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1.
Hair is a useful indicator of a person’s exposure to mercury. For this reason, hair samples from 94 fertile and 117 subfertile Hong Kong residents were compared over four separate age groups. A typical 30 year old Hong Kong male had a hair mercury concentration of approximately 3.3 mg/kg mercury while a 60 year old Hong Kong subfertile male had a hair mercury concentration of about 7.5 mg/kg. Most of this mercury comes from seafood consumption. Individuals consuming four or more meals of fish per week had a hair mercury of 4.07 mg/kg dry weight of hair while those consuming fish less frequently had significantly lower levels (2.56 mg/kg). Hong Kong residents that consumed no fish had only 1.21 mg/kg hair mercury. The relative risks of males with moderate and high levels of mercury in their hair were significant (p=0.062). Age corrected estimates of risk indicated that compared with men with low levels of mercury in their hair, men with higher levels were twice as likely to be subfertile (relative risk, 1.95) and there was a dose–response trend that was highly significant (p < 0.0005). In light of these risks we concluded that the maximum permitted mercury level in food sold in Hong Kong should be lowered from 0.5 mg/kg wet weight to a level to be determined by risk analysis. In Japan, where fish mercury levels and fish consumption rates are lower than those in Hong Kong, the maximum amount of mercury permitted in food for human consumption is 0.3 mg/kg wet weight.  相似文献   

2.
A statewide survey of Tasmanian coastal waters has shown that Platycephalus bassensis, a widespread, easily-caught, non-migratory demersal finfish, is a useful indicator species for mercury pollution. Using approximately twelve fish at each of 31 locations, the mean total mercury concentration in the muscle tissue ranged from 0.03 to 1.06 mg/kg (fresh wt basis), and clearly demonstrated a site dependence for mercury uptake in this species. The correlation between mercury concentration and fish size is shown to be valid only if the effect of location is taken into account. Even then, size accounts for only about 10% of the total variability in mercury concentration.  相似文献   

3.
Total mercury was analyzed as a function of body length, season, and diet in four commercially and recreationally important marine fish, bluefish (Pomatomus saltatrix), goosefish (Lophius americanus), silver hake (Merluccius bilinearis), and summer flounder (Paralichthys dentatus), collected from continental shelf waters of the northwest Atlantic Ocean. Mercury levels in the dorsal muscle tissue of 115 individuals ranged from 0.006 to 1.217 μg/g (wet weight) and varied significantly among species. The relationship between predator length and mercury concentration was linear for bluefish and summer flounder, while mercury levels increased with size at an exponential rate for silver hake and goosefish. Mercury burdens were the highest overall in bluefish, but increased with size at the greatest rate in silver hake. Seasonal differences were detected for bluefish and goosefish with mercury levels peaking during summer and spring, respectively. Prey mercury burdens and predator foraging habits are discussed as the primary factors influencing mercury accumulation.  相似文献   

4.
Concentrations of mercury and methylmercury residues were determined in the muscle tissue of three cartilaginous fishes Chimaera monstrosa (ghostshark), Torpedo nobiliana (electric ray) and Myliobatis aquila (eagle ray) from the Mediterranean Sea. The highest mean levels of total mercury were detected in ghostshark (3.14 mg/kg wet weight), followed by electric ray (2.42 mg/kg wet weight), and eagle ray (0.83 mg/kg wet weight). Such a variability is influenced by quite a number of factors, among which size, fish ecology and feeding habits. The percentages of the methylated form to total mercury ranged from a minimum of 72% in eagle ray to a maximum of 83% in ghostshark. Relationship between specimen size and mercury and methylmercury concentrations were found in ghostshark species.  相似文献   

