Pub Date : 2001-05-01DOI: 10.1080/15298660108984635
N. Goyer, J. Lavoie
This study identified and quantified the main chemical compounds--the substances responsible for the disagreeable odors--and the bioaerosols emitted during the biological treatment of paper mill effluents. It also identified the characteristics of the process that effects the generation or diffusion of these substances. All treatment stages were evaluated. Measuring sites were located as closely as possible to the potential emission sources. Measurements were taken in the summer in 11 paper mills during a 2- to 3-day period in each mill. Chemical compounds were evaluated by direct-reading instruments; bioaerosols were sampled by impaction and counted. Sulfur compounds, emitted into the air when the effluent or the sludge is stirred, had the highest concentrations; their presence was attributable to such things as kraft-type paper pulp. Next in concentration were the carbon and nitrogen oxides, ammonia, and some organic acids, produced by the action of microorganisms. These acids are found mainly in the sludge environment. Terpenes, which come from wood, are present at various locations in paper mills. Odor perception thresholds for most of these substances are much lower than those established to protect the health of workers. Significant concentrations of total bacteria, total molds, and endotoxins were measured at several sites. Gram-negative bacteria were high at only one site, whereas the mold Aspergillus fumigatus was occasionally present at low concentration. No actinomycetes bacteria were detected. The highest concentrations were measured where there was water or dust aerosolization. Emissions are therefore controlled by controlling the operations that lead to the dispersion of water and particles into the air.
{"title":"Emissions of chemical compounds and bioaerosols during the secondary treatment of paper mill effluents.","authors":"N. Goyer, J. Lavoie","doi":"10.1080/15298660108984635","DOIUrl":"https://doi.org/10.1080/15298660108984635","url":null,"abstract":"This study identified and quantified the main chemical compounds--the substances responsible for the disagreeable odors--and the bioaerosols emitted during the biological treatment of paper mill effluents. It also identified the characteristics of the process that effects the generation or diffusion of these substances. All treatment stages were evaluated. Measuring sites were located as closely as possible to the potential emission sources. Measurements were taken in the summer in 11 paper mills during a 2- to 3-day period in each mill. Chemical compounds were evaluated by direct-reading instruments; bioaerosols were sampled by impaction and counted. Sulfur compounds, emitted into the air when the effluent or the sludge is stirred, had the highest concentrations; their presence was attributable to such things as kraft-type paper pulp. Next in concentration were the carbon and nitrogen oxides, ammonia, and some organic acids, produced by the action of microorganisms. These acids are found mainly in the sludge environment. Terpenes, which come from wood, are present at various locations in paper mills. Odor perception thresholds for most of these substances are much lower than those established to protect the health of workers. Significant concentrations of total bacteria, total molds, and endotoxins were measured at several sites. Gram-negative bacteria were high at only one site, whereas the mold Aspergillus fumigatus was occasionally present at low concentration. No actinomycetes bacteria were detected. The highest concentrations were measured where there was water or dust aerosolization. Emissions are therefore controlled by controlling the operations that lead to the dispersion of water and particles into the air.","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":"83721107","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: 10.1080/15298660108984629
C. C. Chen, T. Yu, T. Shih, P. Baron
Fibrous aerosols are of great importance to industrial hygienists because of the severe health risks that may be associated with inhaling such particles. Previous studies on measurement error due to overloading of fibers and nonfibrous particles on the collected sample indicate that a 100-1300 fiber/mm2 filter area is the best filter loading density to reduce bias in fiber counts. The present study investigated the upper fiber and particle concentration limits for reliable counting and identification and the possibility of a procedure for correcting observed fiber counts to account for fiber masking due to overlapping particles or fibers. A computer-generated grid was used to simulate the light microscope graticule field. The resolution of 2000 x 2000 was found to accurately represent the shape of the fibers and nonfibrous particles. Bivariate lognormal distributions were used to describe the length and width distributions of the fibers. The capability of distinguishing particle-overlapped fibers (defined as the resolution index), the coverage of the graticule field, the filter surface loading density, size distributions of fibers and particles, and the fiber-to-particle concentration ratio were the primary parameters in this study. The counting efficiency was found to consistently decrease with increasing filter surface loading density and decreasing resolution index. The recommended upper limit of filter surface fiber density depended not only on the number concentration ratio but also on the filter surface loading densities and size distributions of fibers and particles. The advantage of using a thoracic preseparator on counting efficiency was calculated and found to improve counting efficiency significantly when the count median diameter of nonfibrous particles was close to or larger than the thoracic 50% cutoff point of 10 microm.
