The Chernobyl incident was a tragedy. Thousands of people lost their lives, and now millions are being affected. Cancers are becoming more prevalent in people. The land around the site is loaded with radiation. People often think of radiation as a slimy green goo than causes you to mutate into a superhuman with unstoppable powers.
Radiation can be odorless.
Which is one reason why the effort to attack the consequences of the explosion were not taken seriously. Now people are living with highly dangerous chemicals, and suffering from them.