title: Radon mitigation at Birch Cliff Public School.
abstract: In 1991, Canadian Institute for Radiation Safety (CAIRS) conducted a radon screening program in all Metropolitan Toronto public schools. Birch Cliff Public School had a radon progeny level higher than the action level of 4.16 x 10(-7) Jm-3 (20 mWL). Follow-up radon testing was carried out at the school. Locations on the ground floor and in the basement were tested. All locations on the ground floor had radon progeny levels below the action level. Six locations in the basement had readings above the action level. All cracks and openings in the basement were sealed and a new heating/ventilating (HV) system for the basement was designed and installed. Then, the basement was tested again. Radon progeny levels are now well below the action level with an average of 7.43 x 10(-8) Jm-3 (3.57 mWL). This is about one fifth of the average radon progeny level found in the first stage of follow-up testing.
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D011886:Radon / Q000032:analysis*; D012574:Schools; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
chemical_list: D000396:Air Pollutants, Radioactive; D012990:Soil Pollutants, Radioactive; D011886:Radon