Pub Date : 2001-07-01DOI: 10.1080/15298660108984642
D. Caretti, W. Scott, A. Johnson, K. Coyne, F. Koh
This study evaluated performance of individuals exercising at a fixed workload and wearing full-facepiece respirators modified to provide expiratory resistances of 0.27, 0.47, 1.81, 4.43, and 12.27 cmH20 x s x L(-1). On five separate occasions, 15 volunteers exercised to voluntary endpoint on a treadmill at fixed speeds and grades chosen to elicit 85% of maximal aerobic capacity for an unencumbered condition. Exercise performance time was recorded at the cessation of each test. Results showed that performance time decreased linearly (R2 = 0.79; p<0.001) with increased resistances, and no threshold value below which expiratory resistance has no impact on performance was found. Average oxygen consumption rates and minute ventilation also decreased linearly with increased expiratory resistances, indicating that increases in expiratory resistance result in a considerable level of hypoventilation. From the perspective of respirator design, the results of this study suggest that the only practical expiratory resistance level limitation is the reduction in performance that will be acceptable to the end users.
本研究评估了在固定工作量下运动并佩戴改良的全面罩呼吸器的个体的表现，其呼气阻力分别为0.27、0.47、1.81、4.43和12.27 cmH20 x s x L(-1)。在五种不同的情况下，15名志愿者在跑步机上以固定的速度和等级锻炼到自愿终点，选择在无阻碍的情况下达到85%的最大有氧能力。在每次测试结束时记录运动表现时间。结果显示，工作时间呈线性下降(R2 = 0.79;P <0.001)，阻力增加，没有阈值低于呼气阻力对生产性能没有影响。平均耗氧量和分钟通气量也随着呼气阻力的增加而线性下降，表明呼气阻力的增加导致相当程度的通气不足。从呼吸器设计的角度来看，本研究的结果表明，唯一实际的呼气阻力水平限制是最终用户可以接受的性能降低。
{"title":"Work performance when breathing through different respirator exhalation resistances.","authors":"D. Caretti, W. Scott, A. Johnson, K. Coyne, F. Koh","doi":"10.1080/15298660108984642","DOIUrl":"https://doi.org/10.1080/15298660108984642","url":null,"abstract":"This study evaluated performance of individuals exercising at a fixed workload and wearing full-facepiece respirators modified to provide expiratory resistances of 0.27, 0.47, 1.81, 4.43, and 12.27 cmH20 x s x L(-1). On five separate occasions, 15 volunteers exercised to voluntary endpoint on a treadmill at fixed speeds and grades chosen to elicit 85% of maximal aerobic capacity for an unencumbered condition. Exercise performance time was recorded at the cessation of each test. Results showed that performance time decreased linearly (R2 = 0.79; p<0.001) with increased resistances, and no threshold value below which expiratory resistance has no impact on performance was found. Average oxygen consumption rates and minute ventilation also decreased linearly with increased expiratory resistances, indicating that increases in expiratory resistance result in a considerable level of hypoventilation. From the perspective of respirator design, the results of this study suggest that the only practical expiratory resistance level limitation is the reduction in performance that will be acceptable to the end users.","PeriodicalId":7449,"journal":{"name":"AIHAJ : a journal for the science of occupational and environmental health and safety","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89485403","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 : 2001-07-01DOI: 10.1080/15298660108984648
W. Jo, Sung-Hwan Kim
This study evaluated worker exposure to aromatic compounds and perchloroethylene (PERC) in dry cleaning stores relative to four different solvents. For benzene and toluene, there was no significant difference among the indoor air concentrations of the four different solvents. For ethylbenzene, m,p-xylene, and o-xylene, the air concentrations were significantly higher in the dry cleaning stores using Solvent V, YuClean, and Super New Cleaner than in those using a PERC mixture. Breath concentrations measured prior to and immediately after work were not significantly different for benzene and toluene, whereas breath concentrations of ethylbenzene, m,p-xylene, and o-xylene were significantly higher (p<0.05) in the samples collected immediately after work compared with those collected prior to work. The breath concentrations of benzene and toluene both prior to and immediately after work showed no upward or downward trend for 7 consecutive days excluding Sunday, starting from Monday. In contrast, the breath concentrations of ethylbenzene, m,p-xylene, and o-xylene measured immediately after work showed a slight upward trend in three subjects. However, this trend was most likely not due to an accumulated body burden from repeated daily work, but rather was the result of the amount of solvent used each day. It is concluded that dry cleaning workers using the aromatics-contained solvents are exposed to elevated levels of some aromatic compounds compared with the dry cleaning workers using PERC. Further study is recommended to examine the presence of other air toxics inside dry cleaning stores using these solvents.
