What percent of US population is affected by secondhand smoking?

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Specifically, meta-analyses have shown lifelong non-smokers with partners who smoke in the home have a 20鈥?0% greater risk of lung cancer, and those exposed to cigarette smoke in the workplace have an increased risk of 16鈥?9%. A wide array of negative effects are attributed, in whole or in part, to frequent, long term exposure to second hand smoke. Some of these effects include:
Cancer:
General: overall increased risk; reviewing the evidence accumulated on a worldwide basis, the International Agency for Research on Cancer concluded in 2002 that "Involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) is carcinogenic to humans (Group 1)."
Lung cancer: the effect of passive smoking on lung cancer has been extensively studied. A series of studies from the USA from 1986鈥?003, the UK in 1998, Australia in 1997 and internationally in 2004 have consistently shown a significant increase in relative risk among those exposed to passive smoke.
Breast cancer risk is increased by 70% in younger, primarily premenopausal women. The California Environmental Protection Agency has concluded that passive smoking causes breast cancer and the US Surgeon General has concluded that the evidence is "suggestive," one step below causal.
Passive smoking does not appear to be associated with pancreatic cancer
Ear, nose, and throat: risk of ear infections
Circulatory system: risk of heart disease, reduced heart rate variability, higher heart rate
Lung problems:
Risk of asthma
Pregnancy:
Risk of premature birth
General:
Worsening of asthma, allergies, and other conditions
Risk to children
Risk of sudden infant death syndrome (SIDS)
Risk of developing asthma
Risk of lung infections
More severe illness with bronchiolitis, and worse outcome
Increased risk of developing tuberculosis if exposed to a carrier
Risk of allergies
Risk of Crohn's disease.
Risk of learning difficulties, although this may only be in children exposed before birth. Animal models suggest a role for nicotine and carbon monoxide in neurocognitive problems.
Overall increased risk of death in both adults, where it is estimated to kill 53,000 nonsmokers per year, making it the 3rd leading cause of preventable death in the U.S. and in children.

(I entered "passive smoking" into wikipedia.com database, all footnotes and citing is present if you need it)