Exposure assessment for trace elements from consumption of marine fish in Southeast Asia

Concentrations of 20 trace elements were determined in muscle and liver of 34 species of marine fish collected from coastal areas of Cambodia, Indonesia, Malaysia and Thailand. Large regional difference was observed in the levels of trace elements in liver of one fish family (Carangidae): the highest mean concentration was observed in fish from the Malaysian coastal waters for V, Cr, Zn, Pb and Bi and those from the Java Sea side of Indonesia for Sn and Hg. To assess the health risk to the Southeast Asian populations from consumption of fish, intake rates of trace elements were estimated. Some marine fish showed Hg levels higher than the guideline values by U.S. Environmental Protection Agency and Joint FAO/WHO Expert Committee on Food Additives (JECFA). This suggests that consumption of these fish may be hazardous to the people.     

Tributyltin distribution in the coastal environment of Peninsular Malaysia

The occurrence of tributyltin (TBT) is reported in the coastal waters of a few selected sites in Peninsular Malaysia. Water, bivalves and sediment samples collected were analysed specifically for TBT using sensitive analytical methods which involved a solvent extraction procedure with appropriate clean-up followed by graphite furnace atomic absorption spectrometric measurements. The levels of TBT in the seawater in unexposed areas were found in the range from <3.4 to 20 ng litre(-1) as compared to coastal areas with high boat and ship activities where TBT levels in seawater were generally above 30 ng litre(-1), with the highest level found at 281.8 ng litre(-1). TBT levels in the tissues of random cockle and soft-shell clam samples from local markets were found in the range from <0.5 to 3.7 ng g(-1) wet weight. The levels of TBT found in green mussel samples both from the market (23.5 ng g(-1) wet weight) and those from a mussel farm (14.2 ng g(-1) wet weight) indicate slight accumulation of TBT. In sediments, TBT levels were found ranging from <0.7 ng g(-1) dry weight in unexposed coastal sites to as high as 216.5 ng g(-1) dry weight for a site within a port area.     

Assessment on the distributions and exchange of anionic surfactants in the coastal environment of Peninsular Malaysia: A review

Environmental Science and Pollution Research - Terrestrial anionic surfactants (AS) enter the marine environment through coastal region. Despite that, in general limited knowledge is available on...     

Recovery of astaxanthin from seafood wastewater utilizing fish scales waste

The paper presents basic data on astaxanthin adsorption from fisheries wastewater to fish scales. This process has been proposed to be applicable in fisheries and shrimp waste management [Helgason, Recovery of compounds using a natural adsorbent, Patent WO 01/77230, 2001]. The innovative feature of the method is the application of a solid waste (fish scales) as a natural adsorbent for a carotenoid pigment (astaxanthin) from the seafood industry wastewater. The model investigations were performed with pure synthetic carotenoids to exclude the role of matrix in which astaxanthin is present in the wastewater. Under the experimental conditions used, the maximum loading capacity of astaxanthin onto the scales is 360 mg kg(-1) dry wt. Studies of the thus formed value added product indicated that drying causes significant loss of astaxanthin activity. Due to the effective filtration characteristics of the studied sorption material, we suggest the scale/astaxanthin sorption process to be suitable for treatment of wastewater from different industries.     

Multiple regression analysis in modeling of columnar ozone in Peninsular Malaysia

This study aimed to predict monthly columnar ozone (O₃) in Peninsular Malaysia by using data on the concentration of environmental pollutants. Data (2003–2008) on five atmospheric pollutant gases (CO₂, O₃, CH₄, NO₂, and H₂O vapor) retrieved from the satellite Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) were employed to develop a model that predicts columnar ozone through multiple linear regression. In the entire period, the pollutants were highly correlated (R?=?0.811 for the southwest monsoon, R?=?0.803 for the northeast monsoon) with predicted columnar ozone. The results of the validation of columnar ozone with column ozone from SCIAMACHY showed a high correlation coefficient (R?=?0.752–0.802), indicating the model’s accuracy and efficiency. Statistical analysis was utilized to determine the effects of each atmospheric pollutant on columnar ozone. A model that can retrieve columnar ozone in Peninsular Malaysia was developed to provide air quality information. These results are encouraging and accurate and can be used in early warning of the population to comply with air quality standards.     