本研究评估了工人在干洗店中相对于四种不同溶剂接触芳香族化合物和过氯乙烯(PERC)的情况。对于苯和甲苯，四种不同溶剂的室内空气浓度无显著差异。对于乙苯、间苯、对二甲苯和邻二甲苯，使用溶剂V、YuClean和Super New Cleaner的干洗店的空气浓度明显高于使用PERC混合物的干洗店。在工作前和工作后立即测量的呼吸浓度对苯和甲苯没有显著差异，而在工作后立即收集的样本中，乙苯、间苯、对二甲苯和邻二甲苯的呼吸浓度明显高于工作前收集的样本(p<0.05)。从周一开始，除周日外，上班前和下班后呼气中苯和甲苯的浓度连续7天没有上升或下降的趋势。相比之下，三个人在工作后立即测量的乙苯、间苯、对二甲苯和邻二甲苯的呼吸浓度呈轻微上升趋势。然而，这种趋势很可能不是由于重复的日常工作造成的身体负担的累积，而是由于每天使用的溶剂量。结果表明，与使用PERC的干洗工人相比，使用含芳香族溶剂的干洗工人暴露于某些芳香族化合物的水平较高。建议进一步研究使用这些溶剂的干洗店内是否存在其他空气有毒物质。
{"title":"Worker exposure to aromatic volatile organic compounds in dry cleaning stores.","authors":"W. Jo, Sung-Hwan Kim","doi":"10.1080/15298660108984648","DOIUrl":"https://doi.org/10.1080/15298660108984648","url":null,"abstract":"This study evaluated worker exposure to aromatic compounds and perchloroethylene (PERC) in dry cleaning stores relative to four different solvents. For benzene and toluene, there was no significant difference among the indoor air concentrations of the four different solvents. For ethylbenzene, m,p-xylene, and o-xylene, the air concentrations were significantly higher in the dry cleaning stores using Solvent V, YuClean, and Super New Cleaner than in those using a PERC mixture. Breath concentrations measured prior to and immediately after work were not significantly different for benzene and toluene, whereas breath concentrations of ethylbenzene, m,p-xylene, and o-xylene were significantly higher (p<0.05) in the samples collected immediately after work compared with those collected prior to work. The breath concentrations of benzene and toluene both prior to and immediately after work showed no upward or downward trend for 7 consecutive days excluding Sunday, starting from Monday. In contrast, the breath concentrations of ethylbenzene, m,p-xylene, and o-xylene measured immediately after work showed a slight upward trend in three subjects. However, this trend was most likely not due to an accumulated body burden from repeated daily work, but rather was the result of the amount of solvent used each day. It is concluded that dry cleaning workers using the aromatics-contained solvents are exposed to elevated levels of some aromatic compounds compared with the dry cleaning workers using PERC. Further study is recommended to examine the presence of other air toxics inside dry cleaning stores using these solvents.","PeriodicalId":7449,"journal":{"name":"AIHAJ : a journal for the science of occupational and environmental health and safety","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73621343","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 : 2001-07-01DOI: 10.1080/15298660108984644
R. Szabó, R. Radwin, C. J. Henderson
A novel procedure is described to establish knife steeling schedules for poultry and meat- processing operations based on increased force due to knife dullness from repetitive use to minimize operator exertions and physical stress associated with work-related musculoskeletal disorders. Knife dullness was quantified using a novel apparatus described in this article that measures the area cut by a knife into a carrageenan gel target for a controlled dynamic load at the knife handle. Two meat-cleaning jobs in a poultry-processing plant were studied. One job required significantly more force and a greater number of cuts than the other. Eight experienced operators participated in the study. Four freshly ground and honed knives were randomly used by each operator for 4, 45, 75, or 125 cutting cycles, measured for dullness and reconditioned by the operator using a steel sharpening rod. An empirical model for knife dulling and reconditioning was developed, and the corresponding increase in force was predicted for various cutting and reconditioning frequencies. The model showed that it took 57 and 125 cutting cycles for the high- and low-force jobs, respectively, to achieve a similar reduction in target surface area of 30%. This reduction in target surface area corresponded to a similar percentage increase in force needed for the same cut in carrageenan gel as compared to a freshly honed knife as measured using strain gages. This method may be used in meat processing plants for determining effective reconditioning schedules that reduce operator exertions with minimum effect on quality and productivity.
