Police have issued a warning against the misuse of laughing gas canisters after an appeal revealed the extent of the issue in north Kent.

Several canisters, which contain the anaesthetic gas nitrous oxide, were discovered among the ducks at Bluewater’s popular nature trail last week, just days after a discarded box was found next to Gravesend’s Horn Yard Car Park.

Our sister paper, the Gravesend and Dartford Messenger, put out an appeal on Facebook to get an idea of how widespread the issue was in Dartford and Gravesham, and the response painted a bleak picture of the state of our streets, car parks, and public spaces.

People reported large numbers of the canisters being dumped in car parks at Crossways Business Park and Goals Soccer Centre in Dartford, as well as the gurdwara in Gravesend.

Among the public spaces affected are parks at Windmill Hill and St Gregory’s Crescent in Gravesend, and the canisters have also been littered near schools, nightclubs, and petrol garages.

Although it is sometimes taken as pain relief for dentistry or childbirth, nitrous oxide is also one of the most widely used recreational drugs in the UK, especially among young people.

It can cause dizziness and could be deadly if taken in large amounts over a short period of time. Police have urged people not to misuse it.

A spokesman said: “Nitrous oxide can be very dangerous. It can cause the user to lose awareness, become unconscious and collapse.

“It can also cause heart attacks as well as long-term health problems. The consumption of alcohol with nitrous oxide further increases dangers to the user.”

Sarah Crook, 39, from East Hill, runs Dartford Litter Pickers and said the problem was widespread.

She said: “We collect litter from different areas around Dartford each month and we always find these no matter where we are.

“It’s often quite a few of them in one area. We’ve collected them from Dartford Creek, anywhere people can congregate, like near schools and in alleys.

“We need to educate people to not dump litter in the first place.

“In my opinion these canisters are a small part of a bigger issue. I also think they need to be banned.”

Last week, Dartford council leader Cllr Jeremy Kite (Con) referenced the work of Dartford Litter Pickers when talking about one of his major aims for 2017 — keeping Dartford tidier.

The council is set to introduce a public space protection order (PSPO) later this year and the littering of legal highs is a major reason why.

Speaking about the implementation of a PSPO during a cabinet meeting earlier this month, Cllr Kite said: “Having to clear up shovels full of nitrous oxide canisters every morning is a horrendous thing to be doing in 2017.

“Quite apart from the damage I’m convinced it does to people’s health, this is behaviour that is simply not appropriate in a town centre, where you are inviting families.”

Gravesham council introduced its own PSPO last year, which covers parts of Gravesend town centre and identified legal highs as a problem its enforcement officers needed to clamp down on.

The order states: “Persons in the area will not discard items associated with new psychoactive substances known as legal highs in a public space.

“Such items include, but are not limited to, canisters containing or formerly containing nitrous oxide.”

The laughing gas canisters at Bluewater’s nature trail were reported last Thursday, during the half-term holiday when families would have been enjoying the attraction.

Half a dozen were found and a spokesman for the shopping centre was quick to assure visitors that the trail was regularly checked to ensure it was clear of litter.

“Safety of our guests is paramount at all times,” they said.

“The Nature Trail is incredibly popular with our guests and it is regularly patrolled and cleaned.”

Talk to Frank, the national drugs education service, offers advice on its website.

It states: “Nitrous oxide can cause dizziness or affect your judgement, which might make you act carelessly or dangerously and put you at risk of hurting yourself, particularly in an unsafe environment.

“It can cause unconsciousness, or death from lack of oxygen. This occurs when the available oxygen for breathing is effectively pushed out by the nitrous oxide.

“It can be hard to judge the amount to use safely.

“If you have too much you can end up fainting, having an accident or much worse.”