Estimation of acceptable mercury intake from fish in Taiwan

The US Food and Drug Administration (USFDA) and Environmental Protection Agency (USEPA) are advising women and young children to avoid eating fish that contain high levels of mercury (Hg). However in Taiwan, the annual Black Fin Tuna Festival encourages the public to consume fish. The aim of this study was to assess fish intake in relation to the health risks of mercury exposure and calculate the acceptable and safe intake of fish in children and women of childbearing age. From the Monte Carlo simulation, based on USEPA's reference dose (0.1 microgkg(-1)d(-1)), we found that 21.6%-24.3% and 45.6%-57.4% of the daily mercury dose estimates exceeded the reference dose for typical and high-seafood consumers. The acceptable ingestion rates are <50 g d(-1) (children) and 90.8 +/- 15.7 g d(-1) (women of childbearing). Sensitivity analysis suggests that Hg concentration in fish may be a key parameter to aid governments as they offer guidance for risk management.     

Exposure to polybrominated diphenyl ethers associated with consumption of marine and freshwater fish in Hong Kong

Concentrations of polybrominated diphenyl ethers (PBDEs) in market fish have not previously been reported in Hong Kong. Axial and ventral muscles from 10 each common species of freshwater and marine fish purchased from markets in Hong Kong were analyzed for 22 PBDEs. Among the 10 freshwater fish species, spotted snakehead (Channa maculate) contained the highest level of PBDEs in ventral muscle (130 ng g(-1) wet wt.). For marine fish, bigeye (Priacanthus macracanthus) showed significantly higher levels of PBDEs (60.7 ng g(-1)wet wt. in ventral tissue) than all other marine species. The levels of PBDEs in fish samples ranged from 0.53 to 130 ng g(-1)wetwt. The tetrabrominated congener BDE-47 and pentabrominated BDE-99 were the predominant congeners, which accounted for 27% and 30%, respectively, of the total PBDEs. Daily PBDE intake was calculated according to the different fish consumption rate for Hong Kong consumers, and the results ranged from 222 to 1198 ng day(-1) for marine fish and 403-2170 ng day(-1) for freshwater fish. The daily PBDE intake from fish reported here were higher than those reported from the United States (8.94-15.7 ng day(-1)) and Europe (14-23.1 ng day(-1)).     

Organotropism of total mercury (THg) in Cichla pinima,ecological aspects and human consumption in fish from Amazon region,Brazil

Environmental Science and Pollution Research - Specimens of the Cichla pinima are of ecological and economic importance in the Amazon region and are a good bioindicator species of Hg...     

Total mercury intake from fish and shellfish by Japanese people

Elevated mercury concentrations have been reported in fish in recent years. Japanese people eat a great deal of raw fishes and shellfishes as “Sashimi” and “Sushi”. The action level of large predatory fish such as tuna with total mercury levels exceeding the Japanese maximum permitted limit of 0.4 ppm is exempted from regulation in Japan. Therefore, current total mercury intake from fish and shellfish of Japanese people is unknown. The purpose of this investigation was to estimate the total mercury intake from fish and shellfish. It was found that the mean total mercury concentration of 1.11 ppm in tuna of eatable base as Sashimi or Sushi was clearly higher than the normal level. The mean total mercury intake from fish and shellfish was 0.17mg per capita per week . According to the hypothesis that 75% of total mercury in fish and shellfish is methylmercury, the weekly intake of 0.13 mg as methylmercury was corresponding amount to about 74% of provisional tolerable weekly intake 0.17 mg of methylmercury set by the Welfare Ministry of Japan.     

