radon

In Germany, the radon concentration of 200 Bq/m3 in accordance with the European recommendation (Kommission der Europäischen Gemeinschaften, 1990) is valid as design level for new buildings. Radon from building material can make a significant contribution

The aim of this study is to help dimension the Sol Depressurization System against radon inexisting buildings.First, various remediation techniques implemented on existing buildings are comparedregarding the reduction of indoor radon concentration. The results show that techniques thatdeal with basements have generally the best efficiency and in particular the SoilDepressurization Systems.In situ test equipment has been developed in order to dimension these systems. It has beenused on different basements such as crawl spaces and cellar.

Indoor radon concentrations in high-rise buildings are found to be affected by two majorfactors, namely the ventilation rate and the radon production rate of building materials. In thispaper we present a method to apportion the indoor concentrations to their individual emissionsources. The method consists of two parts: one part is to determine the overall radonproduction rate in a sealed room space, and the other part is to determine the radon productionrate from a particular component. The methods are based upon mass balance models.

The RAGENA model of radon takes into account all the parameters and processes affecting radon levels (in the source, its transport, its entry into a dwelling and its accumulation indoors).The model has been tested in a mediterranean house. The results given by the model are similar to the ones obtained experimentally.

The model estimations aimed at identifying the most important parameters that determine air change rate along with predicting the indoor radon concentration to be expected in new Dutch dwellings under different ventilation conditions.Measurements were compared to the model estimations. To increase infiltration and thus to decrease radon concentation, opening the air inlets and inside doors proved to be efficient.

European radon research and industry collaboration concerted action (ERRICCA2) is establishing a European scientific led industrial forum aimed at reducing risks to health from radiation (principally radon) in the built environment. It brings together 35 organisations from 20 countries.

Guangdong is one of the provinces that have most hot springs in China. This paper presents the results of radon measurements in hot spring hotels of Guangdong province by using NR-667A continuous radon detector. Radon concentrations were measured in hotel rooms with attached bathrooms, tap waters and outdoors air. Radon concentrations were 53.4-292.5 Bq/L in the hot spring water, and 17.2-190.9 Bq/m3 in outdoor air.

Interior Alaska has indoor air quality issues similar to other far northern communities associated with long cold winters and reduced ventilation rates. Moreover, geological features in the hills around Fairbanks, Alaska increase the likelihood of elevated radon levels. Over thirty percent of the tested homes in the hills around Fairbanks had radon levels > 4 pCi/L compared with a nationwide average of 7%. Active sub-slab depressurization systems tested were very effective in reducing indoor radon concentrations (average reduction of over 90% for 8 homes).

Two nation-wide indoor radon surveys have been conducted in Japan. There was a significant difference between the two surveys. The first survey covered over 7000 houses using Karlsruhe passive radon detectors developed in Germany. The first survey provided relatively higher radon concentrations than expected though there are many well-ventilated wooden houses in Japan. The arithmetic mean was estimated to be 20.8 Bq m-3. In the second survey, on the other hand, it was 15.5 Bq m-3.

Radon is a kind of radioactive inert gas. It exists in the soil pore, the underground water and the air. Radon and radon daughters can damage the human body. After they are inhaled into the lungs, radon daughters decay, emit alpha particles, lead to internal irradiation and even cause lung cancer. Radon can accumulate indoors; the problems of indoor radon concentration have aroused a great deal of attention. In this paper, the characteristics, sources, and health effects of radon are discussed in detail.