Che Abd Rahim Mohamed

Surfactants in the sea-surface microlayer and their contribution to atmospheric aerosols around coastal areas of the Malaysian peninsula.

A study was done to determine the concentrations of surfactants on the sea-surface microlayer and in atmospheric aerosols in several coastal areas around the Malaysian peninsula. The concentrations of surfactants from the sea-surface microlayer (collected using rotation drum) and from aerosols (collected using HVS) were analyzed as methylene blue active substances and disulphine blue active substances through the colorimetric method using a UV-vis spectrophotometer. The results of this study showed that the average concentrations of surfactants in the sea-surface microlayer ranged between undetected and 0.36+/-0.34 micromol L(-1) for MBAS and between 0.11+/-0.02 and 0.21+/-0.13 micromol L(-1) for DBAS. The contribution of surfactants from the sea-surface microlayer to the composition of surfactants in atmospheric aerosols appears to be very minimal and more dominant in fine mode aerosols.

Natural radionuclide of Po210 in the edible seafood affected by coal-fired power plant industry in Kapar coastal area of Malaysia

BackgroundPo210 can be accumulated in various environmental materials, including marine organisms, and contributes to the dose of natural radiation in seafood. The concentration of this radionuclide in the marine environment can be influenced by the operation of a coal burning power plant but existing studies regarding this issue are not well documented. Therefore, the aim of this study was to estimate the Po210 concentration level in marine organisms from the coastal area of Kapar, Malaysia which is very near to a coal burning power plant station and to assess its impact on seafood consumers.MethodsConcentration of Po210 was determined in the edible muscle of seafood and water from the coastal area of Kapar, Malaysia using radiochemical separation and the Alpha Spectrometry technique.ResultsThe activities of Po210 in the dissolved phase of water samples ranged between 0.51 ± 0.21 and 0.71 ± 0.24 mBql-1 whereas the particulate phase registered a range of 50.34 ± 11.40 to 72.07 ± 21.20 Bqkg-1. The ranges of Po210 activities in the organism samples were 4.4 ± 0.12 to 6.4 ± 0.95 Bqkg-1 dry wt in fish (Arius maculatus), 45.7 ± 0.86 to 54.4 ± 1.58 Bqkg-1 dry wt in shrimp (Penaeus merguiensis) and 104.3 ± 3.44 to 293.8 ± 10.04 Bqkg-1 dry wt in cockle (Anadara granosa). The variation of Po210 in organisms is dependent on the mode of their life style, ambient water concentration and seasonal changes. The concentration factors calculated for fish and molluscs were higher than the recommended values by the IAEA. An assessment of daily intake and received dose due to the consumption of seafood was also carried out and found to be 2083.85 mBqday-1person-1 and 249.30 μSvyr-1 respectively. These values are comparatively higher than reported values in other countries. Moreover, the transformation of Po210 in the human body was calculated and revealed that a considerable amount of Po210 can be absorbed in the internal organs. The calculated values of life time mortality and morbidity cancer risks were 24.8 × 10-4 and 34 × 10-4 respectively which also exceeded the recommended limits set by the ICRP.ConclusionsThe findings of this present study can be used to evaluate the safety dose uptake level of seafood as well as to monitor environmental health. However, as the calculated dose and cancer risks were found to cross the limit of safety, finding a realistic way to moderate the risk is imperative.

Use of different tissues of Perna viridis as biomonitors of polycyclic aromatic hydrocarbons (PAHs) in the coastal waters of peninsular Malaysia.

For the first time, in May 2007, the distributions of polycyclic aromatic hydrocarbons (PAHs) were studied in the soft tissues (STs) (mantle, gills, foot, gonad, muscle, byssus, and remaining soft tissues) of the green-lipped mussel Perna viridis, collected from eight geographic locations along the coastal waters of peninsular Malaysia. The STs of the mussels collected from the eastern part of the Johore Straits indicated higher bioavailability of and contamination by PAHs than from other areas. The results also indicated a significantly higher concentration of the lower molecular weight (LMW) PAHs in tissues compared to that of the higher molecular weight (HMW) PAHs, perhaps due to the greater bioavailability of the more water-soluble LMW PAHs or related to a partial biotransformation of the higher molecular weight PAHs. The results also suggest that the differences found in the contents of PAHs in various STs of P. viridis were mainly due to differences between individual PAHs volatility and solubility in water, as well as the mechanism of PAH accumulation by mussels. Of the STs in general, the gonad was shown to contain the highest levels of PAHs, but it is not a potential biomonitoring organ because it is highly influenced by spawning conditions. Isomeric PAH ratios were used to differentiate pollution sources.The findings of the study suggest that STs of P. viridis are good biomonitors of the bioavailability and contamination with PAHs in tropical coastal waters.

