Last data update: Sep 23, 2024. (Total: 47723 publications since 2009)
Records 1-8 (of 8 Records) |
Query Trace: Olsen LD [original query] |
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Personal breathing zone exposures among hot-mix asphalt paving workers; preliminary analysis for trends and analysis of work practices that resulted in the highest exposure concentrations
Osborn LV , Snawder JE , Kriech AJ , Cavallari JM , McClean MD , Herrick RF , Blackburn GR , Olsen LD . J Occup Environ Hyg 2013 10 (12) 663-73 An exposure assessment of hot-mix asphalt (HMA) paving workers was conducted to determine which of four exposure scenarios impacted worker exposure and dose. Goals of this report are to present the personal-breathing zone (PBZ) data, discuss the impact of substituting the releasing/cleaning agent, and discuss work practices that resulted in the highest exposure concentration for each analyte. One-hundred-seven PBZ samples were collected from HMA paving workers on days when diesel oil was used as a releasing/cleaning agent. An additional 36 PBZ samples were collected on days when B-100 (100% biodiesel, containing no petroleum-derived products) was used as a substitute releasing/cleaning agent. Twenty-four PBZ samples were collected from a reference group of concrete workers, who also worked in outdoor construction but had no exposure to asphalt emissions. Background and field blank samples were also collected daily. Total particulates and the benzene soluble fraction were determined gravimetrically. Total organic matter was determined using gas chromatography (GC) with flame ionization detection and provided qualitative information about other exposure sources contributing to worker exposure besides asphalt emissions. Thirty-three individual polycyclic aromatic compounds (PACs) were determined using GC with time-of-flight mass spectrometry; results were presented as either the concentration of an individual PAC or a summation of the individual PACs containing either 2- to 3-rings or 4- to 6-rings. Samples were also screened for PACs containing 4- to 6-rings using fluorescence spectroscopy. Arithmetic means, medians, and box plots of the PBZ data were used to evaluate trends in the data. Box plots illustrating the diesel oil results were more variable than the B-100. Also, the highest diesel oil results were much higher in concentration than the highest B-100 results. An analysis of the highest exposure results and field notes revealed a probable association between these exposures and the use of diesel oil, use of a diesel-powered screed, elevated HMA paving application temperatures, lubricating and working on broken-down equipment, and operation of a broom machine. |
Using urinary biomarkers of polycyclic aromatic compound exposure to guide exposure-reduction strategies among asphalt paving workers
McClean MD , Osborn LV , Snawder JE , Olsen LD , Kriech AJ , Sjodin A , Li Z , Smith JP , Sammons DL , Herrick RF , Cavallari JM . Ann Occup Hyg 2012 56 (9) 1013-24 INTRODUCTION: Paving workers are exposed to polycyclic aromatic compounds (PACs) while working with hot-mix asphalt (HMA). Further characterization of the source and route of these exposures is necessary to guide exposure-reduction strategies. METHODS: Personal air (n = 144), hand-wash (n = 144), and urine (n = 480) samples were collected from 12 paving workers over 3 workdays during 4 workweeks. Urine samples were collected at preshift, postshift, and bedtime and analyzed for 10 hydroxylated PACs (1-OH-pyrene; 1-, 2-, 3-, 4-OH-phenanthrene; 1-, 2-OH-naphthalene; 2-, 3-, 9-OH-fluorene) by an immunochemical quantification of PACs (I-PACs). The air and hand-wash samples were analyzed for the parent compounds corresponding to the urinary analytes. Using a crossover study design, each of the 4 weeks represented a different exposure scenario: a baseline week (normal conditions), a dermal protection week (protective clothing), a powered air-purifying respirator (PAPR) week, and a biodiesel substitution week (100% biodiesel provided to replace the diesel oil normally used by workers to clean tools and equipment). The urinary analytes were analyzed using linear mixed-effects models. RESULTS: Postshift and bedtime