Survey of Indoor Radon Concentrations in California Elementary Schools. Final Report.

This paper reports on the concentrations of radon found within a sample of 378 elementary schools in California. Long-term alpha-track radon detectors were placed in 6,485 classrooms within participating schools to detect radon levels for between 220 to 366 days. Only classrooms were tested. Results show that about 5.6 percent of the schools tested had at least one classroom with more than the maximum level of radon (4pCi/1) as recommended by the U.S. Environmental Protection Agency; the maximum measured classroom radon level was 12.8 pCi/1. Affected schools had from one to six classrooms exceeding the level. An adjusted analysis suggests statewide rates of excessive radon to be in 4.7 percent of the schools. Recommendations and statistical data conclude the report. (Contains 12 references.) (GR)