As the article says, quenches sometimes happen.

Effects on the local population? You mean those who work there underground? Their voice may change pitch a little, but its only a temporary effect.

Helium is present in our atmosphere. And presumably on your birthday party when a balloon was popped.

Effects on the wider population?

A couple of delays and reorganizations at the surrounding hotels and restaurants.

Basically: the telephone will ring.

We know what helium and nitrogen gas do and what dangers they represent. We also know how much of them are in the LHC. The main danger is that both displace oxygen, so you can suffocate e.g. if a large amount of helium is released by a quench in a small room. But this isn't any danger to the surrounding area, there just isn't enough liquid helium or nitrogen in there.

Both gases are inert, so they really don't do anything else. There isn't anything to investigate here.

Don't you think the Swiss and French governments wouldn't have thought about safety almost 70 years ago?

Safety is an important part of the collaboration, which is evident when you work there.

This is evaluated by people who understand physics, chemistry, and biology, and it is the alternative science people that tend to not want to believe that and keep warning of dangers that don't exist.

It is good to always remain critical, but after a while you've used up all arguments to explain that the radiation in your microwave is not radioactive.

I guess the scary part is that they called it a leak instead of a hole. I am sure if I say there is a leak in my sock that some will start to worry.

> Don't you think the Swiss and French governments wouldn't have thought about safety almost 70 years ago?

This isn't an argument. 70 years ago France was conducting atmospheric nuclear tests that caused people and inhabited land to be exposed radioactive fallout.

France wasn't conducting atmospheric nuclear tests in Europe. So maybe officials were indeed thinking of safety, but with a hint (or a bucketload) of cynicism...

The was a small leak of helium within the instrument. Such incidents are completely unexceptional with superconducting magnets, and pose no risk to anyone outside the room where it happen, since both helium and nitrogen are about as inert as gases can get. I suspect it wouldn’t even have made the news if it hadn’t delayed the experiments.

You should really do some more extensive research about the possible harmful effects of your comments more carefully before posting.

This one is giving me a headache.

It’s just helium. Have you ever bought a helium balloon, the kind that float? This is the same stuff that’s in the balloon. It’s also used as a mixture gas by deep–sea divers. It's chemically completely inert; breathing it in doesn’t have any particular effect on the body. It’s harmless, unless you fill an entire room with it so that all the oxygen is displaced.

Are people really so scientifically illiterate that they immediately assume that if anything goes wrong with a complicated machine that it will be harmful to their health?

My guess is that people imagine that the high energy particle beam transforms the helium and nitrogen used to cool the magnets in radioactive gases that may be dangerous.

But the beam never colides with the gas deposits. The helium and nitrogen are used to cool the magnets that are used to bend the beam that travels inside a vacuum tube.

[And even if the beam colides with the gas deposits, I don't expect too much radioactive waste. Each particle in the beam has a lot of energy, but there are very few. This links https://public-archive.web.cern.ch/en/lhc/Facts-en.html says "trillions" ( 10^12 ?) of protons, but a glass of water has like 10^26 protons. A nuclear power plant has much more radioactive material and during normal operation produce much more collisions that can turn container radioactive.]

I’m not sure it’s safe to make that assumption. I really think people just hear the word “leak” and assume the worst.