In this study, all of the sampling sites were located quite close to
the large petrochemical complex, with an average distance of 1.5 km.
Hence, the pollution source was only petrogenic, and the reaction
time between the source and receptor areas was short. Therefore, we
suggest that the Ant/(Ant + Phe) ratio was the best MDR in this region
because only the results obtained using this ratio agreed with the specific
petrogenic source.