Artificial pine needle passive air quality sensors (image) University of Utah Share Print E-Mail Caption Peter Lippert (left) and Grant Rea-Downing examine artificial pine branches being tested as passive air quality monitors. Photo from Sept. 2019. Credit Paul Gabrielsen/University of Utah Usage Restrictions Credit as indicated. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.