concentrations were significantly higher than preshift concentrations for most urinary biomarkers. Compared with baseline, urinary analytes were reduced during the dermal protection (29% for 1-OH-pyrene, 15% for I-PACs), the PAPR (24% for 1-OH-pyrene, 15% for I-PACs), and the biodiesel substitution (15% for 1-OH-pyrene) weeks. The effect of PACs in air was different by exposure scenario (biodiesel substitution > dermal protection > PAPR and baseline) and was still a significant predictor of most urinary analytes during the week of PAPR use, suggesting that PACs in air were dermally absorbed. The application temperature of HMA was positively associated with urinary measures, such that an increase from the lowest application temperature (121 degrees C) to the highest (154 degrees C) was associated with a 72% increase in SigmaOH-fluorene and 1-OH-pyrene and an 82% increase in SigmaOH-phenanthrene. Though PACs in hand-wash samples were not predictors of urinary analytes, the effects observed during the PAPR scenario and the week of increased dermal protection provide evidence of dermal absorption. CONCLUSIONS: Our results provide evidence that PACs in air are dermally absorbed. Reducing the application temperature of asphalt mix appears to be a promising strategy for reducing PAC exposure among paving workers. Additional reductions may be achieved by requiring increased dermal coverage of workers and by substituting biodiesel for diesel oil as a cleaning agent. |
Predictors of airborne exposures to polycyclic aromatic compounds and total organic matter among hot-mix asphalt paving workers and influence of work conditions and practices
Cavallari JM , Osborn LV , Snawder JE , Kriech AJ , Olsen LD , Herrick RF , McClean MD . Ann Occup Hyg 2012 56 (2) 138-147 OBJECTIVES: We evaluated personal airborne exposures to polycyclic aromatic compounds (PACs) and total organic matter (TOM) among hot-mix asphalt (HMA) paving workers. The primary objectives of this study were to identify predictors of airborne PAC exposures, identify PAC exposure sources, and characterize how work practices may affect personal airborne exposure to PACs. METHODS: Four workers were recruited from each of three asphalt paving crews (12 workers) and were monitored for three consecutive days over 4 weeks for a total of 12 sampling days per worker (144 worker-days). Three sampling weeks were conducted while maintaining standard working conditions with regard to airborne exposures. The fourth week included the substitution of biodiesel for diesel oil used to clean tools and equipment. Linear mixed-effects models were used to evaluate predictors of airborne exposures including weather parameters (air temperature, wind speed, and relative humidity), worksite conditions (HMA application temperature, work rate, asphalt grade, and biodiesel use), and personal factors (minutes sampled, minutes of downtime, and smoking status). RESULTS: Concentrations of the 33 individual PACs measured in personal air samples were generally below detection limits under all conditions with the exception of fluorene [geometric mean (GM)=65 ng m-3], naphthalene (GM=833 ng m-3), phenanthrene (GM=385 ng m-3), and pyrene (GM=57 ng m-3). The summary measures of TOM (GM=864 mcg m-3) and four- to six-ring PAC (GM=0.13 mcg m-3) were detected in the majority of air samples. Although task was not a predictor of airborne exposures, job site characteristics such as HMA application temperature were found to significantly (P≤0.001) affect summary and individual PAC exposures. Based on the results of multivariate linear mixed-effects models, substituting biodiesel for diesel oil as a cleaning agent was associated with significant (P≤0.01) reductions in TOM, four- to six-ring PACs, and naphthalene and pyrene concentrations that ranged from 31 to 56%. Using multivariate linear mixed-effects models under standard conditions, reducing the application temperature of HMA from 149°C (300°F) to 127°C (260°F) could be expected to reduce airborne exposures by 42-82%, varying by analyte. CONCLUSIONS: Promising strategies for reducing airborne exposures to PACs among HMA paving workers include substituting biodiesel for diesel oil as a cleaning agent and decreasing the HMA application temperature. |