Formation of methyl mercury in an aquatic macrophyte

In the nature, inorganic forms of mercury (Hg) may be transformed to the organic, very toxic, methyl-Hg. Occasionally methyl-Hg has been detected in plants, also so in the aquatic macrophyte water spinach (Ipomoea aquatica), which is a popular vegetable in tropical regions. The objectives of this study were to investigate if methyl-Hg is formed and/or degraded in water spinach. Water spinach plants were exposed to inorganic Hg via spiked soil or spiked nutrient solution. Tests were performed in a climate chamber and in experimental units, one for each individual plant, that were equipped with separated shoot and root compartments. Plant tissues were analysed for total- and methyl-Hg. The results showed that methyl-Hg was accumulated in water spinach, especially in young metabolically active parts, when exposed to external inorganic Hg, even at sterilized conditions. Results also showed that methyl-Hg was formed in water spinach in the absence of external Hg, i.e., during recovery in a not Hg-spiked medium following after HgCl₂-exposure. There was however, no sign of demethylation. Summarizing, most of the Hg that is taken up by the plants is bound in the roots, but of the comparatively small amounts of Hg that reach the young growing shoots, a part will be methylated. Since the young shoots of this plant make a delicious and very appreciated vegetable, Hg in I. aquatica may contribute to human health problems.     

Organochlorine and mercury contamination in fish tissues from the River Nestos, Greece

Polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) isomers, dichlorodiphenyltrichloroethane (DDT) and its metabolites, other organochlorine pesticides such as hexachlorobenzene (HCB), chlordane compounds (CHLs, including trans-chlordane and cis- and trans-nonachlor) and the heavy metal mercury were quantified in muscle and liver of the European chub (Leuciscus cephalus, Linnaeus, 1758) and in the muscle of the barbel (Barbus cyclolepis, Heckel, 1837) at two sampling sites of the River Nestos, Greece. PCBs in muscle and DDTs in the liver tissues were the predominant organochlorinated contaminants. Among the PCBs, congeners 47 (up to 9.60 ng g(-1) wet wt.), 180 (up to 1.15 ng g(-1) wet wt.) and 190 (up to 1.50 ng g(-1) wet wt.) were the most frequent and abundant. The contamination degree by the sum of PCBs on the fish tissue samples from the River Nestos is lower or similar to PCB levels found in other ecosystems. Among the organochlorine pesticides, essentially only p,p'-DDD, p,p'-DDE and alpha-, beta- and gamma-HCH were found, with the former appearing at mean levels up to 30.71 ng g(-1) wet wt. From a public health standpoint, residue organochlorine pesticide levels from our work are considerably lower than the recommended tolerance limits. Finally, mean values of Hg in chub were significant lower (up to 31.04 ng g(-1) wet wt.) compared to those detected on barbel (up to 169.27 ng g(-1) wet wt.). The concentrations of Hg in fresh water fish from the River Nestos did not exceed WHO and US EPA health guidelines, and were suitable for human consumption.     

Evaluation of the exposure methodology for risk-benefit assessment of seafood consumption

This study evaluated the methodology of using existing, international data to calculate the intake of nutrients and contaminants via seafood consumption on a national level. This was done by combining French seafood consumption data with two different datasets. The results showed that a significant correlation was found between the results obtained by using different data sets and that a high percentage of the population was classified in the same category (above or below the intake reference values). As such, the general conclusion that can be drawn from the results: 'whether a part of the population does exceed the toxicological reference values for certain contaminants and whether a part of the population does not reach the recommended intake for certain nutrients' remains the same for the two approaches. Therefore, it can be concluded that the existing, international probability distributions are useful when aiming to perform a cost-effective risk benefit evaluation of seafood consumption on national or regional level. When this evaluation does indicate that more detailed results are needed because a certain health risk exists, it can be decided that it is worth to spend more time and money for the analyses of national samples in order to collect more detailed results.     

