How moss revealed an undetected threat in Portland
Clip: 10/12/2016 | 8m 19s
Portland, Oregon, prides itself on being very focused on the environment. So many people were shocked to discover that certain neighborhoods contain high levels of toxic metals. Scientists made the discovery when ordinary moss samples taken from all over town revealed the unexpected contamination. Special correspondent Cat Wise reports on how it led to some significant changes in the city.
Aired: 10/12/16