5.
Temperate and tropical shallow lakes differ in several fundamental aspects with respect to management of eutrophication. High altitude tropical shallow lakes are a special case, showing similarities with temperate and tropical lakes. We studied the ecology of the eutrophic high-altitude tropical lake Yahuarcocha in the Ecuadorian Andes and evaluated the potential of biomanipulation to control eutrophication. With a toxin-producing Cylindrospermopsis bloom, low Secchi depth and low submerged macrophyte cover, Yahuarcocha is clearly in a turbid ecosystem state. Relatively low nutrient concentrations should theoretically allow for a shift to a clear water state through biomanipulation. Top-down control of phytoplankton by zooplankton, however, is complicated by the (1) absence of predatory fish, (2) fish community dominated by small poecelid species, (3) lack of a refuge for zooplankton from fish predation within the macrophytes, and (4) persistent, grazing resistant bloom of the cyanobacterium Cylindrospermopsis. In these aspects, lake Yahuarcocha is more similar to tropical shallow lakes, probably because water temperature is high relative to the mean air temperature and because of the absence of a cold season. The fish and macrophyte communities consisted almost entirely of exotic species. The exotic fish species probably stabilized the turbid state in the lake.  相似文献   

6.
Carcinus maenas is an important and exploited natural resource in temperate estuaries, being consumed by local populations and also used as fish bait. Through bioaccumulation and bioamplification processes occurring in polluted estuarine ecosystems, this species may directly or indirectly represent a major pathway for Human contamination. No information is available on the overall lifespan bioaccumulation pattern of mercury for this species, which would be an invaluable tool for assessing the risks associated with C. maenas harvest in contaminated areas. Taking that in mind, the main objectives of this work were to clarify the lifespan bioaccumulation pattern of mercury for this species. A consistent lifespan accumulation pattern was found for this species, both for total and organic mercury, and coherent differences were found between genders, suggesting different physiological responses to contamination. From our results two scenarios emerge: (a) for low mercury contamination areas where the diet is the major pathway for metal uptake, with higher levels in muscle and hepatopancreas (twice as high as in gills) and higher organic mercury fractions (as high as 80-90% in muscle), crabs bioaccumulate with age and (b) on high contaminated areas, environmental exposure is predominant, with higher levels found in gills (reaching 0.8 mg kg(-1)), lower organic fractions and no mercury increment with age. Detoxification strategies, dietary differences and species mobility may account for these two accumulation patterns.  相似文献   

7.
《Marine pollution bulletin》2014,78(1-2):235-245
The major aim of this study was to investigate heavy metal content of edible fish in the PRD. Eleven species of fish (consisting of 711 individuals) [catfish (Clarias fuscus), tilapia (Oreochromis mossambicus), grass carp (Ctenopharyngodon idellus), bighead carp (Aristichthys nobilis), mandarin fish (Siniperca kneri), snakehead (Channa asiatiea), black bass (Micropterus salmoides), mangrove snapper (Lutjanus griseus), star snapper (Lutjanu stellatus), snubnose pompano (Trachinotus blochii) and orange-spotted grouper (Epinephelus coioides)] were collected for the analyses of heavy metals. Overall concentrations (mg/kg, ww) in the fish muscles were: As (0.03–1.53), Pb (0.03–8.62), Cd (0.02–0.06), Ni (0.44–9.75), Zn (15.7–29.5), Cr (0.22–0.65), Cu (0.79–2.26), Mn (0.82–6.91). Significant level of Pb were found in tilapia at all locations. It is recommended that heavy metal concentrations in different fish species must be determined on a regular basis in the future so as to reduce human health risks from acute and chronic food intoxication.  相似文献   

8.
Mercury can accumulate in the human body from fish and from other environmental sources, and the amount accumulated is indicated by hair mercury concentration. Anthropogenic mercury losses in many countries have been correlated with Gross National Product (GNP, an indicator of industrial activity), and industrial density (represented by GNP/land area, i.e. GNP/LA) has been used as an indicator of potential pollution for coastal fishing grounds. For a data set taken from the literature, 30% of the 54% variability in hair mercury concentrations explained by national fish consumption can also be explained by GNP/LA. However, using new data, the effect of GNP and GNP/LA on the amount of mercury accumulated in hair of people from many countries was insignificant compared to the effect of national fish consumption. 74.1% of the variability in the hair mercury levels of people who ate the same number of meals of fish was explained by the national average fish consumption. This suggests that fish species and fish size are more important than general indicators of mercury pollution when estimating the mercury accumulation in humans on an international scale.  相似文献   