Factors influencing the total mercury and methyl mercury in the hair of the fishermen of Kuwait

Total and methyl mercury (MeHg) levels in the hair of fishermen are described anticipating that they represent the critical group for dietary exposure. One-hundred human hair samples were collected from fishermen (Egyptians: age range 25-60), living in Doha Fishing Village, Kuwait. Thirty-five additional samples were taken from a control group working in a local construction company (age range 26-35). Overall mean concentrations in the hair of the population of fishermen are 4.181+/-3.220 and 4.025+/-3.130 microg g(-1) for total and MeHg, respectively. The equivalent values for the control are 2.617+/-1.404 and 2.556+/-1.391 microg g(-1) for total and MeHg, respectively. MeHg concentrations are strongly correlated to those of total Hg ( [Formula: see text], [Formula: see text] ) and MeHg concentrations in human hair are unrelated to age and duration of residence in Kuwait but show a positive correlation with the quantity of fish consumed. Levels of Hg in hair also show a tendency to increase in those who prefer to eat the entire fish, including the heads. In general, the concentrations of total and MeHg in fishermens' hair are twice the WHO 'normal' level (2.0 microg g(-1)) but are still less than the WHO threshold level (10.0 microg g(-1)). The results also show that grey hair contains undetectable amounts of Hg and therefore does not reflect individual exposure to this contaminant.     

Assessment of DDT and mercury levels in fish and sediments in the Iriri River,Brazil: Distribution and ecological risk

Abstract

In order to assess the risk of exposure of human populations to dichlorodiphenyltrichloroethane (DDT) and mercury, muscles of five fish species were analysed, along with the surface sediment of 14 Iriri River sampling sites. The fish specimens were sacrificed by the spinal section, prior to sex identification, body weight determination and total length. Considering the fish specimens studied, 11% of them showed concentrations of mercury higher than the maximum established by the World Health Organization for safe human consumption. A positive correlation between fish body weight and mercury concentration was observed, besides a positive correlation between the fish size and Hg concentration. Significant differences (P?<?0.05) were found between mean concentrations of DDT and metabolites among species of fish studied. In the Plagioscion squamossissimus species, the highest concentration of total DDT (151.4?ng/g) was found, while in Eugerres Brasilianus species, the lowest. However, the DDT levels in fish muscle of studied species are below the maximum set by FAO-Alimentarius CODEX. In the sediments, total DDT ranged from 11.58?ng/g to 48.4?ng/g, which is associated with the historical DDT use in the Amazon. According to sediment quality guidelines, these levels have a moderate toxic effect in almost all of the studied region.     

Nationwide monitoring of mercury in wild and farmed fish from fresh and coastal waters of Korea

Mercury (Hg) concentrations were monitored in wild and cultured fish collected from fresh and coastal waters in the Korean peninsula from April 2006 to August 2008 nationwide. Total Hg concentrations were reported for 5043 fish samples, including 78 species from 133 locations. Significant interspecies variation was noted in the Hg levels. The average Hg concentration in each fish species ranged from 6.31 μg kg⁻¹ for mullet (Mugil cephalus) to 200 μg kg⁻¹ for mandarin fish (Siniperca scherzeri). Among the species collected, the maximum concentration of Hg, 1720 μg kg⁻¹, was measured in an Amur catfish (Silurus asotus). Only wild freshwater fish exceeded the WHO ingestion standard. Wild freshwater piscivorous fish samples from a large artificial upstream lake contained the highest Hg levels. Hg concentrations were compared between fish groups categorized as wild and farmed fish from freshwater and coastal waters. Although the wild freshwater fish had similar size ranges, their Hg concentrations were higher than those of the other groups. Compared to the feed of farmed marine and freshwater fishes, the prey of wild freshwater fish had a higher Hg concentration, and the total Hg concentrations in freshwater and associated sediment samples were higher than those in coastal water and associated sediment samples. In the freshwater environment, piscivorous fish bioaccumulated two times more Hg than carnivorous and omnivorous fish and four times more than planktivorous fish. The difference in Hg concentrations among trophic groups might have been due to differences in the size of fish, in addition to the variations among different trophic groups. These data will be useful for developing the fish consumption advisory as a management measure to reduce Hg exposure.     

