KEY POINTS:
Smoking just one cigarette will leave one in four New Zealand children with symptoms of addiction, a ground-breaking research report has found.
And teenage girls are at greatest risk, according to the New Zealand-based survey of almost 100,000 14- and 15-year-olds.
Of respondents who smoked at least one cigarette, 50 per cent went on to become smokers. After smoking 10 cigarettes, more than 80 per cent of children became regular smokers.
After 100 cigarettes, 95 per cent went on to become regular smokers.
Tobacco cravings were reported by 46 per cent of those smoking less than one cigarette each month, while each subsequent cigarette meant a further slide towards addiction.
The study also identified that symptoms of tobacco addiction occurred earlier in girls than boys.
Christchurch cigarette researcher and public health specialist Dr Murray Laugesen, who with Auckland University's Professor Robert Scragg and American researchers Dr Robert J Wellman and Professor Joseph Difranza was responsible for the report, said teenage girls' increased danger of addiction was related to estrogen, the hormone responsible for sexual maturity in females.
Estrogen increased blood levels of nicotine, making the substance more addictive to females, he said.
"And that's not well known. It's a hormonal effect."
But the study's most startling discovery was new evidence of the danger even low levels of cigarette smoking posed to children.
"We knew cigarettes were addictive. But what is new is we have related the addiction to the number of cigarettes. And that hasn't been done before," Dr Laugesen said.
With tobacco smoking projected to cause almost 5000 early deaths annually for the next 30 years, banning tobacco displays would be a good first step in tackling the problem, he said.
That suggestion had been debated over the last year, with Waikato District Health Board - one of the country's biggest - last week calling for a complete ban on the displays.
In a submission to the Ministry of Health, WDHB chief executive Craig Climo said the displays undermined and contradicted health messages, endangered children and young people visiting the retail outlets, and discouraged smokers' quit attempts.
The Ministry was also last week presented with a submission from a coalition representing more than 170 convenience stores and tobacconists, requesting the Government drop proposals to ban the displays.
In its submission, the Stay Displays Coalition of Retailers rejected claims tobacco displays made people take up smoking.
Dr Laugesen admitted the issue was a "hot topic" but said it was "near the goal line already, and this may give it a final push".
A specific warning to youth on cigarette packets could also help lower the uptake rate, he said.
However, children would always be able to find tobacco as long as it was being sold in shops, he said.
"All smoking households are cigarette distribution centres as far as young people are concerned. So are older brothers and sisters, school buses, schools.
"Parents cannot protect their children from smoking. There is a case to consider the elimination of all sales over the next 10 years."
WHAT THE STUDY SHOWS
* 38 per cent of New Zealand 14- 15-year-old smokers smoke daily.
* Signs of addiction are present in 25 per cent of young smokers after the first cigarette.
* Each subsequent cigarette decreases ability of smoker to quit.
* Even irregular tobacco use is linked to addiction.
* Addiction symptoms appear earlier in girls, than boys.
WHAT THE STUDY DID
* Interviewed almost 100,000 New Zealand smokers, aged 14 and 15, from 350 high schools, between 2002 and 2004.
* Collected data on demographics, tobacco use and addiction indicators.
* Compared amount of tobacco use, with symptoms of addiction.
