As public health officials mark the 50th anniversary of the first US Surgeon General’s report warning about the health hazards of smoking, some have pointed out that although we’ve come a long way in reversing our nation’s addiction to nicotine, we still have a long way to go.

One particularly alarming concern: certain brands of cigarettes have increased the amount of nicotine they deliver, potentially rendering them more addictive. That’s the finding of a study released by the Massachusetts Department of Public Health and University of Massachusetts Medical School this week.

The research relied on data provided to the state by four major cigarette manufacturers from 1997 to 2012, as required by state law, and was published online Monday in the journal Nicotine and Tobacco Research.


While the researchers found that the nicotine content in cigarettes remained fairly steady in recent years, the average amount of nicotine delivered from puffing on the products rose from 1.65 milligrams per cigarette in 1999 to a peak of 1.89 mg per cigarette in 2011. That 15 percent increase could have resulted from a redesign of some cigarette brands, increasing the efficiency of nicotine delivery, said study leader Thomas Land, director of the Office of Health Information Policy and Informatics at the State Health Department. For example, manufacturers might have altered the filter or length of their products.

“Young people could have an easier time becoming addicted to cigarettes the first few times they do smoke,’’ Land said.

While our nation’s smoking rate has dropped by half over the decades—43 percent of Americans smoked in 1965 compared to 18 percent today—the decline seen in adolescent smoking rates has slowed through the years.

Each day, 3800 American teens try their first cigarette and 1000 become hooked, according to a 2012 Surgeon General’s report. Those who are unable to quit as adults will die, on average, 13 years earlier than their peers.

The new study found that when measured in smoking machine experiments, three cigarette manufacturers—RJ Reynolds, B&W (now part of RJR), and Philip Morris—all produced brands with higher nicotine yields in 2012 compared to 2005. RJ Reynolds and B&W had the biggest increases. Lorillard was the only manufacturer to produce products with a lower nicotine yield.


RJ Reynolds and Philip Morris declined to comment on the study finding. Philip Morris spokesperson Brian May said the company provides “a significant amount of information about cigarette design and manufacturing’’ to the US Food and Drug Administration, which has been regulating cigarettes since 2009. “The FDA is currently funding several scientific studies related to nicotine,’’ May added, “and we will share our perspective, as appropriate, as part of the regulatory process.’’

Previously, both cigarette makers have argued that changes in their nicotine yield had to do with year to year agricultural variations that may have produced tobacco crops with more concentrated levels of nicotine, depending on the amount of rainfall, for example.

If that were the case, Land said, “we would have seen a similar trend of increased nicotine yield for all cigarette makers since they tend to buy their tobacco from the same regions. We did not.’’

A 2007 analysis from the Harvard School of Public Health found that cigarette manufacturers increased nicotine levels in their products by close to 11 percent between 1997 and 2005. While industry executives disputed the analysis at the time, nicotine concentrations in most brands have remained fairly level since then.

The FDA has not yet moved to set limits on the amount of nicotine allowed in each cigarette, nor on a maximum amount of nicotine yield. The federal law allows the FDA to set new regulations to lower nicotine content as long as the chemical isn’t banned altogether, FDA spokesperson Jenny Haliski said, and the yield per inhale remains above zero.