The relationships between mercury and selenium in plankton and fish from a tropical food web

Background, aim, and scope  Selenium (Se) has been shown to reduce mercury (Hg) bioavailability and trophic transfer in aquatic ecosystems. The study of methylmercury (MeHg) and Se bioaccumulation by plankton is therefore of great significance in order to obtain a better understanding of the estuarine processes concerning Hg and Se accumulation and biomagnification throughout the food web. In the western South Atlantic, few studies have documented trace element and MeHg in fish tissues. No previous study about trace elements and MeHg in plankton has been conducted concerning tropical marine food webs. Se, Hg, and MeHg were determined in two size classes of plankton, microplankton (70–290 μm) and mesoplankton (≥290 μm), and also in muscle tissues and livers of four fish species of different trophic levels (Mugil liza, a planktivorous fish; Bagre spp., an omnivorous fish; Micropogonias furnieri, a benthic carnivorous fish; and Centropomus undecimalis, a pelagic carnivorous fish) from a polluted estuary in the Brazilian Southeast coast, Guanabara Bay. Biological and ecological factors such as body length, feeding habits, and trophic transfer were considered in order to outline the relationships between these two elements. The differences in trace element levels among the different trophic levels were investigated. Materials and methods  Fish were collected from July 2004 to August 2005 at Guanabara Bay. Plankton was collected from six locations within the bay in August 2005. Total mercury (THg) was determined by cold vapor atomic absorption spectrometry (CV-AAS) with sodium borohydride as a reducing agent. MeHg analysis was conducted by digesting samples with an alcoholic potassium hydroxide solution followed by dithizone-toluene extraction. MeHg was then identified and quantified in the toluene layer by gas chromatography with an electron capture detector (GC-ECD). Se was determined by AAS using graphite tube with Pin platform and Zeeman background correction. Results and discussion  Total mercury, MeHg, and Se increased with plankton size class. THg and Se values were below 2.0 and 4.8 μg g⁻¹ dry wt in microplankton and mesoplankton, respectively. A large excess of molar concentrations of Se in relation to THg was observed in both plankton size class and both fish tissues. Plankton presented the lowest concentrations of this element. In fish, the liver showed the highest THg and Se concentrations. THg and Se in muscle were higher in Centropomus undecimalis (3.4 and 25.5 nmol g⁻¹) than in Micropogonias furnieri (2.9 and 15.3 nmol g⁻¹), Bagre spp (1.3 and 3.4 nmol g⁻¹) and Mugil liza (0.3 and 5.1 nmol g⁻¹), respectively. The trophic transfer of THg and Se was observed between trophic levels from prey (considering microplankton and mesoplankton) to top predator (fish). The top predators in this ecosystem, Centropomus undecimalis and Micropogonias furnieri, presented similar MeHg concentrations in muscles and liver. Microplankton presented lower ratios of methylmercury to total mercury concentration (MeHg/THg) (34%) than those found in mesoplankton (69%) and in the muscle of planktivorous fish, Mugil liza (56%). The other fish species presented similar MeHg/THg in muscle tissue (of around 100%). M. liza showed lower MeHg/THg in the liver than C. undecimalis (35%), M. furnieri (31%) and Bagre spp. (22%). Significant positive linear relationships were observed between the molar concentrations of THg and Se in the muscle tissue of M. furnieri and M. liza. These fish species also showed significant inverse linear relationships between hepatic MeHg and Se, suggesting a strong antagonistic effect of Se on MeHg assimilation and accumulation. Conclusions  Differences found among the concentrations THg, MeHg, and Se in microplankton, mesozooplankton, and fishes were probably related to the preferred prey and bioavailability of these elements in the marine environment. The increasing concentration of MeHg and Se at successively higher trophic levels of the food web of Guanabara Bay corresponds to a transfer between trophic levels from the lower trophic level to the top-level predator, suggesting that MeHg and Se were biomagnified throughout the food web. Hg and Se were positively correlated with the fish standard length, suggesting that larger and older fish bioaccumulated more of these trace elements. THg, MeHg, and Se were a function of the plankton size. Recommendations and perspectives  There is a need to assess the role of selenium in mercury accumulation in tropical ecosystems. Without further studies of the speciation of selenium in livers of fishes from this region, the precise role of this element, if any, cannot be verified in positively affecting mercury accumulation. Further studies of this element in the study of marine species should include liver samples containing relatively high concentrations of mercury. A basin-wide survey of selenium in fishes is also recommended.     

