Contamination from microplastics has even penetrated human blood. This is the first evidence of an accurate analysis by researchers from the Free University of Amsterdam. It is not yet clear whether this contamination is harmful. The results of the study appeared in the journal on Thursday Environment International†
The scientists examined the blood of 22 anonymous donors for traces of plastic using a highly sensitive measuring method that they had developed especially for this purpose. In three quarters of the donors, the blood did indeed contain polymers, the molecular building blocks of plastic. These were very low concentrations, an average of 1.6 micrograms per milliliter of blood. Most frequently found in the blood samples were the plastics polyethylene terephthalate (PET), polyethylene (PE) and various types of polystyrene (styrofoam). Polymethyl methacrylate (PMMA) was found in lower concentrations, and the concentration of polypropylene (PP) was so low that its concentration could not be measured accurately.
The researchers write that they prefer to talk about “plastic particles” in the blood, because “microplastic” and “nanoplastic” have varying definitions in the scientific literature. Because they filtered the blood through a sieve with 700 nanometer holes, this is the lower limit for the measured plastic particles in the blood. That’s about one-hundredth the diameter of a human hair.
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The upper limit for particle size in this study is theoretically the diameter of the hypodermic needle used to draw the blood; half a millimeter.
Plastic particles are caused by crumbling and wear of plastic objects. Most particles found in food and the environment are between ten and fifty micrometers (1 micrometer is 1,000 nanometers). Polyethylene and polypropylene are the most widely used in plastic products worldwide. PET is widely used for bottles and other food packaging materials, and in clothing (fleece). Finally, PMMA is widely used in prostheses, including at the dentist.