Forefront of radon research and regulation on residential radon

Two international conferences on radon were held in 2004. The 4th European Conf. on Protection against Radon at Home and at Work was held at Prague, Czechoslovakia, in June, 2004. The noteworthy reports were the factors of change of radon concentration at home by R. Ameon (IRSN in France), the investigation of radon concentration at school and its reduction by D. Fenton (PRII in Ireland) and C. Giovani (ARPA in Italy), and the study of disintegration products aerosol for evaluation of exposure dose by Z. Berka (CTU in Czechoslovakia). The 6th Int. Conf. on High Levels of Natural Radiation and Radon Areas was held at Osaka, Japan, in September, 2004. There were 26 papers and 53 posters. Some notable papers contained the environmental and epidemiological research in high natural radiation area by M. Sohrabi (AEOI in Iran), Sugawara (Japan), and G.M. Kendall (NRPB in England), problems of disagreement of evaluation of dose between epidemiological method and dosimetry by A. Birchall (England), and importance of thoron on environmental research and evaluation of dose by J.H. Lubin (NCI in U.S.A) and Z. Wang (LIH in China). The emission concentration regulation of radon at home and at work is going to determine the radon level in many countries. WHO appealed the residential radon risk (RRR) project to radon researchers in each country in August, 2004. (S.Y.)