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Washington State University study: BPA replacements in plastics cause reproductive problems in lab mice

16 Sep

Brent A. Bauer, M.D. of the Mayo Clinic provides a concise description of bisphenol A (BPA):

What is BPA, and what are the concerns about BPA?
Answer From Brent A. Bauer, M.D.
BPA stands for bisphenol A. BPA is an industrial chemical that has been used to make certain plastics and resins since the 1960s.
BPA is found in polycarbonate plastics and epoxy resins. Polycarbonate plastics are often used in containers that store food and beverages, such as water bottles. They may also be used in other consumer goods.
Epoxy resins are used to coat the inside of metal products, such as food cans, bottle tops and water supply lines. Some dental sealants and composites also may contain BPA.
Some research has shown that BPA can seep into food or beverages from containers that are made with BPA. Exposure to BPA is a concern because of possible health effects of BPA on the brain, behavior and prostate gland of fetuses, infants and children. Additional research suggests a possible link between BPA and increased blood pressure.
However, the Food and Drug Administration (FDA) has said that BPA is safe at the very low levels that occur in some foods. This assessment is based on review of hundreds of studies.
The FDA is continuing its review of BPA, including supporting ongoing research. In the meantime, if you’re concerned about BPA, you can take these steps to reduce your exposure:
• Use BPA-free products. Manufacturers are creating more and more BPA-free products. Look for products labeled as BPA-free. If a product isn’t labeled, keep in mind that some, but not all, plastics marked with recycle codes 3 or 7 may be made with BPA.
• Cut back on cans. Reduce your use of canned foods since most cans are lined with BPA-containing resin.
• Avoid heat. The National Institute of Environmental Health Sciences, part of the National Institutes of Health, advises against microwaving polycarbonate plastics or putting them in the dishwasher, because the plastic may break down over time and allow BPA to leach into foods.
• Use alternatives. Use glass, porcelain or stainless steel containers for hot foods and liquids instead of plastic containers….. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/bpa/faq-20058331

A Washington State University study found there could be problems with some replacements to BPA plastics.

Science Daily reported in BPA replacements in plastics cause reproductive problems in lab mice:

Twenty years ago, researchers made the accidental discovery that the now infamous plastics ingredient known as bisphenol A or BPA had inadvertently leached out of plastic cages used to house female mice in the lab, causing a sudden increase in chromosomally abnormal eggs in the animals. Now, the same team is back to report in the journal Current Biology on September 13 that the array of alternative bisphenols now used to replace BPA in BPA-free bottles, cups, cages, and other items appear to come with similar problems for their mice….

The new findings were uncovered much as before as the researchers again noticed a change in the data coming out of studies on control animals. Again, the researchers traced the problem to contamination from damaged cages, but the effects this time, Hunt says, were more subtle than before. That’s because not all of the cages were damaged and the source of contamination remained less certain.
However, she and her colleagues were able to determine that the mice were being exposed to replacement bisphenols. They also saw that the disturbance in the lab was causing problems in the production of both eggs and sperm.
Once they got the contamination under control, the researchers conducted additional controlled studies to test the effects of several replacement bisphenols, including a common replacement known as BPS. Those studies confirm that replacement bisphenols produce remarkably similar chromosomal abnormalities to those seen so many years earlier in studies of BPA.
Hunt notes that the initial inadvertent exposure of their animals was remarkably similar to what might happen in people using plastics in that the exposure was accidental and highly variable. Not all of the animals’ cages were damaged, and so the findings differed among animals in different cages.
She adds that — although determining the levels of human exposure is difficult — their controlled experiments were conducted using low doses of BPS and other replacement bisphenols thought to be relevant to exposure in people using BPA-free plastics.
These problems, if they hold true in people as has been shown in the case of BPA, will carry over to future generations through their effects on the germline. The researchers showed that, if it were possible to eliminate bisphenol contaminants completely, the effects would still persist for about three generations… https://www.sciencedaily.com/releases/2018/09/180913113940.htm

Citation:

BPA replacements in plastics cause reproductive problems in lab mice
Date: September 13, 2018
Source: Cell Press
Summary:
Twenty years ago, researchers made the accidental discovery that BPA had leached out of plastic cages used to house female mice in the lab, causing an increase in chromosomally abnormal eggs. Now, the same team is back to report that the array of alternative bisphenols now used to replace BPA in BPA-free bottles, cups, cages, and other items appear to come with similar problems for their mice.
Journal Reference:
Tegan S. Horan, Hannah Pulcastro, Crystal Lawson, Roy Gerona, Spencer Martin, Mary C. Gieske, Caroline V. Sartain, Patricia A. Hunt. Replacement Bisphenols Adversely Affect Mouse Gametogenesis with Consequences for Subsequent Generations. Current Biology, 2018; DOI: 10.1016/j.cub.2018.06.070

Here is the press release from Washington State University:

WSU researchers see new plastics causing reproductive woes of old plastics
September 13, 2018

BPA has long been used in bottles, cups, medical and dental devices, and as coatings for food-can linings and cash register receipts.
By Eric Sorensen, WSU News

Washington State University researchers have found that plastic products meant to replace the chemical bisphenol A, or BPA, are also causing genetic abnormalities in mice.

The discovery is a déjà vu moment for Patricia Hunt, who 20 years ago linked abnormalities in egg chromosomes to BPA released by a harsh detergent used on her lab’s mouse cages. This time, she saw reproductive defects in control animals housed in plastic cages made with BPA alternatives.