Urban vs. Marine Based Oil Pollution in the Strait of Johor, Malaysia: A Century Record

Polycyclic aromatic hydrocarbons (PAHs) constitute a class of organic pollutants in the environment that come from combustion of organic matter and petroleum products and from natural sources. Reconstruction of PAH history from two sedimentary cores of the Strait of Johor in peninsular Malaysia showed predominance of urban over marine-based sources of oil pollution. Laboratory analysis of the cores found oil pollution from city-sourced material since 1910 and 1940 in the near-shore and offshore samples, respectively. Using hopane as molecular biomarker of petroleum pollution, this study found a predominance of Southeast Asian-originated oil and its derivatives. This study concludes that crankcase oil, asphalt, street dust and urban sediments considerably contribute to oil pollution of the study area.

Polycyclic Aromatic Hydrocarbons and Hopane in Malacca Coastal Water: 130 Years of Evidence for Their Land-Based Sources

Massive development over the past century has led to environmental oil-related pollution around the Malaysian city of Malacca. To characterize the concentration, sources, and origins of polycyclic aromatic hydrocarbons in Malacca’s coastal water in the Strait of Malacca, sediment cores from near shore and offshore were collected and analyzed. The highest concentration of total polycyclic aromatic hydrocarbons (PAHs) in the Near Shore station core was 4447 ng/g dry weight (dw) (1963–1969), and the lowest was 177 ng/g dw (1949–1955). The lowest concentration of PAHs in the Near Shore sample was 452 ng/g dw (1991 to 1997). In general, the Offshore core showed lower concentrations of total PAHs than did the Near Shore core, ranging from 1.71 (1914–1920) to 714.37 ng/g dw (1963–1969). Diagnostic tools such as specific compound, isomer ratio, and hopane characteristics indicate pollution by petroleum and combustion of oils from Southeast Asia and the Middle East in the study area since the1940s.

Three Centuries of Polycyclic Aromatic Hydrocarbons and Teriterpane Records In Tebrau Strait, Malaysia; Recent Pollution Concern in a Pristine Marine Environment

In the last century, application of fossil fuel as the primary source of energy caused environmental pollution in many countries including Malaysia. Polycyclic Aromatic Hydrocarbons (PAHs) are an important class of petroleum contamination. Two sediment cores were collected from the Tebrau Strait at the southern part of Peninsular Malaysia near the border line to Singapore, where entering into the South China Sea. The samples were sliced in certain intervals, extracted with Dichloromethane in Soxhlet apparatus, cleaned and fractionated in 2-steps column chromatography, and analyzed in Gas Chromatography – Mass Spectrometry. The results showed that PAHs input were started soon after World War II and exponentially increased from 1980 onward by 310 ng/g d. w., in comparison it was negligible and probably nature derived during 18th and 19th century. The application of compound-specific ratios and pentacyclic teriterpanes suggested the vicinity of sources that atmospherically transported to the sampling locations. They were originated from combusted oil of Southeast Asian and the Middle East, polluting urban sediment and street dusts prior to final deposition. Biomass burning appeared historically as a predominant minor background pollution of both cores. Remarkably, crankcase oil was not traced in this study while it was reported as a predominant source in Malaysia. This study suggested ocean-going ships and Singapore International Airport as the main sources of petroleum pollution in recent decades since there was insignificant rural development surrounding the studied area.

Health Risk of Polonium 210 Ingestion via Drinking Water: An Experience of Malaysia

The presence of toxic polonium-210 (Po-210) in the environment is due to the decay of primordial uranium-238. Meanwhile, several studies have reported elevated Po-210 radioactivity in the rivers around the world due to both natural and anthropogenic factors. However, the primary source of Po-210 in Langat River, Malaysia might be the natural weathering of granite rock along with mining, agriculture and industrial activities. Hence, this is the first study to determine the Po-210 activity in the drinking water supply chain in the Langat River Basin to simultaneously predict the human health risks of Po-210 ingestion. Therefore, water samples were collected in 2015–2016 from the four stages of the water supply chain to analyze by Alpha Spectrometry. Determined Po-210 activity, along with the influence of environmental parameters such as time-series rainfall, flood incidents and water flow data (2005–2015), was well within the maximum limit for drinking water quality standard proposed by the Ministry of Health Malaysia and World Health Organization. Moreover, the annual effective dose of Po-210 ingestion via drinking water supply chain indicates an acceptable carcinogenic risk for the populations in the Langat Basin at 95% confidence level; however, the estimated annual effective dose at the basin is higher than in many countries. Although several studies assume the carcinogenic risk of Po-210 ingestion to humans for a long time even at low activity, however, there is no significant causal study which links Po-210 ingestion via drinking water and cancer risk of the human. Since the conventional coagulation method is unable to remove Po-210 entirely from the treated water, introducing a two-layer water filtration system at the basin can be useful to achieve SDG target 6.1 of achieving safe drinking water supplies well before 2030, which might also be significant for other countries.

