Salmon safety
1/26/2004
THE FIRST worldwide study of toxic contaminants in salmon has confirmed what other researchers had already found: that farmed salmon have much higher levels of polychlorinated biphenyls and similar compounds than wild salmon. According to the study, reported in the Jan. 9 issue of Science, the highest levels are in farmed salmon from northern Europe. Farm-fish samples from North America are less contaminated, and those from Chile are even cleaner. The study should spur changes both in the way the government weighs the risk of contaminants in salmon and the way the fish themselves are raised.
After tuna and shrimp, salmon is the third most commonly eaten fish in the United States. Salmon farming has grown dramatically in the past 20 years and now provides more than half of US salmon consumption. Salmon's good taste, affordability, and high levels of heart-healthy omega-3 fatty acids all contribute to its popularity.
But salmon's appeal is at risk if consumers have to weigh its nutritional pluses against high levels of PCBs, a suspected carcinogen, and other compounds. To help individuals make these decisions, two federal agencies -- the Food and Drug Administration and the Environmental Protection Agency -- must reconcile their wildly varying estimates of the PCB risk. According to the FDA, the PCB levels detected in the Science study are well within acceptable limits. Under EPA guidelines, on the other hand, consumers should limit themselves to a half-serving a month of farmed salmon from North America.
The FDA's critics say its standards are more than 20 years old and do not reflect recent research on the health risks of these contaminants. The EPA's standards, on the other hand, might be too conservative. It is up to the Bush administration to force these agencies to stop confusing the public. The federal government should also require that stores and restaurants identify the country of origin of all farmed salmon.
For their part, salmon farmers have an obligation to reduce the level of PCBs in their fish by changing the feed. The contaminants move up the food chain and concentrate in the processed trash fish that are fed to the farm salmon. The industry is investigating the possibility of replacing some of the fish oil in the salmon's diet with vegetable oils. If this change works, it would also curb the increasingly heavy harvesting of trash fish, leaving more for wild predator species.
All over the globe, fish are an important source of protein. But a study published in Nature last year showed there has been a 90 percent decline since World War II in the populations of many large fish species. Farmed fish could fill much of the need, but only under conditions that respect the ocean environment and produce healthful food.
© Copyright 2004 Globe Newspaper Company.
