Oak tree-rings record spatial-temporal pollution trends from different sources in Terni (Central Italy)

Area of Science:

• Environmental Science
• Geochemistry
• Dendrochronology

Background:

• Atmospheric pollution monitoring in industrial areas is crucial for assessing environmental health and safety.
• Terni, Central Italy, is recognized as a highly polluted urban center, necessitating detailed environmental studies.
• Understanding historical pollution patterns aids in evaluating long-term environmental impacts.

Purpose of the Study:

• To investigate the utility of tree-ring chemical composition for monitoring spatial-temporal variability of pollutants.
• To assess the impact of industrial activities, particularly a steel factory, on the local environment.
• To correlate trace element accumulation in tree rings with historical pollution events.

Main Methods:

• Tree cores were collected from 32 downy oaks (Quercus pubescens) at varying distances from pollutant sources.
• Trace element analysis (Cr, Co, Cu, Pb, Hg, Mo, Ni, Tl, W, U, V, Zn) was performed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).
• Tree-ring data from 1958-2009 were analyzed to identify pollution trends and spatial variations.

Main Results:

• Contaminant accumulation in tree rings correlated with anthropogenic activities and varied with proximity to the industrial plant.
• Increased levels of Cr, Ni, Mo, V, U, and W were observed in trees near the steel factory, especially during the 1980s and 1990s.
• Higher Cu, Hg, Pb, and Tl levels suggested contributions from an nearby incinerator, while Uranium (U) content remained difficult to interpret.

Conclusions:

• Tree-ring chemical analysis is a viable method for reconstructing historical atmospheric pollution in industrial urban areas.
• The study demonstrated a clear link between industrial activities and trace element accumulation in tree rings.
• Environmental pollution levels and their spatial distribution can be effectively inferred from tree-ring data, providing valuable insights for environmental management.