The Massachusetts Department of Health recently reported that nicotine levels in cigarettes have risen steadily in recent years, but tobacco firm Philip Morris USA said that nicotine levels in its products have fluctuated from year to year, the Associated Press reported Sept. 11.

"There are variations in the nicotine yield for different Marlboro packings, both up and down from year-to-year, but there is no general trend up or down," the company claimed, saying the variations "occur as part of the normal processes of growing tobacco and manufacturing cigarettes."

But Massachusetts Department of Public Health spokesperson Donna Rheaume responded: "We stand by our study which was based on data supplied by the tobacco companies." State officials said their testing method closely mimics how smokers actually use cigarettes, but Philip Morris said the state's machine-testing methods were flawed.

However, a Philip Morris spokesperson refused to answer when asked by a reporter if the company adds nicotine to its cigarettes. In a landmark court ruling last month, U.S. District Judge Gladys Kessler stated that tobacco companies "manipulated the use of nicotine so as to increase and perpetuate addiction."