Bisphenol S, a chemical thought to be a safe alternative to bisphenol A (BPA), can be just as dangerous for fetal brain development, says a new study.

Using zebrafish, Canadian researchers have found that low-dose exposure to either BPA or its popular replacement chemical, BPS, in the equivalent of a human's second trimester has "real and measurable effects on brain development and behavior."

The study, conducted by researchers from the University of Calgary, was published Monday in the journal, Proceedings of the National Academy of Sciences.

In the study, the zebrafish showed bursts of activity (similar to anxiety) when they were exposed to BPA or BPS.

Exposure to low levels of BPA caused a 180 percent increase in the production of neurons in their hypothalamus; exposure to BPS prompted a 240 percent increase. The hypothalamus is the part of the brain involved in hyperactivity.

BPA has been linked to childhood anxiety and hyperactivity, as well as cancer, early puberty, obesity and even aggression in little girls. It can be found in the plastic coatings inside food cans and aluminum water bottles. It was commonly used in baby bottles and sippy cups before the FDA banned its use in those products.

As MNN's Russell McLendon writes: "BPA belongs to a broad group of substances known as 'endocrine disruptors,' which can cause early puberty in mice, sex changes in fish and a wide range of other animal ailments. That's raised red flags about human health risks, but while BPA and other endocrine disruptors have done some terrible things to lab rats over the years, studies showing similar effects in people are still too sparse to prove a connection."

As a result of their research, the study authors suggested that pregnant women limit their exposure to plastics and receipts. BPA and BPS are often used in the thermal paper used to print cash register receipts.

The researchers were adamant in their stance against using products that contain either BPA or BPS.

"Furthermore, our results show that BPA-free products are not necessarily safer and support the removal of all bisphenols from consumer merchandise."

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Mary Jo DiLonardo Mary Jo writes about everything from health to parenting — and anything that helps explain why her dog does what he does.