9.
Mercury concentrations in stomach contents and muscle tissue are reported for five fish species: herring (Clupea harengus), whiting (Merlangius merlangus), roker (Raja clavata), plaice (Pleuronectes platessa) and dab (Limanda limanda) collected in summer 1992 off the mouth of the River Tyne, North East England. Median muscle mercury concentrations in the area increase in the order plaice < herring < roker < dab < whiting. Absolute mercury concentrations and muscle mercury-length relationships indicate that the environmental availability of mercury in the study area is low. Stomach contents were recovered from dab, plaice and roker only. Median mercury concentrations in stomach contents increased in the order plaice < roker < dab. The variability of the ratio (muscle mercury/stomach content mercury) has been examined for these three species. In dab the variation is relatively low (39.7% RSD), whereas in plaice and roker it is considerably higher (128.4% and 184.6%, respectively). If stomach content mercury concentrations accurately reflect local mercury availability then dab muscle tissue would make a more reliable availability index than muscle tissue of plaice or roker.  相似文献   

10.
Dorsal muscle tissue from 712 red drum, Sciaenops ocellatus, from Florida waters were analyzed for total mercury content. Mercury levels detected in these red drum varied but in most study areas were usually lower than regulatory threshold guidelines. Total mercury levels in individual fish from all study areas ranged from 0.020 to 3.6 ppm (wet weight). Total mercury levels detected in red drum from the Florida Keys-Florida Bay area were often higher than those in fish from all other estuarine study areas. Positive relationships between total mercury levels and fish size (length and weight) and fish age were observed in most Florida study areas, indicating that mercury levels tend to increase over time as red drum grow. The majority of large, mature red drum examined contained mercury levels greater than the 0.5-ppm threshold level set by the Florida Department of Health (DOH). Approximately 94% of all adult red drum from offshore waters adjacent to Tampa Bay contained mercury levels greater than or equal to the 0.5-ppm threshold level, and 64% contained levels greater than or equal to the DOH 1.5-ppm "no consumption" level. All fish from this area with mercury levels greater than 1.5 ppm were large individuals (670 mm SL). Eight percent of legal-size red drum from Florida waters contained total mercury levels greater than or equal to the 0.5-ppm threshold level. The majority (52%) of these legal-size fish greater than or equal to 0.5 ppm were from the Florida Keys-Florida Bay area. In the Florida recreational fishery, the current maximum size limit for this species is an effective filter that prevents humans from consuming those red drum with the greatest likelihood of containing high mercury levels.  相似文献   

11.
The focus of this work is to explore the use of the netted whelk, Nassarius reticulatus (L.), as an indicator of mercury (Hg) contamination, by assessing the concentration of Hg in the sediments and in the whelk along the entire Portuguese coast. Total Hg concentrations ranged from below the detection limit (0.01 ng absolute mercury) up to 0.87 mg kg(-1) dry weight (dwt) in sediments and between 0.06 and 1.02 mg kg(-1) (dwt) for organisms, with no significant differences between males and females. Although organic mercury was not detected in the sediments, it represented, on average, 52% of the total Hg in the whelk tissues, and as high as 88% in some cases, suggesting mercury accumulation from dietary intake. Significant negative correlations were found between the total Hg concentrations in the sediments and the log(10) of Hg concentrations in whelk tissues males (r=-0.64; P<0.01) and females (r=-0.52; P<0.01) indicating that the species is a poor indicator of Hg contamination. Nevertheless, since the highest concentrations of organic mercury in the whelk tissues were found in the least contaminated areas, this species must be highly relevant in the trophic web, namely on the possible biomagnification of mercury. The high dietary mercury accumulation from feeding on carrion and the low bioavailability of mercury to whelks in estuarine sediments may be the basis of the mercury accumulation pattern in N. reticulatus.  相似文献   

