|
|
Balancing the Risks and Benefits of Fish Consumption
A comparative dietary risk framework (hereafter referred to as the framework) has been developed under this Cooperative Agreement for comparing the possible health risks of consuming contaminated fish, while considering the potential health benefits lost by not eating fish. The result of using the framework is a crude quantitative representation of the risk and benefit associated with eating contaminated fish. The output of the framework is referred to as the fish consumption index (FCI).
The FCI is an estimate of relative risk. It is not an estimate of absolute risk. In other words, it does not provide users of the framework with an estimate of their increased or decreased incidence of a particular health outcome. It simply provides a mechanism by which users can weigh the possible health risks versus the possible health benefits of eating contaminated fish. Cultural benefits of catching and eating fish (or detriments of not being able to fish or consume fish) may also be considered, however the current version of the framework does not attempt to quantify these benefits.
Before considering risks and benefits, a determination should be made that alternatives to contaminated fish are not available. Perhaps lower contaminated fish sources are available sufficient to maintain the individual’s desired level of fish consumption. Situations where the weighing of benefits and risks may be necessary may include subsistence populations where alternatives to contaminated locally caught fish are limited.
The framework is designed to provide information for a range of fish consumption rates, allowing a user to roughly estimate the range of consumption rates at which people may have a net benefit, a net risk, and the consumption rate at which no net change in the health index would be likely. However, the suggested framework has a number of significant data gaps. These gaps are sufficiently large so as to prevent any definitive conclusions. Moreover, these gaps prevent making any overall recommendations on the existing fish consumption advisory programs of the U.S. or other countries. Further study is needed to confirm and extend the preliminary findings discussed in this document.
Use of the framework and FCI does not imply the proper choice is simply achieving a situation in which the net risks and benefits are zero. Nor is it a justification for accepting fish consumption risks as long as there is a net benefit. Rather, the framework helps make the risks and benefits transparent. Decisions about acceptable risks and distribution of risks and benefits throughout society should be made collectively by the communities affected, and are not a focus of this text. That the FCI may demonstrate cases in which fish consumption benefits may outweigh the risks is not a license to pollute. Rather, society must determine policy about long-term goals for minimizing environmental pollution based on a range of ethical, economic, social, and other criteria. Again, the purpose of this text is to discuss the underlying scientific issues associated with comparing the risks and benefits of fish consumption. It does not address the social, economic or ethical considerations.
There is some evidence for an association between decreased risk of coronary heart disease (CHD) or myocardial infarction (MI) and consumption of small amounts of fish, including mainly lean (non-fatty) fish. In addition, other health endpoints have been examined and some research suggests that eating fish may be associated with reduced incidences or severity of a number of other endpoints. This evidence, along with the superior nutritional value of fish, is strong enough that public health officials routinely encourage the public to eat more fish.
Consuming uncontaminated fish (or at least fish that are smaller, younger, or in general less contaminated) may provide health benefits as mentioned above, but without the potential health risks associated with contamination. The eating of such "cleaner" fish rather than more contaminated fish, would maximize the net benefit of fish consumption, as we show specifically for low versus high concentrations of chemicals in fish, for those chemicals that either bioaccumulate or not, or for fish contaminated with more that one chemical.
This framework is an initial attempt to evaluate risks and benefits (qualitatively and quantitatively) on a common scale. Constructing this framework has identified numerous areas that need further research and development. Two needs seem paramount. First, better estimations of benefits are needed for the general population and its sensitive subgroups. Although information in this text is highly suggestive of the protective effects of eating fish and allows some quantification, more definitive work is needed to support or modify our chosen quantitative values. Second, better risk information is needed on the chemicals that commonly contaminate fish. Sufficient knowledge on the toxicity of most of these pollutants exists, on which noncancer risks could be quantified. Both sets of information are essential for this framework to be most effective.
For more information, contact Dr. Michael Dourson at 513-542-7475, extension 14 or Dourson@tera.org.
Download the complete report here.
© 2003 Toxicology Excellence for Risk Assessment
2300 Montana Avenue, Suite 409,
Cincinnati OH 45211
Phone: 513-542-7475
Fax: 513-542-7487
Email: TERA@TERA.org