Dendrochemistry in Public Health: A Case Study in North Carolina, USA

Dendrochemistry, the measurement of element concentrations in tree rings for the purpose of assessing temporal changes in chemical environments, was used to study an area in south-central North Carolina, USA, that has experienced higher than expected incidences of a couple human illnesses. A principal objective of applying dendrochemistry around an area with public health problems is to assess the environmental chemistry through time to see if the environmental abundance of any elements has changed recently, which then might inform further research into the possible linkage between those elements and the reported illnesses. Loblolly pine is common in the study area and, therefore, was chosen for sampling. Using acid digestion ICP-MS, decadal chunks of rings were measured for the concentration of multiple elements. Most of the elements measured do not show any particular changes in concentration throughout the time period covered by the trees, but four elements (molybdenum, chromium, iron, and, possibly, vanadium) show concentrations in the most recent decade (the 2010s) that were higher than for previous decades. Because this study was ecologic in design, it is not possible to associate these elements with the illnesses that are being reported for the area based on this study alone, but further environmental monitoring might be merited to confirm the temporal pattern found here.