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White KT, Ashley K, Harper M. The importance of assessing wall deposits in samplers for airborne particulates. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2024; 21:451-454. [PMID: 38652916 DOI: 10.1080/15459624.2024.2337692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Affiliation(s)
| | | | - Martin Harper
- Department of Environmental Engineering Sciences, University of Florida, Gainesville, Florida
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Aubin S, Wingert L, Gagné S, Breau L, Lesage J. Comprehensive methylene diphenyl diisocyanate (MDI) evaluation method comparison using a laboratory generation system. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023; 25:941-953. [PMID: 37039308 DOI: 10.1039/d2em00443g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Isocyanates are reactive semivolatile contaminants that must be assessed in occupational environments, and specific evaluation methods are required to address the challenges related to isocyanate emission characteristics. Several standard methods exist, but significant differences remain regarding the diversity of industrial isocyanate emissions. This study presents a method to establish a baseline comparison of three sampling principles. A fine aerosol (mass median aerodynamic diameter of 250 nm) of pure methylene diphenyl diisocyanate (MDI) was produced (5-60 μg m-3) using a laboratory generation system (n = 31 generation experiments). Airborne MDI was measured with the following four methods, with an emphasis on the spatial distribution of the collected MDI within the sampler: (1) Swinnex cassette 13 mm, glass fibre filter (GFF), 9-(N-methylaminomethyl) anthracene (MAMA-Swin); (2) closed-face cassette (CFC) 37 mm, GFF (end filter and inner walls), MAMA-37; (3) impinger and backup GGF, 1,2-methoxyphenylpiperazine (MP) (ISO 16702/MDHS 25); and (4) denuder and GFF (Asset EZ4-NCO), dibutylamine (DBA) (ISO 17334-1). Bland and Altman analyses determined that there were no significant bias between the methods although Asset was not in agreement with MAMA-Swin (95% confidence interval above the ±20% criteria). Significant correlations (P < 0.05) were observed between airborne MDI concentration levels and their distribution within the Asset (denuder vs. end filter) and impinger (collecting solution vs. backup filter) subsections. The presence of impregnated inner walls in the CFC did not increase collection efficiency for the generated MDI aerosol. Non-uniform MAMA impregnation on GFF was demonstrated, whereas the collected MDI was evenly distributed in the air samples. These results provided the basis of comparison for other studies involving more complex isocyanate emissions.
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Affiliation(s)
- Simon Aubin
- Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Qc, Canada.
- Université Du Québec à Montréal (UQAM), Chemistry Department, Qc, Canada
| | - Loïc Wingert
- Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Qc, Canada.
| | - Sébastien Gagné
- Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), Qc, Canada.
| | - Livain Breau
- Université Du Québec à Montréal (UQAM), Chemistry Department, Qc, Canada
| | - Jacques Lesage
- Université Du Québec à Montréal (UQAM), Chemistry Department, Qc, Canada
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Erekaife G, Park HD, Kashon ML, Chisholm WP, Lee EG. Investigation of particle transfer to sampler covers during the transportation of samples. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2021; 18:295-304. [PMID: 34129437 PMCID: PMC8285000 DOI: 10.1080/15459624.2021.1926467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
This study investigated the effects of particle transfer to the covers of aerosol samplers during transportation of wood dust and welding fume samples. Wood dust samples were collected in a sanding chamber using four sampler types: closed-face cassettes (CFC), CFC with Accu-CAP inserts, disposable inhalable samplers (DIS), and Institute of Occupational Medicine (IOM). Welding fumes were collected in a walk-in chamber using the same samplers, with Solu-Sert replacing Accu-CAP. The samples were divided into two groups, with one group transported by air and the other by land. They were returned in the same manner and analyzed gravimetrically for wood dust and chemically for welding fumes. For wood dust, IOM showed a significantly higher percentage of particles transferred to the covers compared with the other samplers regardless of the transportation mode (p < 0.0001; 64% by air and 15% by land), while other samplers showed less than or close to 10% (3.5-12%). When the percentages of particle transfer to the covers were compared between the air and land transportation, both IOM and CFC samples showed differences between modes of transportation, while others did not. For welding fumes, most samples (61% of samples for copper [Cu] and 76% of samples for manganese [Mn]) showed nondetectable amounts of the analyte on the covers. For all samplers, the particle transfer to the covers for both transportation modes ranged from 0.2-33% for Cu and less than 4.5% for Mn. Overall, this study confirms that particle transfer to sampler covers during transport highly depends upon the transportation mode and sampler type for wood dust, whereas particle transfer seems minimal for welding fumes. The findings of this study are based on two materials and limited sample sizes. Further investigation considering different industry types and tasks, particle size ranges, and materials might be necessary. Nevertheless, occupational professionals should account for this transfer when handling and analyzing samples in practice.
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Affiliation(s)
- Godwin Erekaife
- Industrial & Management Systems Engineering, West Virginia University, Morgantown, West Virginia
| | - Hae Dong Park
- Korea Occupational Safety and Health Agency, Ulsan, South Korea
| | - Michael L. Kashon
- BioAnalytics Branch, Health Effects Laboratory Division (HELD), National Institute for Occupational Safety and Health (NIOSH), Morgantown, West Virginia
| | | | - Eun Gyung Lee
- Exposure Assessment Branch, HELD, NIOSH, Morgantown, West Virginia
- Field Studies Branch, Respiratory Health Division, NIOSH, Morgantown, West Virginia
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Mastrantonio R, Civisca A, Siciliano E, Inglese E, Lippolis T, Pompei D, Cococcetta L, Scatigna M, Fabiani L. Exposure assessment to inhalable and respirable dust in the post - earthquake construction sites in the city of l'Aquila. J Occup Health 2021; 63:e12296. [PMID: 34851000 PMCID: PMC8634115 DOI: 10.1002/1348-9585.12296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 10/22/2021] [Accepted: 11/02/2021] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES Following an earthquake that occurred in middle Italy in 2009, the involved territory hosted in 10 years thousands of construction sites. The aim of this study is to assess inhalable, respirable, and respirable crystalline silica exposure of the construction workers involved in the rebuilding activities. METHODS Six construction companies joined the study and hosted the air sampling activities. We identified four work tasks: bricklayer and similar; scaffolder and carpenter; manual demolition; other tasks. We reported 8-h time-weighted concentrations. RESULTS The "All tasks" geometric mean concentration of inhalable dust was 4.73 mg/m3 and the higher, TLV exceeding exposure was observed for "Manual demolition workers" (13.92 mg/m3 , GM). The "All tasks" geometric mean concentration of respirable dust was 0.25 mg/m3 and no TLV-exceeding exposure (geometric mean values) was observed among the work-related groups. About the respirable crystalline silica dust exposure, the "All tasks" average concentration was 0.004 mg/m3 . No TLV-exceeding exposure was observed among the whole data sample. CONCLUSIONS The comparison of the results shows that manual demolition workers are exposed to high levels of inhalable dust, exceeding the TLV-TWA (Threshold Limit Values-Time Weighted Average) limit of 10 mg/m3 . About the respirable dust concentration, none of the analyzed work task dust concentrations exceeded the TLV-TWA limit of 3 mg/m3 (geometric mean values). Measurements of respirable crystalline silica dust have shown levels below the threshold limit value of 0.025 mg/m3 . Our findings overall match with the available scientific data.
