The U.S. Forest Service researchers who discovered toxic levels of heavy metals in moss surrounding two Portland stained-glass factories have published their study in a national journal—where they describe a national breakthrough in spotting air pollution.

The scientists describe how they found the heavy metal cadmium in moss samples.

The moss tests "are a screening tool that could revolutionize air-quality monitoring," write Sarah Jovan and six other authors in the July issue of Science of the Total Environment.

Meanwhile, the Southeast Portland company Bullseye Glass told state officials April 6 that it will resume using cadmium after installing a new air filter.