BOSTON (AP) - The level of nicotine that smokers typically consume per cigarette has risen about 10 percent in the past six years, making it harder to quit and easier to get hooked, according to a new report released Tuesday by the Massachusetts Department of Health. The study shows a steady climb in the amount of nicotine delivered to the lungs of smokers regardless of brand, with overall nicotine yields increasing by about 10 percent. Massachusetts is one of three states to require tobacco companies to submit information about nicotine testing according to its specifications and the only state with data going back to 1998. Public Health Commissioner Paul Cote Jr. called the findings "significant." The study found the three most popular cigarette brands with young smokers - Marlboro, Newport and Camel - delivered significantly more nicotine than they did six years ago. Nicotine consumed in Kool, a popular menthol brand, rose 20 percent, for example. Jennifer Golisch, a spokeswoman for Altria Group Inc.'s Phillip Morris USA, the nation's largest cigarette maker and manufacturer of Marlboro cigarettes, declined to comment. R.J. Reynolds Tobacco Co., manufacturer of Kool and Camel cigarettes, also declined. Reynolds is part of Reynolds American Inc. The study has always measured nicotine levels based on the way smokers actually use cigarettes, health officials said, for example by partially covering ventilation holes as they smoke and taking longer puffs. Traditional testing methods, which don't take real-life smoking habits into account, typically report lower nicotine contents, researchers said. "The amount of nicotine in a cigarette has increased steadily over the past six years," the department said, indicating in its reports that the smoking habits simulated had not changed in that period. Smokers who choose "light" brands hoping to reduce their nicotine intake are out of luck, according to the report that found for all brands tested in 1998 and 2004, there was no significant difference in the total nicotine content between "full flavor," "medium," "light," or "ultra-light" cigarettes. The finding means that health care providers trying to help smokers quit may have to adjust the strength of nicotine replacement therapies like nicotine patches and gums, according to Department of Public Health Associate Commissioner Sally Fogerty. Rep. Peter J. Koutoujian, D-Waltham, said the report shows tobacco manufacturers are trying to make keep smokers hooked. "As more and more people become aware of the dangers of smoking and the importance of quitting, we see products that are more addictive," said Koutoujian, who is backing bills banning the sale of flavored cigarettes and requiring tobacco manufacturers to provide scientific evidence that light cigarettes pose a lower health risk. Matthew Myers, president of the Campaign for Tobacco Free Kids, said the report "documents that the tobacco industry dramatically increased nicotine in secret ... even as Americans try to cut back on smoking." Smoking-related causes are blamed in the deaths of more than 9,000 Massachusetts residents each year and tobacco-related illnesses kill more people in the state than AIDS, car accidents, homicides, suicides and poisonings combined.