The radiation in our surroundings is roughly distinguishable between "artificial radiation" and "natural radiation."

"Natural radiation" is radiation which exists in a nature.
"Artificial radiation" is radiation made artificially.
Sometmes people say "because it was made artificially, the artificial radiation is worse for the body. "But these are just types of oradiation and are only distinguished as"natural things" and "artificial things." This distinction does not consider the influence on the human body or human health.
　　　　・Natural radiation
　　　　・Artificial radiation

For this project, we used a radiation meter and fog chamber to measured and observed natural radiation.
　　　　・Measurement and Observation