Bisphenols have been a group of chemicals used in the manufacture of plastics, epoxy resins, and others since the 1960s.
What is Bisphenol A?
Bisphenol A (BPA) is an important component of the bisphenols
(bishydroxyarylalkanes) group. Today, BPA is a high-volume chemical that is widely used in the manufacture of polycarbonate plastics and epoxy resins for industrial purposes. Polycarbonate plastics are used in food and beverage packaging (water and infant bottles, CDs, impact-resistant safety equipment, medical devices), whereas epoxy resins are used as lacquers to cover metal products (cans, bottle caps, water supply pipes). Human exposure to BPA is of public health concern because BPA can bind to the membrane and nuclear receptors such as androgens, estrogens, and thyroid receptors, causing endocrine disturbances, tumors, reproductive problems, and transgenerational effects.
Sources of Exposure to BPA
The main source of BPA exposure is food, but BPA is pervasive in the environment, air, dust, and water. BPA can seep into food from internal epoxy resin coatings that protect canned food and consumer products such as polycarbonate tableware, food containers, water bottles, and feeders. While there are controversies about the regulation of BPA, studies have shown that this chemical is an endocrine disruptor, which means that this compound can cause harmful health effects at low and environmentally relevant doses. BPA is ubiquitous in aquatic environments and can be detected in streams, WWTP effluents, and WWTP waters.
Effects of bisphenol A on the reproduction system in humans
BPA is associated with altered reproductive function in both males and females; in fact, very high levels of plasma BPA have been associated with azoospermia in males. In addition, in a cross-sectional study with young males, elevated levels of urinary BPA were positively associated with serum luteinizing hormone (LH) levels and negatively associated with sperm concentration. Other studies indicate that urinary levels of BPA are associated with decreased sperm concentration, decreased sperm quality, decreased levels of antioxidants, decreased DNA integrity of sperm, decreased motility, and increased percentage of immature sperm. Moreover, urinary BPA levels were inversely related to the number of oocytes collected from women undergoing in vitro fertilization and serum estradiol levels.
There are also associations between high urinary levels of BPA and elevated serum levels of testosterone, estradiol, and pregnenolone in girls diagnosed with early puberty. In a recent study, serum BPA concentrations were higher in women diagnosed with polycystic ovarian syndrome than in healthy women.
Furthermore, increased serum BPA levels were associated with decreased fecundity in women who did not have folic acid supplementation before consumption. likewise, studies have shown that elevated serum and urine concentrations of BPA are associated with an increased risk of miscarriage. Similarly, high concentrations of BPA in the maternal blood, urine, or amniotic fluid were associated with weight loss during pregnancy and low birth weight. Collectively, these studies indicate that exposure to BPA is negatively associated with unfavorable reproductive function in both males and females.
How can consumers limit the risks?
BPA is absorbed into the body primarily by food and drink, although contaminated air and dust may also be a factor.
● Reduce canned food or, if you can’t, rinse food with water. Do not microwave food in plastic containers and cans.
● Avoid plastic with a recycling code of 3 or 7 in the bottom, and use non-plastic containers whenever possible for food and beverages.
● Choose water without BPA and feeding bottles (although they probably contain BPS or other alternatives).