Fish and Wildlife Advisory News - April 2003

Recent Advisory News

• South Carolina Issues Swordfish Consumption Warning - On April 1, South Carolina environmental officials added locally caught swordfish to the list of mercury-contaminated fish that people should avoid eating in large amounts. Most of the swordfish served locally in South Carolina restaurants and fish markets comes from Florida, which has not issued warnings against eating swordfish. The State’s annual fish consumption advisory listing, issued by the Department of Health and Environmental Control, currently warns against eating specific fish species from 53 rivers and lakes in the state because of high mercury levels.

  Source: Ken Coons. www.seafood.com. Seafood.com News, April 2, 2003.

Current Events, News and Journal Articles

• Mercury Labeling of Canned Tuna Urged by CA Medical Association and Advocates; JAMA Reflects Growing Exposure Concerns - In California, the issue of mercury-contamination of canned tuna reached new heights with the adoption of a resolution by the California Medical Association (CMA) urging the labeling of canned tuna. This action was taken after release of medical reports of mercury poisoning of patients in San Francisco who consumed canned tuna. The CMA became concerned about the clinical implications for people who are being told to eat more fish for health reasons. Consumption of mercury contaminated fish is a primary exposure pathway humans for methylmercury and canned tuna is one of the most consumed fish in the United States today. To date, ten states warn pregnant women and children to limit consumption of canned tuna. For more information, see the Mercury Policy Project Web site at www.mercurypolicy.org.

  Source: Mercury Labeling of Canned Tuna Urged by CA Medical Association and Advocates; JAMA Reflects Growing Exposure Concerns. U.S. Newswire, April 1, 2003.

• Blood Mercury Levels in US Children and Women of Childbearing Age - The authors of this report provide results of the 1999-2000 National Health and Examination Survey (NHANES) study that examined blood mercury levels in 705 children aged 1-5 and 1,709 women aged 16-49 years. Results of the study show that blood concentrations of total mercury were about 3 times higher in women of child bearing age compared to children. Geometric mean mercury concentrations were nearly four times higher among women who had eaten 3 fish meals in the 30 days prior to the blood sample collection date as compared to women who ate no fish in that period. Blood mercury levels also increased with increased frequency of fish consumption. A similar pattern was also apparent for children. The authors present information on total blood mercury concentrations, primarily representing the distribution of exposure to methylmercury via consumption of fish and shellfish. The NHANES data is the first information on the distribution of blood mercury concentrations in the general US population and can serve as a baseline from which future studies can be compared.

  Source: S.E. Schober, T.H. Sinks, R.L. Jones, P.M. Bolger, M. McDowell, J. Osterloh, E.S. Garrett, R.A. Canady, C.F. Dillon, Y. Sun, C.B. Joseph and K.R. Mahaffey, 1999-2000. 2003. Blood Mercury Levels in US Children and Women of Childbearing Age. JAMA 289 (13): 1667-1674.

• PCDD/Fs and PCBs in Baltic Herring during the 1990s - Baltic herring samples collected in the Baltic Sea during the spring of 1993-1994 and 1999 were analyzed for polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), and polychlorinated biphenyls (PCB). There were strong correlations between concentrations of PCDD and PCDF congeners, and age of herring (r>0.8). There were also correlations between PCB congeners and age of herring. Due to higher fat percentage, herring from the Gulf of Bothnia had higher concentrations of PCDD/Fs and PCBs on fresh weight basis than herring from the Gulf of Finland WHO PCDD/F-TEQ concentrations ranged from 1 to 27 pg/g (wet weight), depending on the age and harvest area of the herring, and WHO PCB-TEQ concentrations reached 32 pg/g (wet weight). The authors reported no temporal trends between the two time periods studied.

  Source: Kiviranta, H., T. Vartiainen, R. Parmanne, A. Hallikainen, and J. Koistinen. 2003. PCDD/Fs and PCBs in Baltic herring during the 1990s. Chemosphere 50 (9): 1201-16.

• Environmental Risk assessment of Metals: Tools for Incorporating Bioavailability - The authors discuss processes which affect metal bioavailability and toxicity in the aquatic environment and the implications for metal risk assessment procedures. In addition to chemical processes (speciation, complexation), attention should also focus on physiological aspects for predicting metal toxicity. The authors suggest that the development of biotic ligand models (BLMs), which combine speciation models with biologically oriented models (e.g. GSIM), offers promise. The BLMs which have been developed for a number of metals (e.g. copper, silver, and zinc) and species (algae, crustaceans, fish) are discussed. The authors illustrate the potential of the BLM approach using a theoretical exercise in which chronic zinc toxicity to Daphnia magna is predicted in three different regions, taking region-specific physico-chemical characteristics into account.

  Source: Janssen, C. R., D. G. Heijerick, K. A. De Schamphelaere, and H. E. Allen. 2003. Environmental risk assessment of metals: Tools for incorporating bioavailability. Environ Int 28 (8): 793-800.

