Quarry operators in Cornwall have joined a national safety campaign that warns of the dangers of unsupervised visits and potential hazards.

The campaign, launched as the weather warms and school holidays start, warns that every year, young people who venture into quarries unsupervised are killed or seriously injured.

Last summer, four teenage boys drowned in disused quarries in separate incidents across the UK.

Quarry operators in Cornwall, which has 24 active quarries producing 2 million tonnes of aggregates per year, are joining forces with the Mineral Products Association (MPA) to keep safety in the spotlight as part of its annual “Stay Safe” campaign.

The campaign will continue over the summer with school presentations and organised quarry visits across the UK.

“Stay Safe” is supported by the parents of teenagers who have died after entering a quarry uninvited. The teenagers who died were engaged in activities that they and their friends perceived as harmless fun when the fatalities occurred.

“If my son had understood the risk he was taking, he might still be with us today. It’s only through campaigns like Stay Safe that we’ll learn how to protect our kids from danger,” says Tracy Walker, whose 15 year old son Ryan drowned in a quarry in 2009 whilst swimming with his friends.

An April 2013 survey by the MPA showed that two thirds of the quarries responding in the South West had experienced problems with trespass in the last twelve months. The MPA survey also analysed the main motivations for trespass.

The most common was theft, usually of cables and fuel, at 55%. Other reasons included recreational activities such as walking (40%), trail and quad bike riding (23%), swimming (22%) wildlife spotting (15%) and rock climbing (8%).

“It is worrying enough that adults put their own lives on the line,” says Mineral Products Association (MPA) chief executive Nigel Jackson.

“But by breaking down fencing and engaging in these activities, they are clearly setting a dangerous example for young people. Through their thoughtless actions, they are potentially exposing young people to the dangers of industrial sites that they then treat as adventure playgrounds.”

The campaign highlights that even very strong swimmers can get into difficulty in the extremely cold or deep water often present in quarry lakes – with the added threat of falling rocks, concealed equipment, unexpected currents and pumps operating beneath the surface, and in some limestone quarries, the alkalinity of the water.

Face edges tcan give way suddenly, steep drops can be concealed by vegetation, and falling rocks and silt ponds, that can act like quick sand, create hazards for walkers and climbers, while unstable terrain and moving plant make quarries unsuitable for trial and quad bikes.

Mr Jackson, added: “I hope that parents, teachers and anyone working with young people can help us get the critical safety message across: please stay safe and stay out of quarries unless you are on a supervised visit.”