By Jason Szep
Boston - The amount of nicotine that smokers typically inhale per cigarette rose by 11 percent from 1998 to 2005, perpetuating a "tobacco pandemic" that makes it harder for smokers to quit, a Harvard study said on Thursday.
Harvard School of Public Health researchers analyzed data submitted by major cigarette brands to the Massachusetts Department of Public Health, which in August released its own study showing nicotine levels steadily rising.
The amount of nicotine that smokers typically consume per cigarette regardless of brand per year rose by an average of 1,6 percent between 1998 and 2005, according to the Harvard analysis of the state's health records.
Massachusetts has required tobacco companies to submit annual reports on cigarette nicotine yields since 1997, longer than any US state.
"Cigarettes are finely tuned drug delivery devices designed to perpetuate a tobacco pandemic," said Howard Koh, the school's associate dean for public health practice and former Massachusetts commissioner of public health.
To boost amounts of nicotine inhaled by smokers, cigarette makers intensified the concentration of nicotine in their tobacco and modified cigarette designs to increase the number of puffs per cigarette, the Harvard researchers said.
"The end result is a product that is potentially more addictive," the study said.
Nicotine yields rose in cigarettes of each of the four major manufacturers and across all major cigarette market categories N from mentholated and non-mentholated to full-flavored, light and ultralight, the study said.
Tobacco industry officials were not immediately available to comment. Phillip Morris, part of Altria Group Inc and the largest cigarette maker, has said nicotine levels fluctuate from year to year but there has been no steady increase.
The most recent federal tobacco tax figures showed that the number of cigarettes sold in the United States fell in 2005 to the lowest level in 55 years, dropping 4,2 percent from 2004, the largest one-year percentage decrease since 1999.
That continued an eight-year decline in cigarette smoking since the 1998 Master Settlement Agreement between US states and the tobacco industry that settled state lawsuits over the costs of treating smoking-related illnesses.
"Our findings call into serious question whether the tobacco industry has changed at all in its pursuit of addicting smokers since signing the Master Settlement Agreement," said Gregory Connolly, director of the Harvard School of Public Health's Tobacco Control Research Programme.
He said tobacco companies had failed to warn consumers about rising levels of nicotine since the 1998 settlement, urging US states to step up scrutiny of the industry.
The major companies that signed the agreement are Philip Morris, a unit of Altria Group Incorporated; RJ Reynolds Tobacco Holdings Inc; British American Tobacco Plc's Brown & Williamson unit; and Lorillard, which trades as Carolina Group and is part of Loews Corporation.
The study received funding from the American Legacy Foundation and the National Cancer Institute.
The US Centres for Disease Control and Prevention considers cigarette smoking the leading preventable cause of death in the United States. About 440 000 people die each year from lung cancer and other diseases related to tobacco use.