Plastic has become an essential feature of human life. From the bottles we use to the clothing we wear — plastic is everywhere. Since plastic was first introduced in the 1950s, humans have produced over eight billion metric tons of plastic. Annually, we continue to produce millions of tons of plastic, most of which are single-use products such as plastic water bottles or drinking straws. With this rate of production, it is almost inevitable that plastic pollution has also become a massive global concern. Improper disposal of plastics and the creation of plastic waste during manufacturing has led to plastics of all shapes and sizes clogging our waterways and polluting the earth.
Each year, eight million metric tons of plastic leak into the ocean, according to a 2015 study by Ocean Conservancy and the McKinsey Center for Business and Environment. Based on global production, the study estimates that the ocean is already full of around 250 million metric tons of plastic to which humans are continually contributing. Over 80 percent of the plastic in the ocean comes from land-based sources, while only 20 percent comes from fishing vessels and other ocean-based production. It is our run-off and litter that composes the majority of plastic debris in the ocean, while other plastic debris is leaked from the waste management system itself. Based on current production and waste trends, the study projects that plastic in the ocean could reach 380 million metric tons by 2025.
Further expanding the problem of plastic pollution is the discovery of microplastics, or tiny particles of plastic, that are present in waterways around the globe. These tiny plastics make up 94 percent of the infamous Great Pacific Garbage Patch and are truly everywhere, including the tap water and the water in the plastic bottles that we drink every day. Microplastics pose an even more serious concern for public health as they are small enough to pass through waste filtration systems and are more difficult to remove than larger plastic debris. Scientists are still studying the impact that microplastics may have, but consumers should be informed about the risks of microplastics in drinking water.
What Are Microplastics?
When plastic waste enters waterways, it does not degrade as natural materials do. Instead, exposure to the sun's rays, reaction to oxygen, and degradation from physical elements such as waves and sand cause plastic debris to break down into tiny pieces. These microscopic pieces of plastic are called microplastics. Microplastics are defined as any piece of plastic measuring between five millimeters (5 mm) and one micrometer (1 μm) in size. Plastics smaller than that – measuring between one micrometer and 100 nanometers (100 nm) – are defined as sub-microplastic. And plastics below 100 nm in size are defined as nanoplastics. All of these types of minuscule plastic particles are typically formed from the breakdown of larger pieces of plastic, such as plastic bags, plastic bottles, or microfiber clothing.
Here are a few primary sources of microplastics:
1. Synthetic Fibers
Many synthetic fibers used in clothing products, bedding or blankets are plastic-based, including polyester, nylon, and acrylic. When clothing made of these synthetic fibers is washed, it sheds small plastic fibers. In one wash, a fleece jacket can shed up to 250 thousand plastic fibers. These microplastics cannot be removed during wastewater treatment, meaning they can end up in the ocean. Clothing and other products made of synthetic materials can also shed plastic fibers from friction and movement as you wear or use them. Microfibers from synthetic fabric make up 85 percent of the human-made material found on shorelines, making them the most common microplastic in our oceans.
2. Paint Dust
When paint flakes off of boats or ships, it breaks down into plastic dust. Paint dust can also be carried to waterways by the wind. This plastic dust has been observed on the ocean surface and is the source of about 10 percent of the microplastic in the ocean.
3. Tire Dust
Friction from tires against the road can cause microplastics to shed from the tires. Plastic dust from tires is then blown into the waterways and the ocean.
4. Fishing Equipment
While the majority of plastic debris in the ocean comes from land-based waste, plastic fishing gear and buoys can also contribute to plastic ocean debris. As they are battered by waves and other elements, plastic fishing equipment breaks down into microplastics.
Microbeads are the most common type of manufactured microplastic. About one millimeter in diameter, microbeads are composed of polyethylene plastic and were created for use as exfoliants in cosmetics and personal care products. Microbeads were once a popular addition to face wash, face scrub, toothpaste, soap, and many other beauty products. As consumers used these products, the microbeads were flushed down drains but were not removed by water and waste processing systems before reaching the ocean. Microbeads are now banned for production and sale in the United States due to the Microbead-Free Waters Act of 2015. However, a large number of microbeads still exist in the earth’s oceans and waterways.
No matter where they came from, microplastics are here to stay. Plastics in our waterways will continue to break down into smaller and smaller particles, but may never fully disappear from our oceans and drinking water.
