Recent Advisory News

• New Statewide Advisory Released in Illinois - The 2002 version of the Illinois Fishing Digest includes many changes to the state's fish consumption advisories. The new advisories in the digest took effect on April 1, 2002. In addition to issuing 21 new advisories for PCBs and rescinding 3 advisories for chlordane, a statewide mercury advisory is now also in effect. The statewide advisory recommends that women of childbearing age and children under 15 years of age restrict their consumption of predator fish to 1 meal per week. The advisory also lists out all of the predator species (15+ species) that are specifically covered under the advisory. For more information, visit the state's website where the new 2002 fishing digest is posted.
• North Dakota Statewide Mercury Advisory - North Dakota's fish consumption advisory was updated early last year to cover all waters in the state, due to mercury contamination. The advisory states that although mercury levels in smaller fish are usually low, the larger fish of some species can contain higher levels of mercury that pose a health risk if those fish are eaten too often. The advisory offers different meal frequency advice for 4 populations: children age 5 and younger, children between ages 5 and 15, pregnant and nursing women, and the general population. Advice is given for largemouth bass, smallmouth bass, white bass, chinook salmon, northern pike, walleye, channel catfish, and yellow perch. The advisory also explains that children over 5 and other adults can frequently consume smaller fish of some of these species. For more information visit North Dakota's website.

Current Events, News and Journal Articles

• Mercury Exposure: Current Controversies and a Clinic's Experience - In the context of controversies surrounding fish consumption advisories, dental amalgams, and commercial hair testing, the authors reviewed cases from an occupational and environmental medicine clinic that had undergone mercury testing. Sixty-nine of 71 (97%) patients tested had no known mercury exposures other than from their diet or dental amalgams. Of these 69 patients, 48 had blood mercury analysis and 58 had urine analysis. The results showed that regular-to-heavy fish consumption explained 10 of 11 cases with blood mercury concentrations exceeding 15 mug/L. Six of these 10 patients reported regular swordfish consumption. For the 31 patients with adequate dietary history, there was a significant relationship between fish consumption and blood mercury concentration. Higher blood mercury levels were not associated with specific patterns of health complaints. Ninety-eight percent of the mercury urine analysis values were less than 10 mug/L. Fourteen patients were evaluated because they were labeled as mercury toxic by other practitioners after unconventional commercial testing. Using standard blood and urine analysis results, however, the authors could not document evidence of mercury toxicity in any of the 14 cases. Furthermore, the authors concluded that consumption of commercially available fish can lead to elevated blood mercury concentrations. The authors believe that a recognized exposure source is a better predictor of significant mercury concentrations in biologic media such as blood or urine than any particular symptom constellation. The authors concluded that unconventional commercial panels that analyze hair or urine for multiple metals have questionable validity and recommended that clinicians use standard blood and urine tests to evaluate a patient’s mercury exposure.

  Source: Kales, S.N. and R.H. Goldman.2002. Mercury exposure: Current concepts, controversies, and a clinic's experience. Journal of Occupational and Environmental Medicine Vol.44(2):143-154.

• Mercury From Falling Leaves? - Leaf-littered waterways represent another source of methylmercury, according to the new study on two southern Minnesota waterways, the Little Cobb River and County Ditch 86. The largest seasonal increase in methylmercury in the Little Cobb River occurred in the fall, when the researchers found as much as 4.9 ng/l. The researchers didn't find nearly that much methylmercury in County Ditch 86. Earlier in the year, the methylmercury concentration in both waterways was typically below 0.5 ng/l. The researchers suggest that leaves falling into the Little Cobb River, combined with stagnant late fall conditions, allowed bacteria to thrive which methylated the mercury the leaves had absorbed from the atmosphere. This study raises the question of whether substantial amounts of methylmercury could be accumulating in fish living downstream from leafy areas like those along the Little Cobb River.

  Source: Harder, B. When the mercury falls. Science News, 3/9/2002, Vol. 161 Issue 10, p148.

• Fish Tissue Quality in Near-Coastal Gulf of Mexico - The objective of this study was to determine inorganic and organic pollutant residues in edible tissue of fish collected from eight coastal areas receiving wastewater discharges and from two reference (control) locations. The authors found that trace metal residues were statistically similar regardless of sampling site. Zinc (100% detection in all samples), total mercury (100%), total arsenic (92%), copper (92%), and selenium (88%) were the most commonly detected trace metals. Mercury concentrations exceeded the Florida health-based standard of 0.5 ppm for restricted fish consumption in 30% of all samples and averaged 0.40 ppm. Mean total PAH concentrations were 1.79 ppb in reference areas and 2.17 ppb in wastewater-impacted areas. The most frequently detected PAH was pyrene (63% of the total samples) and averaged 0.74 ppb. Mean total PCB concentrations were 4.8 ppb for the reference areas and 31.6 ppb for the wastewater-impacted areas. Concentrations of dieldrin and cis-chlordane were about eight times greater, respectively, in fish collected from wastewater receiving waters, whereas total DDT and total pesticide concentrations were not elevated in the same areas. Total PCBs and all chlorinated pesticide concentrations were below US health-based standards.

