There are multiple myths about mercury dangers

Like cell phones and Starbucks, mercury is everywhere. It's in the air, in rocks and soil, as the silvery liquid in old thermometers, in dental fillings and, lately, in headlines. Mercury in swine flu vaccines! Mercury in fish!

Don't hit the panic button. Mercury exposure is serious: It can cause neurological and muscular damage in adults and kids, and especially in babies still in the womb. But there are some serious Internet myths about it, too. Keep yourself healthy with these truths:

Myth: There are high amounts of mercury levels in the swine flu and seasonal flu vaccines.

Truth: Multiple-dose vials of these vaccines do contain the mercury-based preservative thimerosal. But the amount is tiny. A single dose delivers about 28 micrograms of mercury, the same as a small tuna fish sandwich. And while the tuna has methyl mercury, the type that accumulates in your bloodstream and has been linked to nervous-system damage, the type in thimerosal is ethyl mercury, which studies suggest is eliminated from your body relatively swiftly.

Yes, the swine flu shot has thimerosal, but thimerosal has been removed from virtually all other vaccines for kids under the age of 6 and from many given to older kids and adults, too. If you're still concerned about it, some thimerosal-free versions of both vaccines will be available this fall and winter — in single-dose vials, prefilled syringes or "mist" versions that are inhaled instead of injected. But if you can't find one, go with the regular, thimerosal-containing type. Don't die while trying to avoid a tuna sandwich's worth of mercury.

Myth: Since there's mercury in some fish, it's better just to avoid all fish.

Truth: Fish are the top source of mercury in the human diet. But not all fish are bad. Your body needs the heart-healthy omega-3 fatty acids found in some fish (and if you're pregnant or nursing, your growing baby needs 'em too — omega-3s help build better brains). Instead of cutting out all fish, aim for two weekly servings of salmon or trout, both of which are low in mercury, as is canned light tuna (in contrast, albacore's got three times more mercury), pollock and even fish sticks — and cut out higher-mercury types like shark, swordfish, king mackerel and tilefish (some environmental groups add wild striped bass, bluefish, bluefin tuna and marlin to that list). Have varieties like orange roughy, Chilean sea bass and blue crab only once or twice a month. By the way, it isn't just the fish fat that's healthy — it's the fish protein as well.