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Title:	Risk assessment of polycyclic aromatic hydrocarbons in water, sediment and seafood of Langkawi Island, Malaysia
Authors:	Essam Nasher Abduh Abdullah (P48256)
Supervisor:	Lee Yook Heng, Prof. Dr.
Keywords:	Hydrocarbons Sediment Polycyclic aromatic hydrocarbons -- Environmental aspects Dissertations, Academic -- Malaysia Universiti Kebangsaan Malaysia -- Dissertations
Issue Date:	28-Oct-2014
Description:	Tourism related activities around the Langkawi Island can be a significant source of petroleum hydrocarbons, in particular polycyclic aromatic hydrocarbons (PAHs) that may harm the ecosystem of this resort island. The main objective of this study is to investigate the concentration, distribution and sources of PAHs as well as to assess the ecological and health risk due to exposure to PAHs through seafood ingestion. Seawater and sediments were collected from four selected jetties, a port, a harbour, and four fish farms during April, 2010, December 2010 and May 2012. Fish and prawns were also obtained from these fish farms and the local fish markets. Samples were analyzed for 18 PAHs using gas chromatography with flame ionization detector (GC/FID). The average concentrations of total PAHs in sediment were found to be in the range of 725.72 to 2217.50 ng g-1 dry weight with a mean of 1057.70 ng g-1. These were lower than the sediment quality guideline effects range low concentration of 3442.00 ng g-1, which suggests no acute biological damage effects. The average concentrations of total PAHs (particulate and dissolved phase) in whole sea water ranged from 5.68 to 46.23 μg L-1 with a mean of 19.05 μg L-1 indicating that all water samples exceed the maximum admissible concentrations of PAHs for the water standard of European Union (0.20 μg L-1). Calculated diagnostic ratios suggest that the possible sources of PAHs found in the majority of sampling sites for sediment and water are likely to be from pyrogenic sources, due to incomplete fuel combustion of the vehicle and boat engines. Lesser amounts of PAHs were contributed by petrogenic sources (e.g direct discharge of two- stroke engine boats). Total concentrations of PAHs in fish and prawn from fish farms and fish market ranged from 394.6 ng g-1 to 656.8 ng g-1 dry weight. The calculated average daily intake of PAHs via fish and prawn consumption were 66.29 and 84.19 [ng kg-1 body weight] day-1 for man and woman respectively. These values are below the maximum acceptable oral dose of the benzo[a]pyrene of 7.3×106 [ng kg-1 body weight] day-1. The estimated excess risk value, in the average, ranged from 6.01×10−6 to 8.65×10−5 from fish and prawn consumption for general population. These results were in the range of acceptable excess risk level criteria (10-6- 10-4) which probably could not pose a health risk to seafood consumers. This study corroborates that the pollution by PAHs were noticeable, but there are differences in the PAHs abundance between sampling sites. Moreover the risk assessment of PAHs in these samples revealed that the environment of Langkawi Island is still in good health and no adverse biological effects are expected from PAH.,Aktiviti berkaitan pelancongan di sekitar pulau Langkawi boleh menjadi punca utama hidrokarbon petroleum, terutamanya hidrokarbon aromatik polisiklik (PAHs) yang mungkin membahayakan ekosistem pulau peranginan ini. Objektif utama kajian ini adalah untuk mengkaji tahap pencemaran, taburan dan sumber penghasilan PAHs, serta menilai risiko ekologi dan kesihatan akibat pendedahan kepada PAH melalui pengambilan makanan laut. Air laut dan sedimen diperoleh daripada empat jeti terpilih, pelabuhan dan empat kawasan penternakan ikan pada bulan April, 2010, Disember 2010 dan Mei 2012. Ikan dan udang didapatkan dari pada kawasan penternakan dan dari pasar ikan tempatan. Samplel dianalisis bagi menentukan 18 PAHs dengan menggunakan kromatografi gas/ pengesan pengionan nyalaan (GC/FID). Jumlah purata kepekatan PAH dalam sedimen didapati dalam julat 725.72- 2217.50 ng g-1 berat kering dengan min 1057.70 ng g-1. Ini adalah lebih rendah daripada garis panduan kualiti sedimen pelbagai kepekatan rendah iaitu 3442.00 ng g-1 yang mencadangkan tiada kesan akut kerosakan biologi. Jumlah kepekatan purata PAH (zarahan dan fasa terlarut) di dalam air laut keseluruhan adalah antara 5.68 hingga 46.23 μg L-1 dengan purata 19.054 μg L-1. Ini menunjukkan aras dalam semua sampel air melebihi kepekatan maksimum PAH yang boleh diterima bagi piawaian air Kesatuan Eropah (0.20 μg L-1). Nisbah diagnostik yang dikira mencadangkan bahawa sumber-sumber yang PAH ditemui di kebanyakan kawasan persampelan untuk sedimen dan air adalah mungkin daripada sumber pirogenik contohnya pembakaran bahan api yang tidak lengkap dari kenderaan dan bot enjin dan sedikit sahaja daripada sumber petrogenik (contohnya pelepasan terus bot enjin dua lejang). Kepekatan PAHs dalam ikan dan udang adalah pada julat 394,6 ng g-1 hingga 656.8 ng g-1 berat kering. Kiraan Pengambilan harian purata PAH dari pada pemakanan ikan dan udang adalah 66.29 dan 84.19 ng kg-1 berat badan hari-1 untuk masing-masing lelaki dan wanita. Nilai ini adalah lebih rendah daripada dos oral maksimum yang boleh diterima daripada benzo[a]pyrene iaitu sebanyak 7.3×106 [ng kg-1 berat badan] hari-1. Secara purata anggaran nilai risiko yang berlebihan adalah 6.01×10−6 hingga 8.65×10−5 daripada pengambilan ikan dan udang bagi orang awam. Tahap ini adalah dalam lingkungan risiko yang boleh diterima (10-6 - 10-4) yang dijangka tidak akan memberi risiko kesihatan kepada pengguna. Kajian ini menunjukkan bahawa terdapat pencemaran PAH yang ketara, namun ianya berbeza antara tapak-tapak persampelan yang dikaji. Analisis risiko PAH menunjukkan Pulau Langkawi masih berada pada tahap yang baik dan tidak menunjukkan kesan biologi yang buruk oleh PAH.,Ph.D.
Pages:	175
Call Number:	QP801.P639A235 2014 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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