How Dirty Is the Glass of Water on Your Bedside Table?
A glass of water on your bedside table in case you wake up dehydrated in the middle of the night: many people have one there. But how ‘clean’ is a glass of water like that, really? Isn’t it teeming with bacteria?
I also fill a glass with tap water every evening and put it next to my bed, only to take not a single sip from it 9 times out of 10. But hey, better safe than sorry, right? Nothing is more miserable than having to leave your warm bed in the middle of the night and go get a glass of water—with your bare feet on the cold kitchen floor. Sometimes a glass of water like that sits there for a few days. Unhealthy? Gross? Or is it actually not so bad?
Help from an expert
Quest went looking for the answer and enlisted the help of Frederik Hammes, who heads the drinking water microbiology department at a Swiss institute. He says that no scientific study has ever been conducted into the quality of drinking water that has been sitting on your bedside table for a few days. He does explain what is probably happening in that glass of water during the night(s).
House dust
The air is full of millions of dust particles invisible to us, consisting mainly of our own skin flakes and those of our loyal four-legged friends. There are also particles from household insects such as spiders, flies and mosquitoes. During the night, the water also absorbs carbon dioxide from the air, causing the pH level to drop slightly and making that nighttime sip taste just a little more acidic than it does during the day. All in all, not particularly appetizing, but it certainly isn’t dangerous.
No reason to panic
Tap water may be fresh, but it is not completely free of bacteria—good bacteria, admittedly, that won’t make you sick. And the ‘dirt’ from your own saliva at the rim of the glass is no reason to panic either—these bacteria are your own, after all, and you simply drink them again with the next sip. Whether bacteria grow that you would rather not drink is something that will first require further research. For now, Frederik says it will probably all be fine. Bacteria live on nutrients, and those are not present in large quantities in a glass of water.
So, you won’t get sick from drinking water that is a few days old. But according to Frederik, changing your glass every evening certainly can’t hurt.
Also read:
- Why you should clean your water bottle much more often than you already do
- Does hot water really boil faster?
- Why pasta water is worth its weight in gold
Source: Quest
