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EXECUnyE SUMMARY 1 1 



• Scombroid poisoning should be controlled primarily by rapid chilling on the 

 vessel and by maintenance of refrigeration temperatures throughout distribution. 



• Major emphasis should be placed on the development of rapid assays for 

 each of the other natural toxins; without this, control is very difficult. 



• Primary regulatory authority should be at the state level, with funding, quality 

 control, and specialized assistance from a federal seafood safety program. 



• Imported seafoods must be certified to be free of natural toxins through 

 equivalency arrangements or more effective memoranda of understanding (MOUs) with 

 exporters. An MOU refers to a formal agreement between a U.S. government agency 

 (e.g., FDA) and another government agency (federal, state, local), or an informal 

 agreement with a foreign government or other foreign institution. 



• Educational programs on the dangers of natural seafood toxins must be 

 developed for recreational and subsistence fishers, and health providers must be given 

 information to improve the identification and treatment of illness due to seafood toxins. 



Chemical Re!sidues 



Extent of Risk 



Fish and shellfish accumulate chemicals from the environment in which they live, 

 but the extent of accumulation depends on such factors as geographic location, species 

 of fish, feeding patterns, solubility and lipophilicity of the chemicals, and their 

 persistence in the environment. Moreover, whereas land animals used for human 

 consumption are fed mostly food of plant origin, aquatic animals that contribute to the 

 human diet are generally predators of other animals and, in some cases, predators of 

 predators. Because of this, chemicals have an opportunity to become more 

 concentrated through bioaccumulation. 



The most difficult area for risk evaluation is the problem of chemical residues 

 because the health effects suspected do not take the form of obvious, distinctive, and 

 acute illnesses. The potential risks of concern (e.g., modest changes in the overall risk 

 of cancer; subtle impairments of neurological development in fetuses and children) are 

 generally quite difficult to measure directly in people exposed at levels that are 

 common for U.S. consumers. Immunoincompetence may increase cancer risk. 

 Inferences about the potential magnitude of these problems must be based on the 

 levels of specific chemicals present, on observations of human populations and 

 experimental animals exposed at relatively high doses, and on reasonable theories about 

 the likely mechanisms of action of specific toxicants and the population distributions 

 of sensitivity and human exposure. In nearly all cases the current state of knowledge 

 on these subjects must be regarded as quite tentative. Additionally, the number and 

 variety of chemical residues are substantial, although a small minority constitute the 

 bulk of the risk that can be assessed quantitatively at this time. 



Overall, several chemical contaminants in some species of aquatic organisms in 

 particular locations have the potential to pose hazards to public health that are great 

 enough to warrant additional efforts at control. Available information suggests that 

 these risks, in the aggregate, are not generally of a magnitude comparable to the 

 highest environmental health hazards characterized to date; nevertheless, their control 

 would significantly improve public health. Some examples of risks that may be 



