Smoking

in Science

ImageSmoking is “hateful to the nose, harmful to the brain, and dangerous to the lungs.” This was the view of England’s king James I in 1604. For long afterward, smoking was considered harmless. Today, more and more people agree with King James.

TOBACCO AND NICOTINE

Smoking means breathing the smoke of burning tobacco leaves. Tobacco is a plant.

Tobacco is processed for smoking in different ways. People smoke tobacco in pipes, cigars, and cigarettes.

Tobacco smoke contains about 4,000 chemicals. One of them is nicotine. In large amounts, nicotine is a poison. In small amounts in the human body, nicotine stimulates the nerves. It makes the heart beat faster.

Nicotine is highly addictive. This means that smokers become dependent on its effect as a stimulant. When this effect wears off, the body strongly desires more. That is why people who smoke find it hard to stop.

HISTORY

Native Americans smoked tobacco as long as 2,000 years ago. Explorer Christopher Columbus saw them smoking in 1492. His crew brought tobacco to Europe. European sailors spread it around the world. Some people believed then that smoking could cure diseases. By 1600, people smoked mainly for enjoyment.

Cigarettes were invented in Europe. They did not become popular until the 1800s. They were expensive because people had to make them by hand. Then a cigarette-rolling machine was invented.

In the 1940s, doctors began to notice connections between smoking and lung cancer and other diseases. They began to study the chemicals in cigarette smoke. Many of these chemicals were found to cause cancer. A group of scientists prepared a report for the United States government in 1964. The report declared cigarette smoking to be a serious health danger.

Since then, smoking in the United States has greatly declined. Health warnings appear on cigarette packages. Smoking is banned on most airline flights. It is banned from many offices and public places.

SMOKING AND HEALTH

Cancer experts say that cigarettes kill hundreds of thousands of Americans every year. Lung cancer kills more Americans than any other kind of cancer. Smokers are 20 times more likely than nonsmokers to develop lung cancer.

Smokers also are at greater risk for other forms of cancer and other lung diseases. Mothers who smoke can injure the health of their babies.

Quitting smoking greatly lowers the chances of dying from diseases caused by smoking.

Source: Microsoft ® Encarta