12.
We characterize for the first time the presence of DDT and its metabolites in tropical Galapagos sea lions (Zalophus wolleabeki). ∑DDT concentrations in Galapagos sea lion pups sampled in 2005 and 2008 ranged from 16 to 3070 μg/kg lipid. Concentrations of ∑DDT in pups in 2008 averaged 525 μg/kg lipid and were 1.9 times higher than that (281 μg/kg lipid) detected in pups in 2005. These concentrations are lower than those reported in many pinnipeds elsewhere, comparable to those in Hawaiian monk seals, and higher than those in southern elephant seals. The health risk characterization showed that 1% of the male pups exceeded the p,p′-DDE toxic effect concentration associated with anti-androgenic effects reported in rats. The findings provide preliminary guidance on the relationship between DDT use and ecological impacts, serving as a reference point against which possible future impact of tropical DDT use can be assessed.  相似文献   

13.
During the last few decades, the combined effects of natural and human activities acting on the Mediterranean Sea basin have caused a reduction in the swordfish (Xiphias gladius, L. 1758) population. In this project, we investigated the accumulation of lead (Pb), cadmium (Cd) and mercury (Hg) levels in the Atlantic and Mediterranean populations of swordfish during a five-year survey. In the marine environment, top predators such as swordfish accumulate high concentrations of toxic metals, and thus, potentially incur a high toxicological risk. Furthermore, heavy metals, such as chemical pollutants, have strong long-term effects on fish, and thus, constitute a high risk for the resource and humans that consume it. The aim of this work is to contribute to the assessment of the state of European swordfish population health. We analyzed muscle tissue from 56 specimens captured in Mediterranean and Atlantic areas for trace elements. Mean concentrations of Hg, Cd, and Pb were in the following ranges: 0.66-2.41, 0.04-0.16, and 0.97-1.36 mg/kg ww, respectively. These data suggest a need for continuous monitoring to avoid reductions in the population of this fish species of high commercial and ecological interest.  相似文献   

14.
In the present study, we sought to determine the concentration of several trace elements (total and organic mercury, selenium, cadmium, lead, arsenic, copper, chromium, iron, manganese, molybdenum, vanadium and zinc) in muscle tissue of gilthead seabream (Sparus aurata), an edible finfish species that is widely cultured in the Mediterranean area. The phenomenon of bioaccumulation and bioamplification (especially of mercury) was investigated by comparing farmed fish with wild specimens of the same species. Farmed specimens showed mercury and arsenic concentrations significantly lower than wild specimens, and no relationship was found between mercury concentration and body size. The lower level of methylmercury in farmed fish has important implications for consumer health.  相似文献   

15.
《Marine pollution bulletin》2014,78(1-2):428-433
In November 2011 gold was found at Mount Botak, Buru Island, Mollucas Province, Indonesia. Since 2012 mercury has been used to extract the gold requiring large volumes of water and resulting in deposition of mercury into Wamsait River and Kayeli Bay. Total mercury in waste ponds was over 680 mg/kg. In sediments at the mouth of the local river and a small feeder creek >3.00 mg/kg and >7.66 mg/kg respectively. River and bay sediments were proportionately higher in available mercury than elemental mercury and more strongly bound mercuric sulfide compared to that in trommel waste. This preliminary investigation raises concerns about the long term distribution and speciation of mercury. The floodplain is an important agricultural resource, and Mollucas Province is recognised nationally as the centre for Indonesian fish stocks. Challenges for management include communicating the potential future risks to the community and leaders and identifying mechanisms to reduce mercury waste.  相似文献   

16.
During April 1975 thirty-six muscle samples of six predacious species of fish from the Andaman sea were collected for an analysis of their total mercury concentrations. The total mercury levels ranged from 0.026 to 0.234 ppm in yellowfin tuna (Neothunnus albacora), from 0.027 to 0.233 ppmin bigeye tuna (Parathunnus sibi), and from 0.057 to 0.478 ppm in four species of shark. Statistical analysis also showed positive linear regression and there was correlation between the mercury concentration and the weight of the yellowfin tuna, bigeye tuna, and shark. The rates of total mercury accumulation in yellowfin and bigeye tuna were not significantly different. A comparison between the total mercury level in the Andaman yellowfin and the Central Pacific yellowfin tuna is discussed.  相似文献   