{"title":"The influence of knife dullness on poultry processing operator exertions and the effectiveness of periodic knife steeling.","authors":"R. Szabó, R. Radwin, C. J. Henderson","doi":"10.1080/15298660108984644","DOIUrl":"https://doi.org/10.1080/15298660108984644","url":null,"abstract":"A novel procedure is described to establish knife steeling schedules for poultry and meat- processing operations based on increased force due to knife dullness from repetitive use to minimize operator exertions and physical stress associated with work-related musculoskeletal disorders. Knife dullness was quantified using a novel apparatus described in this article that measures the area cut by a knife into a carrageenan gel target for a controlled dynamic load at the knife handle. Two meat-cleaning jobs in a poultry-processing plant were studied. One job required significantly more force and a greater number of cuts than the other. Eight experienced operators participated in the study. Four freshly ground and honed knives were randomly used by each operator for 4, 45, 75, or 125 cutting cycles, measured for dullness and reconditioned by the operator using a steel sharpening rod. An empirical model for knife dulling and reconditioning was developed, and the corresponding increase in force was predicted for various cutting and reconditioning frequencies. The model showed that it took 57 and 125 cutting cycles for the high- and low-force jobs, respectively, to achieve a similar reduction in target surface area of 30%. This reduction in target surface area corresponded to a similar percentage increase in force needed for the same cut in carrageenan gel as compared to a freshly honed knife as measured using strain gages. This method may be used in meat processing plants for determining effective reconditioning schedules that reduce operator exertions with minimum effect on quality and productivity.","PeriodicalId":7449,"journal":{"name":"AIHAJ : a journal for the science of occupational and environmental health and safety","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84291146","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 : 2001-07-01DOI: 10.1080/15298660108984646
M. Nussbaum, L. L. Clark, M. Lanza, K. M. Rice
Shoulder problems are prevalent in industrial work, particularly when tasks require the hands to be used at or above shoulder level. Although extensive research has been conducted on prolonged static exertions, and several guidelines for such efforts exist, there is insufficient information for ergonomic evaluation of tasks that are intermittent and/or dynamic. A laboratory simulation was conducted of overhead assembly work that was both intermittent and dynamic, and which varied the duty cycle (work/rest ratio), arm reach, and hand orientation of a tapping task. Results consisted of endurance times and also the times of fatigue onset as indicated by perceived discomfort and declines in muscle strength. Females exhibited longer (22%) endurance times, delayed reports of discomfort, and slower declines in strength. Significant influences of duty cycle were found on both endurance and fatigue times, yet arm reach and hand orientation did not have consistent effects. Distributions of endurance and fatigue times are presented as criteria for preliminary evaluation of overhead work. Endurance times could be predicted with only moderate accuracy from earlier indicators of fatigue onset. Existing guidelines, albeit developed for static tasks, appeared unsuitable for the simulated overhead assembly efforts examined. Furthermore, such guidelines may fail to capture the substantial interindividual variability observed in this experiment.
