By Jonathan Benson The reproductive damage caused by exposure to endocrine-disrupting chemicals (EDCs) like bisphenol-A (BPA) may take several generations after initial exposure to become evident, according to new research out of Missouri.
A team of biological scientists and toxicologists determined that, even when exposure to BPA doesn’t show immediate health consequences, the second, third, and even fourth generations afterwards can experience reduced fertilization and increased embryo mortality.
Using medaka, or Japanese rice fish, as test subjects, scientists evaluated the effects of BPA and several other EDCs during one week of embryonic development. They then looked at the offspring of these exposed fish throughout the course of four subsequent generations, as Japanese rice fish have shorter generations that are ideal for this type of research.
Interestingly, the first two generations of fish showed no evidence signs of reproductive abnormalities. But the third and fourth generations did, with the third generation showing a 30 percent decrease in fertilization, and the fourth generation showing a 20 percent decrease in fertilization.
None of the subsequent generations of medaka were directly exposed to BPA or the other EDCs, either. They were all indirectly exposed via their ancestors, which somehow passed down the reproductive damage caused by BPA and other EDCs to their offspring.
“BPA has been proven to mimic the function of natural hormones in animals and humans,” stated Ramji Bhandari, an assistant research professor of biological sciences at the University of Missouri and a visiting scientist with the USGS, and one of the study’s authors, about the findings.
“Fish and aquatic organisms often have the greatest exposure to such chemicals during critical periods in their development or even throughout entire life cycles. This study shows that even though endocrine disruptors may not affect the life of the exposed fish, it may negatively affect future generations.”
BPA shown to damage stem cells in human males responsible for healthy sperm production
The study, which was published in the journal Scientific Reports, is backed by earlier research on BPA, including a paper published in the online journal PLOS Genetics.
Washington State University (WSU) geneticist Patricia Hunt found that even very low-level exposure to BPA mimics the activity of estrogen inside the body. For males, this can result in decreased sperm counts and infertility over time, as well as alterations to the master stem cells responsible for producing healthy sperm.
BPA and other estrogen mimickers are “not simply affecting sperm being produced now, but impacting the stem cell population,” stated Hunt about her findings. “And that will affect sperm produced throughout the lifetime.”
An abstract of Hunt’s study can be accessed here.
Cohort of published science proves BPA destroys fertility, but FDA refuses to acknowledge any of it
The implications of these two examples and a number of other related studies suggests that the continued use of BPA and other EDCs in metal can linings, plastic bottles, thermal paper receipts, and various other consumer products is causing long-term damage in the reproductive capacities of both humans and animals.
And yet the U.S. Food and Drug Administration (FDA) refuses to acknowledge the science on BPA, insisting instead that the chemical is completely “safe.” The result is that millions of people continue to be exposed to this and other EDCs that could eventually render that vast majority of the population infertile several generations down the line.
Such a scenario very closely resembles the plot line of the science fiction film Children of Men, in which women all over the world somehow become “mysteriously” infertile, and one lone pregnant women is ushered to safety in order to perpetuate the continuity of the human race.