Plastic particles are found in our organs, blood and even semen. But do they stay in us forever? What damage are they doing? Here are six questions scientists are trying to answer.

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The plastic additive BPA got a clean bill of health in a two-year government study involving thousands of rats. But scientists worried about BPA's risks say the study has flaws.

Many consumers avoid plastic products containing the chemical BPA, but a large study of rats suggests those water bottles and food cans are safe.

Manufacturers are not required to disclose whether products contain BPA, which makes it hard to know which kitchen plastics include the additive — or other functionally identical compounds.

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In 2007, a plastic called Tritan became a hit, partly because it was free of the chemical BPA. Then a competitor began suggesting that Tritan products contained other chemicals that act like estrogen.

The case focuses on a line of plastic resins made by Eastman Chemical. The resins don't contain BPA but may indeed act like estrogens, two other chemical companies allege. Eastman is suing.

Years after chemical companies stop using BPA in baby bottles and sippy cups, the Food and Drug Administration announces a ban. But consumer groups say FDA should do more and ban BPA from all food containers.

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The U.S. Food and Drug Administration called on a high-powered team of government scientists to help answer several key questions about the safety of bisphenol a. Their results suggest it's very unlikely that BPA poses a health risk to people.

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A couple of hours after eating, participants in a Harvard study who consumed canned soup had BPA levels in their urine that were about 12 times higher than the people who didn't. But the health implications of this sort of exposure to the chemical, which can act like the hormone estrogen, are still murky.

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Higher levels of BPA in urine taken from mothers during pregnancy were associated with slightly "worse behavior" among their 3-year-olds, especially in girls, researchers found. But BPA exposure after birth didn't show the same pattern.