SINCE the smoking ban was introduced in Scotland 12 years ago, cigarette smokers have been prohibited from lighting up everywhere from bars, restaurants, and trains to hospital grounds and most recently private cars carrying children.

But one of the few premises exempt under a legal loophole are Scotland's historic bothies - and some hillwalkers say it is ruining their experience of the great outdoors.

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Dave Monk, a New Zealander who now lives Ballater in Aberdeenshire, said he was shocked to discover that smoking is legal within the shelters after an outing in August with his wife and sons, aged 10 and 11, was ruined by another rambler's tobacco fumes.

HeraldScotland: Dave Monk, pictured with son Dylan, outside a bothy on a previous outing

Mr Monk, 40, and his family had pitched up at the Bob Scott's bothy in the Cairngorms after a one and a half hour hike and planned to spend the night.

He said: "We had taken our kids to this bothy and we had been there about an hour.

"We'd set ourselves up, kids had got their sleeping bags out, then these five guys arrive - one of whom proceeded to smoke in the bothy, next to where our kids sleeping bags were.

"They were literally being saturated by this guy's cigarette smoke.

"I said 'surely that's illegal?' and they said 'no, it's not illegal at all and we can smoke in bothies if we want to'. We ended up packing up and making a hasty retreat.

"I've asked around and others have had similar experiences. We've got a friend who's a GP who had the same experience with her kids earlier in the year - she left because of smoking in the bothy."

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Mr Monk said the current rules seemed bizarre.

He said: "To me, it's a public space. A bothy is open for anybody to go and spend the night in, so if it's a public location surely it should be included in the legislation? The fact that it isn't, for me, is a loophole.

"The smoking really detracted from the experience. In a sense it's paradoxical to the clean, fresh air approach that you would expect from getting outdoors as a family."

Bothies - described as "camping without a tent" - are mostly old cottages that historically provided accommodation for itinerant farm workers.

Today, many lie unlocked with the permission of the landowner and are open to hillwalkers use as a shelter with no need to book and no charge.

They are scattered across the Highlands, Borders and southern Scotland but facilities are basic - no running water, toilets, or beds.

When legislation for the smoking ban was drawn up there was fierce debate among the hillwalking community over whether the "enclosed space" rule should apply to bothies.

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In the end, a loophole categorising them as a residential dwelling means they remain exempt.

Neil Stewart, a spokesman for the Mountain Bothies Association, a charity which maintains around 100 bothies, said a ban would be much trickier to enforce compared to commercial premises.

He said: "Our view is that any ban, were Parliament to introduce one, would be very difficult to enforce. This is because bothies are open shelters, there is no booking system, no warden, and no record of who has visited.

"And as the MBA does not own any bothies - apart from one in the Scottish Borders - any restriction would be a matter for the owner to enforce, not the MBA. The MBA is a bothy maintenance organisation, not an accommodation provider."

However, Mr Stewart said the MBA did advocate "good bothy etiquette" with regard to other users, the building and the environment.

He added: "We would hope that that respect includes taking into account the wishes of others with regard to smoking within the confines of the bothy."

Exposure to second-hand smoke is associated with an increased risk of lung cancer, stroke, childhood asthma, food allergies, cervical cancer and meningococcal disease in children.

Sheila Duffy, chief executive of health charity ASH Scotland, said: “Bothies are a shared resource that rely on a community spirit and respect for others. Tobacco smoke is avoidable air pollution.

"I'd ask anyone who smokes to show respect for others and take it right outside, and for those who own or are in charge of bothies to embed this expectation in their information and codes.

"This would help keep these vital shelters accessible to the next generation of hillwalkers and climbers.”

A spokeswoman for the Scottish Government said: “Bothies are not covered by the smoking ban legislation but we would always encourage the owners of bothies or those in charge of them to impose their own smoke-free policies.