- Microplastics
“Multiple sources are now confirmed, including primary microplastics in cosmetics and paint as well as the pellets and flakes used to make plastic products, along with secondary microplastics generated by the abrasion of larger items during use, including textiles and tires, and the fragmentation of larger debris in the environment. Microplastics can be redistributed by wind and water and have since been reported in diverse locations, from the sea surface to deep-sea sediments, from farmland to our highest mountains, and in sea ice, lakes, and rivers. They have been detected in 1300 aquatic and terrestrial species, from invertebrates at the base of the food web to apex predators, with evidence of impacts at all levels of biological organization, from cellular to ecosystem. Microplastics are pervasive in the food we eat, the water we drink, and the air we breathe. They have been detected in multiple tissues and organs of the human body, with emerging evidence of potential effects.”
https://www.science.org/doi/10.1126/science.adl2746
These plastic microbeads are often found as small spheres in exfoliating face washes or as fine powder in toothpaste and sunscreen. “Typically, they are washed down the drain, slip through water treatment plants, and enter into waterways.”
Secondary microplastics are “large plastic materials that could be used in packaging or building materials that just get ground down over time either through abrasion, wind, or sun rays, and become microplastics,” Anastas explains. Plastics bags, bottles, and food containers, as well as paints, adhesives and coatings, and electronics are all examples of materials that can break down and release secondary microplastics. Washing clothing made with synthetic fibers in washing machines is another common way that households often unknowingly contribute to the microplastics problem.
In a study published Wednesday in Environmental Science & Technology Letters researchers found that boiling tap water for just five minutes—then filtering it after it cools—could remove at least 80 percent of its microplastics.
A new study has found microplastics in human brains for the first time, raising concerns about the potential health impact. Researchers analyzed samples from autopsies and discovered an accumulation of plastic particles in brain tissue, likely due to exposure through food, water, and air.
- Endocrine Disruptors
The effect of endocrine disruptors on wildlife is well-documented., fungicides, and herbicides often contain EDCs. They can contaminate soil, air, and water and affect wildlife.
The impact of one endocrine disruptor is well-known: Dichlorodiphenyltrichloroethane (DDT) caused eagles, condors, and pelicans to produce eggs with very thin shells, killing many baby birds. DDT also caused sea lions to give birth prematurely.
More recently, scientists have linked EDCs with high numbers of frogs and swordfish with intersex characteristics.
Because certain diseases have increased in recent years along with humans’ use of chemicals, many scientists connect the two events. They say that genetic changes do not occur fast enough to explain the growth of these diseases. Some of these conditions are part of the endocrine system, leading some scientists to conclude that EDCs are to blame.
There is proof of human endocrine disruption in one well-known case, though. Many women took diethylstilbestrol (DES), a synthetic estrogen, from 1940 to 1971. Their doctors gave them the drug to treat problematic pregnancies. Years later, doctors discovered that the daughters of women who took DES had a higher risk of several types of cancer. Scientists are closely watching the next generation of women, the DES granddaughters, to see if they have problems, too.
Swan, a Berkeley-trained statistician-turned-epidemiologist, believes she knows why.
In recent years, traces of EDCs have been found in breast milk, placental tissue, urine, blood and seminal fluid.
EDCs could also affect the reproductive systems of your unborn children. The implications of EDCs for human health don’t stop there: they can disrupt thyroid function, trigger cancer and obesity.
“ano-genital distance (AGD), the span from the anus to the base of the penis, it is “also known as ‘the taint’, ‘the gooch’ and ‘the grundle’”, she told the crowd in Copenhagen. She enunciated the words with an innocence that stripped them of prurience. The audience listened intently as she described one of her pivotal discoveries: that AGD can act as a predictor of a man’s ability, years later, to conceive a child. It has provided evidence for her thesis that inadvertent exposure to EDCs in utero can inflict harm on a developing foetus.”
“AGD, or the length of the perineum, she explained, can reflect how much testosterone or androgen a foetus was exposed to during a very small window of pregnancy. “If there’s too little androgen for a boy, he doesn’t get fully masculinised,” she said. “If there’s too much androgen for a girl, she gets over-masculinised.” A mother with polycystic ovary syndrome, for example, will produce an excess of testosterone, and her daughter might have a longer, more masculine AGD.”
“By analysing the urine of mothers from the Future Families project, Swan could determine what level of a particular phthalate they had been exposed to and check for correlation with a shortened AGD in their offspring. She found women in the upper quartile for exposure were 13 times more likely to have a son with a shorter-than-average AGD than those in the lowest quartile.”
“Swan launched the Rochester Young Men’s Study, involving 126 volunteers aged 18-22. It provided the missing link to show that the shorter the AGD, the lower the sperm count.”
“Michael Eisenberg, professor of urology at Stanford University School of Medicine, undertook a number of studies involving men in their thirties and forties, and similarly found an association between a shorter AGD and infertility.”
“A total of 185 studies were examined in detail, using meta-analysis methods not available to the Danish academics 30 years before. The conclusion was deeply unsettling. Sperm count appeared to have declined 52 per cent in 38 years, or something over 1 per cent a year.”
“Chemicals from plastics leach out of containers into food, particularly when heated. Bottle-fed babies are swallowing millions of microplastic particles a day, a 2020 study showed, the health impacts unknown. An ingredient that was used in Teflon, PFOA, has been linked to cancer, ulcerative colitis and birth deformities. (DuPont, Teflon’s manufacturer, was found to have known about the health risks for decades, but only ceased production of PFOA in 2013.”
Andrea Gore, a professor of pharmacology at the University of Texas at Austin, who has led work for the Endocrine Society on EDCs, said that among clinical practitioners in the field there is wide acceptance that chemical exposures in early life can play a part in the development of disease.