The individual compounds and sources of polycyclic aromatic hydrocarbon (PAHs) were studied in the surface sediments
at 32 locations in the tourism area of Langkawi Island. A total of 15 PAHs were determined and quantified by gas
chromatography coupled with mass spectrometry (GC-MS). The total PAH concentrations of surface sediments from
Langkawi Island ranged from 228.13 to 990.25 ng/g and they were classified as being in the low to moderate pollution
range. All sampling stations were dominated by high molecular weight PAHs with 4 rings (31.59%) and 5-6 rings (42.73%).
The diagnostic ratio results showed that in most cases, the sampling stations have pyrogenic input. Further analysis
using principal component analysis (PCA) combined with absolute principal component score (APCS) and multiple linear
regression (MLR) showed that the natural gas emissions contributed to 57% of the total PAH concentration, 22% from the
incomplete combustion and pyrolysis of fuel, 15% from pyrogenic and petrogenic sources and 6% from an undefined source.