{"title":"Fatigue and endurance limits during intermittent overhead work.","authors":"M. Nussbaum, L. L. Clark, M. Lanza, K. M. Rice","doi":"10.1080/15298660108984646","DOIUrl":"https://doi.org/10.1080/15298660108984646","url":null,"abstract":"Shoulder problems are prevalent in industrial work, particularly when tasks require the hands to be used at or above shoulder level. Although extensive research has been conducted on prolonged static exertions, and several guidelines for such efforts exist, there is insufficient information for ergonomic evaluation of tasks that are intermittent and/or dynamic. A laboratory simulation was conducted of overhead assembly work that was both intermittent and dynamic, and which varied the duty cycle (work/rest ratio), arm reach, and hand orientation of a tapping task. Results consisted of endurance times and also the times of fatigue onset as indicated by perceived discomfort and declines in muscle strength. Females exhibited longer (22%) endurance times, delayed reports of discomfort, and slower declines in strength. Significant influences of duty cycle were found on both endurance and fatigue times, yet arm reach and hand orientation did not have consistent effects. Distributions of endurance and fatigue times are presented as criteria for preliminary evaluation of overhead work. Endurance times could be predicted with only moderate accuracy from earlier indicators of fatigue onset. Existing guidelines, albeit developed for static tasks, appeared unsuitable for the simulated overhead assembly efforts examined. Furthermore, such guidelines may fail to capture the substantial interindividual variability observed in this experiment.","PeriodicalId":7449,"journal":{"name":"AIHAJ : a journal for the science of occupational and environmental health and safety","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87381958","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 : 2001-07-01DOI: 10.1080/15298660108984645
S. Rudnick
Irradiating the upper part of a room with 254-nm ultraviolet (UV) radiation from a low-pressure mercury discharge lamp has the potential to be a relatively inexpensive method to reduce transmission of airborne infectious diseases such as tuberculosis. To protect occupants in the lower part of a room from radiation, multilouvered UV germicidal fixtures producing a horizontal, collimated beam are often used, particularly in rooms having a normal ceiling height. Knowledge of the fixture's emission characteristics and the airflow field are needed to estimate the UV dose to airborne microorganisms and assess the fixture's overall effectiveness in controlling disease transmission. In this article, a model is developed to predict the UV fluence rate at any location in the upper room for ceiling-mounted, multilouvered, pendant-type fixtures, which provide 360-degree emission in the horizontal plane. The model also predicts total UV power emitted by the fixture, which is the best single-number effectiveness index for comparing multilouvered UV germicidal fixtures. Model predictions compared favorably with laboratory and field measurements.
{"title":"Predicting the ultraviolet radiation distribution in a room with multilouvered germicidal fixtures.","authors":"S. Rudnick","doi":"10.1080/15298660108984645","DOIUrl":"https://doi.org/10.1080/15298660108984645","url":null,"abstract":"Irradiating the upper part of a room with 254-nm ultraviolet (UV) radiation from a low-pressure mercury discharge lamp has the potential to be a relatively inexpensive method to reduce transmission of airborne infectious diseases such as tuberculosis. To protect occupants in the lower part of a room from radiation, multilouvered UV germicidal fixtures producing a horizontal, collimated beam are often used, particularly in rooms having a normal ceiling height. Knowledge of the fixture's emission characteristics and the airflow field are needed to estimate the UV dose to airborne microorganisms and assess the fixture's overall effectiveness in controlling disease transmission. In this article, a model is developed to predict the UV fluence rate at any location in the upper room for ceiling-mounted, multilouvered, pendant-type fixtures, which provide 360-degree emission in the horizontal plane. The model also predicts total UV power emitted by the fixture, which is the best single-number effectiveness index for comparing multilouvered UV germicidal fixtures. Model predictions compared favorably with laboratory and field measurements.","PeriodicalId":7449,"journal":{"name":"AIHAJ : a journal for the science of occupational and environmental health and safety","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88445259","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 : 2001-07-01DOI: 10.1080/15298660108984653
M. Brophy, L. Achimore, Joyce Moore-Dawson
To reduce musculoskeletal injuries in employees and to lower the financial costs associated with them, a 525-bed county nursing home in upstate New York initiated a five-step ergonomics program and purchased mechanical lifting devices. The five steps in the program were (1) creation of a resident transfer evaluation team, (2) establishment of an accident review committee, (3) mandatory ergonomics training for new nursing aides, (4) regular maintenance checks for lifting equipment, and (5) direct access to the management and budget process. During the 7-year period of this study, 8 smooth movers, 10 hydraulic stretchers, 7 Hoyer lifts, 1 Arjo lift, 9 Sarita lifts, and 1 Maxilift were purchased. Comparisons in health and financial outcomes were made between the preintervention period (1992-1993) and the intervention period (1994-1998). There was a significant reduction in the number of low-back injuries per 100 full-time nursing aides from 15.7 in the preintervention period to 11.0 in the postintervention period (p<0.05). The total number of lost workdays was significantly (p<0.05) reduced from 1476 per year before the intervention to 625 per year after the intervention. In addition, the lost workdays per full-time nursing assistant was significantly reduced from 7.8 to 3.0 (p<0.05). Although the average number of lost workdays per injury decreased from 49 to 27 days, this decrease was not statistically significant. Financially, there was a significant reduction in the average yearly cost associated with low-back injuries from $201,100 before the intervention to $91,800 during the intervention.
