Hair Testing for Mercury before Considering Pregnancy

Because, as editorialized in the Journal of Pediatrics last year, “Almost all fish contain some mercury,” women who plan on getting pregnant may want to first get tested for mercury. “Due to the considerable uncertainty,” they showed that “specific guidelines for number of servings of fish, which are ‘safe for women of reproductive age,’ may not be sufficiently specific to practically prevent fetal risk.” So, they conclude: “Analysis of hair mercury may be warranted before pregnancy” in women who eat a lot of fish. It’s a simple test. All they need is a hair sample, because mercury contaminates your whole body when you eat it.

The reason they’re so concerned is because they found that “even at the number of [fish] servings recommended by the FDA [as safe], there were women with hair mercury [levels] above the LOAEL [lowest observable adverse effect level] of 0.3…”

And some question the federal safety limits. A recent review from researchers at Harvard and elsewhere on the adverse effects of methylmercury notes that the U.S. EPA limit suggests an adult should be exposed to no more than 50 micrograms. But if that’s the case, then seafood better contain less than 0.1 per gram, and “current regulations in the United States and the European Union allow up to 10 times as much”  mercury in fish as the EPA limit allows.

And they go on to criticize the EPA safety limit as being way too high itself. They argue that “Thus, (based on new data), the exposure limits estimated by the U.S. EPA [and international bodies] would need to be halved.”

So, our fish is allowed to have 20 times more mercury than may be considered safe.

To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Serena Mylchreest.

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• Oken E. Fish intake and mercury levels: only part of the picture. J Pediatr. 2010 Jul; 157(1):10-2.
• Schoeman K, Tanaka T, Bend JR, Koren G. Hair mercury levels of women of reproductive age in Ontario, Canada: implications to fetal safety and fish consumption. J Pediatr. 2010 Jul; 157(1):127-31.
• Grandjean P, Satoh H, Murata K, Eto K. Adverse effects of methylmercury: environmental health research implications. Environ Health Perspect. 2010 Aug; 118(8):1137-45.

• fish
• Harvard
• mercury
• pregnancy
• reproductive health
• safety limits
• seafood
• women's health