Evidence of the health risks of cigarette smoking go back to the 1950s. However, the percentage of cigarette smokers was at its peak in 1964, when the US surgeon general first issued an official warning that smoking cigarettes was hazardous to one's health.

Following the surgeon general’s formal warning about cigarette smoking, many reports were released on the link between cigarette smoking and heart disease, lung disease, and cancer of the mouth. However, the cigarette smoking habit continued, particularly with young smokers who were most likely smoking as a sign of rebellion and/or independence.

For adults, though, smoking cigarettes marked an addiction to nicotine - the key ingredient that makes cigarette smoking both pleasurable and addictive. This addiction to nicotine led to another warning from the surgeon general in 1988, which put nicotine addiction on the same level as addictions to cocaine and heroin.

The danger in cigarette smoking comes from the chemical substances released either as a gas or as a particulate. Nitrogen oxides, hydrogen cyanide and most especially carbon monoxide are gaseous emissions from cigarette smoke that threaten to poison the body.

Nicotine is one of several hazardous particulates emitted from smoking cigarettes. These particulates damage the cilia - the little hairs lining the lungs that help transport mucus out of the lungs. When the cilia malfunction, pollutants remain in the lungs and the likelihood of influenza and bronchitis, emphysema and other diseases increases.

Unfortunately, cigarette smoking has been cited as the cause of over 400,000 deaths in the US every year.

However, government agencies, scientists and health officials have also established that passive smoking, or second-hand smoke, also has negative effects on the human body. The National Center for Chronic Disease Prevention and Health Promotion has reported that over 4,000 chemicals are generated by second-hand smoke, with more than 50 of those believed to be cancer-causing agents.

In fact, in 1975, the Centers for Disease Control released a report noting that toxic chemicals released from cigarettes stay in the air and are inhaled by unsuspecting victims. Thus, the concern over cigarette smoking shifted from a private-health issue to a public-health issue.

For pregnant women, the negative effects of cigarette smoking and second hand smoke raises even more issues. Cigarette smoking and second-hand smoke increases the chances of low birth-weight and even miscarriage. And, children less than a year old are twice as likely to have lung infections if their mothers smoke cigarettes compared to counterparts whose mothers do not smoke cigarettes. Likewise, children who already have asthma, allergies or other respiratory ailments can worsen their conditions if their parents smoke cigarettes.

Over the years some cigarette smokers have gradually quit smoking cigarettes, while non-smokers have become the focus of more protection as the government has worked on policies and legislation to curb cigarette smoking.

In the 1990s, class action suits started to bombard state and federal courts, claiming that cigarette manufacturers employed deceptive marketing tactics to keep consumers from knowing that nicotine was addictive and worked on ways keep cigarette smokers hooked on their product.

More recent suits against the cigarette and tobacco industry charge manufacturers of also misleading consumers into thinking that "lights" and similar cigarette products were healthier alternatives to regular cigarettes. These more recent cases later led to the multi-billion dollar settlement between the US government and the cigarette and tobacco industry in the late 1990s.

These lawsuits and the consistency of health lobbyists and persuasive government programs have helped pull down US cigarette smoking rates on a consistent basis over the last four decades. With the health risks of cigarette smoking so abundantly clear, it is likely that these cigarette smoking rates in the US will continue to decrease.