Kate Wing's Blog
Heavy metal drives you mad
January 18, 2008
Posted by Kate Wing in Reviving the World's Oceans
My astute friend at blogfish caught this press release from Micro Analytical Systems, Inc. on mercury in fish you might buy at the store. As blogfish points out, mercury poses the most concern for children, mothers and mothers-to-be, but people who eat a lot of seafood can also find themselves suffering the effects of mercury poisoning: fatigue, hair loss, stomach upset. In 2003, NRDC did an interview with Dr. Jane Hightower about her work on mercury poisoning in adults. Suffice it to say that mercury is not a nutrient.
Now, MASI runs a private testing program -- Safe Harbor -- through which they test fish for mercury for companies such as Pacific Seafood, the largest seafood processor on the west coast. So they do have a vested interest in these data. But there's no question that the FDA data on mercury in seafood are woefully out of date and lacking in samples. According to MASI's newsletter, they sampled more fish in 2007 than the FDA has in its entire dataset, which relies on reports from as far back as 1978. Here's Table 1 from MASI's report:
The press release singles out a subset of these fish--only the ones bought in markets--for its finding that 80% of tested swordfish had higher mercury levels than the FDA guidelines of 1 ppm. If you include all the fish tested, as the chart above does, its closer to 40%. Which is still surprising since they're trying to select swordfish that might have lower mercury and thus be able to pass their Safe Harbor labeling test. These data confirm that the FDA's numbers don't accurately reflect mercury levels in fish today and perhaps should not be relied on as consumption guides.
I'm also excited that MASI's testing might help us get at another vexing issue: calling fish by their true names. When I called MASI's press person about the report, I asked him what kind of halibut were tested and he said that for market samples they just rely on the store's labelling. No way to differentiate between California halibut and Pacific halibut there, but since MASI's testing at processing plants, perhaps we will have finer-scale data in the future.
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Katie Riley — Jan 25 2008 11:48 AM
Oceana, an international marine conservation organization, has just published an extensive national study on mercury levels in fresh tuna, swordfish and tilapia from supermarkets, and tuna and mackerel from sushi restaurants, and there were some surprising results. Oceana’s tuna samples tested almost twice as high as FDA data had previously suggested! Additionally, almost 90 percent of seafood counter attendants could not provide the FDA advice when asked. The good news is that mackerel and tilapia are low-mercury fish and can be eaten safely. The bad news is that swordfish and fresh tuna have high levels of mercury, and consumers should be leery.
The Food and Drug Administration has recommended that women of childbearing age and children completely avoid eating swordfish and limit consumption of fresh tuna to six ounces or less a week. Even if people are familiar with this advice concerning mercury, they probably don’t readily carry it while dining out or shopping for their weekly groceries. And you probably shouldn’t rely on seafood counter attendants to give you the government advice either in light of Oceana’s new findings!
Posting signs in grocery stores would provide this crucial information in a way that is accessible and easily understood. Major grocery companies like Kroger, Safeway and Albertsons are posting the FDA advice at their seafood counters. Still other grocers, like Costco, Publix and A&P, refuse to post a sign and give this important information to their customers. There is no reason to cut seafood totally out of your diet, but it is important to know what kinds of fish are potentially harmful and how to avoid them. Check out Oceana’s new report and get the full story.