Predictors of dermal exposures to polycyclic aromatic compounds among hot-mix asphalt paving workers
Cavallari JM , Osborn LV , Snawder JE , Kriech AJ , Olsen LD , Herrick RF , McClean MD . Ann Occup Hyg 2012 56 (2) 125-137 OBJECTIVES: The primary objective of this study was to identify the source and work practices that affect dermal exposure to polycyclic aromatic compounds (PACs) among hot-mix asphalt (HMA) paving workers. METHODS: Four workers were recruited from each of three asphalt paving crews (12 workers) and were monitored for three consecutive days over 4 weeks for a total of 12 sampling days per worker (144 worker days). Two sampling weeks were conducted under standard conditions for dermal exposures. The third week included the substitution of biodiesel for diesel oil used to clean tools and equipment and the fourth week included dermal protection through the use of gloves, hat and neck cloth, clean pants, and long-sleeved shirts. Dermal exposure to PACs was quantified using two methods: a passive organic dermal (POD) sampler specifically developed for this study and a sunflower oil hand wash technique. Linear mixed-effects models were used to evaluate predictors of PAC exposures. RESULTS: Dermal exposures measured under all conditions via POD and hand wash were low with most samples for each analyte being below the limit of the detection with the exception of phenanthrene and pyrene. The geometric mean (GM) concentrations of phenanthrene were 0.69 ng cm-2 on the polypropylene layer of the POD sampler and 1.37 ng cm-2 in the hand wash sample. The GM concentrations of pyrene were 0.30 ng cm-2 on the polypropylene layer of the POD sampler and 0.29 ng cm-2 in the hand wash sample. Both the biodiesel substitution and dermal protection scenarios were effective in reducing dermal exposures. Based on the results of multivariate linear mixed-effects models, increasing frequency of glove use was associated with significant (P<0.0001) reductions for hand wash and POD phenanthrene and pyrene concentrations; percent reductions ranged from 40 to 90%. Similar reductions in hand wash concentrations of phenanthrene (P=0.01) and pyrene (P=0.003) were observed when biodiesel was substituted for diesel oil as a cleaning agent, although reductions were not significant for the POD sampler data. Although task was not a predictor of dermal exposure, job site characteristics such as HMA application temperature, asphalt grade, and asphalt application rate (tons per hour) were found to significantly affect exposure. Predictive models suggest that the combined effect of substituting biodiesel for diesel oil as a cleaning agent, frequent glove use, and reducing the HMA application temperature from 149°C (300°F) to 127°C (260°F) may reduce dermal exposures by 76-86%, varying by analyte and assessment method. CONCLUSIONS: Promising strategies for reducing dermal exposure to PACs among asphalt paving workers include requiring the use of dermal coverage (e.g. wearing gloves and/or long sleeves), substituting biodiesel for diesel oil as a cleaning agent, and decreasing the HMA application temperature. |
Study design and methods to investigate inhalation and dermal exposure to polycyclic aromatic compounds and urinary metabolites from asphalt paving workers: research conducted through partnership
Kriech AJ , Osborn LV , Snawder JE , Olsen LD , Herrick RF , Cavallari Jr M , McClean MD , Blackburn GR . Polycycl Aromat Compd 2011 31 (4) 243-269 Innovations in science may require crossing traditional boundaries between industry, unions, government, and academia. While such collaborations have the potential to be highly beneficial and productive, opportunities for such collaborations are often missed due to some of the inherent challenges. This collaborative research effort demonstrates an example of how a successful partnership can optimize the ability to answer complicated scientific questions. Specifically, these researchers collaborated to investigate inhalation and dermal exposures to polycyclic aromatic compounds and related urinary metabolites in hot-mix asphalt paving workers. Reported here are details of the partnership process used to create the study design, the review processes, and details of the analytical methodologies employed to help attain the study goals related to the identification of the nature, source, pathway, and biological relevance of exposure during hot-mix asphalt paving operations. The actual results of the study are being prepared for future publications. |
