The title picture comes from: Visual China

According to a study published on March 19 in Nature’s (Scientific Reports) When opening plastic bags or unpacking plastic packages such as plastic bottles, a small amount of microplastics will be produced, which will unknowingly cause contamination of food.

Microplastics are small plastic particles less than 5 mm in length. It is generally believed that microplastic pollution often comes from industrial products, such as exfoliating skin care products, or indirectly from the long-term decomposition of larger plastic objects. However, the microplastics produced in daily life such as tearing, tearing, and unscrewing plastic packaging and containers have not been fully understood.

Cheng Fang and colleagues at the University of Newcastle, Australia, monitored the process of tearing chocolate bags, scoring sealing tape, and opening plastic bottle caps, and further confirmed the microplastics produced by these processes through chemical testing and microscopy.

It was found that the action of tearing or slicing can produce microplastics of different shapes and sizes, including fibers, fragments or triangles, ranging in size from a few nanometers to a few millimeters. Fragments and fibers are the ones that produce the most.

The author estimates that every 300 centimeters of plastic may produce 10 nanograms to 30 nanograms when it is drawn or unscrewed. (0.00001 mg to 0.00003 mg ) microplastics, depending on how they are opened and the conditions of the plastic itself, such as hardness, thickness, or density.

The results of this study also suggest that daily activities such as opening plastic bags and bottles may be an additional source of small amounts of microplastics; however, the risks, potential toxicity, and how they are ingested remain to be recognized. Further research on human exposure is needed.

An unknowing pollution

Microplastics (Microplastics) , generally refers to plastic particles smaller than 5 mm in size. It comes from a wide range of sources, including various plastic products, such as hygiene products (face wash and braces) , textiles and car tires.

Scientists now find the presence of microplastics in almost all environmental waters, and the number is increasing. Even more worrying is that people have also detected microplastics in tap water. In 2017, a US NGO survey revealed that the detection rate of microplastics in tap water worldwide was 83%.

Microplastics can be divided into primary microplastics and secondary microplastics according to their source: the former refers to various artificial industrial plastic products, such as particles in toothpaste, hair gel, facial cleanser, and air freshener. Into the surrounding environment through the discharge of other means; the latter is broken up by various plastic wastes through physical, chemical and biological processes.

Some studies have shown that these microplastics can be taken up by aquatic and marine organisms, which will first cause physical hazards to the organism itself, such as blocking its feeding auxiliary organs and digestive tract, and creating a pseudo-satiated feeling; in addition, due to microplastics It is not easily degradable and light and durable, which makes it easy to transfer in the food chain, and exposes more animals to harmful substances, such as toxic monomer additives in plastics, and its accumulation of persistent organic pollutants and heavy metals from the surrounding environment.

Research results show that the average microplastic concentration in the middle and lower reaches of the Yangtze River is about 500,000 microplastic particles per square kilometer. From the Mariana Trench to the Antarctic Frozen, scientists have discovered the presence of microplastics. In addition, microplastics with different concentrations have been detected in some remote water bodies, such as lakes in Tibet and Qinghai.

Microplastics are entering our body

At the European Gastroenterological Society 2018, researchers reported that as many as nine microplastics were detected in human feces for the first time, with diameters between 50 and 500 microns. This study shows that plastic will eventually reach the human stomach.

According to the logs provided by the participants from 8 different countries who participated in the study, they all ate food in plastic packaging, drank bottled water, and 6 of them also ate seafood. There are 20 particles in every 10 grams of stool sample. The most common particles are polypropylene (PP) and polyethylene terephthalate < span class = "text-remarks" label = "Remarks"> (PET) , they are the main components of plastic bottles and caps.

Experts say that the specific source of these microplastics has not been determined, and whether they can remain in the human body also requires further research. But it is worth noting that the smallest microplastics can enterMicroplastics in the intestine can affect the immune response of the digestive system when it enters the blood, lymphatic system, or even the liver.

Microplastics can cause physical damage to organs, and the toxic chemicals it filters out, such as endocrine interferon BPA and pesticides, can also destroy immune function and endanger the growth and reproduction of organisms. Microplastics and toxic substances can also accumulate in the food chain, potentially affecting the entire ecosystem, such as the health of the soil on which it is grown. In addition, Microplastics in air and water can also directly affect humans .

A previously published study showed that fish exposed to microplastics reduced reproduction, and that their offspring did so without direct exposure to microplastics. This shows that microplastics can affect the reproduction of species. In addition, there is evidence that different degrees of microplastics intake are closely related to the occurrence of thrombosis, cancer and lung disease.

Perhaps we haven’t fully understood how toxic microplastics are when they enter the human body. How much microplastics do I ingest? But now it is certain that the world we live in has been penetrated by microplastics, and microplastic pollutants are everywhere.

Like the PM2.5 pollution that everyone paid special attention to in the past few years, maybe it is time for us to pay attention to microplastic pollution.

Reference:

https://nature.com/articles/s41598-020-61146-4

https://www.eurekalert.org/emb_releases/2020-03/sr-eop031620.php

https://www.scientificamerican.com/article/from-fish-to-humans-a-microplastic-invasion-may-be-taking-a-toll/