SOIL CHARACTERIZATION FOR INDOOR RADON POTENTIAL AT 18 SCHOOLS IN NEW-YORK-STATE

During the two school years between 1991 and 1993, 60 schools were mea sured for indoor radon in New York State. Schools were solicited from areas considered to be at risk for above-average indoor radon based on residential indoor radon measurements and on the geology of the area. Eighteen of the sixty schools participating in the New York State stu dy were selected for soil-radon potential characterization. Soils near the perimeter of the school, in the school yard, and in crawl spaces were measured for soil Ra-226 concentration, soil-gas Rn-222 concentra tion, and permeability for gas flow. In general, above-average indoor radon concentrations in the schools were found to correlate with highl y permeable, gravelly soils. At 10 schools, the average soil permeabil ity for gas flow was greater than 3 x 10(-10)m(2) for each school, and 47% of the rooms tested in these 10 schools had long-term indoor rado n concentrations greater than 150 Bq/m(3). The soils near the 10 schoo ls were generally glacial outwash gravel deposits containing average c oncentrations of Ra-226 and soil-gas Rn-222. Copyright (C) 1996 Elsevi er Science Ltd.