Newsletter—May 2009

EPA submits comments on FDA’s draft of commercial fish consumption risk/benefit analyses

In January this year, the FDA released two draft documents concerning the risks and benefits of commercial fish consumption. The public comment period on these reports ended on April 21. EPA’s comments on these reports contend that they are scientifically flawed and have major deficiencies including inadequate discussion of at-risk populations. To read EPA’s comments please visit the EPA Fish Advisory home page at www.epa.gov/waterscience/fish.

Source: EPA Fish Advisory web site, www.epa.gov/waterscience/fish.

EPA proposes rule to reduce mercury emissions from cement plants

The EPA recently proposed a rule that will require cement plants to reduce emissions of mercury, dust and other pollutants. The new rule applies to 99 cement plants in 35 states and is expected to reduce pollutants by 90 percent. The Portland Cement Association, a trade group for the 99 plants with 163 active kilns, issued a statement saying it is reviewing the proposed rule and that it has "worked with the EPA to collect data for this anticipated proposal and continues to support regulatory approaches that allow the industry to produce the cement necessary for constructing and rebuilding the nation's infrastructure in an environmentally responsible manner".

Source: San Francisco Chronicle (CA), 4/22/2009.

New cost-effective method to remove toxins from fish oil

Norwegian and French companies and researchers have developed a cheaper process for purifying fish oils to remove harmful components. The team found that a thin ceramic membrane could be used to filter the fish oil, removing dioxins and PCBs, cutting costs by 40 percent compared to traditional filtration methods. The method has been used to develop modular industrial units which can be used by small companies, meaning fish oils do not have to be transported to large sites, which is more costly.

Source: ScienceDaily, 4/14/2009

Fish, walnuts reduce heart disease risk

A recent study in the American Journal of Clinical Nutrition found that walnuts lower cholesterol more than fish, that fatty fish lower triglycerides, and that both foods can lower heart disease risk. Using American Heart Association guidelines, the researchers found that a diet including two servings (4 ounces each) of fatty fish (salmon) per week decreased triglyceride levels by 11.4%. Additionally, salmon increased high-density lipoprotein, or "good" cholesterol, by 4%, but also slightly increased LDL cholesterol (or "bad" cholesterol) compared to the control diet. Eating 1.5 ounces of walnuts each day lowered serum total cholesterol by 5.4% and LDL cholesterol by 9.3% compared to a control diet.

Source: United Press International (CA), 4/13/2009.

Alcoa speaks out on NC fish consumption advisory

Alcoa Power Generating Inc. (APGI) took exception with the North Carolina PCB advisory issued in February for largemouth bass and catfish caught in Badin Lake. In a statement, APGI says it appealed the advisory "… because the State changed its stated evaluation criteria after the study was complete and held Badin Lake to a different standard than other lakes and rivers in North Carolina … the State has monitored similar levels of chemicals or contamination in fish tissue caught in other waterways in North Carolina, but has not issued a fish advisory in those instances."

Source: Stanly News & Press (NC), 4/13/2009.

Conservation group tests SC fishermen for mercury

Conservation groups opposed to a proposed coal-fired power plant in Florence County are testing hair samples from area fishermen for mercury. The group SCSaysNO is made up of several organizations opposing the plant, including the Sierra Club and Conservation Voters of South Carolina. SC DHEC spokesman Thom Berry said the state wants to study the issue, but right now there isn't enough funding for it. The group SCSaysNO plans to test the hair of 20 people of various ages and races who fish from the Pee Dee. A certified lab will test the hair for mercury, and volunteers should have the results in a few weeks.

Source: Associated Press, 4/9/2009.

Ohio EPA warns of mercury in some area fish

Spotted bass caught in Ohio Brush Creek between Louden and the Ohio River should only be eaten once per month due to the level of mercury found in samples of fish taken in 2007, according to a new advisory issued by the Ohio EPA. Four samples were taken of spotted bass from the creek. The fish averaged 12 inches long and had an average concentration of 312 ppb of mercury. No pesticides were found in the samples.

Source: The People’s Defender (OH), 4/8/2009.

Fatty fish may cut prostate cancer risk

A study in the April issue of Clinical Cancer Research reports that men who eat salmon and other fish high in omega-3 fatty acids on a regular basis have a decreased risk for developing advanced prostate cancer. Study participants who ate one or more servings of fatty fish a week were found to have a 63% lower risk for developing aggressive prostate cancer than men who reported never eating fish.

Source: WebMD Health News, 3/24/2009.

