F. Golbabaei, A. Tirgar, S. Shahtaheri, K. Nourijelyani, Tehran University of Medical Sciences, Tehran, Iran (Islamic Republic of); M. Ganjali, University of Tehran, Tehran, Iran (Islamic Republic of); F. Akbar-Khanzadeh, Medical University of Ohio, Toledo, OH.
The process of electroplating is a leading source of airborne chromium pollution, and a majority of workers in electroplating facilities are exposed to hexavalent chromium (Cr+6) mist. Cr+6 is relatively unstable and is likely to be reduced to its trivalent (Cr+3) state, potentially causing unacceptable sampling errors. To account for this reduction during sampling and sample storage and analysis, appropriate sampling parameters for Cr+6 must be selected. Therefore, this study examined some major parameters of Cr+6 mist sampling during electroplating operations. A chromium electroplating bath producing homogenous mist generated Cr+6 mist in a laboratory setting and a total of 48 Cr+6 mist samples were collected using the U.S. National Institute for Occupational Safety and Health method 7600. The results of the sampling campaign revealed that Cr+6 concentration was higher: (1) for sampling by closed-face filter cassettes than for sampling by open-face filter cassettes (P<0.01); (2) for samples collected at 35 cm above the electroplating solution surface than for samples collected at 50 cm (P< 0.001); (3) for sampling duration of 30 minutes than for sampling duration of 180 minutes (P< 0.001); and, (4) for samples extracted immediately after sampling than for samples with delayed extraction (24 hours after sampling) (P< 0.001). It is concluded that the accuracy of Cr+6 mist sampling in electroplating shops is enhanced when: (1) a closed-face filter cassette is used to prevent liquid splash contamination; (2) the sampling height is suitable as determined by further research with regard to mist generation factors such as bath temperature and the liquid agitation rate; (3) the sampling duration is short—approximately 30 minutes; and, (4) the extraction of the Cr+6 sample is performed as soon as the sampling is completed.
A. Siert, S. Woods, Xcel Energy, Denver, CO; K. Blehm, Colorado State University, Fort Collins, CO; D. Dechant, Marshall University, Huntington, WV.
Hexavalent chromium (CrVI) exposure assessment was conducted over 9 years in 16 electric generation power plants located in three states. The purpose of this study was to better characterize worker exposures in various processes and job tasks and to identify variables that determined exposure. Processes with significant exposures included welding and thermal cutting on chromium alloy steels or chromate painted steel, abrasive removal of chromate paint prior to welding or thermal cutting, surface preparation for repainting on chromate painted surfaces, and coal fly ash removal. The major exposure determinant in welding was process used and chromium content of the consumable, whereas the major determinant in thermal cutting was base metal. CrVI was found to be present, more often than not, in surface coatings intended for corrosion protection. CrVI was also found in coal fly ash where exposures varied according to coal rank as evidenced by air monitoring and bulk fly ash samples. CrVI exposures, grouped by process/task/material, were ranked and some exposure reduction options via substitution were identified. Exposure reduction controls that were implemented to achieve regulatory compliance under the OSHA Air Contaminants Standard CrVI PEL were contrasted with controls and requirements that will need to be implemented under the proposed OSHA CrVI Standard. Recommendations for air monitoring, exposure assessment methods, and related techniques for the various processes are identified in this work. The current state of the industry including expected changes are discussed, with the largest effects anticipated to be in welding and thermal cutting.
D. Friedman, SAIF Corporation, Salem, OR.
A combination of area and personal air samples for elemental carbon, benzene, and total hydrocarbons as toluene was collected on two different sets of firefighters using different diesel exhaust control technologies. One group rode a fire engine that was equipped with diesel particulate filters, and the other group rode an engine that was housed in a fire station with a stationary diesel exhaust collection ventilation system. Each group conducted three simulated medical emergency response runs during the monitoring period. Medical response calls, rather than fire response calls, constitute the majority of this fire department’s emergency response runs. The sample results indicated that regardless of the diesel exhaust control technology used, exposures were minimal when using elemental carbon, benzene, and total hydrocarbons as toluene as surrogates for exposure.
