Does Reverse Osmosis Remove Amoebas (Naegleria Fowleri) in Water?

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A brain-eating parasite sounds utterly terrifying, and unfortunately, it isn’t just something you find in a horror film plot.

There are amoebas present in bodies of water around the globe and some pretty dangerous ones in warm freshwater lakes and springs.

If you are concerned about the presence of brain-eating Naegleria Fowleri and other less sinister amoebas in your water supply, let’s look at what you can do to ensure they don’t come anywhere near you.

For starters, can you use reverse osmosis to remove amoebas from water?

Key Takeaways

  • Reverse osmosis removes amoebas, including Naegleria Fowleri, from water very effectively.
  • Reverse osmosis does not kill amoebas; it simply removes them from drinking water.

Does Reverse Osmosis Remove Amoebas from Water?

So, does reverse osmosis remove amoebas from water?

Yes, reverse osmosis is highly effective at removing amoebas from drinking water.

That’s because the pore size of a reverse osmosis membrane is approximately 0.0001 microns, and amoebas are considerably larger than that, at least 2 or 3 microns depending on the type, so they simply do not fit through.

Some amoebas are so large they won’t even make it through the pre-filtration steps of your reverse osmosis system! For example, if you have amoebas in your water that are 0.01 inches in size, that roughly equals 250 microns. That is way too large to fit through a sediment or carbon pre-filter with a micron rating of 5 or 10.

blue reverse osmosis membrane

Does Reverse Osmosis Remove Naegleria Fowleri?

Yes, reverse osmosis removes all types of amoebas from water, including Naegleria Fowleri.

Naegleria Fowleri is also known as the “brain-eating” amoeba and can be found in warm freshwater bodies globally. It can cause serious and fatal infections, usually by entering through the nose into the brain, though it can also access the brain through the mouth in rare cases.

Be that as it may, you can use reverse osmosis to eliminate Naegleria Fowleri with ease.

Does Reverse Osmosis Kill Brain-Eating Amoeba?

An important distinction to make is; reverse osmosis does not kill brain-eating amoeba or any amoeba whatsoever. It simply removes them from the water. Hence, be careful what you do with your waste water if you suspect it contains filtered Naegleria Fowleri, as it won’t be suitable for things like bathing or cleaning etc.

Are RO Systems Affected by Amoeba?

Most reverse osmosis systems for home use are recommended to be used with biologically-safe water only. Why?

It is possible for germs like amoebas to accumulate on the surface of the RO membrane, which could affect its performance and deteriorate it with time. Eventually, the germs might make their way into your drinking water, which shouldn’t be taken lightly!

Bottom line: Double-check with the manufacturer if you are planning to use a home reverse osmosis system for amoeba removal. Personally, and depending on the type of amoeba present, we would recommend using a different treatment method as described below.

What Other Water Filters Remove Amoebas?

The best way to eliminate amoeba in water is with chlorination or chloramination, which is regularly performed on most municipal drinking water supplies. Chlorine kills amoeba so they cannot reproduce.

UV water purification is another effective method of inactivating amoeba.

Besides, amoeba infections are becoming more widely recognized; hence, more products are coming out that guarantee their ability to filter them from water. The company Clearly Filtered has a pitcher that they tested to ensure it removes amoebas and gives a guarantee of over 99.99% removal.

Technically, due to the amoebas’ large size, other filtration methods would be capable of removing them, such as nanofiltration, which works with a micron size of 0.001, ultrafiltration with a micron size of 0.01-0.1 microns, and microfiltration with a micron size of about 1. Amoeba range from 2 microns to 0.2 inches! For these larger ones, even a carbon filter would be effective. However, many of these methods have not yet been tested or certified to remove amoeba.

Brita Pitchers

Water filters that are capable of removing amoebas usually need to be NSF 53 or 58 certified for amoeba reduction specifically.

Now, Brita filter pitchers are NSF 53 certified just not for amoebas. Also, they don’t have a micron rating.

On Brita’s official website it says that “Brita® filters are not intended to purify water. Do not use with water that is microbiologically unsafe or of unknown quality without adequate disinfection.

There is even one reported case of a woman becoming fatally infected with an amoeba from using her Neti pot with Brita-filtered water.

So simply put, you shouldn’t use a Brita water filter pitcher to try to remove amoebas from water. It won’t work and it isn’t safe!

What Are Amoebas and Where Are They Found?

Amoebas are pathogens that can be found in freshwater and saltwater. They are larger than many other biological contaminants, and examples of amoebas include Entamoeba Histolytica, Naegleria Fowleri, and Acanthamoeba.

They reproduce quickly by dividing in two, making them easy to spread, and can cause infection in humans if they get into the body via the nose or a wound.

different amoebas on black background

What Are the Health Effects of Amoebas in Water?

Drinking water contaminated with a few amoebas probably won’t make you sick if you are a healthy adult, as they are killed by stomach acid. People with weak immune systems, children, and older people may be at risk from oral consumption.

Amoebic dysentery can develop in susceptible individuals, causing abdominal pain, nausea, vomiting, and bloody diarrhea. If left untreated, it can be fatal.

Brain-Eating Amoeba

Brain-eating amoeba such as Naegleria Fowleri are a type of microorganism that can cause a rare but potentially fatal infection. They are found in lakes, rivers, and hot springs. While it is uncommon for people to become infected with the amoebas, those who do may develop an infection called primary amebic meningoencephalitis (PAM).

This can cause a severe headache that does not improve with over-the-counter medications, fever, nausea, vomiting, confusion, stiff neck, and sensitivity to light. The infection can be fatal within 1-2 weeks of symptom onset if it isn’t treated.

If you have any thoughts about the question, does reverse osmosis remove amoebas, 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.
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