I’ve just got one word for you: “plastics”
Myron Yaster MD and Lynne G. Maxwell MD
In today’s PAAD1 and its accompanying editorial2, the health care dangers of plastics, really micro- and nano-plastics, to human health, particularly cardiovascular heart disease, are presented in the New England Journal of Medicine as a clarion wake up call for all of us. Although not exactly pediatric anesthesia articles, as citizens, the issues raised are so important that I wanted to bring these very scary papers to your attention. Myron Yaster MD
Original article
Marfella R, Prattichizzo F, Sardu C, Fulgenzi G, Graciotti L, Spadoni T, D'Onofrio N, Scisciola L, La Grotta R, Frigé C, Pellegrini V, Municinò M, Siniscalchi M, Spinetti F, Vigliotti G, Vecchione C, Carrizzo A, Accarino G, Squillante A, Spaziano G, Mirra D, Esposito R, Altieri S, Falco G, Fenti A, Galoppo S, Canzano S, Sasso FC, Matacchione G, Olivieri F, Ferraraccio F, Panarese I, Paolisso P, Barbato E, Lubritto C, Balestrieri ML, Mauro C, Caballero AE, Rajagopalan S, Ceriello A, D'Agostino B, Iovino P, Paolisso G. Microplastics and Nanoplastics in Atheromas and Cardiovascular Events. N Engl J Med. 2024 Mar 7;390(10):900-910. doi: 10.1056/NEJMoa2309822. PMID: 38446676.
Editorial
Landrigan PJ. Plastics, Fossil Carbon, and the Heart. N Engl J Med. 2024 Mar 7;390(10):948-950. doi: 10.1056/NEJMe2400683. PMID: 38446681.
“Plastics can pollute the environment by way of ocean currents, atmospheric winds, and terrestrial phenomena, contributing to their widespread distribution. Once released into nature, plastics are susceptible to degradation leading to the formation of microplastics (defined as particles smaller than 5 mm) and nanoplastics (particles smaller than 1000 nanometers). Both types of particles trigger a range of toxicologic effects.3 Several studies have shown that microplastics and nanoplastics (MNPs) enter the human body through ingestion, inhalation, and skin exposure, where they interact with tissues and organs.3 MNPs have been found in selected human tissues, such as the placenta,4 lungs,5 and liver,6 as well as in breast milk,7 urine,8 and blood.9 Recent studies performed in preclinical models have led to the suggestion of MNPs as a new risk factor for cardiovascular diseases.”1,10 In today’s PAAD, Marfella et al. sought “to explore if microplastics are detectable within atheroschlerotic plaques and if they could be responsible for myocardial infarction, stroke or death from any cause.”1
Exposure to MNP’s may occur by ingestion, inhalation, or through the skin and in pre-clinical models their presence may cause injury through mechanisms such as inflammation and oxidative stress as illustrated by Zhu et al. in their literature review of pre-clinical studies.10
OK, what did they find? “A total of 304 patients who were undergoing carotid endarterectomy for asymptomatic carotid artery disease were enrolled in the study, and 257 completed a mean (±SD) follow-up of 33.7±6.9 months. Polyethylene was detected in carotid artery plaque of 150 patients (58.4%), with a mean level of 21.7±24.5 μg per milligram of plaque; 31 patients (12.1%) also had measurable amounts of polyvinyl chloride, with a mean level of 5.2±2.4 μg per milligram of plaque. Electron microscopy revealed visible, jagged-edged foreign particles among plaque macrophages and scattered in the external debris. Radiographic examination showed that some of these particles included chlorine. Patients in whom MNPs were detected within the atheroma were at higher risk for a primary end-point event than those in whom these substances were not detected (hazard ratio, 4.53; 95% confidence interval, 2.00 to 10.27; P<0.001). Thus, patients with carotid artery plaque in which MNPs were detected had a higher risk of a composite of myocardial infarction, stroke, or death from any cause at 34 months of follow-up than those in whom MNPs were not detected.”1
