Microplastics in the Environment and in the Human Body
Concerns About Microplastics
Microplastics are tiny pieces of plastic that are less than five millimetres long. They are created by the degradation of larger items and are also deliberately produced for use in manufacturing. Like much of our waste, they often collect in bodies of water when they are created or discarded. Some people are very concerned about their effects of on aquatic life, and rightly so. There is another area of concern that is worrying researchers, however: the effects of microplastics on humans.
Particles of microplastic have been found in samples of tap water from around the globe and in some of the seafood and sea salt that we eat. They are also present in certain cosmetics, toiletries, and toothpaste. In at least some parts of the world, they are even present in the air that we breathe.
Scientists know that microplastic particles are entering our bodies. They also know that the particles transport molecules that are harmful to humans at certain concentrations. They haven’t yet discovered whether the microplastic is affecting our health, however. Answering this question could be urgent. As the particles continue to collect in the environment and enter our bodies, we might be heading for a range of health problems.
Importance and Composition of Plastic
Plastics are abundant today. In many parts of the world, they are ubiquitous. They are very useful in many aspects of our lives, including medical treatments. While it's true that some plastics could be avoided, others are the best material that is currently available for a particular function.
Some researchers are trying to create safer plastics. The creation of a plastic or a substitute material that has many applications and is also safe for the environment if it's discarded is a challenge. Nevertheless, the effort is very important. Plastics are so common in our lives that eliminating their use seems impossible. I think that recycling and reusing them and the use of safer substitutions whenever possible is vital, however.
Plastics are made of polymers. These are long chains consisting of repeating molecules known as monomers. Polyethylene, polypropylene, and polystyrene are common examples of plastics. Chemicals are added to the material to improve properties such as flexibility or durability. The additives are released into the environment as a plastic degrades.
Determining how much plastic waste enters the ocean each year is a difficult task, but according to the United Nations the amount is at least eight million tons. NOAA (National Oceanic and Atmospheric Administration) says that microplastic particles are less than 5 mm long. Some organizations say that the particles must be less than 1 mm long in order to be called microplastic.
How Do Microplastics Form?
Degradation of Plastic Waste
Plastic debris in the ocean slowly breaks down into microplastic particles due to the action of ultraviolet light from the sun, reaction with oxygen, and physical degradation by wave and current action. Fishing gear, buoys, and domestic and industrial waste contribute to the debris.
Fibres From Clothes
Another common source of microplastic in the ocean is clothing made from synthetic fibres. Tiny fibres of polyester and acrylic (both a type of plastic) are shed when clothing is washed. The facilities that treat wastewater are often unable to remove the fibres, allowing them to reach the ocean.
Microplastic is also added directly to the ocean in the form of pellets or granules known as nurdles. Nurdles are widely used by manufacturers to make plastic items. They are about the size of a lentil, very lightweight, and not easily noticed if they escape from where they belong. They enter the ocean either from the ships that are transporting them or from where they are stored on land. Nurdles are mistaken as prey by some marine animals and are eaten.
Microbeads are plastic particles that are about about a millimetre in diameter. They are added to products to increase their abrasive and cleaning ability. They are found in some toothpastes, soaps, facial cleansers, and facial scrubs, for example.
In 2020, researchers from the University of Manchester reported a significant discovery at the bottom of the Mediterranean Sea. They found up to 1.9 million pieces of plastic per square metre. They say that ocean currents are concentrating the particles in particular areas.
It is estimated that about 80% of marine debris originates as land-based trash and the remaining 20% is attributed to at-sea intentional or accidental disposal or loss of goods and waste.— EPA (Environmental Protection Agency)
Contamination of Foods, Drinks, and Air
Microplastics have been found in some of the foods and drinks that we ingest. This may not mean that they are present in these items everywhere in the world, but on the other hand contamination of the items may be widespread. More testing is needed.
Microplastic particles have been found in the tissues of fish and shellfish species that are sold in stores and markets. A 2018 study of 39 brands of salt produced in North and South America, Europe, Africa, or Asia found that 36 of them were contaminated by microplastic.
In 2017, samples of tap water from different countries were analyzed. 83% of the samples contained plastic fibres. A smaller study in Ireland found microplastic in tap water from that country. In 2014, a pair of scientists found that microplastic particles were present in all of the twenty-four samples of German beers that they tested. The material existed in the form of grains, fragments, and fibres.
Researchers in France, Germany, and China have discovered microplastic particles in the air over their countries. At the end of 2019, British scientists reported that microplastic pollution is "raining down" on people in four UK cities, especially in London. In that city, most of the pollution is in the form of acrylic fibres that have probably come from clothing.
The health impacts of breathing or consuming the tiny plastic particles are unknown, and experts say urgent research is needed to assess the risks.— Damian Carrington, Environmental Editor of the online edition of The Guardian newspaper
Leaching and Sorption
It was once thought that although large pieces of plastic debris could be dangerous to aquatic life due to ingestion or entanglement, plastic didn't interact chemically with either sea or fresh water. Scientists now know that this isn't true.
Plastics slowly degrade into microplastic particles. Chemicals added to plastics to improve their properties leach (escape) into the water as this happens. Leached chemicals attach to microplastic particles by a process called sorption.
Some of the leached and sorbed chemicals are listed below. They are thought to be dangerous for us, but this may be true only when they are sufficiently concentrated.
- PCBs (polychlorinated biphenyls) are synthetic chemicals that are no longer made in the United States. They used to be added to plastics and are still present in the environment, however. They can produce a number of harmful health effects and are classified as a probable carcinogen (cancer causer).
- PAHs (polycyclic aromatic hydrocarbons) are persistant chemicals that don't break down easily, like PCBs. They are added to some plastics. They are a possible carcinogen and can also produce other effects.