  Source: Lewi, MA, GI Scott, DW Bearden, RL Quarles, J Moore, ED Strozier, SK Sivertsen, AR Dias, and M Sanders. 2002. Fish tissue quality in near-coastal areas of the Gulf of Mexico receiving point source discharges. Sci Total Environ 2002 Volume 284(1-3):249-61.

• Special PBDEs Issue of Chemoshpere - Volume 46(5) of the journal Chemosphere contains a number of articles on the significance and occurrence of brominated flame retardents in the environment. Articles include studies on PBDE levels in lake trout, PBDEs in blue mussels, PBDEs in harbor seal blubber, PBDEs in breast milk, and exposure to PBDEs among computer technicians. Go to the Chemosphere website to see a list of the articles in this issue.

  One of the articles from the Chemosphere PBDEs issue is an Overview of Brominated Flame Retardants in the Environment - Over the past decade, the presence of brominated flame retardant (BFR) chemicals, and especially polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD), has become of increasing concern to scientists. Environmental studies conducted in Europe, Japan, and North America indicate that these chemicals are ubiquitous in sediment and biota. PBDE residues appear to be increasing in the environment as well as in human tissues, and these trends indicate the increase may be very rapid. The presence of high levels of specific PBDE isomers may be sufficient to cause adverse effects in some wildlife as well as in sensitive human populations such as young children, indigenous peoples, and fish consumers. The author emphasizes that knowledge about these chemicals, their sources, environmental behavior, and toxicity is limited, making risk assessment difficult. This paper reviews the current state of knowledge and areas for further research recommended to improve future monitoring and risk assessment efforts.

  Source: de Wit,C.A. 2002. An overview of brominated flame retardants in the environment. Chemosphere Vol.46 (5):583-624.

• Case Study of Potential Long-Term Ecological Impacts Caused by Disturbance of Contaminated Sediments - Recently, several submerged barges were moved from the Passaic River, New Jersey into two areas (Areas 1 and 2) containing contaminated sediments. During relocation of the single barge to Area 1, elevated turbidity and chemical parameters were monitored. Higher levels of these parameters were measured in Area 2, where several barges were relocated. In both areas, water column levels on dioxins and furans (PCDD/Fs) and several heavy metals exceeded one or more water quality criteria. The potential bioaccumulation of these pollutants from the water column into residential aquatic organisms was estimated using standard models and assumptions. The results predicted that steady-state tissue concentrations of bioaccumulative chemicals would not result from the brief increase in water column levels that occurred during barge removal, but that metals and PCDD/Fs could bioaccumulate to levels that exceed regulatory ecological criteria during long-term sediment disturbance activities. The authors estimated based on particle settling that bioaccumulation from surface sediments into the food web could result in significant increases in PCDD/F residues in the mummichog, a benthic forage fish. The reported findings are consistent with the few field studies that have measured increased body burdens of bioaccumulative chemicals following dredging. The authors suggest that the potential long-term impacts on the food web must be evaluated prior to consideration of dredging as a remedial alternative for river systems.

  Source: Su, SH, LC Pearlman, JA Rothrock, TJ Iannuzzi, and BL Finley. 2002. Potential long-term ecological impacts caused by disturbance of contaminated sediments: A case study. Environmental Management Vol 29 (2):234-249.

• Bioaccumulation of Chlorpyrifos Through an Experimental Food Chain Study - The authors conducted a study on the accumulation and transfer of chlorpyrifos in an experimental aquatic two-level food chain using two species of brine shrimp and the small fish Aphanius iberus. Adult brine shrimp contaminated by exposure to the pesticide in water were used as live food for the fish. During the exposure phase, fish were fed chlorpyrifos-contaminated brine shrimp from pools with concentrations between 6.5 and 14.5 ppb fresh weight for 32 days. Chlorpyrifos accumulated in fish fed brine shrimp from both exposure concentrations. Effects of chlorpyrifos exposure through the food chain on stress protein (HSP70) synthesis were measured as a general biochemical response of stress in the test fish species. HSP70 levels were significantly higher in fish fed contaminated brine shrimp than in the controls fed uncontaminated brine shrimp. Study results indicated that HSP70 induction in fish could be associated with exposure to chlorpyrifos via food.

  Source: Varo, I, R. Serrano, E Pitarch, F Amat, FJ Lopez, and JC Navarro. 2002. Bioaccumulation of chlorpyrifos through an experimental food chain: study of protein HSP70 as biomarker of sublethal stress in fish. Archive of Environmental Contamination Toxicolology Volume 42(2):229-35.

• Independent Review of FDA Advice To Be Conducted - The FDA announced that a panel of independent scientists would review its advice to pregnant women about which fish to avoid because of levels of methylmercury in the fish tissues. The FDA currently advises pregnant women or women who are planning to become pregnant to avoid shark, swordfish, king mackerel and tilefish, and to eat no more than 12 ounces a week of other cooked fish, including canned tuna. Some consumer advocates, however, say the limits set for tuna should be much lower, and yesterday the advocacy organization Environmental Working Group accused the FDA of diluting its warning because of pressure from the seafood industry. The agency denied that, but announced its independent food-safety advisory board would review the debate at an upcoming meeting.

  Source: The New York Times and Associated Press. March 1, 2002. Review on Fish-Eating Advice for Women.

Meetings and Conferences

For More Information

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.

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Revised April, 2002