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What is the risk of water without filtration?

Submitted by harrys on Tue, 11/15/2022 - 07:15

Before choosing your outdoor water filter, you need to understand the risks associated with water for travelers. The water in rivers, lakes, and wells can be polluted by human or animal excrement or by sewage from homes. However, except when trekking, you will mainly drink tap water during your trip. It is controlled almost everywhere in the world, but in developing countries, these controls as well as the treatment and distribution facilities are sometimes deficient. If the water is contaminated, the main risk is to catch a more or less violent “tourista”: diarrhea, vomiting, and stomach cramps. It may be due to the presence of dangerous micro-organisms (bacteria, etc.).


Bacteria is the first cause of diarrhea of ​​the traveler. They do not multiply directly in water but in suspended organic matter. These are the easiest pathogens to eliminate. Bacteria are ten times larger than viruses.

● E. Coli

● Choléra

● Salmonella

● Dysentery

● Campylobacter

● Shigella

● Yersinia

● Aeromonas.

filtered by all the water filter system


Protozoa are often single-celled parasites that cause serious intestinal problems. When conditions become unfavorable they encyst, ceasing their movements and taking on a spherical shape. They are then more difficult to eliminate.

● Giardia

● Cryptosporidium

● Amibiase

● Douve du foie

● Echinococcose

● Vers parasites (Ténia)

Processed by: filters with pores smaller than 0.2 microns, UV lamps. Some cysts are quite resistant to chemical treatments. Thus, Micropur must be left to act for at least two hours to eliminate Giardia and Aquatabs are ineffective against Cryptosporidium.


Viruses need a living host cell to multiply

because they do not have their own metabolism. Due to their tiny size, they are very difficult to remove using a water filter. In turbid water, viruses usually attach themselves to suspended particles. It is therefore possible to eliminate them almost completely by using a filter whose pores are less than 0.015 microns. Nevertheless, to take no risks, it is recommended to purify the water after having filtered it. It is also advisable to get vaccinated against hepatitis A and against polio.


Hepatitis A






Treated by: almost completely by a filter whose pores are smaller than 0.015 microns, but in order not to take any risk, it is recommended to use a UV lamp or a chemical treatment.


According to the medical journal Prescrire, chemicals and heavy metals generally do not cause acute disorders for travelers. Adverse health effects are only to be feared in the event of prolonged exposure or significant accidental contamination (industrial accident, illegal release).










Processed by: carbon filters and charged layer membrane filters. They only filter residues of chemical pollutants and heavy metals if they are present in very small quantities and have a very short lifespan.


Tap water is usually clear, but water from rivers, lakes and wells can be cloudy. It may contain dissolved organic matter, clay particles, and fine sands. Once the bacteria, viruses and parasites are treated, these particles are not dangerous, but they can give a bad taste and odor to the water.

Treated by: all filters, but not chemical treatments or ultraviolet lamps (the latter are also ineffective in treating bacteria, protozoa, and viruses in cloudy water). Activated carbon filters remove bad taste and odors.


Be careful, water is not the only way you can catch a tourist. To limit the risks:

Eat foods that are cooked and served hot, fruits and vegetables that you have washed with treated water and peeled yourself, and pasteurized dairy products.

Avoid foods served at room temperature, raw fish, and rare meat.

Avoid ice cubes, as they are usually made with tap water.