It's common knowledge that smoking is bad for your health - but it's not just people with heavy habits who could be puffing their way towards problems. This year's No Smoking Day is urging part-time smokers to quit too. Abi Jackson reports.

Every year since the mission began in 1983, No Smoking Day has been rallying smokers to stub out for good.

Last year's efforts encouraged a million people to quit, and the British Heart Foundation (BHF; the charity merged with the campaign in 2011) is hoping to inspire even higher numbers this year.

But it's not just those with 40-a-day habits being targeted; the campaign wants to shift the focus this year to include part-time and social smokers. Because while the last few decades have seen a wealth of research highlighting the dangers of being a heavy smoker, the increased risk of certain cancers being most notable, there's been very little emphasis on 'light' smokers.

A recent study, published this year in the Smoking In Britain journal, looking at non-daily smoking and common misconceptions, revealed that awareness of potential health risks of part-time smoking is low.

Only a quarter (25%) of the non-daily smokers surveyed said they were worried that cigarettes might be damaging their health, while the significant majority weren't concerned.

Dr Mike Knapton, the BHF's associate medical director, isn't surprised by the findings.

"People often think, including some doctors actually, 'Well, if you only smoke a bit, it's not going to do you too much harm'," he says. "Part of that's driven by the lack of evidence; most research is done on people who smoke more.

"We don't say enough about part-time smoking."

There may be less data on the health risks of part-time smoking, but that doesn't mean none exists.

A major 2005 study, which followed thousands of men and women from the Seventies through to 2002, looking at the consequences of smoking between one and four cigarettes a day, revealed heart disease deaths were three times higher than in people who didn't smoke at all.

These two studies alone are cause for concern for the BHF. "I think we can say with confidence that one, there is damage being done [if you're a part-time smoker], and two, awareness of that is pretty low," says Knapton. "So this is an important message to get out there."

There may be 'guidelines' for sensible consumption levels for alcohol, for instance, but when it comes to smoking, Knapton's view is clear - there is no such thing as a 'safe' lower limit.

"An unequivocal no," he says. "There's no safe limit as far as we're aware."

There are 1.1 million part-time smokers in the UK. The non-daily smoking survey also found that just one in seven (15%) of them feel they're addicted to cigarettes, compared to one in three daily smokers.

Nicotine is a highly addictive substance though, and whether or not somebody experiences powerful physical cravings, smoking can be a very tough habit to break.

"It becomes a social or psychological habit too - you have a cup of tea and a cigarette, for instance, and that becomes difficult to change over time," notes Knapton.

Reasons for part-time smoking vary. Some say it's a stress reliever, or to help them cope with they're anxious. For many, it's a social thing - lighting up with colleagues during a work break, joining in with other smokers on a night out; having something to hold and 'do' can be a comfort in itself.

Despite the low number of 'light' smokers admitting to health worries, two in five (40%) said they've tried to quit in the past year.

Clare Skidmore, 30, had been a social smoker since she was 18, before finally managing to quit as a New Year resolution.

Though she never felt physically addicted to the point of craving cigarettes daily, she'd often light up with friends and colleagues during work breaks and find herself chain-smoking on a Saturday night out.

"For me, it was certain situations where it just became a habit," she explains. "Like after a meal or out with friends. The thing is though, I never really enjoyed smoking, but I did it anyway, and over time, it just became more and more of a habit."

While serious long-term health worries often weren't at the front of her mind, Skidmore did notice the cigarettes taking their toll.

"After a night out, I'd always wake up with a horrible sore throat and really husky voice, and I was getting more and more throat infections. It reached a stage where I just kept thinking, 'Why am I doing this?'"

She says she feels much better in herself now that she's stopped smoking completely; as well as having far less sore throats, she also doesn't have to deal with the constant nagging guilt, and that's a weight off her mind.

Skidmore's a prime example though of how a casual weekend habit can eventually turn into something bigger. All smokers - even those who light up just a few times a week - run the risk of developing a heavier habit further down the line, Knapton stresses, and he also sees first-hand the impact part-time smoking's having on younger people.

"Smoking increases your risk of acute respiratory infection as it reduces your ability to fight off viral illnesses," he says. "As a GP, I see a disproportionate level of younger people coming into the surgery with these infections, and they've taken their toll in a way that perhaps they wouldn't in somebody who doesn't smoke at all."

People who smoke, he adds, also tend to report being more breathless, particularly during exercise - and this could potentially be another negative health factor in itself for some, if it puts them off or prevents them from being active.

As Skidmore also shows though, it is possible to quit - and that's the key purpose of No Smoking Day.

The campaign's 'V for Victory' theme is purposefully upbeat and positive, because this is what's most likely to help people feel motivated to quit.

"It's not about demonising smokers," says Knapton. "We know it's not easy to quit, but there's lots of support out there and we're urging people to try and quit on March 12.

"But I think it's important to say to everyone, 'Don't get despondent if you don't succeed at first', most people need a few quit attempts before they finally get there, and No Smoking Day is part of an annual round of dates people can use as a motivator.

"So long as you're moving in the right direction, you're on the right track."

Get set to stub out

:: NHS Smokefree offers a range of support services for anybody wishing to quit smoking. Ask your GP for information or visit www.nhs.uk/smokefree

:: Focus on positive reasons for wanting to quit - like other ways you can enjoy the money you'll save, being less out of breath when you exercise and being in good health for your kids or grandchildren - positive motivation has far higher success rates.

:: Remind yourself regularly why you're making the effort - for example, sticking photos on the fridge can be a great trick, whether that's snaps of your loved ones or that dream holiday you could afford with the £££s saved not buying cigarettes.

:: Tell your friends and family; their support could really help.

:: Don't give up giving up! It doesn't matter if it takes lots of attempts - you'll get there eventually.

:: No Smoking Day is March 12. For more information visit www.nosmokingday.org.uk