NOAA reports flame retardants in all U.S. coastal waters

Based on data from the Mussel Watch program, NOAA scientists have issued a new report stating that polybrominated diphenyl ethers (PBDEs) are found in all United States coastal waters and the Great Lakes, with elevated levels near urban and industrial centers. As recently as 1996, studies indicated that PBDEs were present in only a limited number of sites around the nation. In the new report, New York’s Hudson Raritan Estuary has the highest overall concentrations of PBDEs, both in sediments and shellfish. A growing body of research points to evidence that exposure to PBDEs may produce detrimental health effects, including impairment of liver, thyroid and neurobehavioral development.

Source: ScienceDaily, 4/10/2009.

Fish advisory for Earvin “Magic” Johnson Park

Los Angeles county health officials are warning people not to eat fish caught in the lakes of Earvin "Magic" Johnson County Park in Willowbrook after testing showed that the fish may be contaminated. Preliminary tests showed levels of mercury and PCBs to be in excess of federal guidelines. The lake is stocked with catfish, but some bass were also present in the lake, most likely added by the public, officials said. Preliminary reports pointed to the bass fish as being the problem, but officials said that until further testing is complete, the public should avoid eating any fish caught in the lake.

Source: Los Angeles Times (CA), 3/28/2009.

Cardiovascular effects of mercury contamination from whale meat consumption

The authors examined 42 Faroese whaling men to assess the health effects of methylmercury contamination from consumption of pilot whale meat. Results showed that the average mercury concentrations from toenail samples varied widely with a mean of 2 microg/g; hair concentrations averaged about 3 times higher. Mercury exposure was significantly associated with increased blood pressure and carotid intima-media thickness (IMT), supporting their hypothesis that increased mercury exposure results in adverse cardiovascular effects.

Choi, A. L., P. Weihe, et al. 2009. "Methylmercury exposure and adverse cardiovascular effects in Faroese whaling men." Environmental Health Perspectives 117(3): 367-72.

Hair mercury levels in ancient Aleutian Island Native remains

Human hair samples from the remains of 500-year-old Aleutian Island Natives (4 adult and 5 infant specimens) were tested for mercury. Adult samples had an average total mercury concentration of 5.8ppm and average methylmercury concentration of 1.2ppm, while infant samples averaged 1.2ppm and 0.2ppm, respectively. These levels are similar to or lower than those found in present day native populations who consume less subsistence food than pre-historic humans. The authors say these results support increased anthropogenic release of mercury during the past several hundred years.

Egeland, G. M., R. Ponce, et al. 2009. "Hair methylmercury levels of mummies of the Aleutian Islands, Alaska." Environmental Research 109(3): 281-286.

Bioaccumulation in caged carp at contaminated sites

This study measured the bioaccumulation of cadmium, lead, and organic pollutants in carp caged at four locations in Belgium with different levels of contamination. Levels of cadmium and lead at some of the exposure sites increased during the four week period and were comparable to levels in fish from moderately metal-contaminated sites. For most organic pollutants, levels in carp did not increase significantly. The authors suggest that caged carp might be a useful tool for assessing bioaccumulation.

Bervoets, L., K. Van Campenhout, et al. 2009. Bioaccumulation of micropollutants and biomarker responses in caged carp (Cyprinus carpio). Ecotoxicology and Environmental Safety 72(3): 720-728.

Spatial variation of mercury levels in yellow perch in the Superior National Forest of Minnesota

The spatial relationships between yellow perch total mercury tissue concentrations and a total of 45 watershed and water chemistry parameters were evaluated for 2005 and 2006. Results show that watershed area, lake water pH, nutrient levels and dissolved iron are important predictive factors for total mercury concentrations in fish. A greater percentage of surrounding wetland area was also related to higher mercury levels in fish, suggesting that these wetlands are main locations for mercury methylation. Regression models developed by the authors demonstrated that upland soil O-horizon total mercury explained 60% of the variance in resident yellow perch mercury levels for 2005, and lake water dissolved iron and watershed area explained 73% of variance for the 2006 samples.

Gabriel, M. C., R. Kolka, et al. (2009). "Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield." Sci Total Environ: Apr 4. [Epub ahead of print].

Evaluating relationships between episodically consumed foods and health outcomes

The authors propose an extension of a method for modeling the dietary assessment of episodically consumed foods to predict individual usual intake of such foods and to evaluate the relationships of usual intakes with health outcomes. Their results suggest that additional covariates potentially related to usual intake may be used to increase the precision of estimates of usual intake and of diet-health outcome associations.

Kipnis, V., D. Midthune, et al. (2009). "Modeling Data with Excess Zeros and Measurement Error: Application to Evaluating Relationships between Episodically Consumed Foods and Health Outcomes." Biometrics: Feb 26. [Epub ahead of print].

