Millions of Americans smoke cigarettes—there's even a chimp who loves puffing on cigs. But as we should all well know, smoking isn't good for you, which is why the government is cracking down on smoking inside public housing. If the danger of cigarettes wasn't already clear, a new study spells it out even further: There is no safe level of smoking. Period.

A new study from researchers at the National Cancer Institute reported that even one cigarette a day can lead to early death. The study, published online by JAMA Internal Medicine, found that "low-intensity smoking over the lifetime was associated with a significantly higher risk of all-cause mortality, including deaths from lung cancer and cardiovascular disease. Former smokers who had consistently used fewer than one or one to 10 cigarettes per day but who had quit smoking had progressively lower risks with a younger age at cessation."

So what does that mean? The researchers concluded, "Individuals with lifelong, low-intensity smoking have higher mortality risks than those who never smoked and would benefit from cessation."

Even if you're only smoking a handful of cigarettes a week—averaging less than one cigarette per day—you have a 64 percent higher risk of earlier death than people who have never smoked. More specifically, those who averaged less than a cigarette a day were nine times as likely to die from lung cancer as never smokers.

Smoking between one and 10 cigarettes—a half pack or fewer—gives you an 87 percent higher risk of earlier death than never smokers. For that level of smokers, the risk of dying from lung cancer is 12 times higher than the risk for people who have never smoked. Compared to those who have never smoked, the group is six times more likely to die from respiratory diseases and roughly one and a half times more likely to die from cardiovascular disease.

The study's lead author, the National Cancer Institute's Dr. Maki Inoue-Choi explained, "Together, these findings indicate that smoking even a small number of cigarettes per day has substantial negative health effects and provide further evidence that smoking cessation benefits all smokers, regardless of how few cigarettes they smoke."

The study notes, "Tobacco smoking poses a major public health challenge around the world and has been estimated to cause 5 million deaths per year globally." In our country alone, according to the Centers for Disease Control and Prevention, cigarette smoking is the leading cause of preventable death, killing nearly 500,000 Americans each year.

Fortunately, though, smoking is on the decline in America. According to the New York Times, the number of Americans who smoke cigarettes has fallen below 40 million for the first time since the record keeping started 50 years ago. In 2005, there were 45.1 million smokers in America, and in 2015 that was down to 36.5 million. In that same decade, the percentage of Americans who smoked cigarettes dropped from 21 percent to 15 percent—thanks to significant declines in smoking across the board.