Highland walkers fall sick despite using a portable water filter
It’s been reported this week that two men became very ill while on the West Highland Way, potentially after drinking water from a burn near Conic Hill in Stirling, Scotland. Lomond Mountain Rescue was called to help on two separate incidents.
Both men used straw-style water filters to try to avoid such an outcome, which is obviously very concerning. We don’t yet know exactly what infection they picked up; if it was a virus (Rotovirus or Norovirus), then a filter straw was never going to help; if it was a bacterial infection (E. coli, Listeria, Salmonella), the straw should have kept them safe, but any cross-contamination would have compromised its efficacy.
A similar ‘outbreak’ happened last year in Scotland, where a number of people were taken ill after drinking contaminated water at different locations.
What can we learn from this?
Firstly, if you want to be sure of removing ALL kinds of microbiological contaminants from wild water, you need to choose a reputable water purifier rather than a filter. Look for one with NSF-level certification and failsafe functionality so you can’t accidentally drink contaminated water. Pick one that safely removes bacteria AND viruses; unfortunately, a straw-style filter can never offer that level of protection. And check the testing methods which should cover the entire life of the filter – not just the first few litres. Adsorption filters become less effective the more they are used and start letting contaminants through; ultrafiltration filters become blocked as they remove contaminants, eventually stopping water flow altogether.
Secondly, make sure you avoid cross-contamination, which will render even the very best purifier or filter redundant.
- Never allow the mouthpiece, nozzle, or tap to come into contact with untreated water. Clean it thoroughly with an alcohol wipe if that does happen
- If your hands get wet while filling or using a purifier, use hand sanitizer before you touch the mouthpiece or tap
- If using a scavenger hose, keep it away from the mouthpiece or tap and store it away from the out hose. Sanitize your hands after you’ve touched it.
- Never share a straw or bottle while on a hike – your companion may have picked up a bug that can be passed to you
For more information or advice on choosing the best solution for your travels, please get in touch.
You can read the full BBC report here.
See also our blog: The Water Might Look Clean But...