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Affiliation(s)
- Riccardo Mastrantonio
- Department of Life, Health & Environmental SciencesUniversity of L'AquilaL'AquilaItaly
| | - Angela Civisca
- Department of Life, Health & Environmental SciencesUniversity of L'AquilaL'AquilaItaly
| | - Eugenio Siciliano
- Regional Directorate of AbruzzoNational Institute for Insurance Against Industrial InjuriesL’AquilaItaly
| | - Enrica Inglese
- Local Health Authority of Avezzano‐Sulmona‐L'AquilaL'AquilaItaly
| | - Tamara Lippolis
- Department of Life, Health & Environmental SciencesUniversity of L'AquilaL'AquilaItaly
| | - Domenico Pompei
- Local Health Authority of Avezzano‐Sulmona‐L'AquilaL'AquilaItaly
| | - Lucio Cococcetta
- Ente scuola edile – Comitato paritetico territorialeL'AquilaItaly
| | - Maria Scatigna
- Department of Life, Health & Environmental SciencesUniversity of L'AquilaL'AquilaItaly
| | - Leila Fabiani
- Department of Life, Health & Environmental SciencesUniversity of L'AquilaL'AquilaItaly
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Recent Advances in Occupational Exposure Assessment of Aerosols. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17186820. [PMID: 32962023 PMCID: PMC7559367 DOI: 10.3390/ijerph17186820] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/27/2020] [Accepted: 08/31/2020] [Indexed: 01/15/2023]
Abstract
Exposure science is underpinned by characterization (measurement) of exposures. In this article, six recent advances in exposure characterization by sampling and analysis are reviewed as tools in the occupational exposure assessment of aerosols. Three advances discussed in detail are (1) recognition and inclusion of sampler wall deposits; (2) development of a new sampling and analytical procedure for respirable crystalline silica that allows non-destructive field analysis at the end of the sampling period; and (3) development of a new sampler to collect the portion of sub-300 nm aerodynamic diameter particles that would deposit in human airways. Three additional developments are described briefly: (4) a size-selective aerosol sampler that allows the collection of multiple physiologically-relevant size fractions; (5) a miniaturized pump and versatile sampling head to meet multiple size-selective sampling criteria; and (6) a novel method of sampling bioaerosols including viruses while maintaining viability. These recent developments are placed in the context of the historical evolution in sampling and analytical developments from 1900 to the present day. While these are not the only advances in exposure characterization, or exposure assessment techniques, they provide an illustration of how technological advances are adding more tools to our toolkit. The review concludes with a number of recommended areas for future research, including expansion of real-time and end-of-shift on-site measurement, development of samplers that operate at higher flow-rates to ensure measurement at lowered limit values, and development of procedures that accurately distinguish aerosol and vapor phases of semi-volatile substances.
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Stacey P, Simpson A, Hambling S. The Measurement of Wood in Construction Dust Samples: A Furnace Based Thermal Gravimetric Approach. Ann Work Expo Health 2019; 63:1070-1080. [PMID: 31550344 DOI: 10.1093/annweh/wxz072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/01/2019] [Accepted: 08/28/2019] [Indexed: 11/14/2022] Open
Abstract
A furnace-based thermal gravimetric method was developed to measure wood in inhalable construction dust. The application of this method showed that reliance on the inhalable concentrations alone may substantially overestimate carpenters' exposures to wood dust at construction worksites. Test samples were prepared by collecting aerosols of gypsum, calcite, quartz, concrete, and wood dust onto quartz fibre filters using the Button inhalable sampler. The average difference between the measured and loaded mass of wood is 2% over the whole analytical range. Ninety percent of thermogravimetric measurements on all test samples (n = 35) were 13% or less. The limit of detection was measured as 0.065 mg. The thermal gravimetric method was applied to samples collected from four new build construction sites and one shop fitting worksite. The workplace inhalable wood dust results ranged from 15% to 104% of the total inhalable dust values. In addition, an x-ray diffraction (XRD) Rietveld method was applied as a complimentary approach to explain the composition of the remaining inhalable dust. Most combined thermal gravimetric and XRD measurements were within 10% of the total inhalable dust mass values, determined gravimetrically. Ninety-five percent were within 26%. The median proportion of mineral dust containing gypsum, calcite, quartz, dolomite, or rutile was 30%. The proportion of mineral dust on individual filters varied considerably.
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Affiliation(s)
- Peter Stacey
- The Health and Safety Executive, Harpur Hill, Buxton, UK
| | - Andrew Simpson
- The Health and Safety Executive, Harpur Hill, Buxton, UK
| | - Susan Hambling
- The Health and Safety Executive, Redgrave Court, Bootle, Merseyside, UK
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Devoy J, Remy AM, La Rocca B, Wild P, Rousset D. Occupational exposure to beryllium in French industries. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2019; 16:229-241. [PMID: 30570429 DOI: 10.1080/15459624.2018.1559926] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Beryllium (Be) is a metal mainly used in the form of alloys, with copper (Cu) and aluminium (Al) in the metal industry. Be is an extremely toxic element which must be handled under strictly controlled conditions to avoid health hazards to workers. Exposure to Be can be responsible for Chronic Beryllium Disease, a pulmonary disease preceded by sensitization to the element, and for lung cancer. The goals of the current study were to investigate Be exposure in France, to determine the airborne Be occupational exposure levels, the associated impregnation of employees through their urinary Be levels and the factors that might affect them, and finally to study a possible relation between biomonitoring and airborne data. Seventy-five volunteer subjects were thus atmospherically and biologically monitored in five French companies involved in Cu or Al casting, Al smelting, CuBe machining or AlBe general mechanical engineering. Airborne exposure was quite low with only 2% of measurements above the current French Occupational Exposure Limit (2 µg/m3); the population potentially most exposed was foundry workers. Impregnation with Be was also low with only 10% of quantified urinary Be measurements above the current German BAR value (0.05 µg/L). Using a Bayesian statistical modelling approach, the mean subject-specific urinary excretion of Be was found to increase significantly with the mean subject-specific exposure to airborne Be. From this relationship, and based on the current French OEL-8 hr, a Biological Limit Value of 0.08 µg/L (= 0.06 µg/g creatinine) could be proposed.