F. Boelter, M. Weeks, C. Simmons, Boelter & Yates, Inc., Park Ridge, IL.
Asbestos was used historically in a number of components still found in railroad equipment today. These components include friction devices, wire and cable, insulators, and mounting boards. Most of these components are classifiable as encapsulated nonfriable materials while some are not. One challenge facing an operating railroad is not being able to visually distinguish an old asbestos containing component from a newer nonasbestos containing component. A series of negative exposure assessments were performed while experienced signal maintainers performed their normal activities. These activities included adjusting and maintaining switch machine clutches, cutting and splicing cable, handling “bakelite” terminal strips, and rewiring motor mounting boards. Bulk samples confirmed the materials were asbestos containing. Both 8-hr TWA personal samples as well as 30-min STEL personal samples were collected during a reasonable maximum number of events and worst case scenarios. Analyses were performed in accordance with OSHA ID-160 for total fibers and NIOSH 7402 for asbestos fibers. In all the scenarios evaluated, the data showed the airborne concentrations of asbestos fibers were either nonquantifiable or significantly below the 8-hour Occupational Safety and Health Administration permissible exposure limit of 0.1 f/cc and the 30-minute excursion limit of 1 f/cc.
L. Berman, E. Indacochea, L. Conroy, P. Scheff, S. Erdal, University of Illinois at Chicago, Chicago, IL.
To understand welding fume exposures related to specific process and material combinations under isolated field conditions, three artist welders who employed shielded metal arc welding on stainless steel (SMAW/SS) and mixed mild steel (SMAW/MS) and metal inert gas welding on mild steel (MIG/MS) were monitored in their breathing zone. Exposures to respirable and elemental components of fume were measured under both field and laboratory (exposure chamber) conditions. The field-based exposure concentrations for SMAW/SS ranged from 0.53–7.71 mg/m3. The exposure concentrations for SMAW/MS ranged from 0.34–0.73 mg/m3 and from 0.58–3.17 mg/m3, under two different ventilation conditions. The MIG/MS exposure concentrations ranged from 0.20–0.53 mg/m3. The elements comprising the greatest percentage of field-collected SMAW/SS metal fume mass were: Fe (32%), Mg (31%), K (20%), Cr (14%), Mn (13%), Ni (8%), and Ti (6%), whereas the primary chamber-collected fume elements were Fe (22%), Mn (22%), Cr (20%), K (19%), and Ti (10%). The elements comprising the greatest fraction of field-collected SMAW/MS metal fume mass, collected under the two ventilation conditions, respectively, were: Fe (80% and 70%), K (5% and 8%) Mn (5% and 5%), Na (4% and 8%), Ti (1% and 0.6%), and Zn (1% and 2%), whereas chamber-collected fume elements were Fe (70%), K (15%), Mn (9%), Na (2%), and Zn (2%). The primary field-collected MIG/MS elements were: Fe (74%), Mn (10%), and Ni (2%), whereas chamber-collected fume elements were: Fe (65%), Mn (24%), Zn (7%), Cu (3%), and Ni (2%). The field samples incorporated welding, cutting, and often grinding activities, whereas the chamber samples were “welding-only.” The differences between field- and chamber-collected samples demonstrate the importance of recognizing welding-related activities as contributors to respirable fume exposure, which is an important consideration for industrial hygiene monitoring and compliance studies.
D. Brown, C. Harvey, Eastern Kentucky University, Richmond, KY.
The purpose of this presentation is to report on the methods employed by Eastern Kentucky University to develop survey instruments that can be used to predict individuals who will be satisfied with a career in environmental health science (EHS) or industrial hygiene (IH). Between January and February 2003, a study was conceived and two survey instruments developed, one quantitative and one qualitative. The qualitative survey was designed, based on an approach known as “biographical data” or biodata, founded on the assumption that the best predictor of future behavior is past behavior. Survey items included demographic questions; a measure of “satisfaction with your major;” “satisfaction with your classes;” and a 50-item personality measure that assessed the traits of extraversion, conscientiousness, emotional stability, agreeableness, and openness to experience. Items for the qualitative survey were generated using the career history approach. Specifically, the goal of the career history approach, applied to environmental health science, was to assess past life experiences identified by subject matter experts as possibly relevant to satisfaction with a career in environmental health science or industrial hygiene. This method generated a qualitative survey consisting of 15 open-ended questions to be used as an interview guide. Together, both surveys were administered to segments of 193 undergraduate students, divided into three arms. It is anticipated that the outcome of the ability to predict who will be a good candidate to engage in EHS or IH is threefold: (1) it will allow for a more well-adjusted student, in that the student will have immediately found a profession that suits their needs; (2) will assist higher education institutions to recruit such candidates and can be disseminated to other IH departments; and (3) will allow for better targeting of recruitment efforts of future IH students in a time of scare resources.
