Fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp in Hong Kong following an oil spill

L. Ke, Teresa W.Y. Wong, Y. S. Wong, Nora F.Y. Tam

Research output: Contribution to journalArticlepeer-review

107 Citations (Scopus)

Abstract

The fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp (Yi O) in Hong Kong after an oil spill accident was investigated. The concentrations and profiles of PAHs in surface sediments collected from five quadrats (each of 10m×10 m) covering different degrees of oil contamination and the most contaminated mangrove leaves were examined in December 2000 (30 days after the accident) and March 2001 (126 days later). The concentrations of total PAHs in surface sediments ranged from 138 to 2135 ngg-1, and PAHs concentrations decreased with time. In the most contaminated sediments, total PAHs dropped from 2135 (30 days) to 1196 ngg-1 (120 days), and the decrease was smaller in less contaminated sediments. The percentage reduction in sediment PAHs over three months (44%) was less significant than that in contaminated leaves (85%), indicating PAH in or on leaves disappeared more rapidly. The PAH profiles were very similar in sediments collected from quadrats Q1 and Q2 with benzo[a]anthracene and pyrene being the most abundant PAH compounds, but were different in the other three quadrats. The proportion of the light molecular weight PAHs to total PAHs increased after three months, especially phenanthrene. Results suggest that physical and photo-chemical weathering (tidal washing and photo-oxidation) of crude oil in surface sediments and on plant leaves were important processes in the first few months after the oil spill. The PAH contamination in Yi O swamp came from both petrogenic and pyrolytic sources. The petrogenic characteristic in the most contaminated sediment was confirmed with high values of phenanthrene to anthracene ratio (10) and low values of fluoranthene to pyrene ratio (0.3-0.4).

Original languageEnglish
Pages (from-to)339-347
Number of pages9
JournalMarine Pollution Bulletin
Volume45
Issue number1-12
DOIs
Publication statusPublished - Sept 2002
Externally publishedYes

Keywords

  • Mangrove leaf
  • Oil spill
  • PAH profile
  • Petrogenic
  • Sediments

Fingerprint

Dive into the research topics of 'Fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp in Hong Kong following an oil spill'. Together they form a unique fingerprint.

Cite this