{"title":"Computer simulation of particle overlap in fiber count samples.","authors":"C. C. Chen, T. Yu, T. Shih, P. Baron","doi":"10.1080/15298660108984629","DOIUrl":"https://doi.org/10.1080/15298660108984629","url":null,"abstract":"Fibrous aerosols are of great importance to industrial hygienists because of the severe health risks that may be associated with inhaling such particles. Previous studies on measurement error due to overloading of fibers and nonfibrous particles on the collected sample indicate that a 100-1300 fiber/mm2 filter area is the best filter loading density to reduce bias in fiber counts. The present study investigated the upper fiber and particle concentration limits for reliable counting and identification and the possibility of a procedure for correcting observed fiber counts to account for fiber masking due to overlapping particles or fibers. A computer-generated grid was used to simulate the light microscope graticule field. The resolution of 2000 x 2000 was found to accurately represent the shape of the fibers and nonfibrous particles. Bivariate lognormal distributions were used to describe the length and width distributions of the fibers. The capability of distinguishing particle-overlapped fibers (defined as the resolution index), the coverage of the graticule field, the filter surface loading density, size distributions of fibers and particles, and the fiber-to-particle concentration ratio were the primary parameters in this study. The counting efficiency was found to consistently decrease with increasing filter surface loading density and decreasing resolution index. The recommended upper limit of filter surface fiber density depended not only on the number concentration ratio but also on the filter surface loading densities and size distributions of fibers and particles. The advantage of using a thoracic preseparator on counting efficiency was calculated and found to improve counting efficiency significantly when the count median diameter of nonfibrous particles was close to or larger than the thoracic 50% cutoff point of 10 microm.","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":"90316577","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: 10.1080/15298660108984638
G. Piacitelli, W. Sieber, D. O'brien, R. Hughes, R. Glaser, J. Catalano
Sampling was conducted in 79 small machine shops to assess airborne exposures to metalworking fluids (MWFs). Measured exposures were compared with data from the literature and exposure criteria currently recommended by the National Institute for Occupational Safety and Health and the Occupational Safety and Health Administration MWF Standards Advisory Committee. Sixty-two percent of 942 personal samples collected were less than the recommended exposure limit (REL) of 0.50 mg/m3 for total particulate. However, at least 1 sample exceeded the REL in 61 of the 79 facilities studied; 100% of the samples collected in 10 shops were greater than the REL. Similar trends were found for thoracic particulate exposures where 75% of 238 samples were below the thoracic particulate REL of 0.40 mg/m3. The ratio between thoracic and total particulate for 238 paired samples was 0.55 (r2=0.73). Workers exposed to straight fluids had the highest exposures (GM=0.67 mg/m3) when compared with workers exposed to other classes of MWFs. The highest exposures were measured for grinding and hobbing (GM=0.67 and 0.60 mg/m3, respectively). Measurements using personal impactors indicated that particle size distributions of MWF aerosols had an average mass median aerodynamic diameter of 5.3 microm. Straight oils and soluble fluids tended to be associated with larger particles than were other fluid types; grinding and turning produced the largest particles, whereas hobbing resulted in the smallest. In general, exposures were similar in magnitude and particle size to those previously reported in large automotive plants. Therefore, workers in these small shops may have risks of adverse health effects similar to those demonstrated in the automotive industry.