Fish oil and the management of high triglycerides

High blood triglyceride level, also known as hypertriglyceridemia, is a frequently observed disorder in the Arab region. This paper reviews the evidence from human trials that omega-3 fatty acids from either fish or fish oil supplements significantly reduce blood triglyceride levels. Patients with hypertriglyceridemia have responded well to dietary supplements of omega-3 fatty acids, and a prescription form of omega-3 fatty acid has been approved by the FDA to help treat very high triglyceride levels in adults.

Mattar, M. and O. Obeid (2009). "Fish oil and the management of hypertriglyceridemia." Nutr Health 20(1): 41-9.

Effect of cooking on PBDE and PAH levels in food

The authors investigated the effects of cooking on the levels of PBDEs, hexachlorobenzene (HCB), and 16 polycyclic aromatic hydrocarbons (PAHs) in various foods including fish (sardine, hake and tuna), meat, string bean, potato, rice, and olive oil. HCB concentrations were highest in pre-cooked sardines, while samples after cooking had lower levels of HCB. HCB levels in hake were increased by cooking, while very little difference could be noted in tuna samples (raw and cooked). The highest PAH concentrations were found after frying the fish, except hake, where the highest total PAH levels corresponded to roasted samples. The results show that cooking is not a valuable method for reducing PBDE, HCB and PAH concentrations in food.

Perello, G., R. Marti-Cid, et al. (2009). "Concentrations of polybrominated diphenyl ethers, hexachlorobenzene and polycyclic aromatic hydrocarbons in various foodstuffs before and after cooking." Food and Chemical Toxicology 47(4): 709-715.

Selenium health benefits as a criteria for fish consumption advice

The authors of this review discuss the health benefits of consuming marine fish with high selenium-to-mercury ratios. High mercury exposure inhibits the activity of selenium-dependent enzymes, but additional selenium intake can maintain normal enzyme activity and thus prevent brain damage and other adverse consequences of mercury toxicity. Since more typical varieties of ocean fish contain much more selenium than mercury, the authors suggest this may explain why maternal mercury exposure from eating ocean fish is associated with major IQ benefits in children instead of harm. They go on to suggest that due to these expected benefits, ocean fish consumption should be encouraged during pregnancy. Since selenium levels in freshwater fish are often far lower than mercury levels, the same benefits would not apply. The authors conclude that mercury- to-selenium ratios need to be incorporated in food safety criteria to provide the most accurate advice to pregnant women regarding the consumption of freshwater and marine fish.

Ralston, N. V. (2009). "Selenium Health Benefit Values as Seafood Safety Criteria." Ecohealth: Apr 14. [Epub ahead of print].

Trends in mercury concentrations in Adirondack fish

This study compared current mercury concentrations in yellow perch from a group of Adirondack lakes with data collected 12-17 years earlier and found an average decline of 14% in fish mercury levels over that time period.

Simonin, H. A., J. J. Loukmas, et al. (2009). "Trends in Mercury Concentrations in New York State Fish." Bull Environ Contam Toxicol: Mar 28. [Epub ahead of print].

Effect of dietary fatty acids on inflammatory gene expression

This study tested the hypothesis that increased omega6/omega3 polyunsaturated fatty acids (PUFA) ratios may impact inflammatory gene expression in humans. Healthy subjects were placed on a controlled diet for one week, then given fish oil and borage oil for an additional four weeks. The results showed that PUFA may regulate the expression of signal transduction genes and genes for proinflammatory cytokines.

Weaver, K. L., P. Ivester, et al. (2009). "Effect of dietary fatty acids on inflammatory gene expression in healthy humans." J Biol Chem: Apr 9. [Epub ahead of print].

Metabolism of PBDE in Chinook salmon liver

The authors investigated the capacity of Chinook salmon liver fractions to debrominate 2,2',4,4',5-pentabromodiphenyl ether (BDE 99), a model PBDE congener readily debrominated by common carp. While debromination of BDE 99 to BDE 47 was not observed, salmon liver microsomes slowly debrominated BDE 99 to BDE 49, a unique debromination product whose formation has not been reported in other fish. This study that the high concentrations of BDE 47 found in resident Chinook salmon from the Puget Sound are not a result of hepatic metabolism of BDE 99.

Browne, E. P., H. M. Stapleton, et al. 2009. "In vitro hepatic metabolism of 2,2',4,4',5-pentabromodiphenyl ether (BDE 99) in Chinook Salmon (Onchorhynchus tshawytscha)." Aquatic Toxicology: Mar 9. [Epub ahead of print].

11th Annual Workshop on Brominated Flame Retardants

May 19–20, 2009, Ottawa, Ontario. For more information, please visit:

http://www.ec.gc.ca/scitech/default.asp?lang=En&n=6D0D0FE3-1

NEHA's 73rd Annual Educational Conference (AEC) & Exhibition

June 21–24, 2009, Atlanta, Georgia. For more information, please visit:

http://www.neha.org/AEC/2009/index.html