Mengchen Xiao Zhen was sent from The Temple of Oufei
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Plastic not only pollutes the environment, but ultimately also pollutes human beings themselves.
A news of the first discovery of microplastics in human blood triggered heated discussion among netizens, once ranking 3rd on the Zhihu hot list, and the number of Weibo reads reached 240 million.
The latest research, from the Vrije Universiteit Amsterdam and the Netherlands Delta Institute, is a leading research institute in the field of the environment.
The scientists collected blood samples from 22 volunteers, of which 77 percent found microplastic particles, with an average concentration of 1.6 micrograms per milliliter.
This became the first quantitative evidence of plastic entering the blood circulation of the human body, of which there are three types of plastics that can be quantified and detected.
50% of people contain PET (polyethylene terephthalate), which is commonly found in beverage bottles such as cola juice mineral water, as well as some medicine bottles.
36% of the participants contained PS (polystyrene), which is commonly found in food packaging such as foam lunch boxes.
In addition, 23% of the participants contained PE (polyethylene), which is the main raw material for plastic bags.
In addition, PMMA (acrylic, aka plexiglass), PP (polypropylene, commonly used in medical devices and woven bags, etc.) have also been detected, but they have not been quantified.
The presence of plastic in human blood is worrying, and perhaps the most serious consequence is that it can break through the blood-brain barrier and destroy the brain.
South Korean scientists have found that particles smaller than two microns can accumulate in mice's nervous system microglia within a few days, leading to apoptosis.
In this way, after a few years, the scolding may not say "the brain is in the water", but "the brain is in the plastic".
What are the dangers of microplastics?
Since the 1950s, humans have been mass-producing and discarding plastics. The pollution of large pieces of plastic to the environment and the harm to animals are obvious.
Microplastics with a diameter of less than 5mm have gradually become a hot research direction in the academic community.
In fact, not only blood, liver and intestines and other human organs, placenta, human feces have been detected in the presence of microplastic particles.
According to the Medical University of Vienna, the total weight of the plastic particles that enter the intestinal mucosa on average per week is equivalent to that of a credit card.
Plastic particles are difficult to be metabolized and absorbed by the body, and the parts that cannot be excreted will accumulate in the body, causing cell damage, triggering local inflammation and immune response.
Microplastic particles in the digestive system can reduce the diversity of the intestinal flora, especially the number of beneficial bacteria, causing metabolic diseases such as obesity and diabetes.
The main material of the beverage bottle, PET, contains the environmental hormone (Xenohormones), which is a carcinogen.
Studies have found that the PET content in babies is 14 times that of adults, perhaps related to the accelerated release of particles in plastic bottles by hot water brewing milk powder.
Microplastics of the fabric fiber type enter the respiratory tract and may also trigger inflammatory responses and respiratory damage.
Overall, research on the harm of microplastics to humans is just beginning and lacks critical in vivo evidence.
But in-animal studies have confirmed that microplastics in seawater can cause cognitive impairment in fish and crabs, making it slower for hermit crabs to find suitable shells.
How microplastics enter the human bloodstream
According to the authors of the latest Dutch paper, there are at least three ways for microplastics to enter the bloodstream, namely through skin/mucosal contact, oral administration, and inhalation.
The first type of skin or mucous membrane contact, but does not refer to direct contact with healthy skin, but damaged skin or mucous membranes.
For example, tattoo tools, medical plastics (implants, injections, etc.), which can cause damage to the skin and mucous membranes during use and manipulation, can lead to microplastic particles entering the body.
The second type of oral, refers to the microplastic particles are absorbed through the intestinal epithelial cells and enter the systemic circulation.
Theoretically, plastic has a chance to pass through the intestinal mucosa and be absorbed by the body, eventually entering the bloodstream. Including takeaway and other food and drug packaging, daily necessities (toothpaste cleanser, etc.), food chain (marine rivers pollute fish, being eaten by humans, etc.), implant fillings, and even drinking water, may allow various microplastic particles to enter the body.
The third type of inhalation refers to the process of microplastic particles in the air entering the bloodstream through tissues such as alveoli.
Studies have shown that air particles between 1 nm and 20 nm are considered to be inhalable, for example, people who work in dust for a long time may develop pneumoconiosis, and microplastic particles can also enter the lungs in this way.
Of course, humans will also discharge a part of the plastic particles through coughing and other ways, but sometimes they swallow it unconsciously... Then, it enters the intestines orally...
But it is worth noting that it is also unreasonable to talk about toxicity aside from the dose.
For example, samples of microplastic particles in oceans and rivers are likely to come from tools that scientists carry themselves when they investigate.
A new study from Stefflat University found that many scientists wear plastic-containing clothes and shoes, hold plastic bottles, and collect samples of microplastic particles in the environment:
Then, even more than 70 percent of the plastic in the collected samples came from the scientists' own clothes and tools...
Compared with these, many scientists have begun to find ways to solve plastic products.
Brick or give the fungus to eat
A typical approach is to eat plastic with bacteria or fungi.
Scientists from China, Japan, Germany and other countries have studied how to eat plastics with bacteria, for example, they found that a fungus called Tabinella can secrete an enzyme that allows PU (polyurethane) to decompose quickly.
In addition, including pet, which is often used in beverage bottles, scientists have also found that corresponding bacteria can break it down.
However, these fungi and bacteria also need certain conditions to decompose plastics, and are still in the stage of further research.
Another way is to "manually" break down plastics.
Recently, scientists at ETH (ETH Zurich) in Switzerland successfully used a solvent to break down a plastic long-chain polymer into simple molecules with an efficiency of 92%.
According to the researchers, this solvent can be recycled.
In addition, there are some ways to achieve the secondary utilization of plastics.
For example, plastic is turned into bricks or used to pave roads, and even the state has set up a special plastic bank to recycle these products.
△ Make plastic into a park bench
But in any case, it is still much easier to make plastic than to decompose.
In this regard, some netizens looked more open, saying that maybe human beings will slowly adapt to evolution in the future:
Some netizens joked that it seems that health care products can play the banner of "row plastic" in the future:
What do you think?