{"title":"Metalworking fluid exposures in small machine shops: an overview.","authors":"G. Piacitelli, W. Sieber, D. O'brien, R. Hughes, R. Glaser, J. Catalano","doi":"10.1080/15298660108984638","DOIUrl":"https://doi.org/10.1080/15298660108984638","url":null,"abstract":"Sampling was conducted in 79 small machine shops to assess airborne exposures to metalworking fluids (MWFs). Measured exposures were compared with data from the literature and exposure criteria currently recommended by the National Institute for Occupational Safety and Health and the Occupational Safety and Health Administration MWF Standards Advisory Committee. Sixty-two percent of 942 personal samples collected were less than the recommended exposure limit (REL) of 0.50 mg/m3 for total particulate. However, at least 1 sample exceeded the REL in 61 of the 79 facilities studied; 100% of the samples collected in 10 shops were greater than the REL. Similar trends were found for thoracic particulate exposures where 75% of 238 samples were below the thoracic particulate REL of 0.40 mg/m3. The ratio between thoracic and total particulate for 238 paired samples was 0.55 (r2=0.73). Workers exposed to straight fluids had the highest exposures (GM=0.67 mg/m3) when compared with workers exposed to other classes of MWFs. The highest exposures were measured for grinding and hobbing (GM=0.67 and 0.60 mg/m3, respectively). Measurements using personal impactors indicated that particle size distributions of MWF aerosols had an average mass median aerodynamic diameter of 5.3 microm. Straight oils and soluble fluids tended to be associated with larger particles than were other fluid types; grinding and turning produced the largest particles, whereas hobbing resulted in the smallest. In general, exposures were similar in magnitude and particle size to those previously reported in large automotive plants. Therefore, workers in these small shops may have risks of adverse health effects similar to those demonstrated in the automotive industry.","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":"80037677","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: 10.1080/15298660108984639
K. Rosenman, A. Sims, A. Hogan, J. Fiałkowski, J. Gardiner
The usefulness of a statewide laboratory-based blood lead surveillance system to initiate workplace enforcement inspections was studied. In particular, the effectiveness of inspection of companies in which at least one worker had a blood lead level (BLL) 30-39 microg/dL but no greater than 39 microg/dL was considered. The surveillance system identified all individuals who had been tested for blood lead. Adults with BLLs > or =30 microg/dL were interviewed. Companies where lead exposures occurred were identified and enforcement inspections performed there. Companies were grouped into four categories: one or more employees with BLL > or =50 microg/dL; one or more employees with highest BLL of 40-49 microg/dL; one or more employees with highest BLL of 30-39 microg/dL; and companies that used lead but from which no blood lead reports were received. The number of citations and amounts of penalties, and BLLs before and after, were compared among the three blood lead groups and with a control group of no lead-using companies. A cost-benefit analysis was performed. Citations and penalties did not differ among the three blood lead groups but were markedly increased compared with the lead using but no blood lead group. Violations of specific lead standard components were similar among the three blood lead groups. Blood lead companies had increased citations and penalties as compared with nonusing lead control companies. No significant decrease in blood leads was seen postinspection. Total cost to identify lead-exposed workers at problem work sites was $125 ($53-$459) per lead-exposed worker. Followup of companies identified through the surveillance system was an effective method to target workplace inspections. It is recommended that routine inspection be instituted for all companies in which an employee is reported to have a blood lead of 30 microg/dL or greater.
{"title":"Evaluation of the effectiveness of following up laboratory reports of elevated blood leads in adults.","authors":"K. Rosenman, A. Sims, A. Hogan, J. Fiałkowski, J. Gardiner","doi":"10.1080/15298660108984639","DOIUrl":"https://doi.org/10.1080/15298660108984639","url":null,"abstract":"The usefulness of a statewide laboratory-based blood lead surveillance system to initiate workplace enforcement inspections was studied. In particular, the effectiveness of inspection of companies in which at least one worker had a blood lead level (BLL) 30-39 microg/dL but no greater than 39 microg/dL was considered. The surveillance system identified all individuals who had been tested for blood lead. Adults with BLLs > or =30 microg/dL were interviewed. Companies where lead exposures occurred were identified and enforcement inspections performed there. Companies were grouped into four categories: one or more employees with BLL > or =50 microg/dL; one or more employees with highest BLL of 40-49 microg/dL; one or more employees with highest BLL of 30-39 microg/dL; and companies that used lead but from which no blood lead reports were received. The number of citations and amounts of penalties, and BLLs before and after, were compared among the three blood lead groups and with a control group of no lead-using companies. A cost-benefit analysis was performed. Citations and penalties did not differ among the three blood lead groups but were markedly increased compared with the lead using but no blood lead group. Violations of specific lead standard components were similar among the three blood lead groups. Blood lead companies had increased citations and penalties as compared with nonusing lead control companies. No significant decrease in blood leads was seen postinspection. Total cost to identify lead-exposed workers at problem work sites was $125 ($53-$459) per lead-exposed worker. Followup of companies identified through the surveillance system was an effective method to target workplace inspections. It is recommended that routine inspection be instituted for all companies in which an employee is reported to have a blood lead of 30 microg/dL or greater.","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":"77415630","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: 10.1080/15298660108984631
