In order to understand influences of main meteorological parameters upon indoor radon levels, the following parameters were simultaneously measured for 48 h : indoor radon concentration, temperature, relative humidity, precipitation, and wind velocity in an experimental one-floor concrete building at the National Institute of Radiological Sciences, Chiba. A typhoon passed nearby during the observation period The radon concentration ranged from 28.1-218.6 Bq m-3 with an arithmetic mean of 103.1 Bq m-3 and a geometric mean of 89.8 Bq m-3. Arithmetic means of temperature, relative humidity, precipitation, and air pressure during the observation period were 25.6°C, 88%, 42.9 mm, and 996.3 hPa, respectively. The regression analysis indicates that the relative humidity, air pressure, and water in soil at depth of 90 cm were estimated to be more effective factors to influence the radon concentration in air than others.
We applied an ozone generator to sterilize and to deodorize the waste water from radioisotope facilities. A small tank connected to the generator is placed outside of the drainage facility founded previously, not to oxidize the other apparatus, The waste water is drained 1 m3at a time from the tank of drainage facility, treated with ozone and discharged to sewer. All steps proceed automatically once the draining work is started remotely in the office. The waste water was examined after the ozone treatment for 0 (original), 0.5, 1.0, 1.5 and 2.0 h. Regarding original waste water, the sum of conform groups varied with every examination repeated probably depend on the colibacilli used in experiments; hydrogen sulfide, biochemical oxygen demand and the offensive odor increased with increasing coliform groups The ozone treatment remarkably decreased hydrogen sulfide and the offensive odor, decreased coliform groups when the original water had rich coliforms.