Frequently, environmental samples are collected and analyzed in order to investigate the extent of pollution. The resulting concentrations of pollutants at various sites are compared with the standard concentration levels in order to determine compliance with environmental regulations. These methods, however, have drawbacks when the area polluted is very large or contains heterogeneous structures. In the study, a methodology is proposed which is based on the extent of pollution by hazardous chemicals. The method involved a statistical approach in order to obtain the probability density function, geometric standard deviation and the geometric mean for the collected data. As a case study, an oil-spilled coastal area was selected and 167 sediment samples were collected from the intertidal zone. 16 different polyaromatic hydrocarbons(PAHs) were analyzed fur each sample. In addition, toxicity equivalence factors(TEFs) for 7 PAHs were used for estimating the pollution level. In the work, pollution probability above the standard pollution level suggested by National Oceanic and Atmospheric Administration(NOAA) and florida Department of Environmental Regulation(FDEP) were calculated based on the total PAH concentrations and the concentration of each PAM component. Results showed that acenaphthene and benzo(a)anthracene could be two representative components among 16 PAHs for the typical pollution index in he oil-spilled coastal region. The extents of pollution in sites could be classified by the one toxic concentration converted with TEFs of each PAH. The method suggested in this study could apply for the preparation of soil Pollution map or assessment of environmental impat by toxic release in a chemical plant or landfill area.