A Forest Service
using moss collected from urban trees to develop fine-scale maps of air pollution in Portland, Oregon shows that moss can be used as an inexpensive screening tool to help cities quickly identify where to place pollution monitoring equipment. It would have cost more than $17 million to use instruments at the same spatial resolution as the moss sampling in Portland.
The Oregon Department of Environmental Quality is phasing in the use of moss in its monitoring, and other cities are also interested in doing so. The study has had further implications for human health and policy.