Why refilling your water bottle is unhygienic

A human can go more than three weeks without food. But water? A week is the absolute maximum we can last without it. Being composed of roughly 60 per cent water, and given how we lose around three to four litres a day through sweat, urine and breathing, staying hydrated is of paramount importance to us. In our quest to drink the recommended two litres of water a day, we all do what we can. Including utilising water bottles. Many of us will buy a bottle of water, then hang on to it, refilling it and using it throughout the day. Good for the environment and the pocket, right? Well, yes. But it's also bad news for your health. Whether you're at work, school or exercising, your trusty reusable drinking receptacle could be heaving with thousands of bacteria which thrive off moisture.
By using your water bottle over and over again, according to TreadmillReviews.net, you could be making yourself unwell. The team at Treadmill Review conducted research into this matter, swabbing the lids of 12 reusable water bottles used by athletes and sent their findings off for lab analysis. The team found the reusable bottles may be hosting a HUGE number of bacterial cells, "more than 300,000 colony-forming units per square centimeter (CFU/sq cm)." In layman's terms this means, "drinking from the average refillable bottle can be many times worse than licking your dog's toy."
The results did vary depending on the type of bottle you use and were broken down as follows.
Slide-top bottles were the worst offender, being responsible for hosting 900,000 CFU/sq cm.
Squeeze-top bottles came in second place, housing 162,000 CFU/sq cm , and screw-top containers came in third, with just under 160,000 CFU/sq cm . Harmful bacteria-wise, this places them on par with eating from your pet's food dish, which we're assuming you wouldn't want to do.
Straw-top bottles came out the cleanest, containing a tiny 25 CFU/sq cm. But if you do own and use one of these, don't get too smug.
However, buying a new bottle every time you need a drunk of water is not only wasteful, but also adds up, money-wise. Treadmill Review recommends purchasing a stainless steel canteen or flask, never leaving it partly full for a length of time and running it through the dishwasher as frequently as possible.

Source: Mirror