Study of radon-222 concentration levels inside kindergartens in Amman

In this work, measurements of the indoor radon concentration levels were carried out for 74 kindergartens in Amman, Jordan. The number of children (four to six years old) attending these kindergartens are about 15,000. This study was performed during winter season by using time-integrated passive radon dosimeters, containing CR-39 solid state nuclear track detectors. We found that the radon concentrations inside the classrooms of these schools range from 40.7 to 193.5 Bq/m(3) with an average of 76.8 Bq/m(3). This average value is twice that of Amman's dwellings (mostly residential houses) found in previous studies (Abumurad et al., 1994 and 1996). An average radon level of 79.4 Bq/m(3) was found in the schools which are over 10 years old (65% of the schools), while an average level of 71.7 Bq/m(3) was found in those under 10 years old (35%). On the other hands, for the schools that have central heating systems (32.4%) the average radon level inside them was 78.6 Bq/m(3). For the schools that use kerosene portable heaters (51.4%), the average radon level was 72.9 Bq/m(3) and for those do not have any heating system (16.2%) their average was 86.5 Bq/m(3). Consequently, we believe that better ventilation rate is recommended.