Dr Dingle's Blog / PFOa
Since the 1980's, there has been a growing amount of research toward the potential interaction between these environmental estrogens and wild animals, with a number of reports detailing the emergence of 'feminised wildlife’ around the world, and a range of adverse effects in humans including decreased sperm count, increased cases of testicular cancer and testicular abnormalities, increased breast cancer in men and women and premature or precocious puberty. Other adverse health outcomes linked with EDC’s include headache, migraine, depression, gastrointestinal disturbances, insomnia, changes in breast tissue and in vaginal bleeding. More chronic symptoms affect the cardiovascular system, the skin (itching, rash, abnormal pigmentation), the gallbladder, and tumours particularly of the breast but also uterus, cervix, vagina and liver. While other studies have shown increases in the organ weight of estrogen-sensitive tissues such as the uterus, and calcium and bone metabolism are all examples of the estrogenic effects. Even how we age and age at menopause can be affected by these chemicals. In support of this at least one professional and very conservative group, the Endocrine Society, has concluded that sufficient evidence now exists linking endocrine disrupting chemicals (EDCs) to adverse human reproductive effects, including possible epigenetic and trans-generational effects.
Unfortunately, our babies are being born pre-polluted with chemicals detectable in their blood, in the placenta and in amniotic fluid because of exposure to these chemicals during pregnancy and throughout the mother’s life. The placental barrier has been shown to allow these chemicals to cross, as many of them have been measured in human fetal cord blood, fetal serum, human amniotic fluid and even newborn stools (meconium). Exposure to these chemicals before birth poses a serious health risks to developing fetus, infants and young children as shown by the increasing adverse effects including negative birth outcomes, childhood obesity and increasing intellectual disabilities. It is believed that current levels of environmental estrogen exposure results in lower birth weights, smaller head circumferences, poorer neuromuscular maturity and visual recognition, delays in psychomotor development, short term memory problems, and growth retardation in newborn babies. Fetal exposure to these environmental estrogens are suspected of disrupting thyroid functioning, sexual differentiation of the brain in foetal development and cognitive motor function and cause anxious behaviour. They are also able to bind to neurotransmitters such as epinephrine, neuroepinophrine and dopamine enabling estrogens to influence the body's central nervous system (CNS). Environmental estrogens have also been shown to effect the body’s immune system.
Studies have found strong links with exposure to excessive levels of estrogen in males with penis abnormalities, lower libido, congenital anomalies, failure of the testes to descend and testicular cancer, reduced penis size and increased embryo mortality.
What is most concerning regarding control of these chemicals is that there are no indications given or regulations set regarding the minimal age at which they should be used or exposed to them. Increasingly, pregnant mothers, infants, pre-pubescent and pubescent children are being exposed to a large number of products containing these chemicals, with no research to show that exposure is safe during these critical periods of development.
Equally strong is the evidence that these same chemicals can cause some of the most common cancers: prostate and testicular cancer in men and breast cancer in women. One of the most troubling is their association with breast cancer. Breast cancer is the major cancer affecting women in the Western world and one of the most disturbing and well documented current trends is the alarming increase in breast cancer incidence over the past few decades. Fifty years ago the risk rate was one woman in 20; today it is one in 8 and approximately two-thirds of breast tumors are estrogen receptive, and environmental estrogens like parabens, phthalates and BPA are known to bind to estrogen receptors. Estrogen-dependent cancers, such as breast cancer, are known to be highly responsive to estrogens for growth. Even more disturbing is the increase in numbers of young girls developing breast cancer.
Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are persistent synthetic chemicals that are widely used in industrial applications and often detectable in humans. Some PFASs have a long half-life (how long it takes for half of the chemical to break down and be eliminated from the body) in humans. For example, the half-life of perfluorooctanoate (PFOA- which is used in the production of teflon), perfluorooctane sulfonate (PFOS), and perfluorohexanesulfonate (PFHxS) has been estimated at 3.8, 5.4, and 8.5 years, respectively. That is, they will be in your body for a many years even after one exposure.
In rats, PFASs can interfere with the estrous cycle and have been linked with reduced fecundity, indicated by increased time to pregnancy (TTP) and risks of infertility. Dysfunction of menstrual cycle is a major cause of infertility and lower fecundity. Animal and human evidences suggest that PFASs affect formation of steroid hormones and hormone levels manifesting in altered menstrual cycles such as prolonged lengths. A recent epidemiologic study suggested that menstrual cycles may be lengthened in women with the highest serum concentrations of PFOA in comparison to those with the lowest concentrations.
In this study of PFASs in 950 pre-pregnant women with higher levels had increased odds of self-reported history of irregular menstrual cycle, long menstrual cycle and levels were negatively associated with self-reported history of menorrhagia. The study concluded that certain PFASs are associated with abnormal menstruation in humans. https://doi.org/10.1289/EHP1203
Studies have found around 15 chemicals that are positively associated with younger menopausal age and the two major culprits were phthalates found in everyday makeup and personal care products.
Of the 13 chemicals the strongest influence was 3.8 years younger for mono-(2-ethyl-5-hydroxyhexyl)phthalate, compared with less-exposed women.
Another study found a link between early menopause and elevated serum levels of perfluorooctanoic acid (PFOA), or teflon an industrial chemical used in several nonstick and stain-repellant applications. Manufactured for decades, PFOA is now widespread in the biosphere, and most people have some in their bodies. The chemical accumulates in blood, so women of reproductive age will eliminate some of it when they menstruate.
This result was also found in two prior studies of polyfluoroalkyl chemicals (PFCs) including PFOA.