C. Timchalk, T. Poet, Y. Lin, K. Weitz, R. Zhao, K. Thrall
There is a need to develop reliable portable analytical systems for biomonitoring lead (Pb) in noninvasively collected saliva samples. In addition, appropriate pharmacokinetic analyses are used to quantitate systemic dosimetry based on the saliva Pb concentrations. A portable microfluidics/electrochemical device was developed for the rapid analysis of Pb based on square wave anodic stripping voltammetry, in which a saliva sample flows over an electrode surface, Pb2+ is chemically reduced and accumulated, and the electric potential of the electrode scanned. The system demonstrates a good linear response over a broad Pb concentration range (1-2000 ppb). To evaluate the relationship between saliva and blood Pb, rats were treated with single oral doses ranging from 20 to 500 mg Pb/kg of body weight, and 24 hours later were administered pilocarpine, a muscarinic agonist to induce salivation. To correlate saliva levels with internal dose, blood and saliva were collected and quantitated for Pb by inductively coupled plasma-mass spectrometry (ICP-MS) and by the microanalytical system. The quantitation with the microanalytical system was slightly less (approximately 75-85%) than with ICP-MS; however, the response was linear, with concentration suggesting that it can be used for the quantitation of salivary Pb. To facilitate modeling, a physiologically based pharmacokinetic (PBPK) model for Pb was modified to incorporate a salivary gland compartment. The model was capable of predicting blood and saliva Pb concentration based on a limited data set. These results are encouraging, suggesting that once fully developed the microanalytical system coupled with PBPK modeling can be used as important tools for real-time biomonitoring of Pb for both occupational and environmental exposures.
{"title":"Development of an integrated microanalytical system for analysis of lead in saliva and linkage to a physiologically based pharmacokinetic model describing lead saliva secretion.","authors":"C. Timchalk, T. Poet, Y. Lin, K. Weitz, R. Zhao, K. Thrall","doi":"10.1080/15298660108984631","DOIUrl":"https://doi.org/10.1080/15298660108984631","url":null,"abstract":"There is a need to develop reliable portable analytical systems for biomonitoring lead (Pb) in noninvasively collected saliva samples. In addition, appropriate pharmacokinetic analyses are used to quantitate systemic dosimetry based on the saliva Pb concentrations. A portable microfluidics/electrochemical device was developed for the rapid analysis of Pb based on square wave anodic stripping voltammetry, in which a saliva sample flows over an electrode surface, Pb2+ is chemically reduced and accumulated, and the electric potential of the electrode scanned. The system demonstrates a good linear response over a broad Pb concentration range (1-2000 ppb). To evaluate the relationship between saliva and blood Pb, rats were treated with single oral doses ranging from 20 to 500 mg Pb/kg of body weight, and 24 hours later were administered pilocarpine, a muscarinic agonist to induce salivation. To correlate saliva levels with internal dose, blood and saliva were collected and quantitated for Pb by inductively coupled plasma-mass spectrometry (ICP-MS) and by the microanalytical system. The quantitation with the microanalytical system was slightly less (approximately 75-85%) than with ICP-MS; however, the response was linear, with concentration suggesting that it can be used for the quantitation of salivary Pb. To facilitate modeling, a physiologically based pharmacokinetic (PBPK) model for Pb was modified to incorporate a salivary gland compartment. The model was capable of predicting blood and saliva Pb concentration based on a limited data set. These results are encouraging, suggesting that once fully developed the microanalytical system coupled with PBPK modeling can be used as important tools for real-time biomonitoring of Pb for both occupational and environmental exposures.","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":"83080369","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: 10.1080/15298660108984630
N. M. Osmond, P. Phillips
Respirator canister designers and manufacturers have a responsibility to provide canisters with increasingly higher capacity and longer service life due to rising safety standards in the workplace. Optimizing the service life of conventional canisters is not about simply increasing the depth of adsorbent present in the canister because this will lead to an increased resistance to airflow, and a greater physiological burden on the user. To optimize canister design it is necessary to establish how the physical dimensions of the adsorbent bed affect breathing resistance and adsorption performance. The study presented in this article investigated both the pressure drop and cyanogen chloride chemisorption performance of a granular activated carbon adsorbent. Results obtained show relationships that correlate adsorption performance and pressure drop to the quantity of adsorbent, the linear flow velocity, and, where applicable, the challenge vapor concentration. Altering the linear velocity by increasing cross-sectional surface area has a more beneficial impact on canister performance than altering the adsorbent bed depth. The application of these relationships to the design of canisters is demonstrated.