Microplastics in Bottled Water
In recent years, studies have revealed that microplastics are present in drinking water across the globe. A 2017 study by Orb Media tested tap water samples from over a dozen countries around the world and found microplastics in 83 percent of tap water samples. In the United States, that percentage was even higher, with 94 percent of tap water samples testing positive for microplastics. The prevalence of microplastics in tap water varied from place to place, but researchers identified microplastics in at least 70 percent of tap water at each tested location.
While consumers may be tempted to respond to the plastic contamination of tap water by turning to bottled water, recent studies have revealed that microplastics are present in bottled water too. Orb Media also tested over 250 individual bottles of water from eleven different major brands across nine countries. Some of the brands tested were well-known names, such as Aquafina, Dasani, and Evian. The study revealed that 93 percent of bottled water contained some degree of microplastics. The microplastics identified included nylon, polypropylene, and polyethylene terephthalate, among others.
In each bottle of water, there was an average of 10.4 microplastic particles that were larger than 100 microns in size, which is larger than the width of a hair. When microplastics as small as 6.5 microns are included, the number of microplastics in bottled water rose to an average of over 300 per bottle. Because the study of microplastics and their potential health risks is fairly new, there are currently no regulations to control microplastics in bottled water. Because scientists are not yet certain of the health impacts of microplastics, they have not set acceptable limits for microplastics in water.
The presence of microplastics in tap and bottled water implies that they are likely in a wide variety of processed foods and beverages that use water in their manufacturing processes. A 2018 study sampled 12 brands of North American beer and found microplastics in all of them with an average of about 4.05 particles per liter. Just like the plastic debris found in the ocean, most of these microplastics were synthetic fibers. As we continue to study microplastics, it is likely that policies will be developed to regulate their prevalence in food and beverages, but for now, it is up to producers and consumers to respond to the epidemic of plastic in drinking water.
Why Should Microplastics Be Removed From Drinking Water?
The precise effect of microplastics on human health is difficult to determine for a variety of reasons. There are many different types of plastics, as well as different chemical additives that may or may not be present. Manufacturing practices for plastics have also changed over time, making it even more difficult for scientists studying microplastics to determine exactly what materials and chemical additives may be present in samples. The concentration of microplastics that are consumed in water or food can vary, which also impacts their potential effects. Microplastics may be able to pass through our bodies or could break down before they can cause any lasting harm. On the other hand, it is possible that higher concentrations of microplastics could accumulate in the body and cause a variety of adverse health effects.
Complicating the matter further, scientists used to believe that plastic debris did not interact chemically with water, but we now know that chemical additives in plastics can leach into the ocean water. While these leached chemicals alone are harmful, they can also attach to microplastics in a process called sorption, which is both a physical and chemical adhesion. Sea life, animals, and humans then ingest these microplastics.
While there are still a lot of gray areas surrounding the impacts of microplastics on human health, we can take a guess based on the observed impacts of plastics and chemical additives on sea life. Studies have shown that ingestion of microplastic is linked to reproductive problems and abnormal growth in animals. Consuming microplastics can also irritate the gastrointestinal tract and disrupt normal lipid and energy metabolizing.
Knowledge about the chemicals that are commonly added to plastics can also provide insight into the potential health impacts of microplastics. Polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) are both used in plastic manufacturing and are possible carcinogens. While PCBs are no longer produced in the US, they are still present in the environment. PAHs are similarly difficult to break down and likely to persist in the ocean and other waterways. Other harmful chemicals added to plastics include flame retardants, pesticides, and hormone-disrupting chemicals.
Another growing concern about human exposure to microplastics is the presence of nanoparticles of plastic in drinking water. Microplastics that are measured on a nanometer scale are so small that they can pass directly through cell membranes to enter the body. As plastic waste continues to break down in waterways, more nanoparticles will be present that humans may consume and absorb into their bodies. Nanoparticles also pose a particular challenge when it comes to establishing policies for safe levels of microplastics in drinking water as they are difficult to measure and more difficult to filter out.
Interpreting the Evidence
The World Health Organization has taken the position that no reliable evidence exists to show that microplastics in water pose health concerns. It casts doubt on the quality of several 2018 and 2019 water research studies designed to assess the harms associated with ingesting microplastics in drinking water, and it states that regular monitoring of microplastics in water is currently unnecessary. It does caution that further research is needed before scientists can draw any definite conclusions about the health risks or safety of microplastics ingestion.
