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Water: News

Newsletter—April 2011

 The mouth of the Oak Orchard River in the town of Carlton, Orleans County, New York.  (Photograph by Matthew D. Wilson, licensed under the Creative Commons Attribution-Share Alike 2.5 Generic license.)

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Recent Advisory News

EPA mercury rules hailed as help for NY lakes

Environmental groups say that new federal standards proposed by the U.S. Environmental Protection Agency (EPA) to limit coal-fired power plant air pollutants, including mercury, are a major step toward reversing damage to New York's lakes. Neil Woodworth, executive director of the Adirondack Mountain Club, said the new standard will cut mercury emissions from power plants by 91 percent. Studies by the Hubbard Brook Research Foundation in Hanover, N.H., in 2007 estimated that 40 to 65 percent of mercury deposition in the Northeast was caused by coal-fired power plants. Those studies also found that mercury levels in fish and wildlife can decline quickly in response to decreased airborne mercury emissions.

Link to original article: http://www.boston.com/news/local/new_hampshire/articles/2011/03/20/epa_mercury_rules_hailed_as_help_for_ny_lakes/. Exit EPA Disclaimer

The Associated Press via The Boston Globe, www.boston.com (MA), 3/20/2011.

Arkansas Game and Fish Commission report on the studies on mercury loadings of fish

A study last year showed high mercury levels in fish from certain areas of the Lower Ouachita River System in Arkansas. Periodic evaluations have been done since mercury was discovered in the waters in the early 1990s. The most recent data, collected by the Arkansas Game and Fish Commission in 2010, show that mercury levels in some sizes of fish from the Felsenthal Reservoir and the Saline River System exceed the Arkansas Department of Health mercury action level. The Game and Fish Commission recommended that the Arkansas Department of Health reword mercury advisories for the Lower Ouachita and Saline Rivers and continue to inform the public about the risks of consuming excess mercury.

Link to original article: http://www.thegurdontimes.com/topstories/x13285160/Arkansas-Game-and-Fish-Commission-report-on-the-studies-on-mercury-loadings-of-fish Exit EPA Disclaimer

Source: The Gurdon Times (AR), 3/18/2011.

Scientist questions safety of Gulf seafood

One scientist interviewed by a Louisiana television station said she is concerned about polycyclic aromatic hydrocarbon (PAH) levels in Gulf seafood after last year’s Deepwater Horizon oil spill. Dr. Wilma Subra, a chemist who served as the Vice Chair of the Environmental Protection Agency (EPA) National Advisory Council for Environmental Policy and Technology and as a consultant to the government during the oil spill, wants the FDA and EPA to increase testing of gulf seafood. However, the Louisiana Seafood Promotion and Marketing Board, which has worked closely with the EPA and the FDA during and since the oil spill, says that seafood has been tested and is safe to eat, and that current testing is rigorous and will continue for many years to come.

Link to original article: http://www.katc.com/news/scientist-questions-safety-of-gulf-seafood Exit EPA Disclaimer

KATC.com (LA), 2/28/2011.

Fish oil fights wasting during chemotherapy

Results from a small study of 40 patients have shown that fish oil supplements may help prevent weight and muscle loss during chemotherapy for non-small cell lung cancer (NSCLC). Patients who started taking fish oil when they began 10 weeks of chemotherapy actually gained about a pound each, and those in the control group lost about 5 pounds each by time their chemotherapy had ended. Muscle mass increased or stayed the same for 69% of patients taking the fish oil supplements, compared with only 29% among controls. Weight loss among advanced cancer patients is associated with reduced survival, the researchers noted, and loss of muscle mass also affects a patient’s eligibility for additional types of treatment.

Link to original article: http://www.medpagetoday.com/HematologyOncology/Chemotherapy/25081 Exit EPA Disclaimer

Source: MedPageToday.com, 2/28/2011.

Senators ask FDA to up seafood consumption recommendations

Senators Kirsten Gillibrand (D-New York) and obstetrician Tom Coburn, MD (R-Oklahoma) are asking the FDA to raise the maximum amount of seafood it recommends for women and children to eat. Based on a survey conducted by the FDA in 2008, seafood consumption had fallen to less than two ounces per week on average after joint FDA and EPA fish consumption advice was released in 2004. Currently the FDA and EPA advise young children and pregnant/nursing women to eat up to 12 ounces a week of fish, chosen from species low in mercury such as salmon and cod. “While the guidance is in many ways medically accurate, the recommendations communicate an overly risk-averse, precautionary principle that has led to unhealthy reductions in seafood consumption among pregnant women,” the senators wrote.