- Flame retardants, chemicals that act as hormone disrupters, and pesticides are also carried by microplastic particles. Each of these can produce a range of harmful effects, which depend on the identity of the chemical.
Is Microplastic Dangerous to Humans?
Researchers know that for many of us—and perhaps for most of us—microplastic particles are present in the water that we drink, at least some of the food that we eat, and perhaps in the air that we breathe. What they don't yet know is whether the particles or their chemical cargo are hurting us.
There are a number of possible fates for the microplastics that enter our body. Some are listed below. We won't know whether they are true until scientists perform appropriate research.
- Microplastic particles may leave our bodies without being absorbed or without releasing their chemical cargo.
- They may be absorbed but may be quickly broken down or eliminated before they have time to harm us.
- They may be absorbed but then encapsulated so that they don't hurt the body.
- The particles or the chemicals that they carry may not be sufficiently concentrated to hurt us even if they are absorbed.
- The particles or their cargo may be hurting us.
- The particles may not be hurting us yet, but they may do so if they become more concentrated.
Some researchers speculate that microplastics consisting of nanoarticles may be more dangerous for us than ones consisting of larger particles. Nanoparticles are 1 to 100 nm in length. A nanometre (nm) is a billionth of a metre or a millionth of a millimetre. In studies in other areas of chemistry, scientists have discovered that nanoparticles of a substance often behave differently in living things than particles with a larger size. Nanoparticles are small enough to enter cells.
Photo A above shows artificial turf on top of ground rubber tire (GRT) in a football field; most tires are made of synthetic rubber that is actually a type of plastic.
Photo B shows microplastic washed off the field by rain.
A Present Problem and Potential Ones
While we don't need to panic about the existence of microplastic particles in our body, I think they are a concern. A major problem associated with the particles is that we may not be able to avoid their entrance into the body. We have to drink water and breathe air. Eating fish and other types of seafood is not as essential, but the animals are nutritious foods. Adding sea salt to our food is optional, but some types of processed food already contain it.
The increasing number of news reports about the ways in which microplastics are entering our body is troubling. If scientists eventually discover that the particles are causing health problems—or if they eventually do so if their concentration increases—it may be too late to avoid the problems.
- Microplastics found in supermarket fish and shellfish from the CBC (Canadian Broadcasting Corporation)
- Salt around the world is contaminated by plastic from The Weather Channel
- Plastic fibres found in tap water around the world from The Guardian newspaper
- German beers are contaminated by microplastics from the ScienceDaily news service
- Toxicity of polychlorinated biphenyls (PCBs) from the Agency for Toxic Substances and Disease Registry at the CDC (Centers for Disease Control and Prevention)
- Polycyclic Aromatic Hydrocarbons (PAHs) from Tox Town at the NIH (National Institutes of Health)
- "Influence of Various Aqueous Conditions on Additives Releasing From, and Pollutants Sorbing to, Microplastic Debris" from NOAA (National Atmospheric and Atmospheric Association)
- "UN Declares War on Ocean Plastic" from the United Nations
- Microplastic pollution is raining down on city dwellers from The Guardian
- High microplastic concentration found on ocean floor from the BBC (British Broadcasting Corporation)
This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.
Questions & Answers
Are you aware of any side effects from microbeads?
Unfortunately, as far as I know, researchers haven't yet discovered whether microbeads and other forms of microplastic can hurt us. This could be a problem. The particles are collecting in the environment and entering our body. We need to know their effects. Perhaps they aren't hurting us, but on the other hand, they may be.
Microbeads in toothpaste can get stuck in our gums. Once again, though, the effects of the microbeads are unknown. Some oral health experts worry that the beads can harm the gums; others point out that this hasn't been proven.Helpful 6
Which toothpastes do not contain microbeads?
You would have to do some Internet research related to where you live to find the answer to this question. In Canada, microbeads in toiletries were banned on July 1st, 2018, with a couple of exceptions, as mentioned in my answer to the previous question. You could visit the website of your favorite toothpaste or email the company if you want to be certain that the version of their product that is sold in your country no longer contains microbeads.
How can we avoid contamination from plastics in our foods and drinking water? How is the longterm exposure likely to affect us?
It's hard to avoid microplastics because plastic items are ubiquitous. The computer, tablet, or mobile device that you used to type your question probably contains plastic, and so do many pens used for writing. Eventually, these items are discarded. It's probably best to avoid drinking water from plastic bottles, however, since many of these containers have been found to contain a higher level of microplastics than the equivalent amount of tap water.
We don't know how microplastics affect us. I don't think we need to panic about the situation, but it is a concern.
Can we potentially stop microplastics from entering rivers and oceans? Would filters work? Or would the filters be unreliable?
The problem is that microplastic particles are so tiny and—especially in the ocean—so widespread. Removing the particles is a huge challenge. Some water treatment plants can remove the bigger particles, but many are too tiny for them to trap. The particles could be a major problem if we discover that they have harmful effects. Someone may eventually create a special filter or another device that can remove them, though. I hope this is the case.
Surely the government cannot ignore the threat to health from plastics entering our bodies?
I can't speak for other countries, but in Canada (where I live) the government has expressed some interest in microplastics this year. The interest is in relation to protecting the marine environment rather than what is happening in our bodies, but it's still good.
The first link below says that the government has funded research on microplastics and other ocean contaminants. The research is designed to look at the impact of contaminants on aquatic species. The second link from the Government of Canada says that as of July 1st, 2018, the manufacture and import of toiletries containing microbeads was prohibited. The sale of toiletries containing microbeads was also prohibited unless the items were natural health products or non-prescription drugs. These will be prohibited as of July 1st, 2019.Helpful 2
© 2017 Linda Crampton