London - Lucy, like most 18-year-olds, has been enjoying her new freedom as lockdown has eased. She has started gathering with friends in the park in North London.
But unlike teenagers from a previous generation she doesn’t smoke, and only drinks occasionally. Instead, she is a frequent user of nitrous oxide – or laughing gas – which she and her friends inhale from balloons. She has been since she was 15.
"Almost every party I’ve been to, people have been doing it or I have done it," she says. "It makes me laugh and feel light-headed and sort of light in my body. I like it."
She is not alone. As anyone who has walked round a park recently may have noticed, the paths and roads are littered with the tell-tale canisters. Seven centimetres long, they resemble large, silver bullets. They contain the gas which is released into a balloon. Suck the gas from the balloon and you get a high lasting about a minute.
From Hove on the South coast to Ilkley in West Yorkshire, the beaches and parks of Britain have become strewn with these steel bulbs (which are almost impossible to recycle) as youngsters emerge from lockdown. Determined to let off steam, but with few options to do so, many have turned to this cheap high, which costs about £1 (about R21) a go.
"I’d say every party I go to there are people doing it," says Phil, 17, also from London.
In 1998, three in ten 16 to 24-year-olds took drugs - last year it was just two in ten, according to the Office for National Statistics (ONS). Today’s teenagers are, mostly, better behaved than their parents were.
But the number of young people taking "nos" - pronounced "nos, short for nitrous oxide — or balloons, as teens call it (even if their grandparents may refer to it as "hippy crack") has shot up.
It was not even recognised as a drug back in the 1990s. Now, of the young people taking drugs, it is the second most popular after cannabis, taken by nine percent of them.
I ask Lucy if she worries about health implications. "I do worry about the risks as I’ve heard stories about people dying from doing it - something to do with their lungs, I think - but I don’t do it that much," she says. Some experts believe this nonchalance is misplaced.
Last week, leading pharmaceutical professionals, in an article on the British Medical Journal website, warned of the dangers of nitrous oxide use, deadpanning that it was ‘no laughing matter’.
Co-author Luigi Martini, chief scientist at the Royal Pharmaceutical Society, tells me: "People think it is laughing gas, so it must be safe. A lot of parents do not understand these things are dangerous."
How dangerous? In terms of the risk of dying - not very. Five people died in 2017 with nitrous oxide listed on the death certificate, according to the ONS, compared with 1 337 deaths relating to heroin and morphine and 637 relating to cocaine.
But these statistics should not lead us to dismiss nitrous oxide as harmless. Every year The Global Drug Survey interviews over 100 000 people worldwide to get a "feel" for trends in drug usage.
Of those who had used nitrous oxide in the past 12 months, 21 percent reported fainting. A far more worrying 3.4 percent reported persistent numbness or tingling, known as paraesthesia, in their hands or feet - still apparent ten days or so after taking it.
The heavier the user, the more likely they were to suffer this.