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Affiliation(s)
- Jérôme Devoy
- a Toxicology and Biomonitoring Division, Institut National de Recherche et de Sécurité , Vandoeuvre-les-Nancy , France
| | - Aurélie Martin Remy
- a Toxicology and Biomonitoring Division, Institut National de Recherche et de Sécurité , Vandoeuvre-les-Nancy , France
- d EA 4360 APEMAC, Université de Lorraine , Ecole de Sante Publique de Nancy , Vandoeuvre-les-Nancy , France
| | - Bénédicte La Rocca
- a Toxicology and Biomonitoring Division, Institut National de Recherche et de Sécurité , Vandoeuvre-les-Nancy , France
| | - Pascal Wild
- b Research and Study Management , Institut National de Recherche et de Sécurité , Vandoeuvre-les-Nancy , France
| | - Davy Rousset
- c Pollutants Metrology Division, Institut National de Recherche et de Sécurité , Vandoeuvre-les-Nancy , France
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Andrews RN, Feng HA, Ashley K. Interlaboratory evaluation of cellulosic acid-soluble internal air sampling capsules for multi-element analysis. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2016; 13:40-7. [PMID: 26308974 PMCID: PMC4754578 DOI: 10.1080/15459624.2015.1072635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An interlaboratory study was carried out to evaluate the use of acid-soluble cellulosic air sampling capsules for their suitability in the measurement of trace elements in workplace atmospheric samples. These capsules are used as inserts to perform closed-face cassette sample collection for occupational exposure monitoring. The interlaboratory study was performed in accordance with NIOSH guidelines that describe statistical procedures for evaluating measurement accuracy of air monitoring methods. The performance evaluation materials used consisted of cellulose acetate capsules melded to mixed-cellulose ester filters that were dosed with multiple elements from commercial standard aqueous solutions. The cellulosic capsules were spiked with the following 33 elements of interest in workplace air monitoring: Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, In, K, La, Li, Mg, Mn, Mo, Ni, P, Pb, Sb, Se, Sn, Sr, Te, Ti, Tl, V, W, Y, Zn, Zr. The elemental loading levels were certified by an accredited provider of certified reference materials. Triplicates of media blanks and multielement-spiked capsules at three different elemental loadings were sent to each participating laboratory; the elemental loading levels were not revealed to the laboratories. The volunteer participating laboratories were asked to prepare the samples by acid dissolution and to analyze aliquots of extracted samples by inductively coupled plasma atomic emission spectrometry in accordance with NIOSH methods. It was requested that the study participants report their analytical results in units of μg of each target element per internal capsule sample. For the majority of the elements investigated (30 out of 33), the study accuracy estimates obtained satisfied the NIOSH accuracy criterion (A < 25%). This investigation demonstrates the utility of acid-soluble internal sampling capsules for multielement analysis by atomic spectrometry.
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Affiliation(s)
- Ronnee N Andrews
- a U.S. Department of Health and Human Services , Centers for Disease Control and Prevention , National Institute for Occupational Safety and Health , Cincinnati , Ohio
| | - H Amy Feng
- a U.S. Department of Health and Human Services , Centers for Disease Control and Prevention , National Institute for Occupational Safety and Health , Cincinnati , Ohio
| | - Kevin Ashley
- a U.S. Department of Health and Human Services , Centers for Disease Control and Prevention , National Institute for Occupational Safety and Health , Cincinnati , Ohio
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Rousset D, Durand T. Beryllium solubility in occupational airborne particles: Sequential extraction procedure and workplace application. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2016; 13:71-83. [PMID: 26327570 DOI: 10.1080/15459624.2015.1078467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Modification of an existing sequential extraction procedure for inorganic beryllium species in the particulate matter of emissions and in working areas is described. The speciation protocol was adapted to carry out beryllium extraction in closed-face cassette sampler to take wall deposits into account. This four-step sequential extraction procedure aims to separate beryllium salts, metal, and oxides from airborne particles for individual quantification. Characterization of the beryllium species according to their solubility in air samples may provide information relative to toxicity, which is potentially related to the different beryllium chemical forms. Beryllium salts (BeF(2), BeSO(4)), metallic beryllium (Bemet), and beryllium oxide (BeO) were first individually tested, and then tested in mixtures. Cassettes were spiked with these species and recovery rates were calculated. Quantitative analyses with matched matrix were performed using inductively coupled plasma mass spectrometry (ICP-MS). Method Detection Limits (MDLs) were calculated for the four matrices used in the different extraction steps. In all cases, the MDL was below 4.2 ng/sample. This method is appropriate for assessing occupational exposure to beryllium as the lowest recommended threshold limit values are 0.01 µg.m(-3) in France([) (1) (]) and 0.05 µg.m(-3) in the USA.([ 2 ]) The protocol was then tested on samples from French factories where occupational beryllium exposure was suspected. Beryllium solubility was variable between factories and among the same workplace between different tasks.
