Exposure to chemical bisphenol A (BPA), commonly found in plastic household items like plastic cans and bottles, can cause fertility defects in adults, a new study on mice has revealed.
University of Illinois scientists have found that chronic exposure to low doses of BPA can impair the growth and function of adult reproductive cells.
Jodi Flaws, who led the study with graduate student Jackye Peretz, said that a healthy, mature follicle, called an antral follicle, includes a single egg cell surrounded by layers of cells and fluid that support the egg and produce steroid hormones.
"These are the only follicles that are capable of ovulating and so if they don't grow properly they're not going to ovulate and there could be fertility issues," she said.
"These follicles also make sex steroid hormones, and so if they don't grow properly you're not going to get proper amounts of these hormones.
"Such hormones are essential for reproduction but they're also required for healthy bones, a healthy heart and a healthy mood," she added.
Human studies have found BPA in many tissues and fluids, including urine, blood, breast milk, the amniotic fluid of pregnant women, and the antral fluid of mature follicles.
The new study showed that follicle growth was impaired after 48 hours of exposure to BPA.
There were also reductions in three key steroid hormones - progesterone, testosterone and estradiol - within120 hours of exposure to BPA.
After the exposure, mouse follicle cells produced about 85 percent less estradiol, 97 percent less progesterone and 95 percent less testosterone.
Previous studies have already shown that exposure to plastic chemical reproductive problems in the offspring of pregnant mice.
The new study points to possible concerns in adults as well, Flaws said.
"I think there's a need for more studies where people look in adult humans to see if BPA is affecting follicle growth and steroid hormone levels," she said.
If it is, that might help explain some infertility or menopausal symptoms, she adds.
The findings were presented at annual meeting of the Society for the Study of Reproduction.