According to the data of FAO in 20 17, for rodents and dogs, microplastics with a diameter over 150 micron will not be absorbed, but will be excreted through feces. However, more than 90% of microplastics and nano-plastic particles absorbed by human body will not be absorbed by human body, so it is considered that microplastics will not cause harm to human body. However, some studies also believe that although most of microplastics ingested by human beings is excreted with feces, a small amount will remain in the body, and long-term accumulation may cause harm. This is because both the plastic itself and the components absorbed by the plastic may cause harm to the human body. For example, many bacteria and fungi can be adsorbed on the surface of microplastics. These pathogenic bacteria bring pathogenic microorganisms into human body through microplastics vector.
Although microplastics's harm to human body has not been confirmed, its harm to other creatures has been studied. A study of 20 16 in Sweden showed that high dose of polystyrene microplastics could inhibit the hatching and growth of perch. Studies in France have confirmed that oysters exposed to polystyrene beads will be disturbed by energy absorption and distribution, thus affecting their reproduction and the health of their offspring. A study of 20 15 in the United States found that microplastics may cause liver damage to Japanese tiger fish. Microplastics has strong adsorbability, which can adsorb many harmful substances. It has been found that 1 g microplastics can contain up to 24,000 nanograms of POPs, which are highly toxic, persistent, bioaccumulative, oleophilic and hydrophobic, and can also cause damage to organisms at low concentrations. Dioxins are persistent organic pollutants.
If microplastics can enter the human circulatory system, it may be harmful to human body. Some studies show that plastic particles with a diameter less than 20 microns can enter the circulation system. These small particles will enter the blood and may be harmful to the human body. Although the impact of microplastics on human body has not been determined, there are potential risks, which should be paid great attention to. It is imperative to reduce microplastics from the source. A study in 20 13 years found that1700,000 plastic particles were deposited on the bottom of Lake Erie in North America. In new york, 65,438+09 tons of beads are washed into sewers every year. It is estimated that about 15-5 1 trillion pieces of plastic are deposited in the ocean.