TITLE: Micro- and nanoplastics in the body are passed on during cancer cell division, finds study
https://medicalxpress.com/news/2024-03-micro-nanoplastics-body-cancer-cell.html
EXCERPT: The gastrointestinal tract is already known to researchers as a major storage site for micro- and nanoplastic particles (MNPs) in the human body. A research consortium consisting of the University of Vienna, the Medical University of Vienna and other partners under the leadership of CBmed GmbH in Graz has now investigated the effects of the tiny plastic particles on cancer cells in the human gastrointestinal tract.
The study showed that MNPs remain in the cell for much longer than previously assumed, as they are passed on to the newly formed cell during cell division. The first indications that the plastic particles could promote the metastasis of tumors were also discovered. The results of the study were recently published in the journal Chemosphere.
Besides respiration, ingestion is the most important route for MNPs into the organism. Plastic particles up to the weight of a credit card (approx. 5 grams) enter the gastrointestinal tract every week. The team led by Verena Pichler (University of Vienna, CBmed) and Lukas Kenner (MedUni Vienna, CBmed, Vetmeduni Vienna) investigated the interactions between MNPs and various colon cancer cells.
In their analyses, they were not only able to show how MNPs enter the cell and where exactly they are deposited, but also observed their direct effects: The MNPs are taken up into lysosomes like other waste products in the body. Lysosomes are cell organelles that are also known as the "stomach of the cell" and break down foreign bodies in the cell. However, the researchers observed that, unlike foreign bodies of biological origin, the MNPs are not degraded due to their foreign chemical composition.
Depending on various factors, the MNPs are even passed on to the newly formed cell during cell division and are therefore likely to be more persistent in the human body than originally assumed. In addition, there are initial indications that MNPs increase the migration of cancer cells to other regions of the body and thus possibly promote the metastasis of tumors. This effect is now to be investigated further in a follow-up study.
TITLE: Nanoplastics linked to heart attack, stroke and early death, study finds
https://www.cnn.com/2024/03/06/health/nanoplastics-heart-attack-study-wellness/index.html
EXCERPT: Microplastics are polymer fragments that can range from less than 0.2 inch (5 millimeters) down to 1/25,000th of an inch (1 micrometer). Anything smaller is a nanoplastic that must be measured in billionths of a meter.
Nanoplastics are the most worrisome plastics for human health, experts say. At 1,000th the average width of a human hair, the minuscule bits can migrate through the tissues of the digestive tract or lungs into the bloodstream.
From there, nanoplastics can invade individual cells and tissues in major organs, potentially interrupting cellular processes and depositing endocrine-disrupting chemicals such as bisphenols, phthalates, flame retardants, heavy metals and per- and polyfluorinated substances, or PFAS.
In studies of pregnant mice, researchers have found plastic chemicals in the brain, heart, liver, kidney and lungs of the developing fetus 24 hours after the pregnant mother ingested or breathed in plastic particles. Other research has shown that micro- and nanoplastics may cause oxidative stress, tissue damage and inflammation in cells, while animal studies have shown such particles may alter heart rate and impede cardiac function.
Nanoplastics have been found in human blood, lung and liver tissues, urine and feces, mother’s milk, and the placenta. Until now, however, research has yet to determine just what impact those polymers may have on the body’s organs and functions.
“There currently is no scientific consensus on the potential health impacts of nano- and microplastic particles. Therefore, media reports based on assumptions and conjecture do nothing more than unnecessarily scare the public,” said a spokesperson for the International Bottled Water Association, an industry association, in an email.
A recent study found 1 liter of bottled water — the equivalent of two standard-size bottled waters typically purchased by consumers — contained an average of 240,000 plastic particles from seven types of plastics — 90% were nanoplastics.
“It is important to note that bottled water is just one of thousands of food and beverage products packaged in plastic containers,” the spokesperson said. “The largest sources of microplastics in the environment are from erosion and abrasion of synthetic rubber tires, synthetic textiles (e.g., washing clothes made of polyester), and the breakdown of city and household waste.”
TITLE: Glitter Has a Dark Side, And It's Causing Even More Harm Than We Realized
https://www.sciencealert.com/glitter-has-a-dark-side-and-its-causing-even-more-harm-than-we-realized
EXCERPT: Glitter is essentially a microplastic in disguise, whose whimsical nature distracts from its insidious contributions to plastic pollution. That has begun changing to some degree, however, as seen in the recent ban on microplastic glitter in the European Union.
As a microplastic, glitter typically resists degradation, helping it persist and accumulate in the environment. And since it's often too small to be filtered by wastewater treatment plants, it can end up in waterways, potentially harming freshwater aquatic life or traveling on to pollute the ocean.
Led by researchers from the Federal University of São Carlos (UFSCar) in Brazil, the new study points to an additional problem.
While flecks of glitter are made of plastic – typically Mylar, the researchers note –they often feature a metallic coating, too, made from aluminum, bismuth, iron, or titanium. The presence of these metals can prevent aquatic plants from getting enough sunlight, the study suggests.
"These findings support the hypothesis we began with, which was that glitter interferes with photosynthesis, possibly owing to the reflection of light by the microplastic particles' metallic surface," says lead author Luana Lume Yoshida, a master's student at the Bioassay and Mathematical Modeling Laboratory (LBMM) in UFSCar's Department of Hydrobiology.
The study focused on the large-flowered waterweed (Egeria densa), a macrophyte or aquatic plant native to Argentina, Brazil, and Uruguay.
Macrophytes like this serve an array of ecosystem functions, the researchers note, such as providing food, shelter, shade, and oxygen for their neighbors.
They're also valuable in phytoremediation efforts, which rely on plants to help detoxify contaminated places, and for their oxygenation services, which are widely used in aquariums and artificial lakes.
Yoshida and her colleagues incubated 400 bits of the waterweed in flasks, using water they collected from the Monjolinho reservoir on the UFSCar campus. They also used common glitter, the type sold at retail stores, with an average particle surface area of 0.14 square millimeter.
The researchers grew waterweed among 0.04 grams of glitter per liter of water, and waterweed without glitter as a control, both in light and in darkness.
Photosynthesis rates were 1.54 times higher in the absence of glitter, the study found. Tiny glitter particles reduced the amount of light in the water, the researchers concluded, noting the plants' respiration was affected, too, but not as significantly.
If a macrophyte like this is affected, the effects may ripple much farther into the ecosystem, notes co-author Marcela Bianchessi da Cunha-Santino, one of LBMM's principal investigators.
"In this experiment, we specifically observed the physical interference of glitter in a species of macrophyte, but there are better-known references in the scientific literature to water contamination and consumption of these particles by other aquatic organisms," she says.