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Affiliation(s)
- Davy Rousset
- a Institut National de Recherche et de Sécurité (INRS) , Département Métrologie des Polluants , Vandoeuvre , France
| | - Thibaut Durand
- a Institut National de Recherche et de Sécurité (INRS) , Département Métrologie des Polluants , Vandoeuvre , France
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Ceballos D, King B, Beaucham C, Brueck SE. Comparison of a Wipe Method With and Without a Rinse to Recover Wall Losses in Closed Face 37-mm Cassettes used for Sampling Lead Dust Particulates. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2015; 12:D225-D231. [PMID: 26125330 PMCID: PMC4558231 DOI: 10.1080/15459624.2015.1009991] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Closed-face 37-mm polystyrene cassettes are often used for exposure monitoring of metal particulates. Several methods have been proposed to account for the wall loss in air sampling cassettes, including rinsing, wiping, within-cassette dissolution, and an internal capsule fused to the filter that could be digested with the filter. Until internal capsules replace filters, other methods for assessing wall losses may be considered. To determine if rinsing and wiping or wiping alone is adequate to determine wall losses on cassettes, we collected 54 full-shift area air samples at a battery recycling facility. We collected six replicate samples at three locations within the facility for three consecutive days. The wall losses of three replicate cassettes from each day-location were analyzed following a rinse and two consecutive wipes. The wall losses of the other three replicates from each day-location were analyzed following two consecutive wipes only. Mixed-cellulose ester membrane filter, rinse, and wipes were analyzed separately following NIOSH Method 7303. We found an average of 29% (range: 8-54%) recovered lead from the cassette walls for all samples. We also found that rinsing prior to wiping the interior cassette walls did not substantially improve recovery of wall losses compared to wiping alone. A rinse plus one wipe recovered on average 23% (range: 13-33%) of the lead, while one wipe alone recovered on average 21% (range: 16-22%). Similarly, we determined that a second wipe did not provide substantial additional recovery of lead (average: 4%, range: 0.4-19%) compared to the first wipe disregarding the rinse (average: 18%, range: 4-39%). We concluded that when an internal capsule is not used, wall losses of lead dust in air sampling cassettes can be adequately recovered by wiping the internal wall surfaces of the cassette with a single wipe.
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Duquenne P, Simon X, Demange V, Harper M, Wild P. Endotoxin deposits on the inner surfaces of closed-face cassettes during bioaerosol sampling: a field investigation at composting facilities. ANNALS OF OCCUPATIONAL HYGIENE 2014; 59:504-13. [PMID: 25535181 DOI: 10.1093/annhyg/meu108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 11/05/2014] [Indexed: 12/30/2022]
Abstract
A set of 270 bioaerosol samples was taken from 15 composting facilities using polystyrene closed-face filter cassettes (CFCs). The objective was to measure the quantity of endotoxin deposits on the inner surfaces of the cassettes (sometimes referred to as 'wall deposits'). The results show that endotoxins are deposited on the inner surfaces of the CFCs through sampling and/or handling of samples. The quantity of endotoxins measured on inner surfaces range between 0.05 (the limit of detection of the method) and 3100 endotoxin units per cassette. The deposits can represent a large and variable percentage of the endotoxins sampled. More than a third of the samples presented a percentage of inner surface deposits >40% of the total quantity of endotoxins collected (filter + inner surfaces). Omitting these inner surface deposits in the analytical process lead to measurement errors relative to sampling all particles entering the CFC sampler, corresponding to a developing consensus on matching the inhalable particulate sampling convention. The result would be underestimated exposures and could affect the decision as to whether or not a result is acceptable in comparison to airborne concentration limits defined in terms of the inhalability convention. The results of this study suggest including the endotoxins deposited on the inner surfaces of CFCs during analysis. Further researches are necessary to investigate endotoxin deposits on the inner cassette surfaces in other working sectors.
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Affiliation(s)
- Philippe Duquenne
- 1.INRS - Institut National de Recherche et de Sécurité, Aerosols Metrology Laboratory, Pollutants Metrology Division, 1 rue du Morvan CS 60027, Vandœuvre-lès-Nancy Cedex 54519, France
| | - Xavier Simon
- 1.INRS - Institut National de Recherche et de Sécurité, Aerosols Metrology Laboratory, Pollutants Metrology Division, 1 rue du Morvan CS 60027, Vandœuvre-lès-Nancy Cedex 54519, France
| | - Valérie Demange
- 1.INRS - Institut National de Recherche et de Sécurité, Aerosols Metrology Laboratory, Pollutants Metrology Division, 1 rue du Morvan CS 60027, Vandœuvre-lès-Nancy Cedex 54519, France
| | - Martin Harper
- 2.NIOSH - National Institute for Occupational Safety and Health, Health Effects Laboratory Division, 1095 Willowdale Road, Morgantown, WV 26505, USA
| | - Pascal Wild
- 1.INRS - Institut National de Recherche et de Sécurité, Aerosols Metrology Laboratory, Pollutants Metrology Division, 1 rue du Morvan CS 60027, Vandœuvre-lès-Nancy Cedex 54519, France
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Lee EG, Chisholm WP, Burns DA, Nelson JH, Kashon ML, Harper M. Comparison of lead and tin concentrations in air at a solder manufacturer from the closed-face 37-mm cassette with and without a custom cellulose-acetate cassette insert. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2014; 11:819-825. [PMID: 24856841 PMCID: PMC4706070 DOI: 10.1080/15459624.2014.925116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A polyvinyl chloride (PVC) cassette insert with PVC filter (ACCU-CAP) in a 37-mm closed-face cassette (CFC) was designed for gravimetric analysis. A customized version of the ACCU-CAP, also to be used in the CFC, was manufactured from an acid-digestible cellulose-acetate cassette insert joined to a mixed cellulose ester (MCE) filter for wet chemical analysis. The aim of this study was to compare metal particle concentrations as sampled by the customized insert (CI) in a CFC sampler with the traditional sampling method using only a MCE filter in the CFC. Thirty-nine personal and 13 area samples were taken using paired filter-based CFC and the CI in CFC samplers at a solder manufacturing plant. The CI was removed from its CFC, and digested and analyzed as a whole. The MCE filter from the typical CFC was removed for analysis and then the interior of the cassette was wiped with Ghost Wipe for a separate analysis. The MCE filter only, Ghost Wipe, and CI were separately dissolved in heated nitric acid for ICP-MS analysis. Overall, the geometric mean concentration of the filter-only (FO) samples was considerably lower than that of the CI samples, by 53% for lead and 32% for tin. However, if the FO analysis was added to the corresponding Ghost Wipe analysis, i.e., filter+interior wipe (FW), the geometric mean concentrations of the FW results were similar to those of the CI results (by 113% for lead and 98% for tin). For both lead and tin the comparison of (log-transformed) metal concentrations between the FW and CI results showed no statistically significant difference (p-value = 0.3009 for lead and 0.800 for tin), while the comparison between the FO and CI results shows statistically significant differences (all p-values < 0.05). In conclusion, incorporating the sampler internal non-filter deposits by wiping or use of an internal filter capsule gave higher results than analyzing only the filter. Close agreement between the two methods of including non-filter deposits is an indication of general equivalency.
