Factor analysis of trace-element data from tree-bark samples in The Netherlands.

Area of Science:

• Environmental Science
• Geochemistry
• Analytical Chemistry

Background:

• Biomonitoring using tree bark is an emerging technique for assessing air pollution.
• Understanding the influence of soil material on trace-element concentrations in bark is crucial for accurate biomonitoring.
• Previous studies have utilized epiphytic lichens for air pollution biomonitoring in The Netherlands.

Purpose of the Study:

• To investigate the suitability of tree bark as a biomonitor for air pollution.
• To apply Monte Carlo-assisted factor analysis to trace-element data from tree bark.
• To compare air pollution source types identified in bark with those identified in lichens.

Main Methods:

• Collection of 20 trace-element concentration data from 123 tree-bark samples across The Netherlands.
• Application of Monte Carlo-assisted factor analysis to understand uncertainties and significance levels.
• Comparison of factor analysis results with data from an earlier biomonitoring study using epiphytic lichens.

Main Results:

• Factor analysis identified five significant pollution source types in tree bark.
• These identified pollution sources align with those previously found in lichen biomonitoring studies.
• A notable difference in lead concentrations was observed between bark and lichen samples.
• The study demonstrated the significant influence of soil material on trace-element levels in bark.

Conclusions:

• Tree bark is a suitable and effective biomonitor for assessing air pollution.
• Monte Carlo-assisted factor analysis can accurately identify pollution sources and quantify soil contributions.
• The analytical power of factor analysis may eliminate the need for extensive sample washing procedures in biomonitoring studies.