Field Testing a Global Positioning System (GPS) Linked With a Direct Reading Air Sampling Instrument in an Exposure Assessment

It is often difficult to collect location information during an exposure assessment. Typical options, such as an exposure diary, are cumbersome or impractical in an occupational setting. In this study, a "local positioning system" (LPS) that uses the global positioning system to track location was used in an exposure assessment of Coast Guard personnel that patrol the Houston Ship Channel. Coupled with a conventional direct reading multi-gas detector, the LPS recorded concentrations of sulfur dioxide, hydrogen sulfide, and volatile organic compounds along with the geographic position where they occurred. Results showed that concentrations varied from none detected to 0.2 ppm, 1.6 ppm, and 5.5 ppm for SO2, H2S, and VOCs, respectively. Statistical analysis showed significant differences in mean contaminant concentrations over the six-day period of study, as well as significant differences in mean concentrations recorded in certain areas of the channel.Master of Science in Public Healt