Sediment and Organisms as Marker for Metal Pollution

Pollution caused by metal elements has drawn increasing attention worldwide due to the increase of anthropogenic contaminants to the marine ecosystems. Pollution of the natural environment by metals is a serious problem because these elements are indestructible and most of them have toxic effects on living organisms, when they exceed a certain concentration. Sediments are widely used as geo-marker for monitoring and identifying the possible sources since sediment can act as sink for the pollutants. Most metals are bound in fine-grain fraction because of its high surface area-to-grain size ratio where they have a greater biological availability compared to those in larger fraction. Lying in the second trophic level in the aquatic ecosystem, shellfish species have long been known to accumulate both essential and non-essential metals. Many researchers have reported the potentiality of using mollusks, especially mussel and oyster species, as bioindicators or biomarkers for monitoring the metal contamination of the aquatic system

Recent sedimentation rate and sediment ages determination of Kemaman-Chukai mangrove forest, Terengganu, Malaysia

Two 20 cm sediment cores were collected with a D-section corer in the Kemaman-Chukai mangrove forest and analyzed for 210Pbex (excess 210Pb) in order to understand the sedimentation pattern. The activities of 210Pb along with the 208Po tracer were measured by Alpha Spectrometry on a silicon surface barrier detector connected to a multi channel analyzer. Sedimentation rates were determined applying 210Pb dating method and found to vary between 0.94-1.11 cm year-1. The highest accumulation rates were recorded near the river mouth and the lowest rates at the downstream. Assuming that the sedimentation rate values are accurate, this implies that the sediments in the upper 100 cm at Kemaman-Chukai mangrove forest were deposited during the past 90 years ago

Metals Pollution in Tropical Wetlands

Metals pollution has drawn worldwide attention due to increase of anthropogenic contaminants to the coastal area, especially wetlands area. Metals are indestructible and have toxic effects on living organisms. Sediment can act as an indicator of metals pollution due to the ability of the sediment that can trap metals through complex physical and chemical process. Therefore, they are always used as geo-marker for identifying the possible source of metals pollution. Besides that, wetlands such as mangrove have a diverse diversity of organisms that provide proteins to local communities such as clam, oyster, crab, and fishes. Therefore, it is important for us to know the levels of metals in the sediment and those organisms that we consume nowadays that live at the mangrove area. Such findings can provide important information on the seafood safety level and potential impact especially to humans via consumption according to the provisional tolerable weekly intake and daily intake

An assessment of metals (Pb and Cu) contamination in bottom sediment from South China sea coastal waters, Malaysia

Problem statement: The accumulation of metal contaminants in sediments can pose serious environmental problems to the surrounding areas. Trace metal contamination in sediment could affect the water quality and the bio-assimilation and bioaccumulation of metals in aquatic organisms, resulting in potential long-term implications on human health and ecosystem. Approach: About 154 bottom sediment samples were collected using Smith McIntyre in a transect pattern from South China Sea East Coast coastal water (Terengganu, Pahang and Johor coastal area). The study focused on the levels of Pb and Cu in order to assess the extent of environment pollution and to discuss the origin of these contaminants in the sediment. Results: Results showed that the average concentration of Pb and Cu was 33.70 μg g-1 dry weights and 22.40 μg g-1 dry weights, respectively. Pb and Cu have relatively lower Enrichment Factors (EF) value and geo-accumulation (Igeo) indices in study area and these analysis validated that elevated heavy metals concentration in most sample are not due to artificial contamination. Conclusion: Overall, geochemistry of the samples showed the effect of both natural and anthropogenic inputs to the catchment, however, natural processes were more dominant than anthropogenic inputs in concentrating metals. Results obtained would help to develop strategies for pollution control and sediment remediation of coastal waters in the South China Sea. © 2009 Science Publications

Concentration of Zn, Cu and Pb in some selected marine fishes of the Pahang coastal waters, Malaysia