{"title":"Reducing incidence of low-back injuries reduces cost.","authors":"M. Brophy, L. Achimore, Joyce Moore-Dawson","doi":"10.1080/15298660108984653","DOIUrl":"https://doi.org/10.1080/15298660108984653","url":null,"abstract":"To reduce musculoskeletal injuries in employees and to lower the financial costs associated with them, a 525-bed county nursing home in upstate New York initiated a five-step ergonomics program and purchased mechanical lifting devices. The five steps in the program were (1) creation of a resident transfer evaluation team, (2) establishment of an accident review committee, (3) mandatory ergonomics training for new nursing aides, (4) regular maintenance checks for lifting equipment, and (5) direct access to the management and budget process. During the 7-year period of this study, 8 smooth movers, 10 hydraulic stretchers, 7 Hoyer lifts, 1 Arjo lift, 9 Sarita lifts, and 1 Maxilift were purchased. Comparisons in health and financial outcomes were made between the preintervention period (1992-1993) and the intervention period (1994-1998). There was a significant reduction in the number of low-back injuries per 100 full-time nursing aides from 15.7 in the preintervention period to 11.0 in the postintervention period (p<0.05). The total number of lost workdays was significantly (p<0.05) reduced from 1476 per year before the intervention to 625 per year after the intervention. In addition, the lost workdays per full-time nursing assistant was significantly reduced from 7.8 to 3.0 (p<0.05). Although the average number of lost workdays per injury decreased from 49 to 27 days, this decrease was not statistically significant. Financially, there was a significant reduction in the average yearly cost associated with low-back injuries from $201,100 before the intervention to $91,800 during the intervention.","PeriodicalId":7449,"journal":{"name":"AIHAJ : a journal for the science of occupational and environmental health and safety","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82481852","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 : 2001-07-01DOI: 10.1080/15298660108984641
D. W. Booth, S. Guffey
This research evaluated the effectiveness of screening methods in identifying obstructed branches in industrial ventilation systems. These methods were divided into two categories: pressure comparisons and pressure ratio comparisons. The first category contained techniques that compare measured static pressures with the corresponding design static pressures or with previously measured pressures. Certain aspects of the method suggested in the Industrial Ventilation Manual were also tested. The second category compares the ratios of two measured pressures and includes the new reference ratio method. Data were collected from six industrial ventilation systems. Four of the systems were used to control wood dust, and two were used to control metal shavings from a saw-sharpening operation. Each system was tested for naturally occurring or deliberately inserted obstructions. Appropriate static and velocity pressures were measured to calculate each troubleshooting method's parameter. The change in the parameter was compared with a range of thresholds for the test cases. Receiver operator characteristic curves and bootstrapping techniques were used to identify the best method for determining the presence of obstructions or alterations. The pressure ratio methods were found to be substantially superior to the pressure comparison methods at detecting obstructions.
