Microplastics are in the food we eat, the water we drink, and the air we breathe. Now they are being discovered in the blood, lung tissue and placentas of living people. So what are they and what can we do about it? Let's explore this topic on Earth Day.
About Microplastics
Plastics are carbon-based polymers (long-chain molecules that repeat their structures over and over) and we make them mostly from petroleum. 'Microplastic' is a general name for plastic materials that appear in a configuration of particles and microscopic fibers the size of a micron (μm)(micrometer) and up to a five millimeters, or smaller than a pencil eraser. Since there is no defined lower size limit, some authors of scientific papers will also refer to ‘nanoplastic’ as a term for plastic particles in the sub-micron range, (<1μm). In the nanotechnology field, ‘nanoplastic’ may refer to engineered particles less than one hundred nanometers (<100 nm), i.e. the nanotechnology application size limit.
Being so small, humans and animals may inhale or ingest them without knowing. Indeed, bits of plastic dust have been floating around our environment for as long as humans have been using plastic. This has been measured with some sobering results; for example, in the western United States, samples taken from 11 different national park lands found that plastic airborne dust was accumulating to the tune of more than 1,000 metric tons of microplastics—the weight of 120 million to 300 million plastic water bottles, falling from the sky each year.2
Why Are These Microplastics Getting So Small?
There are different types of plastics, some biodegradable and some not. "Most conventional plastics such as polyethylene, polypropylene, polystyrene, poly(vinyl chloride) and poly(ethylene terephthalate), are non biodegradable, and their increasing accumulation in the environment has been a threat to the planet".3 Since these don't decompose and are not broken down by fungi or bacteria, they have the potential to just continue to split into smaller and smaller sized particles. Thus upon environmental release, when plastics are exposed to oxidation, mechanical stress and biological action, they result in embrittlement and fragmentation, eventually forming microplastics
and ultimately nanoplastics.
Some of these plastics could potentially last for centuries, others perhaps a thousand years, depending on factors such as temperature, sunlight and composition. So it doesn't really go anywhere, just gets resized into continually tinier pieces. And as if there wasn't enough plastic already, we keep making more of it! Humans globally produce over 367 million tons of it annually!4
‘Bio-plastic’ is a term used confusingly and not exactly the best solution we were hoping for. Generally, bio-plastics consist of either 'biodegradable plastics' (i.e., plastics produced from fossil materials) or 'bio-based plastics' (i.e., plastics synthesized from biomass like corn starch or renewable resources). Though it is true often a biodegradable bag will break down in a couple of months versus hundreds of years, as is the case with its synthetic counterpart, for this reaction to happen, oxygen and light are required. These are both in low supply once biodegradable packaging reaches the ocean. According to an extensive report released by the U.N., biodegradable plastics degrade far too slow in the oceans, voiding any apparent practical benefit.5
What Microplastics Are Being Found In Our Lungs?