“There’s growing evidence that many of these common replacements are not safe,” said Hunt, a professor in WSU’s School of Molecular Biosciences and lead author of a study in the latest Current Biology. “We stumbled on an effect yet again. This is a more stable plastic but it induced similar effects on the process of making eggs and sperm. Importantly, when we tested the chemicals in controlled experiments, we got similar results for each of them.”

BPA has long been used in bottles, cups, medical and dental devices, and as coatings for food-can linings and cash register receipts. After Hunt and other researchers began tying BPA exposure to developmental defects in numerous animal species, the U.S. Food and Drug Administration banned it in baby bottles and children’s drinking cups. The Washington legislature has also limited its use.
Hunt and her colleagues say mice exposed to the common BPA replacement bisphenol S, or BPS, underwent changes in the way the germ cells in their testes and ovaries copy and splice DNA while producing sperm and eggs. Both sexes had problems getting DNA to recombine correctly, leading to a reduction in viable sperm and an increase in abnormal eggs. Hunt and her colleagues had similar results with the replacements BPF, BPAF, and diphenyl sulfone.

“These findings add to growing evidence of the biological risks posed by this class of chemicals,” Hunt and her colleagues write.

Problems in the male germline lasted several generations after the initial exposure.
In addition to risking human reproductive health, the replacement plastics can also be compromising the integrity of biological research.

“It’s now becoming almost impossible to run experiments without contamination,” said Hunt, called the “accidental toxicologist” by Scientific American magazine. “And it’s not that I live under my own black cloud. It’s that I have a super sensitive system. A germ line is like the canary in the coal mine. As soon as something hits, we see it. Other investigators in my facility don’t see it but it doesn’t mean that it doesn’t impact their research.”

Hunt’s WSU colleagues in the research are Tegan Horan, a research intern and the paper’s first author, as well as scientific assistants Hannah Pulcastro and Crystal Lawson and former postdoctoral fellows Mary Gieske and Caroline Sartain. Joining them are Roy Gerona and Spencer Martin of the University of California, San Francisco.
The study was funded by the National Institutes of Health.
Media contact:
Patricia Hunt, professor, WSU School of Molecular Biosciences, 509-335-4954, pathunt@wsu.edu

The question is whether there are safe plastics.

Timothy Banas wrote in the Livestrong.com article, Which Plastic Containers Can I Safely Use?

Type 1: Polyethylene Teraphthalate – Do Not Reuse
You commonly find Type 1 plastic in bottles for juices, salad dressing, water, vegetable oil and mouthwash. Peanut butter and pickle jars often contain type 1 plastic as well. Polyethylene teraphthalate is light-weight, clear and smooth; its manufacturers intend it for a single use only.
While it does not contain bisphenol A or phthalates, it does contain antimony, a possible human carcinogen. Also, harmful bacteria can build up in it as you reuse it. Polyethylene teraphthalate containers may have the symbol “PET” on them.

Type 2: High-Density Polyethylene – Safe
Milk containers, detergent bottles, freezer bags and plastic grocery bags often contain high-density polyethylene, a relatively stiff plastic. Type 2 plastic neither contains bisphenol A nor phthalates. It is not known to contain other harmful chemicals. High-density polyethylene containers may have the symbol “HDPE” on them.
Type 3: Polyvinyl Chloride – Contains Phthalates
Polyvinyl chloride contains phthalates that can cause reproductive problems in animals and humans. Type 3 plastic can be plasticized or unplasticized; the former is clear and flexible, the latter is more rigid. Food containers commonly made with polyvinyl chloride include fruit juice bottles, cooking oil bottles and clear food packaging. Plasticized PVC pipes and siding contain phthalates as well. Polyvinyl chloride containers may have the symbol “V” on them.
Type 4: Low-Density Polyethylene – Safe
Frozen foods packaging and condiment squeeze bottles often contain Type 4 plastic because it is flexible and resistant to solvents. Type 4 plastic does not contain any known harmful chemicals. Low-density polyethylene containers may have the symbol “LDPE” on them.
Type 5: Polypropylene – Safe
Polypropylene containers do not leach harmful chemicals into foods or liquids. They commonly contain yogurt, medicine, drinks, ketchup and medicines. Type 5 plastic is flexible, hard and semi-transparent and has high resistance to solvents. Polypropylene containers may have the symbol “PP” on them.
Type 7: Polycarbonate
You should avoid type 7 plastic containers because they may contain bisphenol A that leaches into their contents. Type 7 plastics often have the symbol “PC” or “Other” on them. You will find polycarbonate plastics in 3- and 5-gallon water-cooler bottles; hard, plastic reusable water bottles; and to-go coffee mugs. Manufacturers use polycarbonate for these purposes because it is virtually shatter-proof…. https://www.livestrong.com/article/158674-which-plastic-containers-can-i-safely-use/

The Washington State University research indicates that this list may have to be studied further to determine safety.

Resources:

Safe Plastic Numbers (Guide)                                             http://www.babygreenthumb.com/p-122-safe-plastic-numbers-guide.aspx

Pots, Pans, and Plastics: A Shopper’s Guide to Food Safety https://www.webmd.com/food-recipes/features/cookware-plastics-shoppers-guide-to-food-safety#1

Which Plastics Are Safe?                                                  https://www.care2.com/greenliving/which-plastics-are-safe.html

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