• Contamination of Fish in Streams of the Mid-Atlantic Region: An Approach to Regional Indicator Selection and Wildlife Assessment - The authors discuss the extent of contamination of fish in the Mid-Atlantic Region. The evaluation was based on a regional assessment conducted in 1993 as part of the U.S. EPA’s Monitoring and Assessment Program. Fish assemblages from wadeable streams were dominated by small, short-lived fishes (e.g., darters, minnows, and sculpins) that were more widely distributed than larger fishes typically selected for tissue contaminant studies (e.g., trout, largemouth bass, sunfish, and carp). Chemical residues in whole-fish homogenates exceeded detection limits for mercury, DDT, and polychlorinated biphenyls (PCBs) in 75 to 100% and 84 to 100% of the streams assessed using small fishes and large fish, respectively. The authors developed Wildlife values (WVs) representing a threshold for toxic effect to allow for evaluation of the spatial extent of potential risk to fish. For mercury, DDT, dieldrin, and chlordane, estimates of the extent of streams where fish tissue concentrations exceeded the WVs were greater when based on small fishes than on large fishes. These authors demonstrate that the greater abundance and distribution of small fishes provide better estimates of the extent of contamination for first- through third-order streams and can be used for regional assessments of potential wildlife exposure.

  Lazorchak, J. M., F.H. McCormick, T.R. Henry, and A. T. Herlihy. 2003. Contamination of fish in streams of the Mid-Atlantic Region: An approach to regional indicator selection and wildlife assessment. Environ Toxicol Chem 22 (3): 545-53.

• Mercury, Arsenic, Lead, and Cadmium in Fish and Shellfish from the Adriatic Sea - Tissue concentrations of total mercury, total arsenic, lead and cadmium were measured in common edible fish and shellfish from the Adriatic Sea. Estimates of the intake of these elements were calculated based on seafood consumption of the general population. The highest mercury and arsenic levels were found in hake (Merluccius merluccius) and the lowest in mackerel (Scomber scombrus). Lead and cadmium levels were almost 10 times higher in shellfish than in finfish. The highest lead and cadmium levels were found in mussel (Mytilus galloprovincialis) and the lowest in hake. Concentrations of all analysed metals were below acceptable levels for human consumption established by the Croatian Ministry of Health, except for total arsenic. Estimated intake of these trace elements through seafood consumption by the general population did not exceed the provisional tolerable weekly intake recommended by the Joint FAO/WHO Committee on Food Additives.

  Source: Juresa, D. and M. Blanusa. 2003. Mercury, arsenic, lead, and cadmium in fish and shellfish from the Adriatic Sea. Food Addit Contam 20 (3): 241-6.

• Age- and Size-specific Patterns of Heavy Metals in the Organs of Freshwater Fish Abramis Brama L. Populating a Low-Contaminated Site - Concentrations of cadmium, copper, mercury, lead, and zinc were determined in muscle, gill, and liver tissue of bream (Abramis brama L.) to evaluate the relationship between the metal load and fish age and size, and the seasonal variation of pollutant loads. Fish were harvested from the Western basin of Lake Balaton (Hungary) in October 1999 and May 2000. Mean metal concentrations (on a dry weight basis) of different organs varied for each pollutant. The highest Cd, Cu, Pb and Zn levels were detected in the gill or liver tissue, whereas the highest Hg levels were measured in muscle. Pearson correlation analysis revealed positive associations related to age and size (length, net weight) in the liver of bream for cadmium, and copper, as well as for muscle, gill, and liver for mercury. In the muscle and gill, copper, lead and zinc concentrations, revealed negative associations related to age and size. For liver, lead and zinc concentrations also revealed negative associations related to age and size. The seasonal variations in the heavy metal load of bream could be attributed to seasonal changes in the condition factor of fish rather than to variations in the pollutant load.

  Source: Farkas, A., J. Salanki, and A. Specziar. 2003. Age- and size-specific patterns of heavy metals in the organs of freshwater fish Abramis brama L. populating a low-contaminated site. Water Res 37 (5): 959-64.

• Release of Mercury from Broken Fluorescent Bulbs - Although the primary human exposure pathway to mercury is from ingestion of fish contaminated with methyl mercury (HgCH3), exposures to elemental mercury vapor and mercury compounds via inhalation and dermal contact may also occur. Fluorescent light bulbs contain mercury. Estimates of the total amount of mercury released when these bulbs are discarded varied widely. The authors developed a new method for measuring mercury released from broken bulbs. The authors assumed that all mercury released is as the elemental vapor and they found that between 17-40% of mercury in broken fluorescent bulbs is released to the air during a 2-week period immediately following breakage. In addition, higher temperatures contributed to higher mercury release rates. The authors found that one-third of the mercury released occurs during the first 8 hr post-breakage. Typically, a discarded bulb releases between 3 and 8 mg of elemental mercury vapor over a 2-week period. In the U.S., an estimated 620 million fluorescent bulbs are discarded annually, and many are broken during disposal. Based on the estimated release rate (3-8 mg per broken bulb), discarded bulbs release about 4,000- 8,000 pounds of mercury per year in the US.

