A total of 150 scientific studies have shown that bisphenol A (BPA), a controversial component of plastic bottles and canned food linings, may be used in quantities too small to negatively affect human health.

The analysis, presented at the American Association for the Advancement of Science's annual meeting here by toxicologist Justin Teeguarden of the Department of Energy, shows that BPA in the blood of the general population is many times lower than blood levels that consistently cause toxicity in animals.

The result suggests that animal studies might not reflect the human BPA experience appropriately, the study said.

"Looking at all the studies together reveals a remarkably consistent picture of human exposure to BPA with implications for how the risk of human exposure is interpreted," said Teeguarden. "At these exposure levels, exposure to BPA can't be compared to giving a baby the massive dose of estrogens found in a birth control pill, a comparison made by others."

Teeguarden also analyzed another set of BPA studies that looked at the chemical's toxicity in animals and cells in the lab.

According to his analysis, the "low doses" actually span an immense range of concentrations, a billion-fold.

"The term low-dose cannot be understood to mean either relevant to human exposures or in the range of human exposures," said Teeguarden. "However, this is in fact what it has come to mean to the public, as well as many in the media."