Problem statement: Heavy metals constitute one of the most hazardous substances that could be accumulated in biota. Fish populations exploited by man often live in coastal area environments that contain high levels of heavy metals, coming from human activities such as industrial and agricultural wastes. A problem to deal when using fishes as biomonitors of heavy metals is the relationship existing between metal concentration and several intrinsic factors of the fish such as organism size, genetic composition and age of fish. Approach: Concentration of Zn, Cu and Pb were determined in eight commercially valuable fish species, Selaroides leptolepis, Euthynnus affinis, Parastromateus niger, Lutjanius malabaricus, Epinephelus sexfasciatus, Rastrelliger kanagurta, Nemipterus japonicus and Megalaspis cordyla from Pahang coastal water. The concentration was measured by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The study focuses on the level of Zn, Cu and Pb in order to assess the environmental pollution by using fishes as an indicator. Results: Concentrations of the heavy metals in examined fish species ranged as follow: Zn 19.27 µg g-1 dry weight; Cu 2.88 µg g-1 dry weight and Pb 0.26 µg g-1 dry weight, respectively. The concentrations of Zn, Cu and Pb were found to follow the order: stomach > muscle > gills. Significant correlations were found between fish weight and heavy metals concentration in the fish organs. Conclusion: The estimated values of all metals in muscles of fish in this study were below the established values. Therefore, it can be concluded that the fish from Pahang coastal water are comparatively clean and do not constitute a risk for human health

Selected heavy metals content in commercial fishes at different season landed at Fisheries Development Authority of Malaysia Complex (LKIM) Complex, Kuala Terengganu, Malaysia

Fish is a common table food consumed by people for protein nourishment in Kuala Terengganu state. Therefore, a study was carried out to determine the bioaccumulation level of selected heavy metals; copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) in muscle of four most popular and landed fish species which are Nemipterus furcosus (Fork-tailed threadfin bream), Katsuwonus pelamis (Skipjack tuna), Decapterus macrosoma (Shortfin scad) and Atule mate (Yellowtail scad) which were caught at different season and landed at Fisheries Development Authority of Malaysia Complex, Kuala Terengganu, Malaysia. A total of 30 individuals for each species were collected during monsoon (December 2015) and non-monsoon season (September 2016). Concentrations of these heavy metals (Cu, Zn, As, Cd and Pb were determined by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) after 0.05 g of dried samples were digested with 1.5 mL of Suprapur nitric acid. The average concentrations of Cu, Zn, As, Cd and Pb for samples of non-monsoon season are 3.31±0.26 mg/kg dry wt., 14.9±2.68 mg/kg dry wt., 9.12±3.45 mg/kg dry wt., 0.05±0.01 mg/kg dry wt. and 0.23±0.08 mg/kg dry wt., respectively. On the other hand, the average concentration of the same metals in samples of monsoon season are 5.25±1.23 mg/kg dry wt. for Cu, 32.7±9.67 mg/kg dry wt. for Zn, 24.9±6.77 mg/kg dry wt. for As, 0.11±0.07 mg/kg dry wt. for Cd and 0.66±0.21 mg/kg dry wt. for Pb, respectively. Generally, the average metals concentrations in this study were below the permitted levels set by Malaysian Food Act 1983 and Food Regulation 1985 except for As and Cd. However, the provisional tolerable weekly intake (PTWI) have been calculated for each metals and found that the PTWI value for Cd in K. pelamis caught during monsoon season was exceeded the permitted level set by FAO/WHO. This study would be useful for creation of guidelines to protect the public from the harmful effects of the toxicant present in the fish that is consumed by Kuala Terengganu people

Levels of non-essential (Cd, Pb and Hg) elements in muscle tissues of Anguilla bicolor bicolor, McClelland 1844 from Kedah and Anguilla bengalensis bengalensis, Gray 1831 from Perak and human consumption risks