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Affiliation(s)
- Eun Gyung Lee
- Health Effects Laboratory Division, Exposure Assessment Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - William P. Chisholm
- Health Effects Laboratory Division, Exposure Assessment Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Dru A. Burns
- Health Effects Laboratory Division, Exposure Assessment Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - John H. Nelson
- Health Effects Laboratory Division, Exposure Assessment Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Michael L. Kashon
- Health Effects Laboratory Division, Biostatistics and Epidemiology Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
| | - Martin Harper
- Health Effects Laboratory Division, Exposure Assessment Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia
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Soo JC, Lee T, Kashon M, Kusti M, Harper M. Quartz in coal dust deposited on internal surface of respirable size selective samplers. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2014; 11:D215-9. [PMID: 25204985 PMCID: PMC4733624 DOI: 10.1080/15459624.2014.960575] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The objective of the present study is to quantify quartz mass in coal dust deposited on the internal cassette surface of respirable size-selective samplers. Coal dust was collected with four different respirable size-selective samplers (10 mm Dorr-Oliver nylon [Sensidyne, St. Petersburg, Fla.], SKC Aluminum [SKC Inc., Eighty Four, Pa.], BGI4L [BGI USA Inc., Waltham, Mass.], and GK2.69 cyclones [BGI USA Inc.]) with two different cassette types (polystyrene and static-dissipative polypropylene cassettes). The coal dust was aerosolized in a calm air chamber by using a fluidized bed aerosol generator without neutralization under the assumption that the procedure is similar to field sampling conditions. The mass of coal dust was measured gravimetrically and quartz mass was determined by Fourier transform infrared spectroscopy according to the National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods, Method 7603. The mass fractions of the total quartz sample on the internal cassette surface are significantly different between polystyrene and static-dissipative cassettes for all cyclones (p < 0.05). No consistent relationship between quartz mass on cassette internal surface and coal dust filter mass was observed. The BGI4L cyclone showed a higher (but not significantly) and the GK2.69 cyclone showed a significantly lower (p < 0.05) internal surface deposit quartz mass fraction for polystyrene cassettes compared to other cyclones. This study confirms previous observations that the interior surface deposits in polystyrene cassettes attached to cyclone pre-selectors can be a substantial part of the sample, and therefore need to be included in any analysis for accurate exposure assessment. On the other hand, the research presented here supports the position that the internal surface deposits in static-dissipative cassettes used with size-selective cyclones are negligible and that it is only necessary to analyze the filter catch.
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Affiliation(s)
- Jhy-Charm Soo
- Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Taekhee Lee
- Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Michael Kashon
- Biostatistics and Epidemiology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Mohannad Kusti
- Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Martin Harper
- Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
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Harper M, Ashley K. Acid-soluble internal capsules for closed-face cassette elemental sampling and analysis of workplace air. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2013; 10:297-306. [PMID: 23548078 PMCID: PMC3664911 DOI: 10.1080/15459624.2013.777310] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Airborne particles that are collected using closed-face filter cassettes (CFCs), which are used widely in the sampling of workplace aerosols, can deposit in places other than on the filter and thereby may not be included in the ensuing analysis. A technique for ensuring that internal non-filter deposits are included in the analysis is to collect airborne particles within an acid-soluble internal capsule that, following sampling, can be dissolved along with the filter for subsequent elemental analysis. An interlaboratory study (ILS) was carried out to evaluate the use of cellulosic CFC capsule inserts for their suitability in the determination of trace elements in airborne samples. The ILS was performed in accordance with an applicable ASTM International standard practice, ASTM E691, which describes statistical procedures for investigating interlaboratory precision. Performance evaluation materials consisted of prototype cellulose acetate capsules attached to mixed-cellulose ester filters. Batches of capsules were dosed with Pb-containing materials (standard aqueous solutions, and certified reference material soil and paint). Also, aerosol samples containing nine target analyte elements (As, Cd, Co, Cr, Cu, Fe, Pb, Mn, and Ni) were generated using a multiport sampler; various concentrations and sampling times were employed to yield samples fortified at desired loading levels. Triplicates of spiked capsules at three different loadings were conveyed to each volunteer laboratory; loading levels were unknown to the participants. The laboratories were asked to prepare the samples by acid dissolution and to analyze aliquots of extracted samples by atomic spectrometry in accordance with applicable ASTM International Standards. Participants were asked to report their results in units of μg of each target element per sample. For the elements investigated, inter-laboratory precision and recovery estimates from the participating laboratories demonstrated the utility of the cellulosic capsule inserts for the measurement of sampled trace elements.
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Affiliation(s)
- Martin Harper
- National Institute for Occupational Safety and Health, Health Effects Laboratory Division, Morgantown, West Virginia 26505, USA.
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Ashley K, Harper M. Closed-face filter cassette (CFC) sampling-guidance on procedures for inclusion of material adhering to internal sampler surfaces. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2013; 10:D29-33. [PMID: 23339418 PMCID: PMC4636115 DOI: 10.1080/15459624.2012.750554] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Affiliation(s)
- Kevin Ashley
- U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA.
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Harper M, Ashley K. Preliminary studies on the use of acid-soluble cellulose acetate internal capsules for workplace metals sampling and analysis. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2012; 9:D125-D129. [PMID: 22702231 PMCID: PMC4657748 DOI: 10.1080/15459624.2012.691354] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Particles entering filter cassettes used to collect samples of aerosol can deposit elsewhere than on the filter. One suggested procedure for ensuring that those deposits are included in the analysis is to collect them within an internal capsule that can subsequently be digested along with the filter. An inter-laboratory evaluation was carried out to evaluate the use of cellulosic capsule inserts for their suitability in the determination of trace elements in workplace air samples. The inter-laboratory study (ILS) was performed in accordance with an applicable ASTM International standard practice, ASTM E691, which describes statistical procedures for investigating inter-laboratory precision. Performance evaluation materials consisted of prototype cellulose acetate capsules attached to mixed-cellulose ester filters, which were spiked with lead-containing materials (aqueous salt solutions, certified reference soil and paint) at ≈ 20 and ≈ 50 µg Pb per sample. Triplicates of each spiked capsule plus media blanks were conveyed to each volunteer laboratory; spiking levels were unknown to the participants. The laboratories were asked to prepare the samples by acid digestion and analyze aliquots of extracted samples by atomic spectrometry procedures described in applicable ASTM International standard test methods D7035 and/or D7439. Participants were then asked to report their data in units of µg per sample. Preliminary inter-laboratory precision and recovery estimates from six participating laboratories demonstrated the utility of the cellulosic capsule inserts for the measurement of sampled trace elements.