However, 2020 saw the emergence of new work examining the potential health harms associated with microplastic ingestion. One detailed literature review study published in the International Journal of Environmental Research and Public Health cited the potential for cytotoxicity, adverse immune responses, hypersensitivity and other possible health risks, though it also concluded that more research is necessary for definitive conclusions.
Another study published in Environmental Health and Preventative Medicine emphasized the alarming potential for micro- and nanoplastics to breach the human intestinal wall, enter the bloodstream and distribute themselves to the tissues and organs, concurring that more research is likely necessary. A study published in Science of the Total Environment emphasized the likelihood that ingested microplastics could disrupt immune function and cause uncontrolled cell growth or damage the central nervous system. It also cautioned that we still know too little about microplastics' effects on human health.
Because the health impact of microplastics in drinking water is largely unknown, it is better to be safe than sorry. It may take a long time for scientists to fully understand the extent of the effect microplastics may have on ecosystems and public health, but consumers should take steps now to remove plastic contaminants from drinking water.
Microplastics in Tap Water
In 2018, Mary Kosuth, a microplastics researcher and graduate of the University of Minnesota School of Public Health, conducted a study of anthropogenic debris – aka, man-made inorganic particles such as plastics and microplastics – in tap water, beer, and sea salt. She examined 159 samples of globally sourced tap water, 12 brands of Laurentian Great Lakes beer, and 12 brands of commercial sea salt.
Utilizing a dye that stains organic substances, Kosuth was able to filter out and examine the inorganic particles present in her test samples. She discovered that 81% of the tap water samples contained microplastics, with the highest average concentration sourced from waters in the United States, and the lowest average concentration sourced from water in the European Union.
Of the twelve brands of beer samples, every single brand tested positive for the presence of microplastics, and a further study found that the results could not be solely blamed on the use of microplastic-contaminated tap water. This indicates that the beer brewing process itself may be a factor in their contamination.
Like the beer samples, all twelve brands of sea salt tested positive for the presence of microplastics.
The study concludes with a general concern at the presence of microplastic contamination in tap water because although both beer and salt intake can be modified or reduced, water is a daily necessity that is involved in all sources of hydration.
How to Remove Microplastics From Tap Water
People use home tap water for drinking, hand washing, cooking, brushing their teeth, and so much more. Smart consumers should take preventative action to protect themselves from microplastics and other impurities in their tap water. Luckily, there are a variety of technologies available for filtering and purifying water to remove plastic particles and other harmful chemicals from tap water. Consumers can choose from a variety of filter types and methods to best suit their needs. Here are a few of the most effective water filters for removing microplastics:
- Granular activated carbon (GAC) filters: These filters can filter out contaminants down to 5 micrometers. This means that some microplastics will be removed. GAC filters can be used to filter a home's entire water supply with a point of entry filter or smaller filters can be attached to home faucets.
- Carbon block filters: Carbon block filters can filter contaminants as small as 0.5 microns, or micrometers. Most microplastics are about 2.5 micrometers, which makes carbon block filters an effective option for eliminating microplastics from drinking water. Carbon block filters are also very affordable for home use and are an environmentally friendly option. Carbon block filters can be used for entire home filtration, but are most popular for faucets or point of use filtration.
- Reverse osmosis: With the ability to filter particles as small as 0.001 microns, reverse osmosis filters are the most effective for removing microplastics. However, they are also the most expensive and require maintenance that can be extremely costly for homeowners — plus, the technology removes all the natural minerals like calcium and magnesium and can waste up to 5 gallons of water for every gallon it makes. Reverse osmosis filters are available for point-of-use water filtration.
In the long term, consumers should be conscious of ways to reduce the amount of plastic waste that is entering our ecosystem and waterways in the first place. Avoiding single-use plastic products and choosing to recycle are great ways to keep microplastics out of our drinking water. Consumers can also choose reusable containers for drinks and food and choose organic fibers for their clothing. However, because of the global prevalence of microplastics in the ocean and other waterways, it will take a long time for them to be effectively removed, meaning they are likely to be present and bottled and tap water for many more years. Microplastics in tap and bottled water are also not yet regulated, so it is up to consumers to remove microplastics and other contaminants from their drinking water.
Drink Clean With Multipure Carbon Block Filters
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