MICROPLASTICS: How do they affect our health?

Nowadays, as we know, microplastics are everywhere. From the water we drink to the food we eat and the air we breathe, they are distributed everywhere. Many studies have shown that the effects that microplastics have on our health are unpredictable and dangerous.

Yongming Luo, a professor at the Yantai Institute of Coastal Zone Research and Nanjing Institute of Soil Science, and his colleagues in China, reported on the accumulation of microplastics in wheat and cabbage plants exposed to microplastics in the laboratory. The researchers grew plants in hydroponic and soil systems with microplastics coated with fluorescent dyes. The researchers analyzed cross sections of the plants under a microscope equipped to detect fluorescence. The roots, stems, and leaves lit up.

"For decades, scientists believed that plastic particles were too large to pass through the physical barriers of intact plant tissue, but the new study refutes that assumption," Luo told EHN.

Luo's team reports that microplastics seemed to enter plants through fissures in the roots where lateral branching occurs, as well as spreading through the cells in developing root tips.

In early 2020, a team of scientists also reported finding microplastics in Italian supermarket produce, including carrots, apples, broccoli, potatoes, and pears. The researchers write that they found the highest concentration of microplastics in apples and the least in pears. They speculated that the perennial nature of a fruit tree allowed microplastics to accumulate more than in annual crops.

"If microplastics enter our vegetables, they enter everything we eat ... That means they are also in our meat and milk," said Luo. Microplastics have also been found in honey, beer, and seafood. With clear and uncontrolled pathways in the human food systems, swallowing microplastics is practically unavoidable, but the consequences of ingestion are still unknown.

Microplastic fibers have been found in the lung biopsies of cancer patients. These plastics may have been inhaled rather than swallowed, but the concern that microplastics can enter tissue and cause dangerous inflammation remains a fact. Studies of forced-fed lab animals have also provided evidence that microplastics can pass through cell walls, move through the body, and accumulate in organs, adversely affecting the immune system.

Microplastics are chemically active materials capable of attracting and binding to known compounds that harm human health. In addition to cadmium, microplastics have been shown to accumulate lead, PCBs, and pesticides. Furthermore, plastic is produced with its own group of toxic compounds, which may include BPA, an endocrine disruptor.

Researchers have suggested that both acquired and endogenous constituents may leach into their environment from degrading plastic, whether in soil or human tissue.

"Due to concerns that microplastics may harm our health, we are shocked that the precautionary principle is not being applied. As long as there is no evidence, we simply cannot ignore that we are exposed to these particles every day, from food, water, and even the air we breathe," says Sophie Vonk, a researcher at the Plastic Soup Foundation in the Netherlands, a group dedicated to ending plastic pollution.

Research: Microplastics in Human Lungs

Researchers have found microplastics deep in human lungs for the first time. For this study, they collected tissue from surgical procedures on patients as part of routine medical practice.

The study, conducted by Hull York Medical School in England and published in the journal Science of the Total Environment, is the first to identify plastics in living humans' lungs.

"Microplastics have been found before in human cadaver autopsies," says Laura Sadofsky, a senior lecturer in respiratory medicine and one of the lead authors of the study.

"We did not expect to find the levels of particles we found in the lower regions of the lungs, or the large size of the particles we found," Sadofsky says.

"This is surprising because the airways in the lower regions of the lungs are much smaller, and we expected the particles of this size to be filtered out of the body and not to be lodged so deeply in the lungs." she adds.

/Source: NPR news/

Research: Microplastics in Human Blood

In a study published in Environment International, researchers found plastic in the blood of 17 out of 22 study participants, or 77%. "Our study is the first indication that we have polymer particles in our blood, a very big discovery," says author Dick Veethak, an ecotoxicologist at Vrije Universiteit Amsterdam in the Netherlands, for The Guardian newspaper.

Researchers took blood samples from healthy adults and looked for plastics that were between 700 and 500,000 nanometers in size. 700 nm is about 140 times smaller than the width of a human hair, says Aathira Perinchery of The Wire Science.

PET (polyethylene terephthalate) plastic, most commonly used for bottled water, was the most commonly found polymer in nearly 50% of donors. The second most common was polystyrene (PS), which is used in food packaging and polystyrene foam, found in 36% of participants.

Veethak says that as a result of the study, he has stopped his exposure to plastics by limiting the use of single-use plastics and covering food and drinks to prevent plastic entry.

Participants may have been exposed to these microplastics through air, water, and food, as well as personal care products such as toothpaste or lip gloss (which may be accidentally swallowed), dental polymers, implant parts, or even tattoo ink residue.

The authors say that more studies are needed on this topic to define the health risks of plastics in the bloodstream.

/Source: Smithsonian magazine/