After a few decades of scientists studying the growing plastic problem in the environment, researchers started investigating how these particles may affect our health. Scientists began with studies using urine or stool samples, as well as autopsies on cadavers. Such research helped to establish human exposure to microplastics. Patients with respiratory symptoms working in occupational environments at risk have been shown to have microplastics. Even decades ago, it had been established that synthetic fibers had been observed within human lung tissue samples,6 yet until recently, limited studies had confirmed the presence of microplastics within the lungs alongside a chemical analysis to further verify the findings. Among such alarming research, it was found that we inhale and ingest enough microscopic pieces of plastic to create a credit card each week!7
However, this year, in an article published in the Science of the Total Environment, was the first time researchers discovered plastic particles lodged in specific regions of the lungs of living patients, and were able to further identify them using μFTIR spectroscopy.8
Among the microplastics detected, the most common polymer types were:
polypropylene, (PP) (23%)
polyethylene terephthalate, (PET) (18%)
resin (15%)
The results support inhalation as a route of exposure for environmental microplastics. Airborne microplastics have already been shown to be globally ubiquitous and especially prevalent indoors where humans spend many hours a day, such as the home and the office.9,10 Humans are thus continuously exposed to atmospheric microplastics, with inhalation estimates ranging from
6 to 272 microplastics/day. "It is the smallest and least dense microplastics and nanoplastic particles that are the most cause for concern regarding respiratory health, as these microplastics are most likely to deposit within the lungs... . In contrast to nanoparticles, microplastic particles in the full micro-size range(10 μm–5 mm) have yet to be considered in terms of health implications and potential impacts, perhaps not having been a priority compared with the smaller, ultrafine particles".8
The presence of these compounds in the lungs is likely associated with multiple types of adverse health conditions and could be influenced by particle properties such as small size, density, concentration, shape, monomer type, chemical leachates and environmental adsorbents (e.g. bacteria, heavy metals and polyaromatic hydrocarbons). Microplastics have been implicated as
contributors to cytotoxicity,11 inflammation,12 and oxidative stress. 13 Indeed, a newer study from last year by Tel Aviv University researchers found that in a marine environment, microplastics absorb and concentrate toxic organic substances and thus increase their toxicity by a factor of 10, which may lead to a severe impact on human health.14
What Microplastics Are Being Found In Our Blood?
But our respiratory tract is not the only spot where these compounds are turning up.
Until now, scientists didn't know whether those microplastics were entering the bloodstream. A new pioneering human biomonitoring study demonstrated that plastic particles are bioavailable for uptake into the human bloodstream after measuring plastic particles ≥700 nm in human whole blood from 22 healthy volunteers.15
Researchers analyzed subjects' blood samples for traces of the presence of different polymers, which are the building blocks of plastics, and found:
Most prominent was 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 in the samples, 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 found in subjects' blood was polyethylene, a material regularly used in the production of paints, sandwich bags, shopping bags, plastic wrap, detergent bottles, and in toothpaste.
Since the highest amounts of the types of plastic they found are most commonly used in soft drink bottles and food packaging, and these explain an easy source for contamination, those sources are of particular interest and concern.
If a reader is still surprised, you shouldn't be. One study from 2019 sought to quantify just how much plastic Americans are consuming. "Evaluating approximately 15% of Americans' caloric intake, we estimate that annual microplastics consumption ranges from 39000 to 52000 particles depending on age and sex. These estimates increase to 74000 and 113000 when inhalation is considered. Additionally, individuals who meet their recommended water intake through only bottled sources may be ingesting an additional 90000 microplastics annually, compared to 4000 microplastics for those who consume only tap water".16,17
Microplastics Are Even Being Found In Human Placentas?
Sad but true. In a study of six human placentas, collected from consenting women with physiological pregnancies, a total of 12 microplastic fragments (ranging from 5 to 10 μm in size), with spheric or irregular shape were found in 4 placentas. All of them were pigmented and all were used for man-made coatings, paints, adhesives, plasters, finger paints, polymers and cosmetics and personal care products.18
Of course researchers are investigating potential affects on human health. Remember above the image showing nanoplastics as small enough to cross the blood-brain barrier? Could these affect the brain, digestive system and other parts of the body? We will review some of the evidence about these and other health implications on our next blog.
Testing Options and Lifestyle Choices
You may be interested in having levels on plasticizers, bisphenol A, and other contaminants checked if experiencing symptoms of:
Fatigue/weakness
Poor memory, difficulty finding words
Unusual skin sensations, tingling, numbness
Morning stiffness and/or joint pain
Headache, light sensitivity
among others...
At Northeast Natural Medicine, we offer testing for many natural pollutants, and although not looking in the blood for microplastics, some testing options cover plasticizers, preservatives, and volatile organic compounds, among others. Testing can be done through urine collection, or even hair tests if assessing things like heavy metals.
