A peer-reviewed study published this week in Environment International has reported traces of microplastics had been found in the human blood of 17 of the 22 volunteers, thus raising questions about the possible penetration of these particles into organs.
Half of the samples contained PET (polyethylene terephthalate), one of the most widely used plastics in the world, particularly in the manufacture of bottles and polyester fibers.
For the first time we were able to detect and quantify these microplastics in human blood, stated Dick Vethaak, an ecotoxicologist at Amsterdam's Free University. This proves that we have plastic in our body, and we shouldn't, he told AFP.
Researchers say the findings support the hypothesis that human exposure to plastic particles results in absorption of particles into the bloodstream. Previous studies have shown that people and animals were known to consume microplastics via food and water, as well as by breathing them in through air pollution. They have also been found in the feces of babies and some adults.
According to the study, the microplastics detected could have entered the body by multiple routes: airborne, aquatic or via food, or hygiene and cosmetic products. It is scientifically probable that blood particles can be carried to the organs via the blood system, reads the study, funded by the Netherlands Organization for Health Research and Development and by Common Seas, a UK-based charity that aims to reduce plastic pollution.
Alice Horton, a specialist in anthropogenic pollutants at the British Oceanography Center, said that despite the small sample and the weak concentrations detected, the study's analytical methods are very robust.
This study helps to demonstrate that plastic particles are not only present in the environment, but also in our bodies. The long-term consequences are not yet well known, she added.
According to the study's findings, microplastics can move around in the body and may remain in certain organs. However, it is yet unclear what the long-term health effects may be. An understanding of the exposure of these substances in humans and the associated hazard of such exposure is needed to determine whether or not plastic particle exposure is a public health risk.
To avoid contamination, the scientists used steel syringe needles and glass tubes which were previously tested for residue levels of microplastics.
PET plastic, which is used primarily for bottling soft drinks, juices, and water was found in 50% of the participants. Polystyrene, commonly used in the food-service industry for disposable utensils, cups, and containers was discovered in 36% of the samples, and polyethylene from grocery and garbage bags was found in 23%.
Although the levels of plastics were low -an average of 1.6 micrograms in every milliliter of blood- the study's authors say just the mere presence of microplastics was concerning.
The study describes the plastic fragments as ubiquitous pollutants in the living environment and food chain. Despite this, no previous studies have been able to detect them in the bloodstream.
The plastic particle concentrations reported here are the sum of all potential exposure routes: sources in the living environment entering air, water and food, but also personal care products that might be ingested, dental polymers, fragments of polymeric implants, polymeric drug delivery nanoparticles and tattoo ink residues, the study explained.
If plastic particles present in the bloodstream are indeed being carried by immune cells, the question also arises, can such exposures potentially affect immune regulation or the predisposition to diseases with an immunological base? the Dutch scientific report went on.