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As if plastic pollution in the ocean wasn’t bad enough, now it is contaminating our drinking water too.
That’s right; there is a strong chance that by drinking unfiltered water, you could be ingesting plastic particles along with it.
These plastic particles are so small they mostly cannot be seen with the naked eye either, meaning you won’t have any idea they’re in your water unless you have it tested.
The good news is that specific water filtration systems are able to remove these minuscule bits of plastic. Is the reverse osmosis system one of them? Let’s take a look.
Yes, reverse osmosis removes microplastics from water.
The semipermeable reverse osmosis membranes have tiny pores that are too small for 99.9% or more of the microplastics to pass through.
Other filtration methods can reduce the number of microplastics in water, too, but cannot remove them entirely like reverse osmosis can.
What Are Microplastics?
Microplastics vary in size, but most measure under 5 mm (0.2 inches), with the smallest being 0.1 micrometers (µm) in length (1/10,000th of a mm). They can get even smaller but then would be defined instead as nanoplastics.
Microplastics occur in two ways; the first is when environmental factors slowly break down plastic products into tiny little pieces, which end up floating around in our water supply. These are secondary microplastics. They can also occur by design in commercial products, such as cosmetics and microfibers on fishing nets and textiles. Those are referred to as primary microplastics.
Primary microplastics are tiny particles designed for commercial use, such as cosmetics, microfibers shed from clothing and other textiles like fishing nets. The concerning thing is that plastic can take hundreds to thousands of years to break down properly. This means it remains in bodies of water and our drinking water and will be consumed by marine life and humans alike for years.
Does Reverse Osmosis Remove Microplastics? How?
A decent water filtration system can help to remove these potentially harmful plastics from your home water supply. So yes, reverse osmosis does remove microplastics; and a good quality reverse osmosis system is capable of removing particles under 0.1 nanometers in size which is suitable for all microplastics and some nanoplastics.
Reverse osmosis uses pressure to force water through a semipermeable membrane. This membrane is fine enough to stop certain molecules from getting through to the other side, leaving only clean water.
How Well RO Filters Out Microplastics
Reverse osmosis is capable of removing 99.9+% of microplastics from drinking water, so it is considered to be highly effective. The semipermeable membrane has a tiny pore size (0.0001 microns), smaller than that of a microplastic particle, and will block it from getting through.
Other Ways to Remove Microplastics from Water
Reverse osmosis can remove microplastics from water, but other methods of filtration can only reduce them; they will unfortunately not remove them altogether.
Nevertheless, if an RO filtration system doesn’t appeal to you, here are some other ways to reduce the amount of microplastics in your water supply.
Activated Carbon Filtration
Granular Activated Carbon
Granular activated carbon works by pulling molecules together. As water flows through, specific contaminants are attracted to the activated carbon and held there.
GAC is suitable for pollutants that are larger than 5 micron which includes some microplastics. Nanoplastics are smaller than that, though, and won’t be removed.
Carbon Blocks
Carbon blocks are manufactured by binding powdered activated carbon together. Due to compression, their pores size are as small as 0.1 micron. As such, most microplastics can be filtered out.
Water does take longer to pass through carbon block filters, though, as compared to granular activated carbon.
Water Distillation
When water is distilled, it leaves behind any particulate that may be present in the source water. However, because some microplastics are so tiny, there are some that could be suspended in the air and carried with the water vapor to the distilled water chamber.
Ultrafiltration
Microfiltration works by passing water through a membrane that prevents contaminants from going with it. A microfilter pore size is typically between 0.1 and 1 microns, which is adequate for most microplastics.
However, an even better option is ultrafiltration, which works the same way as microfiltration, but the pore size on the ultrafiltration membrane is even smaller (0.01 to 0.05) and therefore is more effective for microplastics.
Ceramic Water Filters
Ceramic water filters can also reduce the amount of microplastic in water. The pore size of around 0.5 micron is capable of stopping most microplastics from passing through to the clean water catchment.
Other Ways to Reduce Your Exposure to Microplastic in Everyday Life
To reduce the possible impact of microplastics on our health, there are ways we can reduce our exposure to them in everyday life:
Avoid cosmetic products that contain microbeads.
