The preliminary results obtained shows that radon concentration indoors is not a constant, and that it fluctuates with time. In particular, the trend shows a strong correlation with the ventilation rate of the room.
Most studies conducted have also established outdoor radon to be at very low levels, in the range of 5 - 25 Bq m-3. The graph is explained by ventilation in the room.
Radon accumulates when there is a lack of ventilation, and is removed by the ventilation system when there is exchange of air with outdoor air, as seen in figure 2.2. Radon concentration is highly dependent on the ventilation rate of the room. As soon as air was exchanged with outdoor air, the amount of radon is reduced significantly. Newer, modern buildings built to be more energy efficient are more well sealed against influx of outdoor air. This reduces cost of air conditioning for offices, and buildings where the majority of indoor space is air conditioned. However, this also means that natural ventilation and exchanges
between indoor and outdoor air is reduced when the air conditioning system is not switched on. 1,8-11
Based on the preliminary results, it also suggests that being in the office during office hours when the air conditioning system is switched on is not a cause of concern. However, the same could not be said during non-office hours, when the ventilation system is not switched on. The exchange of air is prevented, and radon is allowed to accumulate in the office environment.