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 After decades of decline, the prevalence of smoking in China has held steady in recent years. Coupled with population growth, this means there are now more smokers in China than ever, according to a new study on global smoking prevalence published this month in the Journal of the American Medical Association. 
 
 China gained almost 100 million smokers between 1980 and 2012, despite an overall decrease in smoking prevalence in the same period from 30.4 percent to 24.2 percent. But prevalence has plateaued, remaining nearly unchanged since 2006. Prevalence is defined as the percentage of the population that smokes every day, adjusted for age. 
 
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 Using a wide range of sources, including in-country surveys, government statistics and World Health Organization data, researchers also found that China had the highest number of smokers in the world in 2012 with 281 million, about one-third of the world’s smoking population. A report late last year by the state-run broadcaster CCTV put the number of smokers in China around 350 million. 
 
 The study, titled “Smoking Prevalence and Cigarette Consumption in 187 Countries, 1980-2012,” was conducted by researchers at the Seattle-based Institute for Health Metrics and Evaluation. The paper is among the first to produce a comprehensive global time series on smoking prevalence. 
 
 The findings are significant, said Judith Mackay, senior adviser to the World Lung Foundation, because they highlight the “absolute need for China to awake and really grasp the political nettle of tobacco control.” 
 
 “The study shows that the tobacco epidemic is going to be a whole lot worse before it gets better, particularly in lower income countries,” Dr. Mackay said in a telephone interview. “If they do nothing at all there are going to be massive costs for China in terms of premature deaths, health care costs, environmental costs, economic costs, family costs — there are all manners of costs.” 
 
 Substantial population growth and unchanging smoking prevalence in populous countries such as China, Bangladesh and Indonesia help explain why since 2006 the global decline in daily tobacco smoking has decelerated. 
 
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 The leveling off of smoking prevalence in China and globally can also be attributed in part to varying degrees of addictiveness. 
 
 “Change in tobacco prevalence typically has been slow, underscoring what a hard habit it is to break,” said Emmanuela Gakidou, professor of global health and director of education and training at the Institute for Health Metrics and Evaluation, in a news release. 
 
 The average number of cigarettes consumed daily per smoker in China has increased as well. According to the study, whereas the average smoker consumed about 15 cigarettes a day in 1980, by 2012 that number had risen to 22. 
 
 By contrast, four countries — Canada, Iceland, Mexico and Norway — reduced their smoking prevalence by more than half in the same period. Globally, the average number of cigarettes consumed per smoker per day declined from about 18 to about 17 in 2012. 
 
 The increase in number of smokers in China has taken place in spite of a number of measures enacted by the government in recent years to restrict smoking, which researchers say is among the leading risk factors for death in China. 
 
 These efforts have included a ban on smoking in restaurants and other public places as well as a directive issued in December urging Communist Party officials to quit altogether. But with no penalty for noncompliance, these measures are rarely enforced. 
 
 But while the overall number of smokers in China has increased, the skewed gender ratio of China’s smoking population has only become more pronounced. Only about 4 percent of smokers in China in 2012 were female, down from about 8 percent in 1980. That greater independence and improved economic conditions have not led to an increase in smoking among Chinese women — and Asian women more generally — is “puzzling,” said Dr. Mackay of the World Lung Foundation, considering that these factors have been associated with a rise in smoking among women in the West. 
 
 “It’s been surprising,” said Dr. Mackay. “But we are very thankful for that surprise.” ||||| Image copyright Getty Images Image caption A participant warms up for this year's Beijing Marathon, with a cigarette 
 
 A new study has warned that a third of all men currently under the age of 20 in China will eventually die prematurely if they do not give up smoking. 
 
 The research, published in The Lancet medical journal, says two-thirds of men in China now start to smoke before 20. 
 
 Around half of those men will die from the habit, it concludes. 
 
 The scientists conducted two nationwide studies, 15 years apart, covering hundreds of thousands of people. 
 
 In 2010, around one million people in China died from tobacco usage. But researchers say that if current trends continue, that will double to two million people - mostly men - dying every year by 2030, making it a "growing epidemic of premature death". 
 
 While more than half of Chinese men smoke, only 2.4% of Chinese women do. 
 
 The study was conducted by scientists from Oxford University, the Chinese Academy of Medical Sciences and the Chinese Center for Disease Control. 
 
 But co-author Richard Peto said there was hope - if people can be persuaded to quit. 
 
 "The key to avoid this huge wave of deaths is cessation, and if you are a young man, don't start," he said. 
 
 Analysis: Celia Hatton, BBC News, Beijing 
 
 Image copyright Getty Images Image caption A railway engineer smokes as he waits next to a coal-powered steam engine in Sichuan Province 
 
 In many parts of China, meals often fit a comfortable pattern. After putting down their chopsticks, men commonly push their chairs back from the table and light cigarettes. No wonder China has struggled to impose a smoking ban in public places. Here, relationships are often built amid clouds of smoke. 
 
 Expensive brands of cigarettes, often decorated with gold detailing on the cartons, are given as gifts. And ordinary brands are affordable to all but the very poor, costing just 2.5 yuan ($0.4; £0.25) a pack. 
 
 In a country where smoking is so ingrained in daily life, few understand the harmful effects of tobacco use. According to the World Health Organization, only 25% of Chinese adults can list the specific health hazards of smoking, from lung cancer to heart disease. 
 
 Perhaps it should come as no surprise, then, that only 10% of Chinese smokers quit by choice. Instead, most are forced to give up their cigarettes because they're too sick to continue. 
 
 The country that will not quit smoking 
 
 While smoking rates have fallen in developed countries - to less than one in five in the US - they have risen in China, as cigarettes have become more available and consumers richer. 
 
 China is the world's biggest consumer of cigarettes - one in three cigarettes smoked globally is in China - as well as the world's biggest tobacco producer. 
 
 More than 300 million people - about a quarter of the population - smoke, with the average smoker consuming 22 cigarettes a day. 
 
 Authorities have shown concern over the rise, with Beijing even introducing a public smoking ban. But efforts have been hampered by the habit's popularity, and its usefulness as a source of tax revenue - the government collects about 428bn yuan (£44bn, $67bn) in tobacco taxes each year. 
 
 Globally, tobacco kills up to half of its users, according to the World Health Organization.
– The world's biggest cigarette consumer is taking steps to stamp out smoking in indoor public spaces—and unlike earlier anti-smoking measures in China, officials say this one will be strictly enforced with clear penalties put in place, CNN reports. A third of all smoking worldwide takes place in the country, and "unless there is change in China, we won't proceed further in reducing the tobacco epidemic in the world," a senior adviser at the World Lung Foundation says. Smoking rates in China have dipped a little over the last few decades, but population growth means there are now more smokers in the country than even before, the New York Times finds. The average number of cigarettes smoked daily per smoker has actually risen since 1980, from 15 to 22. Unlike in other countries, however, greater independence has not caused an increase in smoking among Chinese women: Only around 4% of the country's smokers are female, down from 8% in 1980.