Reproductive Problems Reported In Lab Mice after BPA Replacements in Plastics

Twenty years ago, researchers from Washington State University made the accidental discovery that the now infamous plastics ingredient known as bisphenol A or BPA had inadvertently leached out of plastic cages used to house female mice in the lab, causing a sudden increase in chromosomally abnormal eggs in the animals. Now, the same team is back to report that the array of alternative bisphenols now used to replace BPA in BPA-free bottles, cups, cages, and other items appear to come with similar problems for their mice.

Reproductive problems reported in lab mice after BPA replacements in plastics. Image credit: Marianne Casamance/Wikimedia Commons (CC BY-SA 3.0)

The new findings were uncovered much as before as the researchers again noticed a change in the data coming out of studies on control animals. Again, the researchers traced the problem to contamination from damaged cages, but the effects this time were more subtle than before. That's because not all of the cages were damaged and the source of contamination remained less certain.

However, they were able to determine that the mice were being exposed to replacement bisphenols. They also saw that the disturbance in the lab was causing problems in the production of both eggs and sperm.

Once they got the contamination under control, the researchers conducted additional controlled studies to test the effects of several replacement bisphenols, including a common replacement known as BPS. Those studies confirm that replacement bisphenols produce remarkably similar chromosomal abnormalities to those seen so many years earlier in studies of BPA.

These problems, if they hold true in people as has been shown in the case of BPA, will carry over to future generations through their effects on the germline. The researchers showed that, if it were possible to eliminate bisphenol contaminants completely, the effects would still persist for about three generations.

More work is needed to determine whether some replacement bisphenols might be safer than others, noting that there are dozens of such chemicals now in use. Other widely used and endocrine-disrupting chemicals, including parabens, phthalates, and flame retardants, may be having similarly adverse affects on fertility that warrant much more study.

Researchers advice to consumers now is simple: BPA-free or not, "plastic products that show physical signs of damage or aging cannot be considered safe." (Tasnim News Agency)

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