Link to original article: http://fis.com/fis/worldnews/worldnews.asp?monthyear=&day=16&id=41213&l=e&special=&ndb=1%20target Exit EPA Disclaimer

Source: Fish Information and Services, www.FIS.com. 3/16/2011.

Recent Publications

Please note: The following abstracts are reprinted verbatim unless otherwise noted.

The tropical African mercury anomaly: Lower than expected mercury concentrations in fish and human hair.

Mercury is a neurotoxin and global pollutant, and wetlands and newly flooded areas are known to be sites of enhanced production of monomethylmercury, the form of mercury that is readily biomagnified in aquatic food chains to potentially toxic levels. The Okavango Delta in Botswana, Southern Africa, is the largest inland delta in the world and a wetland ecosystem that experiences dramatic annual flooding of large tracts of seasonal floodplains. The Delta was, therefore, expected to be home to high mercury levels in fish and to be an area where local subsistence fishing communities would be at substantial risk of mercury toxicity from fish consumption. Total mercury concentrations measured in 27 species of fish from the Okavango Delta averaged (mean±s.d., wet weight) 19±19ngg(-1) in non-piscivorous fish, and 59±53ngg(-1) in piscivorous fish. These mercury concentrations are similar to those reported for fish from lakes in other areas of tropical Africa, demonstrating that not all wetlands are sites of elevated mercury concentrations in biota. Even more intriguing is that concentrations of mercury in fish from across tropical Africa are systematically and substantially lower than those typically reported for fish from freshwater ecosystems elsewhere globally. The reasons for this apparent "African mercury anomaly" are unclear, but this finding poses a unique opportunity to improve our understanding of mercury's biogeochemical cycling in the environment. Mercury concentrations measured in human hair collected in subsistence fishing communities in the Okavango Delta were similarly low (0.21±0.22μgg(-1) dry weight) despite high levels of fish consumption, and reflect the low mercury concentrations in the fish here.

Source: Black FJ, Bokhutlo T, Somoxa A, Maethamako M, Modisaemang O, Kemosedile T, Cobb-Adams C, Mosepele K, Chimbari M. Sci Total Environ. 2011 Apr 15;409(10):1967-75. Epub 2011 Feb 20.

The skinny on tuna fat: health implications.

OBJECTIVE: Dietary n-3 (omega-3) and n-6 (omega-6) PUFA have significant implications in health and disease prevention. Marine life is rich in long-chain n-3 PUFA. Children and adults in North America are reluctant fish eaters; canned tuna is a common fish in children's diets. Although a multitude of tuna products are available, their respective PUFA contents have not been well described. The aim of the present study was to compare the fatty acid (FA) profiles of different commercially available US tuna products. DESIGN: Fat and FA composition of eight products randomly selected from two US suppliers were analysed with capillary GC after lipid extraction. SETTING: Large north-eastern US grocery store chain. SUBJECTS: Canned tuna. RESULTS: Energy from fat varied from 3 to 33 % and the essential FA (EFA) linoleic acid (18 : 2n-6) and α-linolenic acid (18 : 3n-3) varied tenfold. DHA varied between 90 and 770 mg/serving. The n-6:n-3 ratio was 3:1-4:1 in oil-packaged products, 2:1-7:1 in packaged tuna salads and 1:3-1:7 in water-packaged products. A similar magnitude of differences was seen in the ratio between arachidonic acid (20 : 4n-6) and DHA. CONCLUSIONS: Light tuna canned in water may be a better choice of providing n-3 PUFA to individuals in a healthy population, whereas oil-packaged products may be preferable for those individuals with a need for increased EFA, such as for patients with cystic fibrosis. Awareness regarding PUFA content may aid in consumer product choices and health-care provider advice.

Source: Maqbool A, Strandvik B, Stallings VA. Public Health Nutr. 2011 Feb 16:1-6. [Epub ahead of print]

State calculations of cultural survival in environmental risk assessment: consequences for Alaska Natives.

In 2007, the Alaska Division of Public Health issued their first-ever fish consumption advisory to reduce exposure to methylmercury. Interestingly, they utilized a toxicity level in their calculations of risk that is four times higher than the U.S. Environmental Protection Agency's (EPA) level, arguing that the EPA's calculation is "inappropriately restrictive" for Alaskans. This article explores the institutional reasoning and scientific calculations behind the state's fish consumption advice, with special attention paid to the consequences for Alaska Natives. I argue that a discourse of "Alaskan exceptionalism" is utilized by the health department to justify their assessment of risk. Although this exceptionalist discourse is intended to accommodate the unique lifestyles of Alaskan citizens, it may actually serve to undermine the very lifeways and traditions that it presumes to preserve. This article contributes insights into the ways that states can influence the social and material reproduction of communities through the deployment of "cultural difference" during the risk-assessment process.

