workers. Several scales related to the subjective feeling of comfort were used to quantify the comfort index of a given protector. Simultaneously, the time of usage of each protector was self-recorded by each subject. To test the relationship between the comfort index and the time during which protectors were used, a two-way analysis of variance (two-way ANOVA) was applied.\u0000\u0000\u0000RESULTS AND CONCLUSIONS\u0000The results obtained seem to demonstrate that there are significant differences between catalogued and effective attenuation. Protectors with less catalogued attenuation, but with higher acceptability, i.e. which were more comfortable, tended to be more efficient than protectors with a higher catalogued attenuation, but which were less comfortable. Finally, it must be emphasized that high efficiency can only be achieved through the attainment of an adequate balance between the range of parameters likely to determine its usage.","PeriodicalId":342592,"journal":{"name":"The Annals of occupational hygiene","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130494423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It has been suggested that the non-size-selective sampling methods currently used for fibrous aerosols potentially lead to the presence of large compact particles, agglomerates and fibre clumps in samples, which in turn reduce the accuracy and precision of the manual fibre counting techniques employed to analyse samples. The use of thoracic size-selective samplers has been proposed as an alternative, leading to the prevention of large particles reaching the collection substrate while at the same time bringing fibre sampling into line with general occupational aerosol sampling methodologies. Thoracic samplers should give good agreement with current sampling methods under ideal conditions based on aerodynamic fibre properties. However, the effect of fibre length on sampling efficiency is not known. The sampling efficiency of five thoracic samplers was therefore measured as a function of fibre length for respirable fibres between 10 and 60 microm long. These included the commercially available GK2.69 cyclone and the CATHIA sampler, the IOM thoracic sampler, a modified version of the SIMPEDS cyclone and a modified version of the IOM inhalable sampler. Length-monodisperse fibres were generated using a dielectrophoretic fibre classifier and sampler penetration was measured as a function of fibre length. No length-dependent sampling effects were observed for the CATHIA, GK2.69, modified SIMPEDS and modified IOM inhalable samplers for fibres <60 microm. Data for the IOM thoracic sampler showed a significant trend of reducing sampling efficiency for fibres >30 microm. Overall, the laboratory results indicated that the five sampler types are likely to perform as well as or better than the currently used 25 mm cowled sampler in the field.
{"title":"Thoracic size-selection of fibres: dependence of penetration on fibre length for five thoracic sampler types.","authors":"A. Maynard","doi":"10.1093/ANNHYG/MEF063","DOIUrl":"https://doi.org/10.1093/ANNHYG/MEF063","url":null,"abstract":"It has been suggested that the non-size-selective sampling methods currently used for fibrous aerosols potentially lead to the presence of large compact particles, agglomerates and fibre clumps in samples, which in turn reduce the accuracy and precision of the manual fibre counting techniques employed to analyse samples. The use of thoracic size-selective samplers has been proposed as an alternative, leading to the prevention of large particles reaching the collection substrate while at the same time bringing fibre sampling into line with general occupational aerosol sampling methodologies. Thoracic samplers should give good agreement with current sampling methods under ideal conditions based on aerodynamic fibre properties. However, the effect of fibre length on sampling efficiency is not known. The sampling efficiency of five thoracic samplers was therefore measured as a function of fibre length for respirable fibres between 10 and 60 microm long. These included the commercially available GK2.69 cyclone and the CATHIA sampler, the IOM thoracic sampler, a modified version of the SIMPEDS cyclone and a modified version of the IOM inhalable sampler. Length-monodisperse fibres were generated using a dielectrophoretic fibre classifier and sampler penetration was measured as a function of fibre length. No length-dependent sampling effects were observed for the CATHIA, GK2.69, modified SIMPEDS and modified IOM inhalable samplers for fibres <60 microm. Data for the IOM thoracic sampler showed a significant trend of reducing sampling efficiency for fibres >30 microm. Overall, the laboratory results indicated that the five sampler types are likely to perform as well as or better than the currently used 25 mm cowled sampler in the field.","PeriodicalId":342592,"journal":{"name":"The Annals of occupational hygiene","volume":"203 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131647047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Markku Toivonen, R. Pääkkönen, S. Savolainen, K. Lehtomäki
OBJECTIVES The study was done to determine whether the noise attenuation attained with the use of earplugs can be improved by teaching the proper insertion of earplugs to users. METHODS Fifty-four randomly selected male subjects were divided into an untrained group (25 persons) and a trained group (29 persons). The trained group was given a lecture on earplug insertion and allowed to practise the insertion procedure, whereas the untrained group acted as controls. The untrained group received this training afterwards. The success of the training was measured by the MIRE (microphone in real ear) and REAT (real ear at threshold) methods, visual evaluation and an analysis of the properties of the subjects' ear canals. RESULTS According to the MIRE method, the averaged A-weighted noise attenuation was 21 dB for the untrained group and 31 dB for the trained group. With the REAT method the attenuation at 1000 Hz was 24 dB for the untrained group and 30 dB for the trained group. The visual evaluation of the earplug fit was 1.9 for the untrained group and 2.6 for the trained group (scales 0-3). CONCLUSION The results indicate that training in earplug insertion is important for good attenuation and for diminishing poor attenuation to a minimum.