Source Type Evaluation of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Sediments from the Muar River and Pulau Merambong,Peninsular Malaysia

This article is the most recent report of polycyclic aromatic hydrocarbons (PAHs) in the Muar River and Pulau Merambong, Peninsular Malaysia. A total of 16 priority pollutant PAHs in addition to methylphenanthrene among alkylated PAHs were analyzed in surface sediments during May 2013. Total PAHs ranged from 212 to 440 and 151 to 412 ng g^?1 dw in sediments from the Muar River and the Pulau Merambong, respectively. The Muar River showed an increasing trend of PAH concentrations, while no previous data exist for the Pulau Merambong. Generally, mixed petrogenic and pyrogenic sources of PAHs with predominance of the latter were detected in the study area. Effective management of oil pollution has caused a drastic decrease in petrogenic sources of PAHs.     

Total mercury, methyl mercury, and carbon in fresh and burned plants and soil in Northwestern Ontario

Terrestrial plants and soil contain substantial amounts of organic carbon (C) and mercury. Flooding terrestrial areas stimulates microbial methyl mercury (MeHg) production and fish obtain elevated MeHg concentrations. Our purpose was to determine the loss of C, total mercury (THg), and MeHg from boreal plants and soil after burning to assess the potential of burning before flooding to lower MeHg. Fresh plants contained 4 to 52 ng g(-1) dry weight (dw) of THg and 0.1 to 1.3 ng g(-1) dw of MeHg. Upland soils contained 162+/-132 ng g(-1) dw of THg and 0.6+/-0.6 ng g(-1) dw of MeHg. Complete burning caused plants to lose 96, 98, 97, and 94% of the mass, C, THg, and MeHg, respectively. Upland soil lost 27, 95, 79, and 82% of the mass, C, THg, and MeHg, respectively. Our results demonstrated that a substantial loss of C, THg, and MeHg was caused by burning.     

Total mercury and mercury species in birds and fish in an aquatic ecosystem in the Czech Republic

Total mercury and mercury species (methylmercury-MeHg, inorganic mercury--Hg(2+)) were determined in the aquatic ecosystem Záhlinice (Czech Republic). Four tissues (muscle, intestines, liver and kidney) of three bird species--cormorant, great crested grebe and Eurasian buzzard, muscle tissues of common carp, grass carp, northern pike, goldfish, common tench, perch and rudd, aquatic plants (reed mace and common reed), sediments and water were analysed. Relative contents of MeHg (of total Hg) were in the range from 71% to 94% and from 15% up to 62% in the muscle and intestines and in liver, respectively, for all birds. Statistically significant differences were found between contents of MeHg in liver tissues of young and adult cormorant populations (F(4.60)=56.71, P<10(-5)). Relative contents of MeHg in muscle tissues of fishes were in the range from 65.1% to 87.9% of total Hg.