BOSTON -- You've heard about BPA, or bisphenol A, the potentially dangerous chemical found in some plastic bottles and cans.

Now, a first-of-its-kind study has been released on exactly what is seeping into our bodies.

Boston's WCVB-TV reported that a Harvard University study found that if there is BPA in the plastic you're drinking from, it will end up in your body.

BPA is found in everything from plastic baby bottles to the lining of soup and soda cans.

The first human study last year showed that exposure to BPA, even at lower levels, could increase the risk of heart disease and diabetes. Researchers also believe BPA could be linked to breast and prostate cancer.

"This is the first study that actually ever looked at this and that demonstrates that bisphenol A gets in your body, is absorbed and then excreted," said professor Karin Michels, who co-authored the Harvard study with five of her students at the Harvard School of Public Health.

With help from the Centers for Disease Control and Prevention, researchers compared urine samples of study participants after separate weeks of drinking from a safe bottle and one that contained BPA.

"Just drinking from these bottles, where you fill in the liquid on the same day, so it doesn't even have contact with this plastic for very long -- for a couple of hours -- and just for one week, increases your BPA level in the body by two-thirds," Michels said.

Consumers can tell if a bottle or container has BPA by turning it over and checking the recycling triangle stamped on it. A No. 7 inside the triangle means it could contain BPA. A casual survey showed the No. 7 on several containers, from sippy cups and bottles to coffee cups and office water cooler jugs, even a plastic kiddie cup of mandarin oranges.

Some countries, such as Canada, have banned BPA in baby bottles, but the chemical is still out there in many cans and bottles used in the U.S.