For example, Vibrant Wellness Labs offers a Vibrant Environmental Toxin Panel which uses mass spectrometry to assess levels of the following:
Organochlorine pesticides
2,4-Dichlorophenoxyacetic Acid (2,4-D)
Perchlorate
DDA
Alkylphenol
Bisphenol A (BPA)
Triclosan
4-Nonylphenol
Organophosphate pesticides
Metabolites:
Diethyldithiophosphate (DEDTP)
Dimethyldithiophosphate (DMDTP)
Diethylthiophosphate (DETP)
Dimethylphosphate (DMP)
Diethylphosphate (DEP)
Dimethylthiophosphate (DMTP)
Atrazine
Atrazine mercapturate
Volatile Organic Compounds (VOCs)
Metabolites:
2-Methylhippuric Acid (2MHA)
3-Methylhippuric Acid (3MHA)
4-Methylhippuric Acid (4MHA)
2-Hydroxyisobutyric Acid (2HIB)
Phenylglyoxylic Acid (PGO)
N-acetyl phenyl cysteine (NAP)
Other pesticides/herbcides
Glyphosate
Metabolites:
3-Phenoxybenzoic Acid (3PBA)
Plasticizers/ Preservatives
Phthalate Metabolites:
Monoethyl Phthalate (MEP)
mono-2-ethylhexyl phthalate (MEHP)
mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP)
mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP)
Monoethyl phthalate (MEtP)
Parabens:
Methylparaben
Propylparaben
Butylparaben
Ethylparaben
Acrylic Metabolites:
N-acetyl-S-(2-carbamoylethyl)-cysteine (NAE)
N-Acetyl (2-Cyanoethyl) Cysteine (NACE)
Other Metabolites:
N-Acetyl (2,Hydroxypropl) Cysteine (NAHP)
N-Acetyl (3,4-Dihydroxybutyl) Cysteine (NADB)
2-Hydroxyethyl Mercapturic Acid (HEMA)
N-Acetyl Propyl Cysteine (NAPR)
Diphenyl Phosphate
Tiglylglycine (TG)
By way of lifestyle choices, just start to consider reusable drinking bottles when possible. More to follow on our next blog!
References:
UNEP (2016). Marine plastic debris and microplastics – Global lessons and research to inspire action and guide policy change. United Nations Environment Programme, Nairobi.
Donaldson, K., Brown, R.C., Brown, G.M., 1993. Respirable industrial fibres: mechanisms of pathogenicity. Thorax 48, 390-395.
Gruber, E., et al. To Waste or Not to Waste: Questioning Potential Health Risks of Micro-and Nanoplastics with a Focus on Their Ingestion and Potential Carcinogenicity. Exposure and Health. 2022.
Dris, R., Gasperi, J., Mirande, C., et al., 2017. A first overview of textile fibers, including microplastics, in indoor and outdoor environments. Environ. Pollut. 221, 453-458.
Zhang, Q., Zhao, Y., Du, F., et al., 2020. Microplastic fallout in different indoor environments. Environ. Sci. Technol. 54, 6530-6539.
Prata, J.C., 2018. Airborne microplastics: consequences to human health? Environ. Pollut. 234, 115-126.
Porter, D.W., Castranova, V., Robinson, V.A., et al., 1999. Acute inflammatory reaction in rats after intratracheal instillation of material collected from a nylon flocking plant. J. Toxicol. Environ. Health Part A 57, 25-45.
Schirinzi, G.F., Perez-Pomeda, I., Sanchis, J., et al., 2017. Cytotoxic effects of commonly used nanomaterials and microplastics on cerebral and epithelial human cells. Enivron. Res. 159, 579-587.
Leslie, H. et al., Discovery and quantification of plastic particle pollution in human blood. Environmental International. 2022. March.
The content and any recommendations in this article are for informational purposes only. They are not intended to replace the advice of the reader's own licensed healthcare professional or physician and are not intended to be taken as direct diagnostic or treatment directives. Any treatments described in this article may have known and unknown side effects and/or health hazards. Each reader is solely responsible for his or her own healthcare choices and decisions. The author advises the reader to discuss these ideas with a licensed naturopathic physician.