Dr Seema Pavgi Upadhye, Krish Gupta
We all know that plastics are one of the leading pollutants on the planet, from mountains to oceans large amounts of plastic waste is dumped which enters into food chains.
A recent study on plastics “ Micro-plastics Found In Human Blood For First Time” has shattered the world since it is a direct health hazard when we are using plastic for our daily needs. Tiny particles of plastics, called micro plastic have been detected in the human blood for the first time by a group of researchers from the Netherlands. Microplastics are tiny pieces of plastic less than 0.2 of an inch (5mm) in diameter. The researchers analysed blood samples from 22 anonymous donors and found microplastic in 17 of them, according to the research published in the Journal Environment International.
The levels are low – 1.6 micrograms (1.6 millionths of a gram) in every millilitre of blood – but are enough to raise an alarm. Prof Dick Vethaak, ecotoxicologist at Vrije Universiteit Amsterdam in the Netherlands, and lead author of the study, showed lot of concern and got worried.
The discovery shows the particles can travel around the body and may lodge in organs. The impact on health is as yet unknown, but researchers are concerned as microplastics cause damage to human cells in the laboratory and air pollution particles are already known to enter the body and cause millions of early deaths a year.
This study is the first indication that we have polymer particles in our blood – it’s a breakthrough finding. But more research is needed with increase in the sample sizes, the number of polymers assessed, etc. Previous work had shown that microplastics were 10 times higher in the faeces of babies compared with adults and that babies fed with plastic bottles are swallowing millions of microplastic particles a day.
Existing techniques can detect and analyse particles as small as 0.0007mm. Some of the blood samples contained two or three types of plastic. The team used steel syringe needles and glass tubes to avoid contamination and tested for background levels of microplastics using blank samples. The amount and type of plastic varied considerably between the blood samples.
A recent study found that microplastics can latch on to the outer membranes of red blood cells and may limit their ability to transport oxygen. The particles have also been found in the placentas of pregnant women, and in pregnant rats, which they pass rapidly through the lungs into the hearts, brains and other organs of the foetuses.
Plastic particles may be transported to organs via the bloodstream. The human placenta has been shown to be permeable to 50, 80 and 240 nm polystyrene beads (Wick et al., 2010) and to microsized polypropylene (Ragusa et al., 2021). In a study of acute lung exposure to nanopolystyrene spheres (20 nm) in rats, plastic particles could move to placental and fetal tissues (Fournier et al., 2020). Bioaccumulation of small polystyrene micro-particles in the liver, kidney and gut was observed after oral administration in mice in vivo (Deng et al., 2017).
Further supporting evidence for the translocation of plastic particles comes from drug delivery sciences, where polymeric carriers of pharmaceuticals have been dosed in mammalian test systems (Yee et al., 2021). The polymeric nano-sized carriers are able to deliver drugs across the blood brain barrier (Han et al., 2018). The typical residence time of plastic particle in the bloodstream is at present unknown, as is the fate of these particles in the human body. From polymeric nano-carrier research, researchers expect the residence time to vary with particle chemistry , surface charges, shapes and sizes (Bertrand and Leroux, 2012, Rabanel et al., 2012, Rabanel et al., 2019). In preclinical experiments in drug delivery it is known that a phenomenon termed accelerated blood clearance (Dams et al., 2000) acts to reduce residence time upon repeated (chronic) exposure to polymeric nanoparticles in the bloodstream.
The uptake routes of plastic particles detected in human bloodstream are likely to be via mucosal contact (either ingestion or inhalation). Dermal uptake of fine particles is unlikely except if the skin is damaged (Schneider et al., 2009). Airborne particles between 1 nm and 20 µm are considered respirable. Ultrafine (<0.1 µm) inhaled particles may become absorbed and accumulate in the lung, while most larger particles are expected to be coughed up and eventually swallowed, and have a second chance of absorption via the gut epithelium (Wright and Kelly, 2017).
The plastic particle concentrations reported inrecent study 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 (e.g. PE in toothpaste, PET in lip gloss), dental polymers, fragments of polymeric implants, polymeric drug delivery nanoparticles (e.g. PMMA, PS) and tattoo ink residues (e.g. acrylonitrile butadiene styrene particles).
Human exposure to plastic particles results in absorption of particles into the bloodstream. This indicates that at least some of the plastic particles can be bioavailable and that the rate of elimination via e.g. the biliary tract, kidney or transfer and deposition in organs is slower than the rate of absorption into the blood. It remains to be determined whether plastic particles are present in the plasma or are carried by specific cell types (and to which extent such cells may be involved in translocating plastic particles across mucosa to the bloodstream). If plastic particles present in the bloodstream are indeed being carried by immune cells, what will happen then.? A new review paper published and co-authored by Vethaak, assessed cancer risk and concluded that more detailed research on how micro- and nano-plastics affect the structures and processes of the human body, and whether and how they can transform cells and induce carcinogenesis, is urgently needed, particularly in light of the exponential increase in plastic production. The problem is becoming more urgent with each day.
Humans have produced 18.2 trillion pounds of plastics – the equivalent of 1 billion elephants – since large-scale plastic production began in the early 1950s. Nearly 80% of that plastic is now in landfills, researchers say. By 2050, another 26.5 trillion pounds will be produced worldwide.
Plastic flowing into the world’s oceans, rivers and lakes will increase from 11 million metric tons in 2016 to 29 million metric tons annually in 2040, the equivalent of dumping 70 pounds of plastic waste along every foot of the world’s coastline, according to research from The Pew Charitable Trusts.
