For context, I live in Hong Kong where most people drink tap water after boiling first. Some may install water filter but may still boil the water. Very few drink bottle water unless they're outside and too lazy to bring their own bottles.
Now, I'm researching whether I can drink tap water in Iceland (I'm going there in August), and while it looks like the answer is affirmative, almost no web article mention whether I need to boil the water first. People in Japan (a country I've visited a few times) also seems to be used to drink tap water directly without boiling.
The further I searched, the more it seems to me that in developed countries (like US, Canada and the above examples), tap water is safe to drink directly. Is that true? Do you drink tap water without boiling?
It sounds like a stupid question but I just can't believe what I saw. I think I experienced a cultural shock.
Edit: wow, thanks so much for the responses and sorry if I didnt reply to each one of you but I'll upvote as much as as I can. Never thought so many would reply and Lemmy is a really great community.
2nd Edit: So in conclusion, people from everywhere basically just drink water straight out of tap. And to my surprise, I checked the Water Supplies Department website and notice it asserts that tap water in Hong Kong is potable, like many well-developed countries and regions.
However, as the majority of Hong Kong people are living in high-rise buildings, a small amount of residual chlorine is maintained in the water to keep it free from bacterial infection during its journey in the distribution system. Therefore it is recommended to boil the water so that chlorine dissipates.
So, in short, I actually do not need to boil the water unless I hate chlorine smell and taste. But I guess I'll just continue this old habit/tradition as there's no harm in doing so.
Generally in the west (US/Canada, and most of Europe) tap water is safe to drink. I've been to Iceland and don't remember tap water being a concern. This is something you should double check before every trip though. A good rule of thumb is just going by how developed/rich the country is that you are visiting, with more developed countries usually having potable tap water but this is not a guarantee. (And some countries are far too large and diverse to apply this rule efficiently)
Also asking the locals is not necessarily a good idea either as there immune system might be accustomed to the different bacteria and pollutants in the water. For example drinking tap water in some places in the Middle-East might not be an issue for the locals but as I haven't grown up there I probably wouldn't risk drinking tap if I can avoid it, not to ruin the trip with getting sick.
TLDR: check with your country's official travel recommendations
Edit: someone mentioned bottleded water just being bottled tap water. While this is not uncommon in Europe (not sure about the rest of the world), the water does go through extra steps of filtering and cleaning meaning it might be a bit safer to foreigners.