摘要：Investigation was carried out on some kinds of domestic wares containing natural radioactive substance. These articles, namely a pillow, a tile plate, a belt and so on, are produced in a particular factory and are sold in market with special advertisement for keeping health or for utilizing their weak radiation. The radioactive substance contained in these articles was prepared from a kind of ore called Monazite. The γ-spectrum of this sandy ore with Malti-channel Pulse Height Analyzer was quite identical to that of thorium, and the thorium content was 4.7∼23.7 percent by chemical analysis. We found considerable dose of radiation derived from these articles with Lauritzen electroscope as shown in TABLE I. It is very difficult to consider if these articles might be safe for life, because we can not know the actual dose of radiation during use of them. However, roughly speaking, these articles may not be safe for health, if they are used very freely. We are feeling that we should have a scientifically authorized safety limit or alarm level of the radioactivity for use of these domestic wares.