Reduce the frequency of machine-washing synthetic clothes or purchase clothing made from non-synthetic materials.
Reduce or eliminate your use of single-use plastics such as plastic bags and plastic straws.
Petition for banning single-use plastics and microbeads from cosmetics to effect change on a more global scale.
Where Do Microplastics Originate from?
Non-biodegradable microplastics predominantly come from discarded plastic that degrades over time.
One of the primary sources is the Great Pacific Garbage Patch, which is a patch of garbage floating in the Pacific that has reached the size of an island. Studies have found these microplastics not only in the ocean but in our drinking water, the food we eat, and even the air we breathe.
Microplastics are also found in sources such as cosmetics and synthetic nylon clothing, meaning that after you wash your face or do a load of laundry, you send them down your drains with the wastewater.
Disposable plastics that break down into microplastics due to environmental factors such as UV light and physical abrasion are consumed by marine creatures, which in turn are consumed by us.
How Do Microplastics End Up in Our Water?
While it can be challenging to pinpoint the exact source of microplastics found in your specific source of water, the most common ways they get there are;
From surface run-off
From wastewater effluent
From combined sewer overflows
Degraded plastic waste
Airborne deposits
Surface run-off and wastewater are recognized as the two main sources.
Microplastics in Bottled Water
Bottled water may not be appropriately tested and filtered for microplastics before bottling. Still, the majority of microplastics found in bottled water are likely due to minuscule bits of plastic that come off from repeatedly opening and closing the bottle cap. Studies have shown that the microplastics in bottled water are consistent with the plastic of the bottle and cap.
Microplastics in Tap Water
Particles enter ground and surface water sources after;
Being carried there by air, washed off the soil, or coming from creeks and rivers.
Being flushed into the waterways after heavy rain and sewer overflow.
Being washed down our drains after cleaning synthetic clothing or using products containing microplastics such as cleaning agents, shampoos, face scrubs, and body washes.
How to Detect Microplastic in Drinking Water
Detecting microplastics in drinking water requires the water to be tested.
In a lab, there are two ways this can be done: The micro-Raman spectroscopy, which can identify micro-plastics down to 0.001 microns, or high-performance liquid chromatography (HPLC) for micro-plastics that are larger than 0.05 microns.
If you want to get your water tested, there are certain service providers offering microplastic water tests. They often analyze the water for certain microplastic types and sizes (PE, PP, PVC, etc. between 1 micron and 5 mm).
Out of everything, these statistics are probably the most shocking. Microplastics are found in drinking water in most countries around the world, and 94% of samples from the USA contain microplastics.
The National Geographic predicts that the average American will consume 44 pounds of it over their lifetime, which is at least 39,000 individual bits of microplastic each year.
Health Effects
Plastic contains chemicals linked with human health issues, such as inflammation of the stomach lining, IBS, and hormone level fluctuations.
They can also carry bacteria, viruses, and parasites found in marine life. There is little evidence, however, that the microplastic itself is being absorbed, and more studies need to be done in this area.
PET plastic, which is usually what bottled water comes in, is a known hormone disruptor, and its chemicals have been linked to reproductive, immune, and developmental issues.
If you have any thoughts about the question, can reverse osmosis remove microplastics, please don’t hesitate to leave a comment below!
About the Author Gene Fitzgerald
Gene Fitzgerald is one of the founders of BOS and currently head of content creation. She has 8+ years of experience as a water treatment specialist under her belt making her our senior scientist. Outside of BOS, Gene loves reading books on philosophy & social issues, making music, and hiking.
Learn more about Gene and the rest of the BOS Team.
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Leave a Comment:
Edward Santillan says
January 10, 2024
In discussing sources of microplastics, e.g., shedding, some researchers have said that RO membranes can be a source. Clarifications please? Do they mean in operation or when disposed. What about the plastic tubing used in RO systems? Also plastic tubing inside braided lines to faucets?
Hi Edward,
As far as I know, some studies have found nanoplastics in RO-treated water. But I believe there needs to be done more research on this. Also, nanoplastics =/ microplastics. That’s all I can say really.
Gene
