Radon example

Radon is a colorless, odorless gas that occurs naturally in the earth's crust. From the crust, it can move up into the foundations of buildings. Once there, it can build up to dangerous levels if it is not vented out to the outside air. At these levels, radon is known to cause lung cancer. In fact, though estimates vary, it is generally agreed that radon causes an additional 8,000 deaths due to lung cancer in the United States each year (14).

Radon was first recognized as a danger in the 1970s; an EPA report in 1979 estimated that radon accounted for 10 to 20% of deaths from lung cancer in the United States each year. Exposure to radon is particularly dangerous for smokers; cancer risk increases exponentially. However, it was not until 1985 that concern about radon became at all widespread, when stories about highly contaminated homes in eastern PA were covered by the national television media and the New York Times (15).

The concern about radon has once again faded from the public view. The EPA and state environmental agencies hold regular campaigns to encourage homeowners to test their homes for radon and take the simple precautions needed to vent the gas if high levels are found. Legislation requiring homeowners to test homes before selling them has helped to increase the number of homes tested. Even with the high hazard and the scientific certainty about the negative health impacts, public outrage and awareness about radon risks has remained low.

Example: From a famous EPA ad about the importance of testing for radon:

"It's colorless, it's odorless, but it kills."