Source: Cassady J. Med Anthropol Q. 2010 Dec;24(4):451-71.

Species- and size-specific variability of mercury concentrations in four commercially important finfish and their prey from the northwest Atlantic.

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 1.217μg/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.

Source: Staudinger MD. Mar Pollut Bull. 2011 Feb 8. [Epub ahead of print]

Uterine leiomyomata in a cohort of Great Lakes sport fish consumers.

Diet and endocrine disrupting persistent organic pollutants (POPs) have been associated with gynecologic conditions including uterine leiomyomata (UL), endometriosis, and ovarian cysts. Great Lakes sport fish consumption is a source of exposure to POPs such as p,p'-diphenyldichloroethene (DDE) and polychlorinated biphenyls (PCBs). This study was designed to examine retrospectively the effects Great Lakes sport fish consumption on the incidence of UL and to examine the effects of DDE and PCB serum levels on prevalent UL in women participating in the Great Lakes Fish Consumption Study. We hypothesized that associations of exposures with UL would be modified by breastfeeding status. Years of sport fish consumption, demographic, health, and reproductive data were assessed by survey. In a subgroup, serum was collected and tested for DDE and PCB levels. Effects of years of Great Lakes sport fish and sport fish consumption were modeled using time-dependent Cox proportional hazards regression and effects of POP exposures on UL were modeled using multiple logistic regression. Years of sport fish consumption were associated with UL, with an incidence rate ratio of 1.2 (95% CI 1.0-1.3) for each 10-year increment of fish consumption. Summary measures of POP exposures in the overall group were not associated with UL. In the subgroup of women who never breastfed and in whom PCB measurements were available, however, UL was significantly associated with PCBs and groupings of estrogenic, antiestrogenic, and dioxin-like PCBs. These findings support the possibility that PCB exposures from fish consumption may increase the risk of UL and highlight the importance of additional studies exploring biologic pathways by which they could be acting.

Source: Lambertino A, Turyk M, Anderson H, Freels S, Persky V. Environ Res. 2011 Feb 8. [Epub ahead of print]

A high ratio of dietary n-6/n-3 polyunsaturated fatty acids is associated with increased risk of prostate cancer.

Experimental studies suggest omega-3 (n-3) polyunsaturated fatty acids (PUFA) suppress and n-6 PUFA promote prostate tumor carcinogenesis. Epidemiologic evidence remains inconclusive. The objectives of this study were to examine the association between n-3 and n-6 PUFA and prostate cancer risk and determine if these associations differ by race or disease aggressiveness. We hypothesize that high intakes of n-3 and n-6 PUFA will be associated with lower and higher prostate cancer risk, respectively. A case-control study comprising 79 prostate cancer cases and 187 controls was conducted at the Durham VA Medical Center. Diet was assessed using a food frequency questionnaire. Logistic regression analyses were used to obtain odds ratios (ORs) and 95% confidence intervals (95% CI) for the associations between n-3 and n-6 PUFA intakes, the dietary ratio of n-6/n-3 fatty acids, and prostate cancer risk. Our results showed no significant associations between specific n-3 or n-6 PUFA intakes and prostate cancer risk. The highest dietary ratio of n-6/n-3 was significantly associated with elevated risk of high-grade (OR, 3.55; 95% CI, 1.18-10.69; P(trend) = 0.03), but not low-grade prostate cancer (OR, 0.95; 95% CI, 0.43-2.17). In race-specific analyses, an increasing dietary ratio of n-6/n-3 fatty acids correlated with higher prostate cancer risk among white men (P(trend) = 0.05), but not black men. In conclusion, our findings suggest that a high dietary ratio of n-6/n-3 fatty acids may increase the risk of overall prostate cancer among white men and possibly increase the risk of high-grade prostate cancer among all men.

Source: Williams CD, Whitley BM, Hoyo C, Grant DJ, Iraggi JD, Newman KA, Gerber L, Taylor LA, McKeever MG, Freedland SJ. . Nutr Res. 2011 Jan;31(1):1-8.

Mercury speciation and biomagnification in the food web of Caddo Lake, Texas and Louisiana, USA, a subtropical freshwater ecosystem.

