Mercury Emissions from Polyurethane Flooring in Gymnasiums

From the 1960s to the 1980s, many schools throughout the country installed synthetic flooring in indoor gymnasiums that contained mercury which was used as a catalyst in the polyurethane formulation. Many of these floors now have been found to be releasing mercury vapors into the school gymnasiums, leading to a concern that these mercury concentrations might be elevated enough to cause harmful effects. This paper examines data that have been collected from 57 different school gymnasiums using portable devices, such as the Lumex RA-915+ Portable Mercury Vapor Analyzer, and aggregated for analyses, then compares this data to that obtained in chamber tests performed on samples obtained directly from a gymnasium with mercury-containing floors.

The overall objective of this paper is to determine if the chamber tests can adequately emulate mercury emissions in school gymnasiums, and using the results of the laboratory experiments, successfully analyze the emissions curve to determine what factors drive the profile. The laboratory testing was successful in emulating the condition of a school gymnasium, as data collected from the laboratory setting was comparable to the measured field data. The average mercury concentration in the gymnasium yielded an emission rate 3.1E-05 ug/m2s, while the calculated laboratory emission rate was 3.2E-05 ug/m2s, a negligible difference. The overall objective was met, as it was determined that floor samples taken from a gymnasium could be measured in the laboratory with similar results to those screened in the actual gym with handheld devices. Additionally, using the data collected in the chamber experiments, the emissions profile was characterized.