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 litt

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.