Spatial association of occupational and environmental exposure factors and respiratory cancers in the US

Background: Epidemiological aspects of occupational exposures and related respiratory cancers have been extensively studied. However, GIS techniques on explaining these relationships between exposure and cancer might be a useful tool in field investigations.

Objective: To explore, with different spatial and population weighting techniques, the geographical association among various occupational and environmental exposure factors and respiratory cancers in the US.

Methods: The mortality data for those individuals 15 years of age and older are derived from the Compressed Mortality Files. The outcome mortality variables are respiratory cancers including larynx and lung and the independent and control mortality variables are silica, coal dust, and asbestos exposures. Geographic coverage is at the county and Health Service Area (HSA) units of analysis, while the temporal coverage is for years 1994 to 2003. Publicly available software programs to produce smoothed values that can be used to create maps that are easier to interpret. Created map layers depict high/low incidence regions of mortality and relate them to exposure factors.

Results: Best regionalized results were produced by Head-Bang and selected techniques from GeoDA. Preliminary results showed an expected relationship between various occupations and cancers such as mining and lung cancer. We are continuing to analyze spatially referenced data to investigate further geographic relationships between occupational exposures and related respiratory cancers.

Conclusion: These powerful and relatively easy to use techniques produce regions that can be helpful in understanding geographical associations between exposure factors and respiratory cancers.