Lot of studies are needed to be done on occupationally exposed workers that what is impact of micro plastics on their health. Also studies on environment and ecosystem is needed. Such type of studies done by Dr Mahua Saha at Sal Estuary in Goa, showed impact of microplasticson fish, seafood, plants, water and soil quality .
BOX: What are microplastics?
Micro-plastics are small plastic pieces less than five millimeters long which can be harmful to all life on earth. Nanoplastic is a term for plastic particles in the submicron range, <1 μm. In the nanotechnology field, ‘nanoplastic’ may refer to engineered particles <100 nm, i.e. the nanotechnology application size limit.
As an emerging field of study, not a lot is known about microplastics and their impacts yet. The NOAA Marine Debris Program is leading efforts within NOAA to research this topic. Standardized field methods for collecting sediment, sand, and surface-water microplastic samples have been developed and continue to undergo testing. Field and laboratory studies can tell us how much micro plastic is released into the environment and how much have same impact on living beings and turned into debris.
Micro plastics come from a variety of sources, including from larger plastic debris that degrades into smaller and smaller pieces. In addition, microbeads, a type of microplastic, are very tiny pieces of manufactured polyethylene plastic that are added as exfoliants to health and beauty products, such as some cleansers and toothpastes. These tiny particles easily pass through water filtration systems and end up in the ocean and Great Lakes, posing a potential threat to aquatic life.
Micro-beads are not a recent problem. According to the United Nations Environment Programme, plastic microbeads first appeared in personal care products about fifty years ago, with plastics increasingly replacing natural ingredients. As recently as 2012, this issue was still relatively unknown, with an abundance of products containing plastic microbeads on the market and not a lot of awareness on the part of consumers. They pass unchanged through waterways into the ocean where aquatic life and birds can mistake microplastics for food.
Most prominent are polyethylene terephthalate (PET), a common type of plastic used in making drink bottles, food packaging and fabrics, and even lip gloss.
The second most commonly found plastic are polystyrene, which is used to make a wide variety of common household products including disposable bowls, plates and food containers, and what we call styrofoam.
The third most likely plastic is polyethylene, a material regularly used in the production of paints, sandwich bags, shopping bags, plastic wrap, detergent bottles and in toothpaste.
Polypropylene is used in making food containers and rugs.
Conclusion
Lot of research is needed in this field and have to take lot of steps towards reducing plastics. It is utmost requirement to produce bio plastics which is biodegradable. We have also to reduce daily use of plastics in our life especially for children.
References
Heather A Leslie , Martin J M van Velzen , Sicco H Brandsma , A Dick Vethaak , Juan J Garcia-Vallejo , Marja H Lamoree, Discovery and quantification of plastic particle pollution in human blood, PMID: 35367073 DOI: 10.1016/j.envint.2022.107199
S.L. Wright, F.J. Kelly, Plastic and human health: a micro issue? Environ. Sci. Technol., 51 (12) (2017), pp. 6634-6647
A.D. Vethaak, J. Legler, Microplastics and human health, Science, 371 (6530) (2021), pp. 672-674
P. Wick, A. Malek, P. Manser, D. Meili, X. Maeder-Althaus, L. Diener, P.A. Diener, A. Zisch, H.F. Krug, U. Von Mandach, Barrier capacity of human placenta for nanosized materials, Environ. Health Perspect., 118 (3) (2010), pp. 432-436
A. Ragusa, A. Svelato, C. Santacroce, P. Catalano, V. Notarstefano, O. Carnevali, F. Papa, M.C.A. Rongioletti, F. Baiocco, S. Draghi, E. D’Amore, D. Rinaldo, M. Matta, E. Giorgini, Plasticenta: first evidence of microplastics in human placenta, Environ. Int., 146 (2021), p. 106274
Y. Deng, Y. Zhang, B. Lemos, H. Ren, Tissue accumulation of microplastics in mice and biomarker responses suggest widespread health risks of exposure, Sci. Rep., 7 (2017), p. 46687
M.-L. Yee, L.-W. Hii, C.K. Looi, W.-M. Lim, S.-F. Wong, Y.-Y. Kok, B.-K. Tan, C.-Y. Wong, C.-O. Leong, Impact of microplastics and nanoplastics on human health, Nanomaterials, 11 (2) (2021), p. 496,
J. Han, D. Zhao, D. Li, X. Wang, Z. Jin, K. Zhao, Polymer-based nanomaterials and applications for vaccines and drugs, Polymers, 10 (1) (2018), p. 31,
J.M. Rabanel, V. Aoun, I. Elkin, M. Mokhtar, P. Hildgen, Drug-loaded nanocarriers: passive targeting and crossing of biological barriers, Curr. Med. Chem., 19 (19) (2012), pp. 3070-3102
Dams, E.T., Laverman, P., Oyen, W.J., Storm, G., Scherphof, G.L., Van Der Meer, J.W., Corstens, F. H., Boerman, O. C. Accelerated blood clearance and altered biodistribution of repeated injections of sterically stabilized liposomes. J. Pharmacol. Exp. Ther. 292(3), 1071-1079 (2000).
M. Schneider, F. Stracke, S. Hansen, U.F. Schaefer, Nanoparticles and their interactions with the dermal barrier, Dermatoendocrinol., 1 (4) (2009), pp. 197-206,
S.L. Wright and F.J. Kelly, Plastic and human health: a micro issue? Environ. Sci. Technol., 51 (12) (2017), pp. 6634-6647