{"title":"An evaluation of industrial ventilation branch screening methods for obstructions in working exhaust systems.","authors":"D. W. Booth, S. Guffey","doi":"10.1080/15298660108984641","DOIUrl":"https://doi.org/10.1080/15298660108984641","url":null,"abstract":"This research evaluated the effectiveness of screening methods in identifying obstructed branches in industrial ventilation systems. These methods were divided into two categories: pressure comparisons and pressure ratio comparisons. The first category contained techniques that compare measured static pressures with the corresponding design static pressures or with previously measured pressures. Certain aspects of the method suggested in the Industrial Ventilation Manual were also tested. The second category compares the ratios of two measured pressures and includes the new reference ratio method. Data were collected from six industrial ventilation systems. Four of the systems were used to control wood dust, and two were used to control metal shavings from a saw-sharpening operation. Each system was tested for naturally occurring or deliberately inserted obstructions. Appropriate static and velocity pressures were measured to calculate each troubleshooting method's parameter. The change in the parameter was compared with a range of thresholds for the test cases. Receiver operator characteristic curves and bootstrapping techniques were used to identify the best method for determining the presence of obstructions or alterations. The pressure ratio methods were found to be substantially superior to the pressure comparison methods at detecting obstructions.","PeriodicalId":7449,"journal":{"name":"AIHAJ : a journal for the science of occupational and environmental health and safety","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81057107","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 : 2001-07-01DOI: 10.1080/15298660108984647
B. Bakke, P. Stewart, B. Ulvestad, W. Eduard
Personal exposures to dust and gases were measured among 189 underground construction workers who were divided into seven occupational groups performing similar tasks in similar working conditions: drill and blast crew; shaft-drilling crew; tunnel-boring machine crew; shotcreting operators; support workers; concrete workers; and electricians. Outdoor tunnel workers were included as a low-exposed reference group. The highest geometric mean (GM) exposures to total dust (6-7 mg/m3) and respirable dust (2-3 mg/m3) were found for the shotcreters, shaft drillers, and tunnel-boring machine workers. Shaft drillers and tunnel-boring machine workers also had the highest GM exposures to respirable alpha-quartz (0.3-0.4 mg/m3), which exceeded the Norwegian occupational exposure limit (OEL) of 0.1 mg/m3. Shaft drillers had the highest exposure to oil mists (GM=1.4 mg/m3), which was generated mainly from pneumatic drilling. For other groups, exposure to oil mist from diesel exhaust and spraying of oil onto concrete forms resulted in exposures of 0.1-0.5 mg/m3. Exposure to nitrogen dioxide was similar across all groups (GM=0.4-0.9 ppm), except for shaft drillers and tunnel-boring machine workers, who had lower exposures. High short-term exposures (>10 ppm), however, occurred when workers were passing through the blasting cloud.
{"title":"Dust and gas exposure in tunnel construction work.","authors":"B. Bakke, P. Stewart, B. Ulvestad, W. Eduard","doi":"10.1080/15298660108984647","DOIUrl":"https://doi.org/10.1080/15298660108984647","url":null,"abstract":"Personal exposures to dust and gases were measured among 189 underground construction workers who were divided into seven occupational groups performing similar tasks in similar working conditions: drill and blast crew; shaft-drilling crew; tunnel-boring machine crew; shotcreting operators; support workers; concrete workers; and electricians. Outdoor tunnel workers were included as a low-exposed reference group. The highest geometric mean (GM) exposures to total dust (6-7 mg/m3) and respirable dust (2-3 mg/m3) were found for the shotcreters, shaft drillers, and tunnel-boring machine workers. Shaft drillers and tunnel-boring machine workers also had the highest GM exposures to respirable alpha-quartz (0.3-0.4 mg/m3), which exceeded the Norwegian occupational exposure limit (OEL) of 0.1 mg/m3. Shaft drillers had the highest exposure to oil mists (GM=1.4 mg/m3), which was generated mainly from pneumatic drilling. For other groups, exposure to oil mist from diesel exhaust and spraying of oil onto concrete forms resulted in exposures of 0.1-0.5 mg/m3. Exposure to nitrogen dioxide was similar across all groups (GM=0.4-0.9 ppm), except for shaft drillers and tunnel-boring machine workers, who had lower exposures. High short-term exposures (>10 ppm), however, occurred when workers were passing through the blasting cloud.","PeriodicalId":7449,"journal":{"name":"AIHAJ : a journal for the science of occupational and environmental health and safety","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76124850","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 : 2001-07-01DOI: 10.1080/15298660108984652
Ernest S. Moyer, Simon J. Smith, Gerry O. Wood
This article reviews efforts by researchers and organizations around the world to identify chemicals as substitutes for carbon tetrachloride in measuring activated carbon activity (adsorption capacity) or organic vapor air-purifying respirator cartridge (or other packed carbon bed) breakthrough times. Such measurements usually are done to determine if a minimum performance standard is met. Different criteria have been established, supporting data developed and used, and conclusions reached. This article presents relevant published, unpublished, obscure, and recalculated data which the reader can use to make a choice of replacement chemical and testing conditions. No recommendations for a specific replacement chemical are endorsed or promoted in this review.
