He noted that 80 per cent of people who had taken a "mystery white powder" were already drunk or on drugs when they did so.
"The worry here is the huge variation in what those powders could be – from mephedrone to ketamine to cocaine. You don't know what that's going to do to you or how long the effects are going to last."
The proportion of people who had taken substances without knowing what they were could also be explained by how cheap and readily available club drugs are in the UK, Dr Winstock said.
"When drugs are fairly cheap and there's no problem in getting them, people are much more likely to offer them round," he said. "You probably won't be doing that in New Zealand because they are so expensive."
The Global Drugs Survey also showed more people were buying drugs online than ever before, with cannabis, MDMA and LSD the most popular worldwide.
A spokesperson for the UK drug and alcohol treatment charity Addaction marked this out as a particularly worrying trend.
"If you buy from a dealer, in a way there's a trust there, because it's not in their business interests to make you sick or give you something you didn't expect," he said. "When you buy online that goes out the window."
In terms of alcohol use, the poll found Brits were the most likely in the world to be aware of governmental guidelines, with 80 per cent of us knowing how much we are supposed to drink, compared to 45 per cent globally.
But it also suggested people from the UK were the second most likely to come into work with a hangover in the world – with 46 per cent of us admitting to doing so – behind only Ireland, with 50 per cent.
Source : http://telegraph.feedsportal.com/c/32726/f/568612/s/3963f4ac/sc/8/l/0L0Stelegraph0O0Cmen0Cthe0Efilter0C10A7677210CWhy0Eare0EBrits0Eso0Ereckless0Ewhen0Eit0Ecomes0Eto0Edrugs0Bhtml/story01.htm