While the presence of MNPs in breast milk4 is of concern, it should be noted that the same particles are ubiquitous in the environment and are probably present in infant formula and prepared baby foods. Philip Landrigan, the author of the editorial in today’s PAAD stated that, despite the finding of MNP’s in breast milk, “for the general American population, the balance of evidence is breastfeeding is better than bottle-feeding or any other substitute” as long as a mother can breastfeed and wants to do it.11
Uh oh! Plastics and most specifically polyethylene and polyvinyl chloride are used in EVERYTHING from food and electronic packaging, water pipes, and almost everything we use in the hospital and operating rooms. Just think about your IV solutions, delivery tubing and IV catheters, your anesthesia circuit and endotracheal tubes, your bypass circuits, and the shrink wraps for your drugs and sterile equipment! Plastics are everywhere and the amount produced is increasing logarithmically.2 As this and other studies are now showing, the smaller the microplastic particles we produce when we use these plastics, the more they can defeat our normal barrier protections found in the gut, lungs, and vascular system. And don’t get us started on how plastics in our medical waste are leaching into our drinking water supplies and poisoning us!
We can do a lot about this if we have the will. Send Myron your thoughts and comments and he will post in a Friday reader response.
References
1. Marfella R, Prattichizzo F, Sardu C, et al. Microplastics and Nanoplastics in Atheromas and Cardiovascular Events. The New England journal of medicine 2024;390(10):900-910. (In eng). DOI: 10.1056/NEJMoa2309822.
2. Landrigan PJ. Plastics, Fossil Carbon, and the Heart. New England Journal of Medicine 2024;390(10):948-950. DOI: 10.1056/NEJMe2400683.
3. Vethaak AD, Legler J. Microplastics and human health. Science 2021;371(6530):672-674. (In eng). DOI: 10.1126/science.abe5041.
4. Ragusa A, Svelato A, Santacroce C, et al. Plasticenta: First evidence of microplastics in human placenta. Environment international 2021;146:106274. (In eng). DOI: 10.1016/j.envint.2020.106274.
5. Jenner LC, Rotchell JM, Bennett RT, Cowen M, Tentzeris V, Sadofsky LR. Detection of microplastics in human lung tissue using μFTIR spectroscopy. The Science of the total environment 2022;831:154907. (In eng). DOI: 10.1016/j.scitotenv.2022.154907.
6. Horvatits T, Tamminga M, Liu B, et al. Microplastics detected in cirrhotic liver tissue. EBioMedicine 2022;82:104147. (In eng). DOI: 10.1016/j.ebiom.2022.104147.
7. Ragusa A, Notarstefano V, Svelato A, et al. Raman Microspectroscopy Detection and Characterisation of Microplastics in Human Breastmilk. Polymers (Basel) 2022;14(13) (In eng). DOI: 10.3390/polym14132700.
8. Pironti C, Notarstefano V, Ricciardi M, Motta O, Giorgini E, Montano L. First Evidence of Microplastics in Human Urine, a Preliminary Study of Intake in the Human Body. Toxics 2022;11(1) (In eng). DOI: 10.3390/toxics11010040.
9. Leslie HA, van Velzen MJM, Brandsma SH, Vethaak AD, Garcia-Vallejo JJ, Lamoree MH. Discovery and quantification of plastic particle pollution in human blood. Environment international 2022;163:107199. (In eng). DOI: 10.1016/j.envint.2022.107199.
10. Zhu X, Wang C, Duan X, Liang B, Genbo Xu E, Huang Z. Micro- and nanoplastics: A new cardiovascular risk factor? Environ Int. 2023 Jan;171:107662. doi: 10.1016/j.envint.2022.107662. Epub 2022 Nov 26. PMID: 36473237.
11. Pretzel J. Microplastics have been found in breast milk. Will that hurt my baby? Washington Post, 5 February 2024.