Simple ways to dispel danger

Experiments, particularly those undertaken in Cornwall, on ways of reducing the levels of radon gas in buildings, are reported. In Cornwall a relatively simple method has been found to reduce the radon level by a factor of ten in a school building. In this, a simple brick-built sump was installed beneath a solid floor. The open design of the sump allowed the gas from the earth beneath to collect and, assisted by fans, to be vented to the outside where it disperses harmlessly. Other methods tried in Sweden are mentioned. The National Radiological Protection Board and other bodies, as well as Cornwall's own officers, are monitoring the situation in Cornwall so that, when a cost-effective method has been established, buildings with high levels of radon can be treated. As yet no estimation of the cost has been made. Modification to the threshold limits for radon doses may also be made in the light of the results of the monitoring programme. (U.K.)