April 15th, 2015
It has long been suspected but an element in some plastics known as bisphenol-A or BPA has now been proven to interrupt sperm production. University of Washington scientists conducted the study that has just proven so, published in the journal PLOS Genetics. The team showed that BPA disrupts DNA interactions which are pivotal in making sperm. Lead investigator, geneticist Pat Hunt and her colleagues say they may have proven a theory behind the phenomenon called the “sperm crisis” or the plummeting of male sperm counts in industrialized countries around the world. Sperm levels in first world nations have been in decline since the 1950’s. But the phenomenon wasn’t discovered until Danish scientists noticed this disturbing trend in the 1990’s. The case for one theory dubbed the “estrogen hypothesis,” was strengthened by this research. This is where endocrine disruptors in the environment, which register in the body as estrogen, enter men’s bodies and interfere with sperm production. Hunt says though they went in through the “back door” this research gives insight into the sudden drop in male fertility in recent decades.
The hormone estradiol was also found to affect men’s sperm counts. This is the birth control hormone which is allowed to pass through sewage treatment plants untreated. BPA is known to be in food containers, plastic drink bottles and the lining of certain cans. In this experiment, baby male mice were given doses of BPA orally. They were also administered synthetic estradiol. Those exposed to these while their testes were developing saw poorer meiosis—the process in which genetic material of the parent is packaged for delivery in the sperm. As a result, less sperm were produced correctly and so perished. Hunt has predicted that with each subsequent generation exposed, human sperm counts could continue to fall. Hunt’s words in the report are haunting. Noting that this phenomenon has been going on for decades, and with male infertility becoming more prominent, she asks, what happens after several generations have passed and also, “Are we creating the perfect storm?”