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Affiliation(s)
- Martin Harper
- U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA.
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Demange M, Oury V, Rousset D. Evaluation of sampling methods for measuring exposure to volatile inorganic acids in workplace air. Part 2: Sampling capacity and breakthrough tests for sodium carbonate-impregnated filters. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2011; 8:642-651. [PMID: 21966996 DOI: 10.1080/15459624.2011.617250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In France, the MétroPol 009 method used to measure workplace exposure to inorganic acids, such as HF, HCl, and HNO3, consists of a closed-face cassette fitted with a prefilter to collect particles, and two sodium carbonate-impregnated filters to collect acid vapor. This method was compared with other European methods during the development of a three-part standard (ISO 21438) on the determination of inorganic acids in workplace air by ion chromatography. Results of this work, presented in a companion paper, led to a need to go deeper into the performance of the MétroPol 009 method regarding evaluation of the breakthrough of the acids, both alone and in mixtures, interference from particulate salts, the amount of sodium carbonate required to impregnate the sampling filter, the influence of sampler components, and so on. Results enabled improvements to be made to the sampling device with respect to the required amount of sodium carbonate to sample high HCl or HNO3 concentrations (500 μL of 5% Na2CO3 on each of two impregnated filters). In addition, a PVC-A filter used as a prefilter in a sampling device showed a propensity to retain HNO3 vapor so a PTFE filter was considered more suitable for use as a prefilter. Neither the material of the sampling cassette (polystyrene or polypropylene) nor the sampling flowrate (1 L/min or 2 L/min) influenced the performance of the sampling device, as a recovery of about 100% was achieved in all experiments for HNO3, HCl, and HF, as well as HNO3+HF and HNO3+HCl mixtures, over a wide range of concentrations. However, this work points to the possibility of interference between an acid and salts of other acids. For instance, interference can occur through interaction of HNO3 with chloride salts: the stronger the acid, the greater the interference. Methods based on impregnated filters are reliable for quantitative recovery of inorganic volatile acids in workplace atmosphere but are valuable only in the absence of interferents.
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Affiliation(s)
- Martine Demange
- Institut National de Recherche et de Sécurité (INRS), Vandoeuvre-les-Nancy, France
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Koehler KA, Anthony TR, Van Dyke M, Volckens J. Solid versus liquid particle sampling efficiency of three personal aerosol samplers when facing the wind. ACTA ACUST UNITED AC 2011; 56:194-206. [PMID: 21965462 DOI: 10.1093/annhyg/mer077] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The objective of this study was to examine the facing-the-wind sampling efficiency of three personal aerosol samplers as a function of particle phase (solid versus liquid). Samplers examined were the IOM, Button, and a prototype personal high-flow inhalable sampler head (PHISH). The prototype PHISH was designed to interface with the 37-mm closed-face cassette and provide an inhalable sample at 10 l min(-1) of flow. Increased flow rate increases the amount of mass collected during a typical work shift and helps to ensure that limits of detection are met, particularly for well-controlled but highly toxic species. Two PHISH prototypes were tested: one with a screened inlet and one with a single-pore open-face inlet. Personal aerosol samplers were tested on a bluff-body disc that was rotated along the facing-the-wind axis to reduce spatiotemporal variability associated with sampling supermicron aerosol in low-velocity wind tunnels. When compared to published data for facing-wind aspiration efficiency for a mouth-breathing mannequin, the IOM oversampled relative to mannequin facing-the-wind aspiration efficiency for all sizes and particle types (solid and liquid). The sampling efficiency of the Button sampler was closer to the mannequin facing-the-wind aspiration efficiency than the IOM for solid particles, but the screened inlet removed most liquid particles, resulting in a large underestimation compared to the mannequin facing-the-wind aspiration efficiency. The open-face PHISH results showed overestimation for solid particles and underestimation for liquid particles when compared to the mannequin facing-the-wind aspiration efficiency. Substantial (and statistically significant) differences in sampling efficiency were observed between liquid and solid particles, particularly for the Button and screened-PHISH, with a majority of aerosol mass depositing on the screened inlets of these samplers. Our results suggest that large droplets have low penetration efficiencies through screened inlets and that particle bounce, for solid particles, is an important determinant of aspiration and sampling efficiencies for samplers with screened inlets.
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Affiliation(s)
- Kirsten A Koehler
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523-1681, USA
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Lee T, Harper M, Slaven JE, Lee K, Rando RJ, Maples EH. Wood dust sampling: field evaluation of personal samplers when large particles are present. THE ANNALS OF OCCUPATIONAL HYGIENE 2011; 55:180-91. [PMID: 21036895 PMCID: PMC3037778 DOI: 10.1093/annhyg/meq075] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 08/30/2010] [Indexed: 11/29/2022]
Abstract
Recent recommendations for wood dust sampling include sampling according to the inhalable convention of International Organization for Standardization (ISO) 7708 (1995) Air quality--particle size fraction definitions for health-related sampling. However, a specific sampling device is not mandated, and while several samplers have laboratory performance approaching theoretical for an 'inhalable' sampler, the best choice of sampler for wood dust is not clear. A side-by-side field study was considered the most practical test of samplers as laboratory performance tests consider overall performance based on a wider range of particle sizes than are commonly encountered in the wood products industry. Seven companies in the wood products industry of the Southeast USA (MS, KY, AL, and WV) participated in this study. The products included hardwood flooring, engineered hardwood flooring, door skins, shutter blinds, kitchen cabinets, plywood, and veneer. The samplers selected were 37-mm closed-face cassette with ACCU-CAP™, Button, CIP10-I, GSP, and Institute of Occupational Medicine. Approximately 30 of each possible pairwise combination of samplers were collected as personal sample sets. Paired samplers of the same type were used to calculate environmental variance that was then used to determine the number of pairs of samples necessary to detect any difference at a specified level of confidence. Total valid sample number was 888 (444 valid pairs). The mass concentration of wood dust ranged from 0.02 to 195 mg m(-3). Geometric mean (geometric standard deviation) and arithmetic mean (standard deviation) of wood dust were 0.98 mg m(-3) (3.06) and 2.12 mg m(-3) (7.74), respectively. One percent of the samples exceeded 15 mg m(-3), 6% exceeded 5 mg m(-3), and 48% exceeded 1 mg m(-3). The number of collected pairs is generally appropriate to detect a 35% difference when outliers (negative mass loadings) are removed. Statistical evaluation of the nonsimilar sampler pair results produced a finding of no significant difference between any pairing of sampler type. A practical consideration for sampling in the USA is that the ACCU-CAP™ is similar to the sampler currently used by the Occupational Safety and Health Administration for purposes of demonstrating compliance with its permissible exposure limit for wood dust, which is the same as for Particles Not Otherwise Regulated, also known as inert dust or nuisance dust (Method PV2121).