{"title":"Pressure drop and service life predictions for respirator canisters.","authors":"N. M. Osmond, P. Phillips","doi":"10.1080/15298660108984630","DOIUrl":"https://doi.org/10.1080/15298660108984630","url":null,"abstract":"Respirator canister designers and manufacturers have a responsibility to provide canisters with increasingly higher capacity and longer service life due to rising safety standards in the workplace. Optimizing the service life of conventional canisters is not about simply increasing the depth of adsorbent present in the canister because this will lead to an increased resistance to airflow, and a greater physiological burden on the user. To optimize canister design it is necessary to establish how the physical dimensions of the adsorbent bed affect breathing resistance and adsorption performance. The study presented in this article investigated both the pressure drop and cyanogen chloride chemisorption performance of a granular activated carbon adsorbent. Results obtained show relationships that correlate adsorption performance and pressure drop to the quantity of adsorbent, the linear flow velocity, and, where applicable, the challenge vapor concentration. Altering the linear velocity by increasing cross-sectional surface area has a more beneficial impact on canister performance than altering the adsorbent bed depth. The application of these relationships to the design of canisters is demonstrated.","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":"77161135","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: 10.1080/15298660108984633
K. Willeke, S. Trakumas, S. Grinshpun, T. Reponen, M. Trunov, W. Friedman
The overall filtration efficiency of a vacuum cleaner traditionally has been tested by placing the vacuum cleaner in a test chamber and measuring aerosol concentrations at the chamber inlet and outlet. The chamber test method was refined and validated in this study. However, this chamber test method shows an overall filtration efficiency of close to 100% for most of the industrial vacuum cleaners and for most of the newly developed household vacuum cleaners of midprice range or higher because all these vacuum cleaners have a high-efficiency particulate air (HEPA) or other highly efficient filter installed at the exhaust. A new test method was therefore developed through which the vacuum cleaner was probed in various internal locations so that the collection efficiency of the individual components could be determined. For example, the aerosol concentration upstream of the final HEPA filter can thus be measured, which permits one to estimate the life expectancy of this expensive component. The probed testing method is particularly suitable for field evaluations of vacuum cleaners because it uses compact, battery-operated optical particle size spectrometers with internal data storage. Both chamber and probed tests gave the same results for the aerosol filtration efficiency. The probed testing method, however, also gives information on the performance of the individual components in a vacuum cleaner. It also can be used to determine the dust pickup efficiency and the degree of reaerosolization of particles collected in the vacuum cleaner.
