In 2019, Dr. Paul Sheppard and Melissa Furlong (postdoc in environmental health sciences) received funding for a pilot proposal. The primary aims involve collecting tree cores near EPA air monitors and evaluating how closely annual metals concentrations in the tree rings predicted the gold standard of annual EPA monitored ambient metals concentrations. They have collected cores at a site in Arizona and have a trip scheduled for a site near Atlanta, Georgia for mid-January. Two more site visits are planned for February, with lab analysis for the metals scheduled for February and March. They are also exploring the potential for a new analytical technique, laser ablated ICP-MS, to measure ultra-fine time series of metals within tree rings. This new technique is in collaboration with partners at the University of Georgia and will be compared with more traditional ICP-MS techniques used to measure metals in biomass here at the University of Arizona. The P30 has provided immeasurable support along the way. The IHS core provided personnel support to assist in getting field permits from the National Park Service for permission to sample at sites in Arizona, and to help identify ideal sites for sampling across the United States.
Dr. Sheppard uses tree rings to reconstruct environmental conditions of the past and/or to monitor modern-day environmental change including general pollution studies and concurrent clusters of childhood leukemia.
Dr. Paul Sheppard, Melissa Furlong