Microplastics can be found in different body organs and affect human health.
Microplastics in the placenta
A study published in the journal Environmental International detected microplastics in the human placenta. Raman Microspectroscopy was used to examine six human placentas to evaluate microplastics. Twelve microplastic fragments (ranging from 5 to 10 μm in size) were found in 4 placentas. All were pigmented, and three were identified as stained polypropylene.
The rest were identified as pigments used for man-made coatings, paints, adhesives, plaster, finger paints, polymers, cosmetics, and personal care products.
The actual number of plastics could be much higher. Only a tiny portion of the placenta (23 grams) was tested for plastics and not the whole ( ∼600 grams).
The size of all microplastics was ∼ten μm in size except for two (∼5 μm). According to the authors, these sizes are small enough to be transported by the bloodstream to the placenta. The two possible ways for the microplastics to get inside the mother are the respiratory system and the gastrointestinal tract. [1]
Plastics in the intestines
Another study, published in the Annals of Internal Medicine, detected plastic in all of the stool samples of eight healthy volunteers aged 33 to 65 years.
This time the microplastics were detected using Fourier-transform infrared microspectroscopy. Twenty microplastics (50 to 500 µm in size) per ten grams of human stool were identified. Nine plastic types were seen, with polypropylene and polyethylene terephthalate (PET, PETE) being the most abundant.[2]. PET is used in clothing, containers for liquids, and foods.
There is good news and bad news about plastics in the stool. It is terrible because it proves that plastics get mixed with food. The positive side is that the body can excrete the plastic rather than accumulate them. The kidneys are the other organs that can eliminate plastics.
Plastics in Sputum
A total of 22 patients suffering from different respiratory diseases were recruited in a study from China. This time they used an Agilent 8700 laser infrared imaging spectrometer and Fourier-transform infrared microscope to analyze sputum samples to see if there were microplastics in the respiratory tract.[3] Here is what they found,
The results showed that 21 types of microplastics were identified, and polyurethane was dominant, followed by polyester, chlorinated polyethylene, and alkyd varnish, accounting for 78.36% of the total microplastics. Most of the aspirated microplastics detected are smaller than 500 μm in size.
Among the subjects in the study, most of them smoked and had invasive examinations. It is also possible to inhale microplastics from the environment.
Food sources of microplastics
Nano plastics and microplastics (MPs) have been detected in sugar (0.44 MPs/g), were found in salt (0.11 MPs/g), alcohol (0.03 MPs/g), bottled water (0.09 MPs/g) and honey.[4] It sounds like Himalayan salts may have fewer plastics since they are from the mountains in Pakistan.
Other sources are seafoods, including fish (fresh and dried), mollusks, clams, and
crustaceans like crabs and shrimp.
Aerial sources of microplastics
Microplastics are in the air and carried by the wind. The air picks ups the microplastics from the erosion of agricultural and fertilized lands, dried sludges, and products from wastewater treatment, synthetic clothes fabric, industrial emissions, road dust, and marine aerosols.
How much plastics do we consume?
The total annual intake of microplastic particles for adult males and females is 113,743 and 94,283.[5]
On top of that, individuals who drink only bottled water, assuming they meet their recommended water intake, may ingest an additional 90,000 microplastics annually, compared to 4000 microplastics for those who consume only tap water. According to the authors of Human Consumption of Microplastics, these numbers are probably underestimated. [5]
The table below is the Daily and Annual Consumption and Inhalation of Microplastic Particles for Female and Male, Children and Adults.
Effects of microplastics
Local immune reactions. Since they are foreign bodies, microplastics lead to an inflammatory response from the immune cells.
Microplastics are carriers for other chemicals like environmental pollutants, plastic additives, and heavy metals. They can affect the heart and lungs, alter the metabolism, cause toxicity to the genes, cause inflammation and oxidative stress, affect nutrient absorption, gut microbiome, and reproduction.
The image below shows the studies showing the effects of microplastics on human organs. The colored squares represent organic and inorganic pollutants that could be present with micro and nanoplastics.
Parting thoughts
Plastic pollution in the environment comes back to haunt us. Let’s do our part by minimizing plastic use or recycling them. I avoid using plastic containers to store leftover food and use glass jars instead.
The cans used for beers are lined with plastic. Something to think about next time you drink.
One of the benefits of intermittent fasting and reduction of caloric intake may also be a reduction in the intake of microplastics, heavy metals, and other chemicals.
References:
- Ragusa et al. Plasticenta: First evidence of microplastics in human placenta. Environment International. Volume 146, January 2021, 106274.
- Schwabl, P., et al. Detection of various microplastics in human stool. Ann. Intern. 2019 Med. 171, 453. https://doi.org/10.7326/M19-0618.
- Huang S, et al. Detection and Analysis of Microplastics in Human Sputum. Environ Sci Technol. 2022 Feb 15;56(4):2476-2486. doi: 10.1021/acs.est.1c03859. Epub 2022 Jan 24. PMID: 35073488.
- Campanale C, et al. A Detailed Review Study on Potential Effects of Microplastics and Additives of Concern on Human Health. Int J Environ Res Public Health. 2020;17(4):1212. Published 2020 Feb 13. doi:10.3390/ijerph17041212
- Cox KD, et al. Human Consumption of Microplastics. Environ Sci Technol. 2019 Jun 18;53(12):7068-7074. doi: 10.1021/acs.est.9b01517. Epub 2019 Jun 5. Erratum in: Environ Sci Technol. 2020 Sep 1;54(17):10974. PMID: 31184127.
- Zhang Y, et al. The potential effects of microplastic pollution on human digestive tract cells. Chemosphere. 2022 Mar;291(Pt 1):132714. doi: 10.1016/j.chemosphere.2021.132714. Epub 2021 Oct 29. PMID: 34743871.
- Smith M, et al. Microplastics in Seafood and the Implications for Human Health. Curr Environ Health Rep. 2018;5(3):375-386. doi:10.1007/s40572-018-0206-z