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Affiliation(s)
- Taekhee Lee
- Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV 26505, USA.
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Automatic Sample Production by Depositing Solutions on Filters for the Organization of Proficiency Tests. ANNALS OF OCCUPATIONAL HYGIENE 2009; 54:247-54. [DOI: 10.1093/annhyg/mep089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Brisson MJ, Archuleta MM. The real issue with wall deposits in closed filter cassettes--what's the sample? JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2009; 6:783-788. [PMID: 19894181 DOI: 10.1080/15459620903261427] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The measurement of aerosol dusts has long been utilized to assess the exposure of workers to metals. Tools used to sample and measure aerosol dusts have gone through many transitions over the past century. In particular, there have been several different techniques used to sample for beryllium, not all of which might be expected to produce the same result. Today, beryllium samples are generally collected using filters housed in holders of several different designs, some of which are expected to produce a sample that mimics the human capacity for dust inhalation. The presence of dust on the interior walls of cassettes used to hold filters during metals sampling has been discussed in the literature for a number of metals, including beryllium, with widely varying data. It appears that even in the best designs, particulates can enter the sampling cassette and deposit on the interior walls rather than on the sampling medium. The causes are not well understood but are believed to include particle bounce, electrostatic forces, particle size, particle density, and airflow turbulence. Historically, the filter catch has been considered to be the sample, but the presence of wall deposits, and the potential that the filter catch is not representative of the exposure to the worker, puts that historical position into question. This leads to a fundamental question: What is the sample? This article reviews the background behind the issue, poses the above-mentioned question, and discusses options and a possible path forward for addressing that question.
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Affiliation(s)
- Michael J Brisson
- Savannah River Nuclear Solutions LLC, Aiken, South Carolina 29808, USA.
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Hendricks W, Stones F, Lillquist D. On wiping the interior walls of 37-mm closed-face cassettes: an OSHA perspective. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2009; 6:732-734. [PMID: 19894173 DOI: 10.1080/15459620903012028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
As early as 1976, Occupational Safety and Health Administration (OSHA) methods for analyzing metal samples collected using 37-mm polystyrene closed-face cassettes specified that any loose dust be transferred from the cassette to the digestion vessel, that the cassette be rinsed, and that, if necessary, the cassette be wiped out to help ensure that all particles that enter the cassette are included along with the filter as part of the sample for analysis. OSHA analytical methods for metal analysis were recently revised to explicitly require cassette wiping for all metal samples. This change was based on policy that any material entering the collection device constitutes part of the sample and on OSHA Salt Lake Technical Center research showing that invisible residue on the cassette walls can significantly contribute to the total sample results reported. OSHA procedures are consistent with guidance given in the NIOSH Manual of Analytical Methods. This guidance concludes that internal deposits in sampling cassettes should be included in the analysis and that one way to accomplish this would be to wipe or wash the internal surfaces of the cassette and include the material along with the filter for analysis.
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Virji MA, Woskie SR, Pepper LD. Task-based lead exposures and work site characteristics of bridge surface preparation and painting contractors. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2009; 6:99-112. [PMID: 19065390 DOI: 10.1080/15459620802615772] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
This study of bridge painters working for small contractors in Massachusetts investigated the causes of elevated blood lead levels and assessed their exposure to lead. Bridge work sites were evaluated for a 2-week period during which personal and area air samples and information on work site characteristics and lead abatement methods were gathered. Short-duration personal inhalable samples collected from 18 tasks had geometric means (GM) of 3 microg/m(3) to 7286 microg/m(3). Full-shift, time-weighted average (TWA) inhalable samples (>or=6 hours) collected from selected workers and work sites had GMs of 2 microg/m(3) to 15,704 microg/m(3); 80% of samples exceeded the permissible exposure limit (PEL) of 50 microg/m(3), on average by a factor of 30. Area inhalable samples collected from three locations ranged from 2 microg/m(3) to 40,866 microg/m(3) from inside the containment, 2 microg/m(3) to 471 microug/m(3) from a distance of <6 meters, and 2 microg/m(3) to 121 microg/m(3) from >6 meters from the containment. Seventy nine percent of the area samples from inside the containment exceeded the PEL on average by a factor of 140. Through observations of work site characteristics, opportunities for improving work methods were identified, particularly the institution of engineering controls (which were only occasionally present) and improvement in the design and construction of the containment structure. The high levels of airborne lead exposures indicate a potential for serious exposure hazard for workers and environmental contamination, which can be mitigated through administrative and engineering controls. Although these data were collected over 10 years ago, a 2005 regulatory review by the Occupational Safety and Health Administration (OSHA) of its lead in construction standard reported that elevated lead exposures and blood lead levels, high occurrence of noncompliance with the lead standard, and nonimplementation of newer technology especially among small painting firms employing <10 workers are still widespread. As a result, the findings of this study are still quite germane even a decade after the introduction of the new OSHA standard.
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Affiliation(s)
- M Abbas Virji
- Department of Work Environment, University of Massachusetts Lowell, Lowell, Massachusetts, USA.
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Harper M, Lee EG, Doorn SS, Hammond O. Differentiating non-asbestiform amphibole and amphibole asbestos by size characteristics. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2008; 5:761-770. [PMID: 18828048 DOI: 10.1080/15459620802462290] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Mining or processing asbestos minerals can liberate isolated fibers or fiber bundles regulated as airborne asbestos fibers. Coarsely crystalline amphibole minerals are more common than asbestos in many geologic environments, and disturbance can result in the release of prismatic or acicular single crystals or cleavage fragments resembling asbestos fibers or fiber bundles but that are not currently regulated as asbestos. Bulk samples of six coarsely crystalline amphiboles and their five asbestos analogs were processed to maximize the number of particles meeting the criterion for counting under the current U.S. National Institute for Occupational Safety and Health Method 7400 "A" counting rules (> 5 microm long with an aspect ratio >or= 3:1) and also within the respirable width range, i.e. < 3 microm width. The length distributions of the particles produced showed substantial overlap between cleavage fragments and asbestos fibers. Available data sets generally confirmed the relevance of the size distributions of particles generated from reference materials to airborne particles. The length criterion in the current ASTM International standard D7200-06 causes a large proportion (e.g., 40% grunerite and 39% tremolite) of the non-asbestiform particles to be considered potential asbestos. An alternative procedure may be to use a distinction based on width alone as some, but not the majority of, cleavage fragments were thinner than 1 microm (e.g., 9% of actinolite and 20% of grunerite particles), and not many amphibole asbestos particles were wider (e.g., 5% of crocidolite and 18% of amosite particles). This proposal would need further testing. This research should not be considered as addressing any controversy with regard to the toxicity of non-asbestiform amphibole particles of similar dimensions to asbestos particles.
