Green guardians: Mosses as potential low-cost biomonitors of air pollution in urban Chicago

According to the Lancet Commission, air pollution is one of the single largest environmental causes of premature death in the world. Particulate matter (PM), including metals, is among the pollutants of concern. Bryophytes, especially mosses, have been used for many decades as low-cost biomonitors of environmental deposition of heavy metals. In this exploratory investigation, we use strategically placed Sphagnum moss paired with portable X-ray fluorescence (pXRF) analysis as a living biomonitor for air/particulate metal pollution in and around the city of Chicago, Illinois, U.S.A. Preliminary results reveal a correlation between urbanization and some metal particulate matter, especially iron. The study warrants further investigation and supports the use of mosses and pXRF spectrometry as a rapid, low per-sample cost, and potentially accurate alternative to conventional metal pollution monitoring.