Dennis Zaebst

QUANTITATIVE DETERMINATION OF TRUCKING INDUSTRY WORKERS' EXPOSURES TO DIESEL EXHAUST PARTICLES

As part of a case-control mortality study of trucking industry workers, exposures to diesel aerosol were measured among the four major presumably exposed job groups (road drivers, local drivers, dock workers, and mechanics) in the industry. Eight industrial hygiene surveys were conducted during both warm and cold weather at eight U.S. terminals and truck repair shops. A single-stage personal impactor was used to sample submicrometer-sized diesel particles on quartz fiber filters. Laboratory and field studies demonstrated that the elemental carbon content of the particles is a useful and practical marker of exposure to vehicular diesel exhaust. A thermal-optical analysis technique was used to determine the concentration of elemental carbon in the filter samples. Overall geometric mean exposures to submicrometer-sized elemental carbon ranged from 3.8 micrograms/m3 in road (long distance) drivers (N = 72) to 13.8 micrograms/m3 in dock workers (N = 75). Geometric mean background area concentrations, measured in the same cities where workers were sampled, were 2.5 micrograms/m3 on major highways (N = 21) and 1.1 micrograms/m3 in residential areas (N = 23). A factorial analysis of variance indicated that exposures in two job groups, dock workers (particularly those exposed primarily via diesel forklift trucks, introduced relatively recently) and mechanics (working in poorly ventilated shops during cold weather), were significantly higher than background concentrations and were significantly higher than the exposures in the local and road drivers. The exposures of the truck drivers could not be distinguished from background highway concentrations but were significantly higher than background concentrations in residential areas.

Exposure Assessment for a Study of Workers Exposed to Acrylonitrile. III: Evaluation of Exposure Assessment Methods

Abstract Retrospective exposure assessment in epidemiologic studies is dependent on the availability of historical monitoring results, yet rarely are there sufficient results to rely upon them exclusively. An approach is described that has a formal structure for developing exposure estimates for an epidemiologic study using a variety of methods depending on the information available. The approach identifies criteria for determining what data are needed for each method and the hierarchy for using the methods. The estimation methods include: (1) calculating a mean from the monitoring results of a job; (2) identifying homogeneously exposed jobs and using the mean of the measurements for the jobs as the estimate; (3) applying a ratio of the measurement means of two jobs in one operation to a third job in another operation to estimate a fourth; (4) weighting by time various areas or personal (short or full-shift) measurements representing tasks or locations; (5) taking a deterministic approach that modifies a ...

Evaluation of Concurrent Personal Measurements of Acrylonitrile Using Different Sampling Techniques

In a retrospective assessment of employee exposure to acrylonitrile (AN) for an epidemiological study, investigators from the National Cancer Institute (NCI) and the National Institute for Occupational Safety and Health (NIOSH) evaluated the feasibility of using historic acrylonitrile air samples without modification. The evaluation discussed here was to determine whether the air sampling results across plants were comparable. During site visits to each plant conducted between 1984 and 1986, study investigators collected personal air samples for four days on approximately ten jobs per day. During these visits, IHs at seven of the eight plants also collected personal samples to compare their sample values to the study-collected sample values. Each plants IH collected these concurrent measurements for their own use and independent of the IHs at the other plants. The plant IHs had no common sampling protocol but, rather, used professional judgment in deciding sampling logistics for their concurrent measurem...

Linking microcomputers and dedicated word processing systems for increased productivity

Abstract With the decline in cost of hardware, more and more professionals are acquiring personal computers at their desk. Most common uses of these office computers are word processing and spreadsheet (e.g. LOTUS 123, MULTIMATE, FRAMEWORK, etc. 1 ) applications. Professionals typically generate text directly on the personal computer (in lieu of hand written copy) and use spreadsheet programs to tabulate and analyze collected field data. A problem in some offices is integrating text and data prepared on the personal computer with existing dedicated word processing systems which have existed in many office environments for some time. One solution is to have the text and tabulated data retyped into the word processing system, however, this approach is not an effective use of resources. The Industrial Hygiene Section, Industrywide Studies Branch (DSHEFS), NIOSH has developed procedures for electronically linking personal microcomputers with an office-wide word processing system. Using a commercially available hardware “board” (which may be inserted into an open slot in an IBM-PC or compatible), the rough copy report and tabulated spreadsheet data can be electronically linked and “uploaded” from a microcomputer to the word processing system. At NIOSH, a WANG word processing system is the office-wide system for preparing and publishing final reports. This system is not readily compatible with IBM-PC (or similar) microcomputers; however, using MULTIMATE (a commercially available word processing program) and the hardware board, documents can be readily transferred to the WANG virtually unchanged from the copy generated on the microcomputer. Importantly, spreadsheet data can be similarly transferred and linked to a document on the WANG wordprocessing system. This paper describes the sequence of steps, along with necessary hardware and software, to achieve the integration of written documents and numerical data (analyzed by LOTUS 123) from a microcomputer to a office-wide WANG word processing system.