Polycyclic aromatic hydrocarbons in rainfall in a evergreen broad-leaved forest in Maofeng Mountain, Guangzhou.

The concentrations of 6 polycyclic aromatic hydrocarbons (PAHs) in precipitation, through-fall, stem-flow, runoff, and soil solution were measured by liquid chromatography in a monsoon evergreen broad-leaved forest in Maofeng Mountain in Guangzhou. Results showed that 6 kinds of PAHs were all detected in precipitation, and the concentrations of PAHs during the dry season were higher than those during the wet season. The crown layer and stem-flow had obvious functions on PAH storage. The concentrations of total PAHs in runoff were lower than those in precipitation, which indicates that the forest ecosystem has a strong ability for purifying PAHs. The concentrations of PAHs in soil declined with depth, indicating a filtration function of the forest ecosystem. Total organic concentration in soil plays a major role in the vertical distribution of PAHs.