[en] The present study aimed to investigate the influence of some environmental parameters on the behavior of radon and its short-lived daughters in the air. First it was conducted a radon survey in dwellings at the city of Rio de Janeiro. Different geomorphologic locations were selected such as close to the seashore, hills and far from both which are called here as 'interior locations'. Further, using an experimental station, it was studied the influence of temperature, humidity and rain on the radon and its short-lived daughters concentration in the indoor and outdoor air. Dwellings survey in Rio de Janeiro was done by using passive sampling and tracking etching methodology; the dynamic study was conducted performing simultaneous and continuous indoor and outdoor measurements of radon, temperature and humidity. Radon and its daughters were measured by alpha spectrometer using an active sampling. The radon concentration in Rio de Janeiro ranged from 0.5 Bq.m^-3 - 200 Bq.m^-3. It was observed a strong influence of location (seashore - 24 Bq.^m-3, hills - 54.7 and 'interior location' - 52.2). Regarding the dynamic of random it was observed a hourly variability with a maximum of 13 Bq.m^-3 in the early morning and a minimum of 8.8 Bq.m^-3 at afternoon and seasonally with a maximum of 50 Bq.m^-3 in winter and a minimum of 0.5 Bq.m^-3 in the summer months. Those results are consequence of the strong negative correlation with temperature and positive correlation with humidity. It was shown in this study the importance of the characterization of some environmental parameters in the design of radon survey and the need to establish a methodology for sampling and measurement of radon and its daughters in the air in order to allow intercomparison of results. (author)