17.
Little is known about the impacts of mine waste disposal, including deep-sea tailings, on tropical marine environments and this study presents the first account of this impact on deepwater fish communities. The Lihir gold mine in Papua New Guinea has deposited both excavated overburden and processed tailings slurry into the coastal environment since 1997. The abundances of fish species and trace metal concentrations in their tissues were compared between sites adjacent to and away from the mine. In this study (1999-2002), 975 fish of 98 species were caught. Significantly fewer fish were caught close to the mine than in neighbouring regions; the highest numbers were in regions distant from the mine. The catch rates of nine of the 17 most abundant species were lowest, and in three species were highest, close to the mine. There appears to be limited contamination in fish tissues caused by trace metals disposed as mine waste. Although arsenic (several species) and mercury (one species) were found in concentrations above Australian food standards. However, as in the baseline (pre-mine) sampling, it appears they are accumulating these metals mostly from naturally-occurring sources rather than the mine waste.  相似文献   

18.
After the Hebei Spirit oil spill incident (7th December, 2007) in the west coast of Korea, contamination of biliary PAH metabolite and hepatic biomarkers in a pelagic and a benthic fish was monitored for 1 year. Concentrations of 16 PAHs and alkylated PAHs in fish muscle were highest (22.0 ng/g d.w. for 16 PAHs and 284 ng/g d.w. for alkylated PAHs) at 5 days after the spill and then decreased rapidly to background levels at 11 months after the spill. Fish from the oiled site had elevated biliary PAH metabolite concentrations immediately after the spill; these declined steadily in both species, but were still above reference site concentrations 2 months after the spill. Oiled-site fish showed hepatic CYP 1A induction whose trend closely followed those of biliary PAH metabolite concentrations, implying continuous exposure to PAHs. Brain acetylcholinesterase activity was not related to oil exposure.  相似文献   

19.
Investigations were made of 212 fish samples of eight fish species from 29 lakes of the Schwerin county. Determinations were made gas-chromatographically after chemical derivatization. In lakes with a low anthropogenic load the following concentrations were found: 0.05 mg/kg DDT, 0.03 mg/kg PCB. In lakes with higher pollution, the concentrations were 0.21 mg/kg DDT and 0.42 mg/kg PCB. The limit of tolerance for foodstuffs was never exceeded and predatory fish did not show higher concentrations than non-predacious fish. For ten eels, however, the mean contents were 1.6 mg/kg DDT and 0.36 mg/kg PCB. The total content of DDT in all fishes was composed as follows: 70 … 75% p,p′-DDE, 15 … 20% p,p′-DDD and 5 … 10% p,p′-DDT. Trout from an intensive-breeding plant contained 0.16 mg/kg DDT and 0.04 mg/kg PCB from the contaminated feed. By means of a change-over to different feed the contents were reduced to 0.03 mg/kg DDT and 0.04 mg/kg PCB.  相似文献   

20.
We relate fish biological and ecological characteristics to total and organic mercury concentrations to determine whether accumulation is influenced by trophic level, Hg concentration in the diet, and vertical distribution. Levels of total mercury and methylmercury were determined in the muscle tissue of eight species of fish: Pagellus acarne, Trachurus picturatus, Phycis phycis, P. blennoides, Polyprion americanus, Conger conger, Lepidopus caudatus and Mora moro, caught in the Azores. All such fishes are commercially valuable and were selected to include species from a wide range of vertical distributions from epipelagic (<200 m) to mesopelagic (>300 m) environments. Methylmercury was the major form accumulated in all species, comprising an average of 88.1% of total mercury. Concentrations of mercury (total and methylmercury) increased with age, length and weight. Based on data from other studies, mercury concentrations in fish diet were estimated. Mercury levels in food ranged from 0.08 to 0.32 ppm, dry weight. Hg concentrations in the food and in muscle tissue from different species were positively correlated. Total Hg levels in the muscles were approximately nine times those estimated in food. Total mercury concentrations in muscle were positively correlated with both trophic level and median depth. Such enhanced mercury bioaccumulation in relation to depth appears to be determined primarily by concentrations in food and ultimately by water chemistry, which controls mercury speciation and uptake at the base of the food chain.  相似文献   

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