Mercury Update 2007

Jane Hightower, MD

The issue of mercury pollution continues to bring us lively discussions pitting health impacts against economic ones. The American Medical Association (AMA), as a result of a resolution brought by the Illinois delegation, recently addressed the current state of mercury pollution. It identified the chlor-alkali manufacturing industry (which produces chlorine) as one of the chemical industries that was still continuing to dump mercury into the environment. While fifty-three plants in the USA had changed to a non-mercury system, nine plants in eight states still had not. These Hg-cell plants emit Mercury (Hg)   into the air and water, and their contamination results in the accumulation of mercury and subsequent methylmercury in the surrounding fish and other wildlife. In recent years, sixty-five tons of mercury was unaccounted for by these plants, which prompted a 2003 EPA statement declaring, “The fate of all the mercury consumed at mercury-cell chlor-alkali plants remains somewhat of an enigma.” The industry, in turn, claimed the remainder mercury was contained on site within the manufacturing infrastructure and processing equipment. 

The AMA addressed the Clean Air Mercury Rule in its report as well, stating that the trading of air pollutants that the government was using as a mercury pollution control method was potentially harmful for vulnerable populations, and that the rule that was currently in place by our government was inconsistent with the AMA’s health-protective approach to air pollution. In the end, the AMA urged state governments to be proactive in protecting citizens from harmful mercury emissions, and for the reduction in mercury use in manufacturing whenever possible. It recommended increased vigilance, monitoring, and tracking of mercury use and emissions in chlor-alkali facilities that use mercury in the manufacturing processes. Lastly, the AMA encouraged the U.S. government to assume a leadership role in reducing the global mercury burden and work toward promoting binding, health-protective international standards (American Medical Association 2006).

The federally-funded Women, Infants, and Children program (WIC) had a recent victory. This program gives vouchers for the purchase of select food items to pregnant or nursing mothers, to include twenty-four ounces of albacore tuna per month. The women previously had no other nondairy protein options in the program. Quietly, on August 7, 2006, the Federal Register announced a proposed rule that stated, “for ease of administration by State agencies, to accommodate participant preferences, and to minimize intake of mercury, this proposed rule would authorize the following varieties of canned fish—light tuna, salmon, and sardines.” It also proposed to raise the amount of canned fish allowed to thirty ounces per month. The purchase of albacore tuna was no longer allowed with the federal government voucher (Federal Register 2006).

In February of 2006 I published a paper on the prevalence of elevated mercury levels in the blood of Asians, Pacific Islanders, and Native Americans, otherwise known as “Other” by the Centers for Disease Control (CDC). Although the CDC had been using this group’s data for the final analysis and interpretation of our United States population as a whole, the category itself was not entered into the tables of their reports. While the U.S. population as a whole had the prevalence of 5.66% being over 5.8 mcg/L Hg in their blood, the “Other” group was 16.59% over (Hightower 2006).

It is still unclear why the CDC leaves the “Other” group off of their tables, but for California, it is especially important. In the 2000 United States Census, 4.1 million people identified themselves as Native American or Alaskan Native; 12.5 million identified themselves as Asian or Pacific Islander, with 51% residing in the West. This becomes even more important for our ongoing California Proposition 65 court battle over whether the mercury advisory should be placed near or on cans of albacore tuna. The tuna industry has convinced the judge in the case, through less-than-credible evidence by industry experts, that methylmercury was “naturally occurring” in the fish, which gave them a break under the statute. Also, the judge allowed a terrific amount of watering down through “averaging” of data, to the point of allowing the average albacore mercury levels to be averaged with the average chunk light mercury levels (albacore has three times more mercury than chunk light). As for the human data that is now available to the court, the judge decided that a rat study from 1980 represented the “best quality” and that it yielded the lowest No Observable Effect Level (NOEL) for humans. In this study, sixteen pregnant rats were given varying doses of methylmercury during four days of gestation. The subsequent eighty pups were then put through a series of tests, to include pressing levers to obtain food. I saw nowhere in this paper that the rats were trying to get into Princeton. The Faroes and now even the Seychelles have seen adverse effects on the human fetus, but the industry argued about what “type” of studies could be allowed under the statute. It was a complicated mess and is now on appeal (Hightower 2006, the People vs. the State of California 2006, Bornhausen 1980).

All in all, our Proposition 65 statute seems to be there to protect the “ordinary” or “average” consumer. According to the National Health and Nutrition Examination Survey (NHANES) data, not only do coastal people have higher mercury levels than inland people because of their increased fish consumption, we also have the “Other” people in higher numbers. Our “ordinary” in California is not the “ordinary” of Nebraska.

As for fish consumption in adults, both men and women, the current advice is that two three-ounce servings or one six-ounce serving per week is where the benefits outweigh the risk, but up to twelve ounces is acceptable if the fish are low in contaminants (Mozaffarian 2006).

Jane Hightower, MD, specializes in internal medicine at California  Pacific  Medical Center in San Francisco and has done extensive research on mercury exposure from fish in adults. She is a member of the San Francisco Medical Society and currently serves on the SFMS Board of Directors.

A full list of references is available on our website at www.sfms.org.

REFERENCES:

The American Medical Association: Report 1 of the Council on Science and Public Health (I-06), Mercury Pollution, November 2006. http://www.ama-assn.org/ama/pub/category/print/17010.html (accessed February 2, 2007).

Bornhausen, M., H.R. Müsch, and H. Greim, H. Operant behavior performance changes in rats after prenatal methylmercury exposure. Toxicology and Applied Pharmacology, 1980; 56:305–310.

Federal Register, Department of Agriculture, Food, and Nutrition Service. Special supplemental nutrition program for women, infants, and children (WIC): Revisions in the WIC Food packages. Proposed rules. August 7, 2006; 71(151):44801. http://www.fns.usda.gov/wic/regspublished/foodpackagesrevisions-proposedrulepdf.pdf(accessed Feb 10, 2007).  

Hightower, J.M., A. O’Hare, and G.T. Hernandez. Blood Mercury Reporting in NHANES: Identifying Asian, Pacific Islander, Native American, and Multiracial groups. Environmental Health Perspectives, February 2006, 114(2):173–175.

Mozaffarian D., and E.B. Rimm. Fish intake, contaminants, and human health: Evaluating the risks and the benefits. JAMA, October 18, 2006, 296(15):1885–1899.

People of the State of California, ex rel. Bill Lockyer, Attorney General of the state of California vs. Tri-Union Seafoods, LLC, Del Monte Corporation, Bumble Bee Seafoods, LLC, and Does 1 through 499;and Public Media Center vs. Tri-Union Seafoods, LLC, Del Monte Corporation (formerly sued as H.J. Heinz, Co.), Bumble Bee Seafoods, LLC (formerly sued as Bumble Bee Sea foods, Inc.) and Does 1 through 499. Consolidated Case Nos.: CGC-01-402975 and 04-432394. Superior Court of California. County of San Francisco, 2006.