Second hand smoke or environmental tobacco smoke refers to the smoke emitted by the burning end of a cigar, cigarette or pipe and inhaled unintentionally by nonsmokers. It can also refer to the smoke exhaled by a smoking person and inhaled by another person who does not smoke.

Second hand smoke, environmental smoke or passive smoke is said to contain more than 4,000 chemicals, and more than 60 of them are believed to cause cancer, according to the U.S. National Toxicology Program and the International Agency for Research on Cancer. It is also one of the contributing causes of heart and lung diseases

Here are some of the most common health risks of secondhand smoke:

1. It increases the risk of nonsmokers to heart and lung diseases by 20 – 30 percent.

The inhalation of secondhand smoke has harmful effects to the cardiovascular and respiratory systems. It exposes nonsmokers to heart diseases and lung problems.

2. Inhaling secondhand smoke can bring immediate adverse effects on your blood and blood vessels. It also increases your risk of getting a heart attack or stroke.

The inhalation of second smoke can negatively affect the normal functioning of your circulatory and cardiovascular systems. Even a brief exposure to secondhand smoke can damage the lining of your blood vessels and cause blood platelets to become stickier, the U.S. Center for Disease Control and Prevention says.

3. It is harmful to children.

Secondhand smoke is harmful to children and it increases their risk to allergies, asthma, bronchitis, pneumonia, and ear infections. It is also believed to cause sudden death syndrome in infants.

Older children of smoking parents are also known to get sick more frequently than children of non smoking parents.

4. It is harmful to unborn babies.

Mothers who smoke while pregnant expose their infants to a higher risk of sudden death syndrome.

Secondhand smoke contains many compounds that can change the brain development pattern of the fetus. Most babies of smoking mothers are born with low birth weights. They are prone to infections and and they have weak immune systems. They are prone to develop lung and other diseases when they get older.

These are some of the most common health risks of secondhand smoke. You should avoid them to protect yourself from diseases caused by people around you.