{"title":"Test methods for evaluating the filtration and particulate emission characteristics of vacuum cleaners.","authors":"K. Willeke, S. Trakumas, S. Grinshpun, T. Reponen, M. Trunov, W. Friedman","doi":"10.1080/15298660108984633","DOIUrl":"https://doi.org/10.1080/15298660108984633","url":null,"abstract":"The overall filtration efficiency of a vacuum cleaner traditionally has been tested by placing the vacuum cleaner in a test chamber and measuring aerosol concentrations at the chamber inlet and outlet. The chamber test method was refined and validated in this study. However, this chamber test method shows an overall filtration efficiency of close to 100% for most of the industrial vacuum cleaners and for most of the newly developed household vacuum cleaners of midprice range or higher because all these vacuum cleaners have a high-efficiency particulate air (HEPA) or other highly efficient filter installed at the exhaust. A new test method was therefore developed through which the vacuum cleaner was probed in various internal locations so that the collection efficiency of the individual components could be determined. For example, the aerosol concentration upstream of the final HEPA filter can thus be measured, which permits one to estimate the life expectancy of this expensive component. The probed testing method is particularly suitable for field evaluations of vacuum cleaners because it uses compact, battery-operated optical particle size spectrometers with internal data storage. Both chamber and probed tests gave the same results for the aerosol filtration efficiency. The probed testing method, however, also gives information on the performance of the individual components in a vacuum cleaner. It also can be used to determine the dust pickup efficiency and the degree of reaerosolization of particles collected in the vacuum cleaner.","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":"76838704","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: 10.1080/15298660108984634
L. Brosseau, D. Parker, D. Lazovich, S. Dugan, T. Milton, W. Pan
Measures of workers' inhalable dust exposures, tasks, and ventilation use were made in five small woodworking shops prior to the start of an intervention effectiveness study aimed at lowering personal wood dust exposures. The data were used to (1) design a sampling protocol for an intervention success measure, (2) identify targets for intervention among the tasks and activities responsible for high dust levels, and (3) develop shop-level measures as tools for tailoring intervention activities. Geometric mean dust concentrations ranged from 1.6 to 9.9 mg/m3 in the five shops, with the highest levels occurring in a cabinet shop. All shops had centralized dust collection systems and workers generally used dust control on stationary tools (60-100% of the time) when it was available. Sanding with both stationary and handheld powered tools, cleaning with methods that can disperse dust (e.g., brushes, compressed air), and miscellaneous tasks were all responsible for significant personal exposures. The positive association between miscellaneous tasks and exposures probably reflects the high background levels generated by nearby processes. Sanding with both stationary tools and handheld powered tools represents the most significant influence on personal exposures in small woodworking shops. The authors conclude that pilot studies are useful tools for designing occupational health and safety intervention effectiveness studies.
{"title":"Inhalable dust exposures, tasks, and use of ventilation in small woodworking shops: a pilot study.","authors":"L. Brosseau, D. Parker, D. Lazovich, S. Dugan, T. Milton, W. Pan","doi":"10.1080/15298660108984634","DOIUrl":"https://doi.org/10.1080/15298660108984634","url":null,"abstract":"Measures of workers' inhalable dust exposures, tasks, and ventilation use were made in five small woodworking shops prior to the start of an intervention effectiveness study aimed at lowering personal wood dust exposures. The data were used to (1) design a sampling protocol for an intervention success measure, (2) identify targets for intervention among the tasks and activities responsible for high dust levels, and (3) develop shop-level measures as tools for tailoring intervention activities. Geometric mean dust concentrations ranged from 1.6 to 9.9 mg/m3 in the five shops, with the highest levels occurring in a cabinet shop. All shops had centralized dust collection systems and workers generally used dust control on stationary tools (60-100% of the time) when it was available. Sanding with both stationary and handheld powered tools, cleaning with methods that can disperse dust (e.g., brushes, compressed air), and miscellaneous tasks were all responsible for significant personal exposures. The positive association between miscellaneous tasks and exposures probably reflects the high background levels generated by nearby processes. Sanding with both stationary tools and handheld powered tools represents the most significant influence on personal exposures in small woodworking shops. The authors conclude that pilot studies are useful tools for designing occupational health and safety intervention effectiveness studies.","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":"78727438","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: 10.1080/15298660108984636
D. O'brien, G. Piacitelli, W. Sieber, R. Hughes, J. Catalano
In a study of 23 small machining shops using metalworking fluids (MWFs), real-time air monitoring using an aerosol photometer was performed to investigate the temporal nature of the exposure and to examine the relationship between the instrumental measurements and traditional sampling methods. Time-weighted averages were calculated from the aerosol photometer data and the results were compared to collocated thoracic and 37-mm closed face cassette samplers. The filter samples were analyzed for total mass and the solvent extractable fraction. Depending on the averaging period used, short-term MWF concentrations exceeded 2.0 mg/m3 in 13 to 39% of the plants studied. High short-term exposures were as likely to be found in plants with average concentrations below 0.4 mg/m3 (thoracic-gravimetric) as those above. Regression analyses indicated that the aerosol photometer most closely matched the data obtained from the thoracic fraction of the total mass. In general, the aerosol photometer overestimated the levels determined using the thoracic cyclone and filter, especially when measuring concentrations of water-based fluids. Use of a calibration factor of 0.7 for straight oils or 0.5 for water-based fluids may assist in the interpretation of aerosol photometer measurements if field calibration data are not readily available. Several approaches to determining the calibration factor from field data were evaluated; more complex calibration techniques improved the accuracy of the measurements.
