Statistical Analyses for Assessing Space-Time Exposure Data

Details

• Personal Author:
  Koehler K
• Description:
  Technological advancements in exposure assessment, a necessary component of intervention, control, and compliance, have recently increased the accuracy, reliability, and affordability of portable, direct-reading monitors. These monitors can rapidly assess worker exposures to occupational hazards. By coupling the estimated exposure with a known location, an industrial hygienist has the ability to connect exposures to specific sources. Contour plots of the hazard concentration over space, known as concentration maps, have recently been used to assess the spatial variability of hazards. Concentration maps have the potential to be powerful because they are easily comprehensible for managers, exposed employees, and occupational health scientists to locate areas of concern. Reducing or eliminating exposures in these areas will improve worker health. While we believe there is great potential for direct-reading instruments to aid in the identification and mitigation of workplace exposure hazards, it can be dangerous to apply such a methodology without understanding the uncertainties associated with this new form of exposure assessment. To date, no statistical framework has been applied to these maps. The goal of this project was to collect new hazard mapping data with high spatial and temporal resolution and to evaluate several statistical approaches for the analysis of workplace exposure data collected with direct-reading instruments. There were three specific aims for this project. First, we employed a spatial statistical mapping method to build reliable mapped exposure estimates and compared interpolation methods using a previously collected exposure dataset. Our analysis suggested that Kriging outperformed other spatial interpolation methods and that visual inspection of the experimental variogram and modeled fit were crucial for reliable spatial estimation. Second, we collected comprehensive datasets of hazard concentration as a function of time and space for noise level and, when possible aerosol concentration exposures, at two facilities. The first facility, an engine testing facility, displayed high spatial and temporal variability, while the other, a plastics manufacturing facility, displayed high spatial variability, but low temporal variability. Third, we used the high- resolution datasets to evaluate hazard mapping approaches and data collection methodology and to develop a novel statistical approach to combine data from roving monitors (those that collect short-duration measurements at many locations) and static monitors (those that collect high temporal resolution measurements at few locations). Analysis of the high spatial- and temporal- resolution dataset provided important insight into the collection of data for hazard mapping. Our analysis suggests that short- duration measurements, often collected for the generation of hazard maps can be misleading, resulting in the display of temporal variability as spatial variability. Because spatial correlation indoors tends to be relatively high, we recommend that in locations were temporal variability is expected to be high, collecting replicate measurements at fewer locations is preferable to collecting a single measurement at more locations when seeking to accurately represent the time-weighted average concentrations in a facility. [Description provided by NIOSH]
• Subjects:
  Hazardous Substances Manufacturing And Industrial Facilities Occupational Health Safety
• Keywords:
  Exposure Assessment Hazard Identification Industrial Hygiene Manufacturing Measurement Equipment Monitoring Systems Monitors Spatial Perception
• Series:
  Grant Final Reports
• Publisher:
  National Institute for Occupational Safety and Health
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Final Grant Report
• Place as Subject:
  Maryland ; OSHA Region 3
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  OEP - Office of Extramural Programs
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-7
• NIOSHTIC Number:
  nn:20053680
• NTIS Accession Number:
  PB2019-100320
• Citation:
  Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, K01-OH-009886, 2016 Dec; :1-7
• Contact Point Address:
  Kirsten Koehler, Assistant Professor, Environmental Health Sciences, Johns Hopkins School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205
• Email:
  kirsten.koehler@jhu.edu
• Federal Fiscal Year:
  2017
• NORA Priority Area:
  Manufacturing
• Performing Organization:
  Johns Hopkins University, Baltimore, Maryland
• Peer Reviewed:
  False
• Start Date:
  20110901
• Source Full Name:
  National Institute for Occupational Safety and Health
• End Date:
  20150331
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:9a6732d9e54c43de0c91236ad5856859f53ddce0d9c2cf4e54e6423af8301c0c6466f3f1e68556e21b6b4715f653bf66b41081d0537acca8916be9e05f5c7143
• Download URL:
  https://stacks.cdc.gov/view/cdc/218776/cdc_218776_DS1.pdf
• File Type:
  [PDF - 108.68 KB ]