{"title":"Noise attenuation and proper insertion of earplugs into ear canals.","authors":"Markku Toivonen, R. Pääkkönen, S. Savolainen, K. Lehtomäki","doi":"10.1093/ANNHYG/MEF065","DOIUrl":"https://doi.org/10.1093/ANNHYG/MEF065","url":null,"abstract":"OBJECTIVES\u0000The study was done to determine whether the noise attenuation attained with the use of earplugs can be improved by teaching the proper insertion of earplugs to users.\u0000\u0000\u0000METHODS\u0000Fifty-four randomly selected male subjects were divided into an untrained group (25 persons) and a trained group (29 persons). The trained group was given a lecture on earplug insertion and allowed to practise the insertion procedure, whereas the untrained group acted as controls. The untrained group received this training afterwards. The success of the training was measured by the MIRE (microphone in real ear) and REAT (real ear at threshold) methods, visual evaluation and an analysis of the properties of the subjects' ear canals.\u0000\u0000\u0000RESULTS\u0000According to the MIRE method, the averaged A-weighted noise attenuation was 21 dB for the untrained group and 31 dB for the trained group. With the REAT method the attenuation at 1000 Hz was 24 dB for the untrained group and 30 dB for the trained group. The visual evaluation of the earplug fit was 1.9 for the untrained group and 2.6 for the trained group (scales 0-3).\u0000\u0000\u0000CONCLUSION\u0000The results indicate that training in earplug insertion is important for good attenuation and for diminishing poor attenuation to a minimum.","PeriodicalId":342592,"journal":{"name":"The Annals of occupational hygiene","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123888803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Working in sewage plants can involve exposure to different types of microorganisms, viruses and chemicals. The purpose of this study was to evaluate different measurement strategies to determine airborne bacterial endotoxin in such plants. Sewage treatment plants in three municipalities in western Sweden were included. Measurements of airborne endotoxin were performed in April-May and September-October 2001 using personal and stationary samplers. The air sampling times ranged from 60 to 444 min. In stationary and personal sampler measurements, the amounts of airborne endotoxin detected were generally low. At specific worksites, however, higher endotoxin values were identified, with the highest values at worksites located indoors. The results suggest that the exposure situation is relatively stable over a short time period at a specific worksite and that higher values can be recorded during work practices where agitation of wastewater occurs. The results further suggest that airborne endotoxin exposure situations in sewage treatment plants are complex. Sampling techniques, indoor/outdoor measurements and identification of specific worksites/tasks where there is a risk of airborne endotoxin exposure are important factors that must be considered in order to obtain relevant exposure determinations and establish preventive measures from a health risk perspective.
{"title":"Measurement strategies for the determination of airborne bacterial endotoxin in sewage treatment plants.","authors":"J. Thorn, L. Beijer, T. Jonsson, R. Rylander","doi":"10.1093/ANNHYG/MEF068","DOIUrl":"https://doi.org/10.1093/ANNHYG/MEF068","url":null,"abstract":"Working in sewage plants can involve exposure to different types of microorganisms, viruses and chemicals. The purpose of this study was to evaluate different measurement strategies to determine airborne bacterial endotoxin in such plants. Sewage treatment plants in three municipalities in western Sweden were included. Measurements of airborne endotoxin were performed in April-May and September-October 2001 using personal and stationary samplers. The air sampling times ranged from 60 to 444 min. In stationary and personal sampler measurements, the amounts of airborne endotoxin detected were generally low. At specific worksites, however, higher endotoxin values were identified, with the highest values at worksites located indoors. The results suggest that the exposure situation is relatively stable over a short time period at a specific worksite and that higher values can be recorded during work practices where agitation of wastewater occurs. The results further suggest that airborne endotoxin exposure situations in sewage treatment plants are complex. Sampling techniques, indoor/outdoor measurements and identification of specific worksites/tasks where there is a risk of airborne endotoxin exposure are important factors that must be considered in order to obtain relevant exposure determinations and establish preventive measures from a health risk perspective.","PeriodicalId":342592,"journal":{"name":"The Annals of occupational hygiene","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128258482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：