▎WuXi AppTec Content Team Editor
Water bottles and plastic bags thrown away by humans may one day return to our bodies. This process is not alarmist, but a real possibility.
The plastic first buried under the soil is continuously broken down into tiny particles, and plants may inadvertently absorb some of the microplastic particles while ingesting nutrients, and then insects eat the plants, fish or Birds prey on insects, so as the food chain progresses, microplastics end up on the human table.
According to a study by the University of Eastern Finland published in Nano Today, the authors reproduced what might be in the real world in the lab by first adding some lettuce to the growing environment Tiny particles of polystyrene and polyvinyl chloride, and two weeks later, they harvested the lettuce and fed it to the larvae of a horsefly as food.
After 5 days of continuous cultivation, the larvae were then fed to fish, and after the fish had consumed horsefly larvae for 5 days, the organisms along the food chain were collected for careful analysis. To better track microplastic particles, the authors embedded a core of gadolinium in the microplastics in advance.
▲Microplastic particles are passed in the food chain (Image source: Reference [3])
According to their analysis, the first good news is that microplastics are not enriched step by step, that is, the concentration of microplastics does not vary with The food chain in the experiment peaked in fish. Contamination such as mercury and polychlorinated biphenyls will continue to accumulate in the food chain.
Although the enrichment did not occur, researchers detected the presence of nanoplastic particles in the interior of all three organisms, mainly in the gills and liver of fish. and gut; horsefly larvae in the mouth and gut; lettuce in lettuce leaves.
▲Researchers can observe microplastics inside insects (Image source: Reference [3])
In addition, the degree of transfer of the two plastic particles is different, which is mainly determined by the absorption of the producers. For example, lettuce in the experiment absorbed PVC far more than polystyrene. If there are more, then under the corresponding food chain, polyvinyl chloride will also appear in subsequent organisms.
The authors of the study said that some previous papers have pointed out that earthworms in the soil can accelerate the decomposition of polyethylene, which will increase the amount of microplastics that enter the food chain and eventually accumulate in food and be eaten by humans. , through our body.
The scientific community still has limited understanding of the effects of these microplastics that enter the body with food and drink. However, new research in Environmental Science & Technology has uncovered some clues that microplastic particles can disrupt some normal physiological processes in organ tissue after entering the lungs and liver.
The researchers investigated the effects of plastic particles 80 nanometers wide, because particles less than 100 nanometers wide are already able to enter the blood and internal organs of animals.
They grew a portion of liver cells and lung cells separately in the lab and then grouped them with varying amounts of 80-nanometer plastic particles. Two days later, the authors confirmed under an electron microscope that microplastics had entered the interior of both types of cells, but the cells were not killed.
They then examined substances released by the cells’ mitochondria, which had previously been thought to be particularly sensitive to microplastic particles. The results confirmed that the groups of cells with more microplastic particles released more reactive oxygen species from their mitochondria, in addition to producing different amounts of molecules such as nucleotides, amino acids and peptides.
This means that the more microplastic particles there are, the more the metabolic process of the mitochondria is affected. They also observed abnormal mitochondria in some groups Function. This also suggests that although microplastics do not kill cells immediately, they are likely to quietly disrupt normal physiological processes, and remain a vigilant risk.
The researchers emphasized that more experiments are urgently needed to confirm the impact of microplastics in the future. After all, the microplastic particles that shuttle back and forth in the human body every day are not necessarily harmless things.
Cover Source: 123RF
References:
[1] Study Shows How Microplastics Can Easily Climb The Food Chain. Should We Be Worried? Retrieved September 20, 2022 from https:https://www.sciencealert.com/study-shows-how-microplastics-can-easily-climb-the-food-chain-should-we-be-worried
[2] Nanoplastics can disrupt human liver and lung cell processes in lab experiments. Retrieved September 20, 2022 from https:https://phys.org/news/2022-09-nanoplastics-disrupt-human-liver-lung.html
[3] Siyi Lin et al, Metabolomics Reveal Nanoplastic-Induced Mitochondrial Damage in Human Liver and Lung Cells, Environmental Science & Technology (2022). DOI: 10.1021/acs.est.2c03980
[4] Quantifying the trophic transfer of sub-micron plastics in an assembled food chain. Nano Today (2022). https:https://doi.org/10.1016/j.nantod.2022.101611
