 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 show that specific guidelines for a number of servings of fish, which are quote-unquote safe for women of reproductive age, may not be sufficiently specific to practically prevent fetal risk. So they conclude an 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 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 US 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 US EPA and international bodies would need to be halved. So are fishes allowed to have 20 times more mercury than may be considered safe?