  Source: Aucott, M., M. McLinden, and M Winka. 2003. Release of mercury from broken fluorescent bulbs. J Air Waste Manag Assoc 53 (2): 143-51.

• Bile Metabolites of Polycyclic Aromatic Hydrocarbons (PAHs) in European Eels (Anguilla anguilla) from United Kingdom estuaries - European eels (Anguilla anguilla) were collected from five estuaries in the UK. The deconjugated metabolites of polycyclic aromatic hydrocarbons (PAHs) in the bile of the eels were identified: 1-hydroxy (1-OH) metabolites of phenanthrene, pyrene and chrysene; and the 1-OH, 3-OH and 7,8 dihydrodiol metabolites of benzo[a]pyrene (BaP). Mean concentrations of the six metabolites were highest in eels from the Tyne (49 microM) followed by the Wear (33 microM), Tees (19 microM), Thames (4 microM) and Severn (2 microM) estuaries. The dominant compound in each case was always 1-OH pyrene, although there were significant differences (P<0.05) among sites and estuaries for some metabolites. When metabolites identified were expressed as a percentage of the total detected, the metabolite profile was characteristic for each estuary.

  Source: Ruddock, P. J, D. J. Bird, J. McEvoy, and L.D. Peters. 2003. Bile metabolites of polycyclic aromatic hydrocarbons (PAHs) in European eels (Anguilla anguilla) from United Kingdom estuaries. Sci Total Environ 301 (1-3): 105-17.

• Heavy Metal Contamination in the Taimyr Peninsula, Siberian Arctic - Although the Taimyr Peninsula is directly north of the world's largest heavy metal smelting complex (Norilsk, Russia), there has been little research to examine the extent of contamination of the Taimyr Peninsula biota and environment. The authors analyzed heavy metal concentrations in lichen (Cetraria cucullata), moss (Hylocomium splendens), soils, lake sediment, freshwater fish (Salvelinus alpinus, Lota lota and Coregonus spp.), and collared lemming (Dicrostonyx torquatus) from 13 sites between 30 and 300 km from Norilsk. Metal concentrations were low in both the lichens and moss species, although concentrations of Al, Fe, Cu, Ni, and Pb were significantly higher than those in Arctic Alaska. Surface soils had significantly higher levels of Cd, Zn, Pb, and Mg than soils at depth and lake sediment cores indicated no recent enrichment by atmospherically-transported elements. Heavy metal tissue concentrations in fish and lemming were not elevated relative to other Arctic sites. Results show that the impact of the smelting complex is primarily localized rather than regional, and does not extend northward beyond 100 km.

  Source: Allen-Gil, S. M., J. Ford, B. K. Lasorsa, M. Monetti, T. Vlasova, and D.H. Landers. 2003. Heavy metal contamination in the Taimyr Peninsula, Siberian Arctic. Sci Total Environ 301 (1-3): 119-38.

• Distribution and Relationships of Mercury, Lead, Cadmium, Copper, and Zinc in Perch (Perca fluviatilis) from the Pomeranian Bay and Szczecin Lagoon, southern Baltic - Perch (Perca fluviatilis) from lakes and estuarine areas in the southern Baltic region were investigated for concentrations of zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), and mercury (Hg) in muscle and liver samples. Analysis of variance revealed significant seasonal variations in the tissue concentration results obtained. Winter muscle samples contained higher residues of Cd, Hg, and Pb than summer samples. Muscle Hg and hepatic Cu, Pb and Cd levels increased with the age of the fish. Maximum levels of muscle Pb and Cd detected (0.033 and 0.043 ppm wet wt.) did not constitute a health threat for fish consumers. Maximum levels of muscle Hg detected (0.12 ppm wet wt.) corresponded to 0.1 ppm methylmercury/g wet wt. For people consuming 100-150 g fish flesh daily, this would result in a weekly intake of about 70-105 µg methylmercury, which is below the WHO Provisional Tolerable Weekly Intake of 200 µg.

  Source: Szefer, P., M. Domagala-Wieloszewska, J. Warzocha, A. Garbacik-Wesolowska, and T. Ciesielski. 2003. Distribution and relationships of mercury, lead, cadmium, copper, and zinc in perch (Perca fluviatilis) from the Pomeranian Bay and Szczecin Lagoon, southern Baltic. Food Chemistry 81 (1): 73- 83.

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For more information on EPA's Fish and Wildlife Contamination Program, contact: Jeffrey Bigler at US EPA, 1200 Pennsylvania Ave., NW (4305), Washington, DC 20460; email: bigler.jeff@epa.gov.