Environment How the intake of microplastics can be reduced
The amount of tiny plastic particles in the environment and also in the human body is increasing. Little research has been done into what this means.
05.03.2025, 06:30
SDA
"Microplastics are ubiquitous in the food we eat, the water we drink and the air we breathe," write three researchers in the journal "Brain Medicine" in a commentary on several previous studies. They point out possible dangers - but above all how the intake of such particles can be reduced: by avoiding plastic bottles, for example, ceramic dishes for the microwave and plastic-free teabags.
Another team recently found significantly more tiny plastic particles in liver and brain samples from people who died in 2024 than in those from 2016. The concentration was also much higher in the brain than in the liver or kidneys, the group led by Matthew Campen from the University of New Mexico reported in the journal Nature Medicine in February.
The drastic increase in the concentration of plastic in the brain within just eight years is extremely worrying, said the lead author of the commentary, Nicholas Fabiano from the University of Ottawa.
Particularly tiny plastic particles in the brain
Particularly small particles, less than 0.2 micrometers in size, were discovered in the brain. They consisted mainly of polyethylene, which is found in many everyday objects. Due to their small size, they are able to cross the so-called blood-brain barrier. The effects are still unclear. Microplastics are particles between 1 micrometer (0.001 millimeters) and 5 millimeters. Nanoplastic particles are smaller.
Plastic particles in water and through certain tea bags
Everyone can reduce their own intake of nanoplastics and microplastics, the research trio explains. For example, if a person only consumes water from plastic bottles, they can absorb more than 20 times as many particles as someone who only uses tap water, the researchers write with reference to an earlier study. Water from glass bottles also contains more plastic particles than tap water, as researchers write in an analysis of 21 studies. This could be caused by bottling processes, among other things.
Another source of micro- and nanoplastics is plastic tea bags. Leaving a plastic tea bag to infuse at 95 degrees can release considerable quantities of these, according to the commentary by the trio of researchers. It is therefore better to avoid such teabags.
Plastic containers for food release particles
Avoiding plastic containers for food could also be effective. "Heating food in plastic containers - especially in the microwave - can release large amounts of micro- and nanoplastics," warned co-commentator Brandon Luu from the University of Toronto. Even long-term storage at room temperature or in the refrigerator leads to a significant release of particles, according to the researchers.
"Using glass or stainless steel containers instead of plastic is a small but significant measure to minimize exposure," Luu said.
Chemicals in food cans
Canned food can contain substances derived from plastics, such as bisphenol-A (BPA). In one study, test subjects were given canned soups for five days in a row, after which their BPA levels in urine increased many times over. The trio of researchers also emphasized: "However, the duration of these BPA peaks and their health effects are unclear and require further research." Another US study has shown that highly processed foods contain significantly more microplastics than minimally processed foods.
The trio sees at least one positive finding: "One of the most hopeful aspects of the results so far is the lack of a correlation between age and microplastic accumulation." This suggests "that the body has mechanisms to excrete these particles over time through sweat, urine and feces, despite persistent environmental influences."
Many possible consequences for the body
There is evidence from cell culture and animal studies that the plastic particles could promote inflammation, immune disorders, altered metabolism, abnormal organ development and cancer, among other things, the commentators write. However, the study situation is still poor. Large-scale studies involving humans are needed to determine the potential health risks of microplastics. At the same time, studies should better evaluate the effectiveness of various reduction strategies.
For example, there are only a few studies on the effects of microplastics on the brain. Campen's team discovered an increased concentration in twelve other brain samples from people with confirmed dementia. However, Campen's group emphasizes that the study does not prove a direct cause-and-effect relationship.
It is also conceivable that dementia weakens the blood-brain barrier and therefore allows more microplastics to penetrate, the three commentators write.
