Bisphenol A (BPA) is used as a plasticizer in polycarbonate plastic and epoxy resin production. In addition, it is used as an additive agent in the fabrication process of polyvinyl chloride (PVC) as well as in manufacturing healthcare machines, contact lenses, toys, window foils, and storage media.
It is one of the food contacting materials used widely in food and drink packages and in utensils used in the kitchen. It is a chemical compound manufactured in enormous quantities.
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Human Exposure to BPA
H BPA in several ways such as oral administration, inhalation, and application of transdermal medicines. The chief source of BPA exposure is food products. The key sources of nutritional contact with BPA are preserved or canned foods, as it is extensively used in the making of cans for food preservation and for the internal coating of jar caps.
Sterilization of cans, by application of heat, causes the BPA to outflow from the epoxy coating into the food within the can and, consequently, increases human exposure to BPA.
Humans can also be exposed to BPA through dust from flooring , adhesives comprising epoxy resins, household electronic appliances, and paints. Humans are predominantly exposed to BPA from dust found in workplaces and laboratories where large numbers of electric appliances and furniture are used.
BPA is found in dental fillings, sealants, and substances used for crowns . BPA is also used in paper production, thermal printing, and payment cards.
Effects of BPA on Human Health
BPA is processed in the liver by the enzyme uridine 5’-diphospho-glucuronyl transferase . Epidemiological reports on the relationship between BPA and its health effects in humans have indicated that BPA is very harmful to human health.
BPA is widely known as an endocrine-disrupting chemical (EDC). It has exhibited a role in the pathogenesis of various disorders of the endocrine system that include female and male infertility, hormone-reliant tumors such as breast and prostate cancer, and several other metabolic diseases such as polycystic ovary syndrome. Estimating BPA levels in humans, such as by biomonitoring BPA concentration in urine, is very important as humans are continuously exposed to it and it gets easily accumulated in the body.
Effect of BPA on Newborns
Researchers have reported that BPA concentrations are 11 times higher in infants than in adults. The ability of the liver to metabolize BPA is lower in babies than adults. Hence, the amount of BPA is increased and affects the health of infants. It can also cause childhood asthma in babies or newborns.
Effects on Male and Female Fertility, and Fetal Development
I ncreased BPA in the human body alters sperm function as well as fertilization in both men and women, and affects embryonic development.
In females, BPA can affect endocrine function by altering secretion of gonadotropin-releasing hormones, which in turn impacts puberty and ovulation. BPA exposure has an effect on one of the most common health problems in women (polycystic ovary syndrome), due to a change in hormone secretion.
T here are effects on the ovary due to BPA. For example, BPA exposure will lead to loss of follicles in the ovary. It also causes a decrease in the level of antral follicle counts and a lower survival rate of oocytes.
BPA exposure damages the female reproductive system at various parts of the life cycle and may promote infertility. In addition, the amount of proteins in spermatozoa necessary for fertility is altered, causing infertility in males.
Effects on Breast Cancer
The possible relation between BPA exposure and breast cancer is monitored by estimating the BPA concentration among people with and without breast cancer. The structure of BPA is identical to estrogen. It interferes in hormone pathways and leads to harmful health effects. Chronic exposure to BPA causes malignant tumors in the mammary gland. Studies have shown the association between high levels of BPA and increased mammographic breast density.
Effects in Heart Disease
A higher concentration of BPA in urine is related to certain cardiovascular conditions such as heart attack, angina, and heart problems. Some reports have shown that acute BPA exposure causes development of an irregular heart rhythm, and constant exposure to BPA resulted in atherosclerosis and changes in blood pressure. Therefore, BPA exposure is considered to be a risk factor for heart-related disorders.
Reviewed by Catherine Shaffer, M.Sc.
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