We studied the biomagnification of total mercury and methylmercury in a subtropical freshwater lake, Caddo Lake, Texas and Louisiana, USA. The present study is unique in that it not only included invertebrates (seven species) and fish (six species) but also an amphibian (one species), reptiles (three species), and mammals (three species). Nonfish vertebrates such as those included in the present study are often not included in assessments of trophic transfer of Hg. Mean trophic position (determined using stable isotopes of nitrogen) ranged from 2.0 (indicative of a primary consumer) to 3.8 (indicative of a tertiary consumer). Mean total Hg concentrations ranged from 36 to 3,292 ng/g dry weight in muscle and whole body and from 150 to 30,171 ng/g dry weight in liver. Most of the Hg in muscle and whole-body tissue was found as methylmercury, and at least 50% of the Hg found in liver was in the inorganic form (with the exception of largemouth bass, Micropterus salmoides). Mercury concentrations were positively correlated with trophic position, indicating that biomagnification occurs in the food web of Caddo Lake. The food web magnification factors (FWMFs; slope of the relationship between mean Hg concentration and trophic position) for both total Hg and methylmercury were similar to those observed in other studies. Because most of the total Hg in consumers was methylmercury, the FWMF for methylmercury was not significantly different from the FWMF for total Hg. Some vertebrates examined in the present study had low Hg concentrations in their tissues similar to those observed in invertebrates, whereas others had concentrations of Hg in their tissues that in previous studies have been associated with negative health consequences in fish.

Source: Chumchal MM, Rainwater TR, Osborn SC, Roberts AP, Abel MT, Cobb GP, Smith PN, Bailey FC. Environ Toxicol Chem. 2011 Feb 8. doi: 10.1002/etc.477. [Epub ahead of print]

Mercury and selenium levels in 19 species of saltwater fish from New Jersey as a function of species, size, and season.

There are few data on risks to biota and humans from mercury levels in saltwater fish. This paper examines mercury and selenium levels in muscle of 19 species of fish caught by recreational fisherfolk off the New Jersey shore, as a function of species of fish, size, and season, and risk of mercury to consumers. Average mercury levels ranged from 0.01ppm (wet weight) (Menhaden Brevoortia tyrannus) to 1.83ppm (Mako Shark Isurus oxyrinchus). There were four categories of mercury levels: very high (only Mako), high (averaging 0.3-0.5ppm, 3 species), medium (0.14-0.20ppm, 10 species), and low (below 0.13ppm, 5 species). Average selenium levels for the fish species ranged from 0.18ppm to 0.58ppm, and had lower variability than mercury (coefficient of variation=38.3 vs 69.1%), consistent with homeostatic regulation of this essential element. The correlation between mercury and selenium was significantly positive for five and negative for two species. Mercury levels showed significant positive correlations with fish size for ten species. Size was the best predictor of mercury levels. Selenium showed no consistent relationship to fish length. Over half of the fish species had some individual fish with mercury levels over 0.3ppm, and a third had fish with levels over 0.5ppm, levels that pose a human health risk for high end consumers. Conversely several fish species had no individuals above 0.5ppm, and few above 0.3ppm, suggesting that people who eat fish frequently, can reduce their risk from mercury by selecting which species (and which size) to consume. Overall, with the exception of shark, Bluefin Tuna (Thunnus thynnus), Bluefish (Pomatomus saltatrix) and Striped Bass (Morone saxatilis), the species sampled are generally medium to low in mercury concentration. Selenium:mercury molar ratios were generally above 1:1, except for the Mako shark.

Source: Burger J, Gochfeld M. Sci Total Environ. 2011 Mar 15;409(8):1418-29. Epub 2011 Feb 2.

Species-Specific Differences and Structure-Activity Relationships in the Debromination of PBDE Congeners in Three Fish Species.

Previous studies have suggested that there may be species-specific differences in the metabolism of polybrominated diphenyl ethers (PBDEs) among different fish species. In this study, we investigated the in vitro hepatic metabolism of eleven individual PBDE congeners (tri- through decaBDEs) in three different fish species: rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio), and Chinook salmon (O. tschwatcha). In addition, we evaluated the influence of PBDE structural characteristics (i.e., bromine substitution patterns) on metabolism. Six of the eleven congeners we evaluated, BDEs 99, 153, 183, 203, 208, and 209, were metabolically debrominated to lower brominated congeners. All of the congeners that were metabolized contained at least one meta-substituted bromine. Metabolites were not detected for congeners without one meta-substituted bromine (e.g., BDEs 28, 47, and 100). Metabolite formation rates were generally 10 to 100 times faster in carp than in trout and salmon. BDEs 47, 49, 101, 154, and 183 were the major metabolites observed in all three species with the exception of BDE 47, which was only detected in carp. Carp demonstrated a preference toward meta-debromination, while trout and salmon debrominated meta- and para-bromine atoms to an equal extent. We compared glutathione-S-transferase (GST) and deiodinase (DI) activity among all three species as these enzyme systems have been hypothesized to play a role in PBDE debromination in teleosts. Carp exhibited a preference for meta-deiodination of the thyroid hormone thyroxine, which was consistent with the preference for meta-debromination of PBDEs observed in carp.