Pilot study for the investigation of personal breathing zone and dermal exposure using levels of polycyclic aromatic compounds (PAC) and PAC metabolites in the urine of hot-mix asphalt paving workers
Osborn LV , Snawder JE , Olsen LD , Kriech AJ , Cavallari JM , Herrick RF , McClean MD , Blackburn GR . Polycycl Aromat Compd 2011 31 (4) 173-200 As part of the design of a comprehensive study of hot-mix asphalt paving workers to investigate the relative contribution of personal breathing zone and dermal exposures to polycyclic aromatic compounds, a two-part pilot (Phase I) was performed. The pilot study was important to examine the sources of exposure, the chemical nature of these exposures, and their biological relevance through analysis of biomarkers in urine. Existing, modified, and new sampling and analytical techniques, used in concert with each other, were evaluated to help design the full-scale study (Phase II). Although subject numbers were limited, the air, dermal, and urine sampling, analytical results and field experience provided valuable guidance in the design and implementation of Phase II. An overview of methods used and developed from this study is provided. More details of those methods selected for Phase II are presented in complementary manuscripts. Results of Phase II will be the subject of future publications. |
Assessment of exposure to PACs in asphalt workers: measurement of urinary PACs and their metabolites with an ELISA kit
Smith JP , Biagini RE , Johnson BC , Olsen LD , Mackenzie BA , Robertson SA , Sammons DL , Striley CAF , Walker CV , Snawder JE . Polycycl Aromat Compd 2011 31 (4) 270-285 An enzyme-linked immunosorbent assay (ELISA) kit made for determination of polycyclic aromatic compounds (PACs) in water was adapted for measuring PACs and their metabolites in urine. This method was then applied to a pilot asphalt worker PAC exposure study. Currently, liquid-liquid extraction with gas chromatography/isotope dilution high-resolution mass spectrometry (GC/HRMS) is the preferred method to determine urinary PAC metabolites. Although sensitive and specific, GC/HRMS is time consuming and costly. The ELISA method had a range from 14-720 ng/ml 1-hydroxypyrene equivalents with a lower limit of detection (LOD) of 14 ng/ml urine. ELISA and GC/HRMS PAC metabolite measurements had a statistically significant correlation and the PAC ELISA results were indicative of potential asphalt exposure. PAC ELISA is promising as a more rapid and less costly routine method for determining worker exposure to PACs in asphalt emissions. |
Development of a 5-layer passive organic dermal (POD) sampler
Olsen LD , Snawder JE , Kriech AJ , Osborn LV . Polycycl Aromat Compd 2011 31 (3) 154-172 A 5-layer passive organic dermal sampler was developed to allow the collection, retention, and recovery of a variety of organic compound classes simultaneously. The 5-layers, from outside in, consisted of polypropylene, polyurethane foam, C-18 solid-phase extraction disk, ethylene tetrafluoroethylene, and activated carbon cloth. The layers were enclosed in aluminum foil and placed in a muslin envelope that had a 40.0 mm diameter opening. Ten samplers were spiked separately with three levels of diesel oil, a 50/50 diesel oil/asphalt mixture, and asphalt binder. For the diesel oil spikes, recoveries were 69.9, 71.3, 88.8, and 95.4% for 10, 10, 50, and 100 mg of diesel oil. For the 50/50 mixture, recoveries were 105.4, 92.8, and 92.0% for 10, 50, and 100 mg of the 50/50 mixture. For the asphalt binder spikes, recoveries were 104.7, 100.2, and 100.1% for 10, 50, and 100 mg of asphalt binder. For repeatability assessment, 7 samplers were spiked with 50 mg of the 50/50 mixture and recoveries averaged 92.6% (standard deviation 8.6). Samplers tested on asphalt paving workers proved functional, comfortable, flexible, and durable. |
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