Microplastics in the blood

(MainsGS3: Science and Technology- Developments and their Applications and Effects in Everyday Life.)

Context:

• Scientists have discovered microplastics in human blood for the first time, warning that the ubiquitous particles could also be making their way into organs.
• The tiny pieces of mostly invisible plastic have already been found almost everywhere else on Earth, from the deepest oceans to the highest mountains as well as in the air, soil and food chain.

About microplastics:

• Microplastics are tiny particles of plastics found in various ecosystems like the oceans, and in the environment and now in human blood. 
• There is no universal agreement on the size but the U.S. NOAA (National Oceanic and Atmospheric Administration) and the European Chemical Agency define microplastic as less than 5mm in length. 
• However, for the purposes of this study, the authors were interested in measuring the quantities of plastic that can cross the membranes and diffuse into the body via the bloodstream thus take an upper limit on the size of the particles as 0.0007 millimetre.

Findings of study:

• In the study, blood from 22 adult healthy volunteers was collected anonymously, stored in vessels protected from contamination, and then analysed for its plastic content.
• The study found that 77% of tested people (17 of the 22 persons) carried various amounts of microplastics above the limit of quantification.
• The study found a presence of polyethylene tetraphthalate (PET), polyethylene (used in making plastic carry bags), polymers of styrene (used in food packaging), poly (methyl methylacrylate) in blood.

Significance of the study:

• Making a human health risk assessment in relation to plastic particles is not easy due to the lack of data on exposure of people to plastics; thus, it is important to have studies like this one.
• The authors of the paper also remark that validated methods to detect the tiny (trace) amounts of extremely small-sized (less than 10 micrometre) plastic particles are lacking, hence this study, which builds up methods to check the same, is important. 
• Owing to the small size of the participants, the study results cannot be taken as such to mould policy etc, but the power of this paper is in the method and in demonstrating that such a possibility of finding microplastics in the blood exists.

Health impacts:

• The microplastics could have entered the body by many routes: via air, water or food, but also through the  products such as toothpastes, lip glosses, tattoo ink and disposable tea cups.
• However, it is not yet clear if these microplastics can cross over from the bloodstream to deposit in organs and cause diseases but the human placenta has shown to be permeable to tiny particles of polystyrene.
•  Experiments on rats where its lungs were exposed to polystryrene spheres (20 nanometre) led to translocation of the nanoparticles to the placental and foetal tissue. 
• Thus, further studies have to be carried out to really assess the impact of microplastics on humans.