Source: Roberts SC, Noyes PD, Gallagher EP, Stapleton HM. Environ Sci Technol. 2011 Mar 1;45(5):1999-2005. Epub 2011 Feb 3.

Selenium stable isotope investigation into selenium biogeochemical cycling in a lacustrine environment: Sweitzer Lake, Colorado.

We present a comprehensive set of Se concentration and isotope ratio data collected over a 3-yr period from dissolved, sediment-hosted, and organically bound Se in a Se-contaminated lake and littoral wetland. Median isotope ratios of these various pools of Se spanned a narrow isotopic range (delta80/76Se(SRM-3149)) = 1.14-2.40 per thousand). Selenium (VI) reduction in the sediments is an important process in this system, but its isotopic impact is muted by the lack of direct contact between surface waters and reduction sites within sediments. This indicates that using Se isotope data as an indicator of microbial or abiotic Se oxyanion reduction is not effective in this or other similar systems. Isotopic data suggest that most Se(IV) in the lake originates from oxidation of organically bound Se rather than directly through Se(VI) reduction. Mobilization of Se(VI) from bedrock involves only a slight isotopic shift. Temporally constant isotopic differences observed in Se(VI) from two catchment areas suggest the potential for tracing Se(VI) from different source areas. Phytoplankton isotope ratios are close to those of the water, with a small depletion in heavy isotopes (0.56 per thousand). Fish tissues nearly match the phytoplankton, being only slightly depleted in the heavier isotopes. This suggests the potential for Se isotopes as migration indicators. Volatile, presumably methylated Se was isotopically very close to median values for phytoplankton and macrophytes, indicating a lack of isotopic fractionation during methylation

Source: Clark SK, Johnson TM. J Environ Qual. 2010 Nov-Dec;39(6):2200-10.

The following recent publications are also of interest, but the abstracts are not reprinted here due to copyright restrictions:

Deleterious effects in mice of fish-associated methylmercury contained in a diet mimicking the Western populations' average fish consumption.
Bourdineaud, J.-P. J. P., M. M. Fujimura, et al. (2011). Environment International 37(2): 303-313.

Parameter uncertainty in modeling bioaccumulation factors of fish.
Hauck, M. M., H. W. M. H. W. Hendriks, et al. (2011). Environmental toxicology and chemistry / SETAC 30(2): 403-412.

Influence of Physiochemical and Watershed Characteristics on Mercury Concentration in Walleye, Sander vitreus, M
Hayer, C.-A., S. R. Chipps, et al. (2011). Bulletin of Environmental Contamination and Toxicology 86(2): 163-167.

Meetings and Conferences

2011 Environmental Information Exchange Network National Meeting
April 26-28, 2011 Denver, Colorado
http://exchangenetwork.net/2011Meeting Exit EPA Disclaimer
The Society of Environmental Toxicology and Chemistry (SETAC)
Gulf Oil Spill Focused Topic Meeting
April 26-28 2011, Pensacola Beach, Florida
http://gulfoilspill.setac.org/ Exit EPA Disclaimer
12th Workshop on Brominated and other Flame Retardants (BFR 2011)
June 6-7, 2011 Boston, Massachusetts
http://www.bfr2011.org Exit EPA Disclaimer
10th International Conference on Mercury as a Global Pollutant
July 24–29, 2011 Halifax, Nova Scotia, Canada
http://www.mercury2011.org Exit EPA Disclaimer
American Fisheries Society Annual Meeting
September 4-8, 2011 Seattle, Washington
http://www.fisheries.org/afs2011 Exit EPA Disclaimer
14th World Lake Conference
October 31-November 4, 2011 Austin, Texas
http://www.wlc14.org/Exit EPA Disclaimer
The Society of Environmental Toxicology and Chemistry (SETAC) North America 32nd Annual Meeting
November 13-17 2011, Boston, Massachusetts
http://boston.setac.org/Exit EPA Disclaimer
National Forum on Contaminants in Fish
Fall 2011 – Stay tuned for details and location!

For More Information

Please email the newsletter (Fish_Advisory@epa.gov) if you would like to announce an upcoming meeting, conference, or to submit an article.

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