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Affiliation(s)
- Martin Harper
- Health Effects Laboratory Division, Exposure Assessment Branch, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA.
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Harper M. 10th Anniversary Critical Review: Naturally occurring asbestos. ACTA ACUST UNITED AC 2008; 10:1394-408. [PMID: 19037480 DOI: 10.1039/b810541n] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Asbestos is a naturally occurring mineral in the Earth's crust, and it is not confined to the historic and current asbestos mining areas, but rather quite commonly encountered in certain geological environments across the world. That diseases developed as a result of high exposures suffered by miners and asbestos products workers is incontrovertible. In addition, asbestos contamination as a result of past production and use is considered a serious issue where remediation is normally required. However, the risk to health of living on soil and rock where asbestos is encountered as a result of the natural occurrence of small quantities of asbestos minerals is less obvious. The picture becomes even less clear when the minerals are subject to intensive investigation, since our generally accepted definitions of asbestos are themselves put to the test. The discovery of asbestos or related minerals has consequences beyond any immediate risks to health, including profound effects on the value of and ability to use or enjoy property. This review examines the issue of naturally occurring asbestos (NOA) as it has developed in the United States of America and elsewhere, including some superficial insights into the reactions of communities to the presence of NOA. These responses to 'contamination' by nature deserve further in-depth study.
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Affiliation(s)
- Martin Harper
- Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., Morgantown, WV 26505, USA
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Bartley DL, Slaven JE, Rose MC, Andrew ME, Harper M. Uncertainty determination for nondestructive chemical analytical methods using field data and application to XRF analysis for lead. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HYGIENE 2007; 4:931-942. [PMID: 17957563 DOI: 10.1080/15459620701712712] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Air sampling and analytical methods are developed to provide a basis for decision making. They are evaluated in the laboratory against prescribed fitness-for-use criteria even though laboratory validation does not take into account all possible sources of uncertainty in field application. Field evaluation would be preferable but is complicated by the lack of controlled conditions, which limits the ability to compare analytical methods and to recognize outliers and assess variance homogeneity across the range of interest. The specific situation of evaluating nondestructive field analytical methods against their reference laboratory equivalent is considered here, since the difficulty of providing replicates is obviated in this case. A portable X-ray fluorescence (XRF) analyzer was used to determine the lead content of air filter samples from several workplaces where lead is used or is a contaminant of the process material. The portable XRF method has the advantage of allowing for faster decisions compared with the alternative of submitting the air samples to an off-site laboratory for analysis. Since the XRF method is nondestructive, the same air samples were also subjected to the reference laboratory-based method of analysis. Two statistical approaches were developed specifically to deal with non-normal elements of the data in evaluating the results. The ISO GUM method identifies outliers and then calculates an accuracy range about the true concentration for the remainder of the data. This coverage is then adjusted to account for the rate of outlier occurrence. The bootstrap procedure uses a large number of computer-generated data points that are sampled, with replacement, from the original set including outliers to determine the coverage. No significant difference is seen between the two statistical approaches. Both approaches result in similar coverage and support the adoption of method acceptance criteria specific to field evaluation (a symmetric accuracy range of 35%). The portable XRF analyzer met this criterion when used with several different sampling methods and thus could be used as a method for routine evaluation of compliance with lead limit values. As the method is nondestructive, further analysis of air samples with analytical results near decision points is possible.
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Affiliation(s)
- David L Bartley
- National Institute for Occupational Safety and Health, Cincinnati, OH, USA
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Harper M, Pacolay B, Hintz P, Bartley DL, Slaven JE, Andrew ME. Portable XRF analysis of occupational air filter samples from different workplaces using different samplers: final results, summary and conclusions. ACTA ACUST UNITED AC 2007; 9:1263-70. [PMID: 17968454 DOI: 10.1039/b710591f] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper concludes a five-year program on research into the use of a portable X-ray fluorescence (XRF) analyzer for analyzing lead in air sampling filters from different industrial environments, including mining, manufacturing and recycling. The results from four of these environments have already been reported. The results from two additional metal processes are presented here. At both of these sites, lead was a minor component of the total airborne metals and interferences from other elements were minimal. Nevertheless, only results from the three sites where lead was the most abundant metal were used in the overall calculation of method accuracy. The XRF analyzer was used to interrogate the filters, which were then subjected to acid digestion and analysis by inductively-coupled plasma optical-emission spectroscopy (ICP-OES). The filter samples were collected using different filter-holders or "samplers" where the size (diameter), depth and homogeneity of aerosol deposit varied from sampler to sampler. The aerosol collection efficiencies of the samplers were expected to differ, especially for larger particles. The distribution of particles once having entered the sampler was also expected to differ between samplers. Samplers were paired to allow the between-sampler variability to be addressed, and, in some cases, internal sampler wall deposits were evaluated and compared to the filter catch. It was found, rather surprisingly, that analysis of the filter deposits (by ICP-OES) of all the samplers gave equivalent results. It was also found that deposits on some of the sampler walls, which in some protocols are considered part of the sample, could be significant in comparison to the filter deposit. If it is concluded that wall-deposits should be analyzed, then XRF analysis of the filter can only give a minimum estimate of the concentration. Techniques for the statistical analysis of field data were also developed as part of this program and have been reported elsewhere. The results, based on data from the three workplaces where lead was the major element present in the samples, are summarized here. A limit of detection and a limit of quantitation are provided. Analysis of some samples using a second analyzer with a different X-ray source technology indicated reasonable agreement for some metals (but this was not evaluated for lead). Provided it is only necessary to analyze the filters, most personal samplers will provide acceptable results when used with portable XRF analysis for lead around applicable limit values.
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Affiliation(s)
- Martin Harper
- Exposure Assessment Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., MS-3030, Morgantown, WV 26505, USA
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