Najat Masood

Baseline distributions and sources of Polycyclic Aromatic Hydrocarbons (PAHs) in the surface sediments from the Prai and Malacca Rivers, Peninsular Malaysia

In this study, the surface sediments of the Malacca and Prai Rivers were analyzed to identify the distributions, and sources of Polycyclic Aromatic Hydrocarbons (PAHs). The total PAH concentrations varied from 716 to 1210 and 1102 to 7938 ng g(-1)dw in the sediments of the Malacca and Prai Rivers, respectively. The PAH concentrations can be classified as moderate and high level of pollution in the sediments of the Malacca and Prai Rivers, respectively. The comparison of PAHs with the Sediment Quality Guidelines (SQGs) indicates that the PAHs in the sediments of the Malacca and Prai Rivers may have the potential to cause adverse toxicity effects on the sampled ecosystems. The diagnostic ratios of individual PAHs indicate both petrogenic- and pyrogenic-origin PAHs with dominance of pyrogenic source in both rivers. These findings demonstrate that the environmental regulations in Malaysia have effectively reduced the input of petrogenic petroleum hydrocarbons into rivers.

Anthropogenic waste indicators (AWIs), particularly PAHs and LABs, in Malaysian sediments: Application of aquatic environment for identifying anthropogenic pollution.

Polycyclic aromatic hydrocarbons (PAHs) and linear alkylbenzenes (LABs) were used as anthropogenic markers of organic chemical pollution of sediments in the Selangor River, Peninsular Malaysia. This study was conducted on sediment samples from the beginning of the estuary to the upstream river during dry and rainy seasons. The concentrations of ƩPAHs and ƩLABs ranged from 203 to 964 and from 23 to 113 ng g(-1) dry weight (dw), respectively. In particular, the Selangor River was found to have higher sedimentary levels of PAHs and LABs during the wet season than in the dry season, which was primarily associated with the intensity of domestic wastewater discharge and high amounts of urban runoff washing the pollutants from the surrounding area. The concentrations of the toxic contaminants were determined according to the Sediment Quality Guidelines (SQGs). The PAH levels in the Selangor River did not exceed the SQGs, for example, the effects range low (ERL) value, indicating that they cannot exert adverse biological effects.

Baseline distribution and sources of linear alkyl benzenes (LABs) in surface sediments from Brunei Bay, Brunei

Sewage pollution is one of major concerns of coastal and shoreline settlements in Southeast Asia, especially Brunei. The distribution and sources of LABs as sewage molecular markers were evaluated in surface sediments collected from Brunei Bay. The samples were extracted, fractionated and analyzed using gas chromatography- mass spectrometry (GC-MS). LABs concentrations ranged from 7.1 to 41.3 ng g(-1) dry weight (dw) in surficial sediments from Brunei Bay. The study results showed LABs concentrations variably due to the LABs intensity and anthropogenic influence along Brunei Bay in recent years. The ratio of Internal to External isomers (I/E ratio) of LABs in sediment samples from Brunei Bay ranged from 0.56 to 2.17 along Brunei Bay stations, indicating that the study areas were receiving primary and secondary effluents. This is the first study carried out to assess the distribution and sources of LABs in surface sediments from Brunei Bay, Brunei.

Distribution of Petroleum Hydrocarbons in Surface Sediments from Selected Locations in Kuala Selangor River, Malaysia

A study has been conducted at selected locations along the Kuala Selangor River, Malaysia on seven surface sediment samples to determine the level of hydrocarbon pollution in the sediments. The homogenized sediments were extracted using soxhlet, fractionated and analyzed by using GCMS. PAHs were detected and were found in the range of 563–1,037 ng/g (dryweight). Ratio MP/P was used to determine the anthropogenic PAHs sources where seven stations were found to be polluted by petrogenic sources. Furthermore, MP/P ratios for sediment samples had values ranging from 1.752 to 18.6, while L/H ratios for the same samples ranged from 0.2978 to 1.393. There were 26 compounds of PAHs detected in the samples. Further analysis and more data is needed in order to identify the sources of oil pollution in seven sediment samples with unidentified oil sources.

Forensic investigation of aliphatic hydrocarbons in the sediments from selected mangrove ecosystems in the west coast of Peninsular Malaysia.

Peninsular Malaysia has gone through fast development during recent decades resulting in the release of large amounts of petroleum and its products into the environment. Aliphatic hydrocarbons are one of the major components of petroleum. Surface sediment samples were collected from five rivers along the west coast of Peninsular Malaysia and analyzed for aliphatic hydrocarbons. The total concentrations of C10 to C36 n-alkanes ranged from 27,945 to 254,463ng·g(-1)dry weight (dw). Evaluation of various n-alkane indices such as carbon preference index (CPI; 0.35 to 3.10) and average chain length (ACL; 26.74 to 29.23) of C25 to C33 n-alkanes indicated a predominance of petrogenic source n-alkanes in the lower parts of the Rivers, while biogenic origin n-alkanes from vascular plants are more predominant in the upper parts, especially in less polluted areas. Petrogenic sources of n-alkanes are predominantly heavy and degraded oil versus fresh oil inputs.

Distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in Sediment from Muar River and Pulau Merambong, Peninsular Malaysia

Previous studies indicated that with increasing industrialization and urbanization, pollution problems have become more significant in Malaysia. West coast of Malaysia is more populated and urbanized than the east and therefore more susceptible to various pollutants. Surface sediment samples were collected from Pulau Merambong and Muar river, Peninsular Malaysia during May 2013 where 16 USEPA Priority Pollutants PAHs were analyzed using gas chromatography-mass spectrometry. Total PAHs in the sediments for Muar river ranged from 15.5 to 165.7 ng/g dw whereas the total PAHs for Pulau Merambong ranged from 38.6 to 122.8 ng/g dw. Due to rapid urbanization and motorization, Muar river showed an increasing trend of PAHs concentrations when compared to a study conducted about a decade ago. Pulau Merambong shows relatively lower PAHs concentrations as compared to other locations in Peninsular Malaysia. However, there is no previous data in Pulau Merambong to evaluate the trend in the petroleum hydrocarbons distribution and concentrations. In general, this study revealed that the lowest concentrations were detected in downstream of the Muar and Pulau Meranbong, respectively. This study also found abundance of high molecular weight (HMW) PAHs as compared to low molecular weight (LMW) PAHs suggesting predominance of pyrogenic PAH sources via atmospheric and long-range input. The ratio of LMW PAHs to HMW PAHs (LMW/HMW) were in the range of 0.05–0.33 indicating pyrogenic input and this is consistent with other diagnostic ratios.

Distribution and sources of linear alkyl benzenes (LABs) in surface sediments from Johor Bahru Coast and the Kim Kim River, Malaysia

ABSTRACT This study focuses on sewage pollution, which is one of the most important issues concerning Malaysians. The main location of this study is in Johor Bahru as it is one of the most populated areas in Malaysia. The distribution and sources of linear alkyl benzenes (LABs) were evaluated in surface sediments collected from Johor Bahru Coast and the Kim Kim River, Peninsular Malaysia. The samples were extracted, fractionated and analyzed using gas chromatography-mass spectrometry (GC-MS). This study found that LABs concentrations ranged from 87.6 to 188.7 ng/g dw and 88.2 to 119.02 ng/g dw in surface sediments from Johor Bahru Coast and the Kim Kim River, respectively. Johor Bahru Coast showed an increasing trend of LABs concentrations due to rapid industrialization and population growth. The ratio of internal to external isomers (I/E ratio) of LABs in sediment samples from Johor Bahru Coast ranged from 1.76 to 2.04 while the I/E ratios in sediments from the Kim Kim River ranged from 1.72 to 1.91. All I/E ratios at Johor Bahru Coast and the Kim Kim River stations indicate that the areas were receiving primary and secondary effluents.

Mangrove Oyster (Crassostrea belcheri) as a Biomonitor Species for Bioavailability of Polycyclic Aromatic Hydrocarbons (PAHs) from Sediment of the West Coast of Peninsular Malaysia

ABSTRACT Rapid industrialization and urbanization in the west coast of Peninsular Malaysia has caused increasing pollution particularly of petroleum and petroleum by-products. Surface sediment and mangrove oyster (Crassostrea belcheri) were collected from five mangrove ecosystems in the west coast of Peninsular Malaysia and investigated for bioavailability of polycyclic aromatic hydrocarbons (PAHs). Sampling locations were selected from both remote areas with few or no previous records of petroleum pollution such as Pulau Merambong and polluted areas that are under international attention such as Klang mangrove ecosystem. PAH fractions were obtained through soxhlet extraction and two-step column chromatography and the fractions were injected to gas chromatography-mass spectrometry (GC-MS) for analysis. The concentrations of PAHs ranged from 151 to 4973 ng g−1 dw in the sediments, while from 309 to 2225 ng g−1 dw in the oysters. When tested for diagnostic ratios, a predominance of pyrogenic source PAHs was detected in the sediments, whereas PAHs in the oysters had mixed petrogenic and pyrogenic sources. A significant correlation (p < 0.05) was found between high molecular weight (HMW) PAHs in the sediments and oysters and biota accumulation factors (BAFs) of PAHs were approaching or exceeding unity indicating the ability of mangrove oyster in bioaccumulation of PAHs. Overall, this study indicates that mangrove oyster (C. belcheri) can be used as a biomonitor species for PAHs in an aquatic environment.

Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments from Prai and Malacca Rivers, Peninsular Malaysia

In this study the surface sediments of Malacca River (3 Stations) and Prai River (3 Stations) were analyzed to identify the distributions of PAHs. The concentrations of PAHs were quantified using Gas Chromatography–Mass Spectrometer (GC–MS). Total PAH concentrations varied from 716 to 1210 and 1102 to 7938 ng g−1dw in sediments of Malacca and Prai Rivers, respectively. The concentrations of PAHs in sediments were classified as moderate in sediments of Malacca and high to very high level of pollution in sediments of Prai River. PAHs were dominated by high molecular weight (HMW) in sediments of Malacca River and low molecular weight (LMW) in sediments of Prai River. This indicates that petroleum hydrocarbon pollution in Malacca River is dominated by atmospheric input while that of Prai River is mostly fresh petrogenic input from lateral or horizontal transport via rivers and surface runoffs. The other diagnostic ratios of LMW/HMW, Fluo/(Fluo + Py), Fluo/Py and Comb/TPH in both rivers are consistent with the above statement.