BPA-free plastic doubts raise new health concerns

BPA-free plastic may not be the health safeguard it was once believed to be, with new research indicating the risks involved in plastic bottles and food containers could be just as high as the BPA it replaced. The early study has suggested that – in mice at least – chemicals in BPA-free plastics could trigger reproductive problems.

BPA, or bisphenol A, was flagged as a potential health risk decades ago. Studies found that the chemical, that had been in commercial use since 1957, could exhibit estrogen-mimicking properties. As a result, amid fears it could affect fertility among other things, its use has generally been ceased in products intended for babies, while health-aware adults often look for BPA-free options too.

According to a study at Washington State University, however, some of the common BPA replacements in plastic could have downsides of their own. Lead author, Professor Patricia Hunt, is no stranger to the topic. In fact, she was responsible for some of the earliest BPA health research 20 years ago.

This time around, it was plastic cages housing mice being used as control animals in studies Hunt was undertaking that flagged a potential problem. Those cages used BPA-free plastic, with bisphenol S – or BPS – used instead of bisphenol A.

"This is a more stable plastic but it induced similar effects on the process of making eggs and sperm," Hunt said of the new study's findings. "Importantly, when we tested the chemicals in controlled experiments, we got similar results for each of them."

Mice in the BPS-containing cages saw changes in how the germ cells in their testes and ovaries copy and splice DNA, while producing sperm and eggs respectively. "Both sexes had problems getting DNA to recombine correctly," the team reports, "leading to a reduction in viable sperm and an increase in abnormal eggs."

Perhaps most ominously, the impact wasn't limited to BPS alone. The Washington State team also looked at other common BPA replacements, including BPF, BPAF, and diphenyl sulfone, and observed similar results. "These findings add to growing evidence of the biological risks posed by this class of chemicals," they conclude.

It's too early to say conclusively whether BPA alternatives are also damaging to humans. The study looked solely at a relatively small group of mice, and though the development and reproductive similarities between that animal and humans are present, it's not enough to say that damage observed in one will be mirrored by the other.

Still, the conclusion warrants extra research, and draws attention to the paucity of current safeguards. As the team points out, "it is easier and more cost effective under current chemical regulations to replace a chemical of concern with structural analogs rather than determine the attributes that make it hazardous." Without knowing that, it's hard to say whether alternative chemicals could be doing just as much damage as the substances they replace.

IMAGE Steven Depolo