{"title":"Carbon tetrachloride replacement compounds for organic vapor air-purifying respirator cartridge and activated carbon testing--a review.","authors":"Ernest S. Moyer, Simon J. Smith, Gerry O. Wood","doi":"10.1080/15298660108984652","DOIUrl":"https://doi.org/10.1080/15298660108984652","url":null,"abstract":"This article reviews efforts by researchers and organizations around the world to identify chemicals as substitutes for carbon tetrachloride in measuring activated carbon activity (adsorption capacity) or organic vapor air-purifying respirator cartridge (or other packed carbon bed) breakthrough times. Such measurements usually are done to determine if a minimum performance standard is met. Different criteria have been established, supporting data developed and used, and conclusions reached. This article presents relevant published, unpublished, obscure, and recalculated data which the reader can use to make a choice of replacement chemical and testing conditions. No recommendations for a specific replacement chemical are endorsed or promoted in this review.","PeriodicalId":7449,"journal":{"name":"AIHAJ : a journal for the science of occupational and environmental health and safety","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75184913","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 : 2001-05-01DOI: 10.1080/15298660108984632
N. S. Lan, S. Viswanathan
Three-dimensional models of a variable volume/constant face velocity fume hood were developed and numerically solved to study the effect of the sash opening and rated face velocity on the flow patterns, especially in the exposure area of a person standing in front of the fume hood. These flow details are important in assessing the containment performance of the fume hood. For this study, fully turbulent flow was assumed to enter through the front hood window and exit through the exhaust duct. The finite-difference, control-volume technique, and standard k-epsilon models were employed and solved together with the equations for the conservation of mass and momentum using FLUENT/UNS version 4.2 to obtain the flow solutions. Unobstructed flow cases, as well as the simplified two-dimensional scenarios, also were investigated for comparison. Results indicated that there is no occurrence of recirculation leading to concentration buildup within the region between the person and fume hood entrance. Also, in conformance with other studies, the recirculating flow volume inside the hood decreased with increasing sash openings.
{"title":"Numerical simulation of airflow around a variable volume/constant face velocity fume cupboard.","authors":"N. S. Lan, S. Viswanathan","doi":"10.1080/15298660108984632","DOIUrl":"https://doi.org/10.1080/15298660108984632","url":null,"abstract":"Three-dimensional models of a variable volume/constant face velocity fume hood were developed and numerically solved to study the effect of the sash opening and rated face velocity on the flow patterns, especially in the exposure area of a person standing in front of the fume hood. These flow details are important in assessing the containment performance of the fume hood. For this study, fully turbulent flow was assumed to enter through the front hood window and exit through the exhaust duct. The finite-difference, control-volume technique, and standard k-epsilon models were employed and solved together with the equations for the conservation of mass and momentum using FLUENT/UNS version 4.2 to obtain the flow solutions. Unobstructed flow cases, as well as the simplified two-dimensional scenarios, also were investigated for comparison. Results indicated that there is no occurrence of recirculation leading to concentration buildup within the region between the person and fume hood entrance. Also, in conformance with other studies, the recirculating flow volume inside the hood decreased with increasing sash openings.","PeriodicalId":7449,"journal":{"name":"AIHAJ : a journal for the science of occupational and environmental health and safety","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79541658","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}
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