D. Brown, C. Harvey, Eastern Kentucky University, Richmond, KY.
The number of students enrolled in industrial hygiene programs nationwide is down. In order to improve the future of industrial hygiene, we as a profession must ensure that qualified individuals are available to fill vacancies.
The purpose of this presentation is to report on one of the methods employed by Eastern Kentucky University’s (EKU) Department of Environmental Health Science to recruit students. The university is considered the benchmark program in the United States and is also the biggest program. EKU developed a survey instruments that can be used to predict individuals who will be satisfied with a career in environmental health science (EHS) or industrial hygiene (IH). The survey is 35 questions long and is self-scoring. The questionnaire was developed and validated from approximately 300 student responses. The correlation between final instrument scores and satisfaction with one’s major was very high for EHS majors (r=.509), but weak for non-EHS majors (r=.137). Furthermore, EHS majors scored significantly higher on the measure than non-EHS majors. Thus, we conclude that the initial version of the instrument is valid and has potential as a career guidance tool to identify students who would be satisfied and successful majoring in environmental health science or industrial hygiene.
B. Pathak, CCOHS, Hamilton, ON, Canada; R. Cockerline, Canadian Centre for Occupational Health and Safety, Hamilton, ON, Canada.
We will present lessons learned over two decades of communicating scientific knowledge to workers, employers, and governments in a scientifically accurate, nontechnical, and plain language. In general, the main focus of the occupational health and safety research is to establish link between the occupational exposures and the risk of illnesses among exposed workers. In many instances, scientific studies indicate adverse health effects, but the results are inconclusive causing a widespread concern in exposed workers and their families. As health and safety professionals, it is our duty to communicate health risk information, in a timely manner, to workplaces where it matters. Timely communication of scientific results helps workplaces in developing and implementing appropriate preventive measures to deal with “real world” situations. Results presented in this paper are based on the analysis of the Inquiries Database of the Canadian Centre for Occupational Health and Safety. Using the examples of some popular health and safety concerns, we will illustrate the nature of information needs and gaps in scientific knowledge encountered in meeting these information needs.
Y. Dong-Lee, Korea Occupational Safety and Health Agency, Incheon, Republic of Korea.
To prevent occupational disease from treating chemical material in the workplace, the Korea government changed the Industrial Safety and Health Act in 1995 and has been implementing MSDS system since July 1996. On August 1, 2000, the application of this system was extended to companies hiring fewer than five employees. This system offers workers information on hazardous chemicals through labeling and training so that the workers can protect themselves from accidents.This job involves the investigation of related law in Korea and abroad, the scope of application of the MSDS system and which material should be applied, how to make MSDS, how to use MSDS information offered by the Korea Occupational Safety and Health Agency, and etc. From this study, we can understand the MSDS system in Korea and find out how to make it better in the future.
H. Beaulieu, Industrial Hygiene Resources, Boise, ID; A. Siert, S. Woods, Xcel Energy, Denver, CO.
An exposure assessment was performed for maintenance workers of Colorado coal-fired electric power plants. This assessment was focused on air contaminants encountered by workers when disturbing “fly ash,” the light particulate matter that accumulates in the air pollution control devices after months or years of burning coal. The purpose of this work was to better characterize the worker exposures in the various job tasks of working around this fly ash. Maintenance and cleaning of baghouse systems was performed at six of the power generating stations; cleaning electrostatic precipitators (ESPs) was performed at another station (two ESP units). In the stations equipped with baghouse air pollution control devices, maintenance worker exposures were evaluated during the following operations: filter bag removal, cleanup, and new filter bag installation. Operations evaluated in the station equipped with ESPs included shoveling fly ash from shelves for one type of ESP, and erection of scaffolding and wash down for the other type of ESP. Ash silo operator and ash hauler exposures were also evaluated at three power plants. The operations of cleaning these pollution control devices are extremely dusty. Workers with protection were routinely exposed to fly ash air contaminants in excess of occupational exposure limits, including respirable crystalline silica (quartz), total dust, and numerous metals, including (hexavalent) chromium and arsenic. Differences in worker exposures were described for the coal type burned (bituminous, and sub-bituminous), and unique work practices.
Posted May 30, 2006