The most effective way to establish radon levels inside buildings is to measure with a validated test kit. Due to weather conditions, temperatures, and atmospheric pressure, radon levels vary from day to day, which is why PHE recommends a measurement period of at least three months to obtain an accurate risk assessment. If faster analysis is needed, we recommend a minimum ten-day measurement period, which can be carried out using our specially-designed Rapidos® test kit.
The Government advises that remedial action should be taken in any residential property with an average annual radon level of 200 Bq/m3 or more. Although, the target level to reach is 100 Bq/m3, which is in the line with what The World Health Organization (WHO) recommends as a limit value for radon.
Digital monitors are also an option, however these are normally used for conducting follow-up measurements post-remedial work. We strongly advise against use of radon maps as a definitive means of testing. Maps only highlight local risk due to variations in the soil, and therefore cannot indicate levels within buildings. For school and workplace radon testing there are specific requirements, which you can read more about here.