Benjalak Karnchanasest and Arpapan Satayavibul

pp. 877 - 888

Abstract

Sorption of atmospheric PAHs in orange jasmine leaves, Murraya paniculata (L.) Jack and the
potential of leaves to indicate atmospheric PAHs were investigated. Partitioning experiments between leaves
and water were conducted to determine the partition coefficients of the compounds between the leaves and
the water. The leaf samples were collected on 4 Bangkok roadsides, where the air samples were measured for
24 h using high volume, to analyze 16 PAHs. The actual measured PAH concentrations were compared to
atmospheric concentrations calculated from the leaf/air partition coefficients and PAH leaf concentrations.
It was found that they were well related as indicated by correlation coefficient (r²) > 0.70, particularly low
molecular weight (MW) PAHs, which were ACY, ACE, FLU, PHE and ANT. This was because low MW PAHs
were mostly present in gas phase, which played a major role in leaf sorption. Therefore, high MW PAHs,
existing mainly in particulate phase, exhibited lower correlation coefficient (r² < 0.60).