A research team led by Heather Leslie, an ecotoxicologist, and analytical chemist Marja Lamoree has shown for the first time that microplastics from our living environment are also present in the human circulatory system. The results of the research project, called Immunoplast, appeared in March in the scientific journal Environment International.
The research team, consisting of researchers from VU Amsterdam, Deltares and Amsterdam UMC, VUmc location, developed an analytic method for establishing the trace level of micro- and nanoplastic particles in human blood. The method was applied to the blood of 22 anonymous donors. The blood was examined to identify and quantify the mass of five high production volume polymers - PMMA, PP, PS, PE and PET - commonly applied in plastic materials.
Some 77% of donors, or 17 out of 22, carried a quantifiable mass of plastic particles in their blood. The most commonly detected plastic was PET, followed by polystyrene, polyethylene, and PMMA. Levels were low, at an average of 1.6 micrograms in every millilitre of blood – equivalent to one teaspoon of plastic per 1,000 litres. Polypropylene was also found and analysed, but the concentrations were too low for an accurate measurement.
The microplastics detected in the bloodstream were likely to have been either ingested or inhalated, the researchers wrote, as dermal uptake of fine particles is unlikely except if the skin is damaged.
The researchers concluded that the fate of plastic particles in the bloodstream needs further study to answer questions regarding the potential accumulation in the general population and occupationally exposed workers, the environmental factors contributing to the internal exposure and toxicological and human health effects that may result from different exposure scenarios. For example, it is not yet clear how easily these particles can move from the circulatory system into organs and whether they cause any health effects there.
“This dataset is the first of its kind and must be expanded to gain insight into how widespread plastic pollution is in the bodies of humans, and how harmful that may be," said Marja Lamoree. “With this insight we can determine whether exposure to plastic particles poses a threat to public health.”
This project was one of 15 projects conducted within the scope of the ZonMw Dutch National Organisation for Health Research and Development Microplastics and Health programme. As Frank Pierik, programme manager Microplastics & Health at ZonMw said, “We need to realise that these are only the initial findings. There is still a long way to go before a proper risk assessment can be made.”
The Immunoplast study was funded by the international NGO Common Seas and the ZonMw programme Microplastics & Health.