Secondhand Smoke

My friends and I were chatting and somehow our topic drifted to smoking and secondhand smoke. This topic got me very interested because my friend's uncle just got diagnosed with last stage of lung cancer. He is a very healthy man who doesn't drink or smoke, and yet he got last stage lung cancer.

So I went online and searched for lung cancer and this is what I found:

Secondhand smoke (also called environmental tobacco smoke) is the combination of sidestream smoke (the smoke given off by the burning end of a tobacco product) and mainstream smoke (the smoke exhaled by the smoker). Exposure to secondhand smoke is also called involuntary smoking or passive smoking.

Of the more than 4,000 chemicals that have been identified in secondhand tobacco smoke, at least 250 are known to be harmful, and 50 of these are known to cause cancer. These chemicals include:
arsenic (a heavy metal toxin)
benzene (a chemical found in gasoline)
beryllium (a toxic metal)
cadmium (a metal used in batteries)
chromium (a metallic element)
ethylene oxide (a chemical used to sterilize medical devices)
nickel (a metallic element)
polonium–210 (a chemical element that gives off radiation)
vinyl chloride (a toxic substance used in plastics manufacture)

The U.S. Environmental Protection Agency (EPA), the U.S. National Toxicology Program (NTP), the U.S. Surgeon General, and the International Agency for Research on Cancer (IARC) have classified secondhand smoke as a known human carcinogen (cancer-causing agent).

Inhaling secondhand smoke causes lung cancer in nonsmoking adults. Approximately 3,000 lung cancer deaths occur each year among adult nonsmokers in the United States as a result of exposure to secondhand smoke. The Surgeon General estimates that living with a smoker increases a nonsmoker’s chances of developing lung cancer by 20 to 30 percent.

Secondhand smoke causes disease and premature death in nonsmoking adults and children. Exposure to secondhand smoke irritates the airways and has immediate harmful effects on a person’s heart and blood vessels. It may increase the risk of heart disease by an estimated 25 to 30 percent . In the United States, secondhand smoke is thought to cause about 46,000 heart disease deaths each year.
Children exposed to secondhand smoke are at an increased risk of sudden infant death syndrome (SIDS), ear infections, colds, pneumonia, bronchitis, and more severe asthma. Being exposed to secondhand smoke slows the growth of children’s lungs and can cause them to cough, wheeze, and feel breathless.