Critical aspects of radon remediation in karst limestone areas: some experiences in schools of South Italy.

The final results of radon monitoring in 438 schools located in the province of Lecce (Puglia Region, South Italy) showed an average radon concentration of 215 ± 20 Bq m and that 7% of schools exceeded 500 Bq m, the current Italian action level for radon in workplaces, and consequently required remedial actions. The activity described in the present paper includes the main elements of the remediation project in a subgroup of school buildings. The main radon control systems adopted were sub-slab depressurization (in 57% of schools) and the active ventilation of the crawlspace (in 21% of schools).