Hindawi Publishing Corporation he Scientiic World Journal Volume 2013, Article ID 858309, 13 pages http://dx.doi.org/10.1155/2013/858309 Research Article Assessing the Ecological Risk of Polycyclic Aromatic Hydrocarbons in Sediments at Langkawi Island, Malaysia Essam Nasher, 1 Lee Yook Heng, 1,2 Zuriati Zakaria, 3 and Salmijah Surif 1 1 Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia 2 South-East Asia Disaster Prevention Research Institute (SEADPRI), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia 3 Environment Engineering and Green Technology, Malaysia Japan International Institute of Technology, University Technologi Malaysia, 54100 Kuala Lumpur, Selangor, Malaysia Correspondence should be addressed to Essam Nasher; essam abduh@yahoo.com Received 8 July 2013; Accepted 14 August 2013 Academic Editors: H. A. Alegria, A. C. Ruiz Fern´ andez, and O. Wurl Copyright © 2013 Essam Nasher et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Tourism-related activities such as the heavy use of boats for transportation are a signiicant source of petroleum hydrocarbons that may harm the ecosystem of Langkawi Island. he contamination and toxicity levels of polycyclic aromatic hydrocarbon (PAH) in the sediments of Langkawi were evaluated using sediment quality guidelines (SQGs) and toxic equivalent factors. Ten samples were collected from jetties and ish farms around the island in December 2010. A gas chromatography/lame ionization detector (GC/FID) was used to analyse the 18 PAHs. he concentration of total PAHs was found to range from 869 ± 00 to 1637 ± 20 ng g −1 with a mean concentration of 1167.00 ± 24 ng g −1 , lower than the SQG efects range-low (3442 ng g −1 ). he results indicated that PAHs may not cause acute biological damage. Diagnostic ratios and principal component analysis suggested that the PAHs were likely to originate from pyrogenic and petrogenic sources. he toxic equivalent concentrations of the PAHs ranged from 76.3 to 177 ng TEQ/g d.w., which is lower compared to similar studies. he results of mean efects range-median quotient of the PAHs were lower than 0.1, which indicate an 11% probability of toxicity efect. Hence, the sampling sites were determined to be the low-priority sites. 1. Introduction Langkawi Archipelago in the Straits of Malacca, northwest of Peninsular Malaysia, consists of 104 islands, the largest and most exploited of which is Langkawi Island with an area of 478.5 km 2 . Targeted for ecotourism, Langkawi is protected from engaging in heavy industrial activities [1]. In 2006, the island was declared a National Geopark, and in the following year, it became a UNESCO Global Geopark [2]. In 2010 alone, Langkawi was visited by 2.4 million tourists [2]. From approximately 40,000 in 1991, the local population swelled signiicantly to almost 100,000 in 2010 [1], mainly to cater to the increasing number of tourism-related activities. Unfortunately, the fragile ecosystem of Langkawi Island is also increasingly being threatened by these tourism activities. Among the main attractions of Langkawi are its unique geological formations accessible only by boats. Many ish farms cater to the fresh seafood restaurants that are appearing around the islands. Boating activities, which are an impor- tant tourism component in Langkawi, signiicantly increase petroleum and diesel pollution in the water around the island. One of the most signiicant polluting components of petroleum is polycyclic aromatic hydrocarbons (PAHs). PAHs are a group of over 100 diferent compounds with fused benzene rings [3]. Sixteen PAHs compounds are iden- tiied as priority pollutants due to their toxic, mutagenic, and carcinogenic characteristics [4]. PAHs in the environment can result from petroleum and petroleum products (petro- genic) or from the incomplete or ineicient combustion of diesel fuel, engine oil, wood, coal, biomass of forest, grass ires, waste incinerators, and fossil fuels, all of which are commonly used in industrial operations and power plants (pyrogenic) [5, 6]. PAHs are also widely used in commer- cial products such as intermediaries in pharmaceuticals,