A study on heavy metals accumulation and human health risk assessment in the consumption of two tropical freshwater eel species (Anguilla bengalensis bengalensis) from the Sungai Perak at Kuala Kangsar, Perak and (Anguilla bicolor bicolor) from the Air Hitam irrigation canal, Kampung Kuala Sanglang, Kedah was carried out. Specimens were examined and analyzed for Pb and Cd concentrations using ICP-MS while the total Hg concentration was measured using a direct mercury analyzer (MA-3000). The range for the total concentrations (μg/g wet wt.) in Anguilla bicolor bicolor were 0.01-0.4 (Cd), 0.03-0.77 (Pb) and 0.36-0.94 (Hg) while for Anguilla bengalensis bengalensis, they were 0.76-1.23 (Cd), 0.01-0.10 (Pb) and 0.27-1.5 (Hg). Anguilla bengalensis bengalensis (Sungai Perak) showed a significant strong relationship between Hg/Pb (r = .771, P < 0.05) and Anguilla bicolor bicolor (Air Hitam irrigation canal) with Cd/Pb (r = -.895, P < 0.05) in muscle tissues and the results indicated Hg and Pb were introduced from point and non-point sources, therefore it is of concern. Interspatial comparison with the findings of previous local and international studies showed both species of freshwater eels accumulated Hg to high levels, exceeding the safe limits stipulated in the Malaysian Food Act of 1984, Food Regulations (1985) and USEPA (1997). However, the Target Hazard Quotient (THQ) and Hazard Index (HI) indicated that both freshwater eels from the studied sites are safe to consume as there is no risk posed from consumption based on the health risk assessment results as Pb, Cd and Hg concentrations were under the permissible limits of nutrient intake

The temporal variation of organic carbon during the pre-monsoon and post-monsoon seasons in Pahang river estuary, Pahang, Malaysia

The percentage of organic carbon contents of 62 bottom sediments in Pahang river- estuary were analyzed using the wet dichromate oxidation method. The sediments particle sizes at the same stations were also measured using the dry sieving and laser diffraction methods. In this study, the concentrations of organic carbon are relatively higher during pre-monsoon season and become much lower during the post-monsoon season. The average concentrations of organic carbon for both premonsoon and post-monsoon seasons are 1.61% and 0.88% respectively. This finding indicates that the annual seasonal changes that occur in Pahang river- estuary might probably have the important role in regulating the concentrations of organic carbon

FRACTIONATION OF As, Co, Cu AND Zn BY SEQUENTIAL EXTRACTION IN SURFACE SEDIMENT OF KUALA TERENGGANU RIVER ESTUARY

Development and urbanization processes around Terengganu River estuary are expected to release a significant amount of heavy metals into the existing bottom sediment. However, information on how and why these metals are attached into specific fraction of sediments is still lacking. Therefore, this study aimed to explain the heavy metal concentration distribution in each available fraction at Terengganu River estuary. In this study, nine surface sediments originated from various human activities area in Terengganu River estuary were collected during four different sampling sessions in 2017. Heavy metal content from the collected sediments were extracted using 3-steps BCR sequential extraction method followed by detection using Inductively Coupled Plasma Mass-Spectrometer (ICP-MS) and we discovered that the total concentration of Arsenic (As), Cobalt (Co), Copper (Cu), and Zinc (Zn) ranged from 2.18 to 17.48 mg/kg dry wt., 2.53 to 20.53 mg/kg dry wt., 1.01 to 13.13 mg/kg dry wt., and 6.10 to 65.71 mg/kg dry wt., respectively. Dominance of metals in each fraction can be arranged as follows: As: residual &gt; reducible &gt; exchangeable &gt; oxidizable; Co: residual &gt; exchangeable &gt; reducible &gt; oxidizable; Cu: residual &gt; oxidizable &gt; reducible &gt; exchangeable; Zn: residual &gt; exchangeable &gt; reducible &gt; oxidizable. Availability of metals in sediment at Terengganu River estuary is limited since that majority of metals resides in non-mobilisable fraction of the sediment. In essence, sequential extraction provides information regarding the metals’ fractionation, availability and mobility, which could be used in assessing the environmental contamination in the area