{"title":"An evaluation of short-term exposures to metalworking fluids in small machine shops.","authors":"D. O'brien, G. Piacitelli, W. Sieber, R. Hughes, J. Catalano","doi":"10.1080/15298660108984636","DOIUrl":"https://doi.org/10.1080/15298660108984636","url":null,"abstract":"In a study of 23 small machining shops using metalworking fluids (MWFs), real-time air monitoring using an aerosol photometer was performed to investigate the temporal nature of the exposure and to examine the relationship between the instrumental measurements and traditional sampling methods. Time-weighted averages were calculated from the aerosol photometer data and the results were compared to collocated thoracic and 37-mm closed face cassette samplers. The filter samples were analyzed for total mass and the solvent extractable fraction. Depending on the averaging period used, short-term MWF concentrations exceeded 2.0 mg/m3 in 13 to 39% of the plants studied. High short-term exposures were as likely to be found in plants with average concentrations below 0.4 mg/m3 (thoracic-gravimetric) as those above. Regression analyses indicated that the aerosol photometer most closely matched the data obtained from the thoracic fraction of the total mass. In general, the aerosol photometer overestimated the levels determined using the thoracic cyclone and filter, especially when measuring concentrations of water-based fluids. Use of a calibration factor of 0.7 for straight oils or 0.5 for water-based fluids may assist in the interpretation of aerosol photometer measurements if field calibration data are not readily available. Several approaches to determining the calibration factor from field data were evaluated; more complex calibration techniques improved the accuracy of the 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":"2001-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77408134","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: 10.1080/15298660108984640
F. Rosenthal, B. L. Yeagy
The concentrations and size distribution of metalworking fluid aerosols were investigated in grinding operations in the bearing manufacturing industry. Fifteen paired open- and closed-face cassette samples and five cascade impactor samples were obtained in each of three types of grinding machinery (face, microcentric, and progressive). Aerosol mass concentration as measured by open-face filter sampling ranged from 0.34 to 2.43 mg/m3. As measured by closed-face sampling the range was 0.14 to 2.01 mg/m3. For each grinding process, open-face concentration was significantly higher than the closed-face concentration (paired t-test, p <0.05). Mass median aerodynamic diameter (MMAD) ranged from 3.33 to 6.26 microm. The percentage of mass greater than 9 microm ranged from 8.0 to 45.3. The MMAD and fraction greater than 9 microm were significantly greater for the aerosol produced by the face grinder compared with the other two processes. The results indicate that (1) closed-face sampling results in a lower aerosol mass concentration, as compared with open-face sampling, with the degree of difference being somewhat dependent on grinding process; and (2) the particle size distribution and concentration of metalworking fluid aerosols may vary with the type of grinding operation sampled.
{"title":"Characterization of metalworking fluid aerosols in bearing grinding operations.","authors":"F. Rosenthal, B. L. Yeagy","doi":"10.1080/15298660108984640","DOIUrl":"https://doi.org/10.1080/15298660108984640","url":null,"abstract":"The concentrations and size distribution of metalworking fluid aerosols were investigated in grinding operations in the bearing manufacturing industry. Fifteen paired open- and closed-face cassette samples and five cascade impactor samples were obtained in each of three types of grinding machinery (face, microcentric, and progressive). Aerosol mass concentration as measured by open-face filter sampling ranged from 0.34 to 2.43 mg/m3. As measured by closed-face sampling the range was 0.14 to 2.01 mg/m3. For each grinding process, open-face concentration was significantly higher than the closed-face concentration (paired t-test, p <0.05). Mass median aerodynamic diameter (MMAD) ranged from 3.33 to 6.26 microm. The percentage of mass greater than 9 microm ranged from 8.0 to 45.3. The MMAD and fraction greater than 9 microm were significantly greater for the aerosol produced by the face grinder compared with the other two processes. The results indicate that (1) closed-face sampling results in a lower aerosol mass concentration, as compared with open-face sampling, with the degree of difference being somewhat dependent on grinding process; and (2) the particle size distribution and concentration of metalworking fluid aerosols may vary with the type of grinding operation sampled.","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":"82121940","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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