by A chemical long used in soft, flexible plastics such as PVC may damage the sex cells of some animals and possibly even humans, a new study suggests.
Researchers exposed roundworms (Caenorhabditis elegans) to the chemical benzyme butylphthalate (BBP) at levels within a range previously detected in samples of human urine, semen, blood, cord blood, breast milk, and amniotic fluid.
The team, led by researchers from Harvard Medical School, found that BPP and its byproducts were internalized in worms at similar levels to what is seen in humans, and that the plastic chemical had the strongest negative effect on the germ cells of the animals, including DNA breakage. .
BBP was and in some cases continues to be widely used in products such as vinyl flooring and furniture, exercise balls, carpet backing, children’s toys and other child care products, car care products and cosmetics.
While the chemical has been somewhat limited in the USA, Canada and the European Unionit is often only prohibited at certain concentrations certain circumstances, such as cosmetics or children’s products. And many of us live surrounded by furniture, flooring and other materials that were produced before GDP concerns arose.
“Whether applied topically, sprayed or consumed, the different uses of BBP-containing products introduce three major routes of exposure to humans: dermal absorption, inhalation and ingestion,” the authors write.
We have known for some time that BBP disrupts the endocrine system. And yet, as the authors point out, very few studies have examined the direct effects of endocrine-disrupting chemicals like BBP on the key process that shapes our reproductive cells, meiosis.
The researchers, led by reproductive toxicologist Ayana Henderson of Harvard Medical School, exposed roundworms to BBP doses of 1, 10, 100 and 500 micrometers and examined the impact this had on the worms’ germ cells using mass spectrometry and RNA sequencing. .
Double-stranded DNA breaks occurred at an increased rate throughout the cells. There were also defects in meiosis (cell division that reduces the size of chromosomes in sex cells), where nuclei were formed too early. The chromosome segregation was inaccurate, which can lead to offspring having an abnormal number of chromosomes.
In short, it was a bit of a horror show.
The study found that BPP causes damage by causing oxidative stress, with the body’s antioxidant shield unable to keep up with the job of neutralizing the highly reactive toxin. With this antioxidant carnage, the poison can attack the body’s cells instead. In the gonads, where eggs and sperm are formed, this can have very serious consequences for the next generation.
“TThe fact that the internal levels of BBP and its primary metabolites detected in the worms are comparable to the levels found in several human female biological samples underlines the relevance of using c. elegans to study the reproductive toxic effects of BBP exposure,” the authors write.
“EExposure to these endocrine-disrupting chemicals can pose a threat to human health, both for those directly exposed and for unexposed future generations.”
This research was published in PLOS genetics.
