Influence of analysis methods on interpretation of hazard maps.
Koehler KA; Peters TM
Ann Occup Hyg 2013 Jun; 57(5):558-570
Exposure or hazard mapping is becoming increasingly popular among industrial hygienists. Direct-reading instruments used for hazard mapping of data collection are steadily increasing in reliability and portability while decreasing in cost. Exposure measurements made with these instruments generally require no laboratory analysis although hazard mapping can be a time-consuming process. To inform decision making by industrial hygienists and management, it is crucial that the maps generated from mapping data are as accurate and representative as possible. Currently, it is unclear how many sampling locations are necessary to produce a representative hazard map. As such, researchers typically collect as many points as can be sampled in several hours and interpolation methods are used to produce higher resolution maps. We have reanalyzed hazard-mapping data sets from three industrial settings to determine which interpolation methods yield the most accurate results. The goal is to provide practicing industrial hygienists with some practical guidelines to generate accurate hazard maps with 'off-the-shelf' mapping software. Visually verifying the fit of the variogram model is crucial for accurate interpolation. Exponential and spherical variogram models performed better than Gaussian models. It was also necessary to diverge from some of the default interpolation parameters such as the number of bins used for the experimental variogram and whether or not to allow for a nugget effect to achieve reasonable accuracy of the interpolation for some data sets.
Exposure levels; Hazards; Industrial hygienists; Measurement equipment; Sampling; Models; Monitoring systems; Statistical analysis;
Author Keywords: exposure mapping; hazard mapping; interpolation; kriging
Kirsten A. Koehler, Department of Environmental and Radiological Health Science, Colorado State University, Fort Collins, CO 80523, USA
Grant; Cooperative Agreement
Grant-Number-K01-OH-009886; Cooperative-Agreement-Number-U50-OH-007548; Cooperative-Agreement-Number-U54-OH-007548; M122013 Grant-Number-T42-OH-008491
Agriculture, Forestry and Fishing; Manufacturing
Annals of Occupational Hygiene
Colorado State University, Fort Collins