Natural Radium Detection and Inventory Flux of Isotopes in Particulate and Dissolved Phases of Seawater at Kapar Coastal Area Caused by Coal-Fired Power Plant

Distribution of 226Ra and 228Ra radioactive in marine have been studied at Kapar coastal area that closed to Sultan Salahudin Abdul Aziz Shah (SJSSAS) power station. The concentration level of 226Ra and 228Ra were measured in seawater include total suspended solids (TSSrw) and dissolved phases from September 2006 to February 2008. The measurement technique used for 226Ra and 228Ra was using cation exchange column and counted using Liquid Scintillator Ciunter (LSC). The radioactivities of 226Rasw and 228Rasw in the dissolved phase of seawater ranged from 1.29 ± 0.52 mBq/L - 3.69 ± 1.29 mBq/L and 2.12 ± 0.71 mbq/L - 17.07 ± 6.03 mBq/L respectively. The measurement of radioactivities of radium isotopes in the particulate phase of seawater ranged from 15.62 ± 1.99 Bq/kg - 241.76 ± 100.23 Bq/kg (226Ratsw) and 7.19 ± 3.21 Bq/kg - 879.66 ± 365.74 Bq/kg (228Ratsw). Radium isotopes inventory in this study showed that suspended solid have higher inventory value than seawater and sediment. Study also found that suspended solid play an important role for flux contribution at seawater. Based on the finding, the radioactivity concentration of 226Ra and 228Ra is higher in particulate phase than in dissolved phase.

Natural uranium and thorium isotopes in sediment cores off Malaysian ports

Sediment cores collected from three Malaysian marine ports, namely, Kota Kinabalu, Labuan and Klang were analyzed to determine the radioactivities of 234U, 238U, 230Th, 232Th and total organic carbon (TOC) content. The objectives of this study were to determine the factors that control the activity of uranium isotopes and identify the possible origin of uranium and thorium in these areas. The activities of 234U and 238U show high positive correlation with TOC at the middle of sediment core from Kota Kinabalu port. This result suggests that activity of uranium at Kota Kinabalu port was influenced by organic carbon. The 234U/238U value at the upper layer of Kota Kinabalu port was ≥1.14 while the ratio value at Labuan and Klang port was ≤ 1.14. These results suggest a reduction process occurred at Kota Kinabalu port where mobile U(VI) was converted to immobile U(IV) by organic carbon. Therefore, it can be concluded that the major input of uranium at Kota Kinabalu port is by sorptive uptake of authigenic uranium from the water column whereas the major inputs of uranium to Labuan and Klang port are of detrital origin. The ratio of 230Th/232Th was used to estimate the origin of thorium. Low ratio value (lt; 1.5) at Labuan and Klang ports support the suggestion that thorium from both areas were come from detrital input while the high ratio (> 1.5) of 230Th/232Th at Kota Kinabalu port suggest the anthropogenic input of 230Th to this area. The source of 230Th is probably from phosphate fertilizers used in the oil-palm cultivation in Kota Kinabalu that is adjacent to the Kota Kinabalu port.

Geochronology of 210Pb in Sediments of Sepang Besar River, Malaysia

Geochronological studies to determine pattern and rate of sediment deposition is still lacking in Malaysia. The aim of this study is to investigate geochronological pattern of 210Pb in core sediments of the Sepang Besar River. Sediment cores were collected from rivermouth, middle course and upper course of the river. Sediment cores were cut at 2 cm interval for each layer, treated with established method and analyzed by beta spectrometry. Results showed the activities of 210Pb along Sepang Besar River varied at a wide range. Significantly lower 210Pb activity was found at the rivermouth as compared to middle and upper courses of Sepang Besar River. This could be due to the geology of the watershed and chemical weathering conditions around the area.