Secondhand smoke causes many of the same diseases as direct<unk> , including cardiovascular diseases, lung cancer, and respiratory diseases. These diseases include: * Cancer: * General: overall increased risk; reviewing the evidence accumulated on a worldwide basis, the International Agency for Research on Cancer concluded in 2004 that "Involuntary<unk>  (exposure to secondhand or 'environmental' tobacco smoke) is carcinogenic to humans." The Centers for Disease Control and Prevention reports that about 70 chemicals present in secondhand smoke are carcinogenic. * Lung cancer:<unk>  is a risk factor for lung cancer. In the United States<unk>  smoke is estimated to cause more than 7,000 deaths from lung cancer a year among non-smokers. A quarter of all cases occur in people who've never smoked. * Breast cancer: The California Environmental Protection Agency concluded in 2005 that<unk>  increases the risk of breast cancer in younger, primarily premenopausal females by 70% and the US Surgeon General has concluded that the evidence is "suggestive", but still insufficient to assert such a causal relationship. In contrast, the International Agency for Research on Cancer concluded in 2004 that there was "no support for a causal relation between involuntary exposure to tobacco smoke and breast cancer in never-smokers." A 2015 meta-analysis found that the evidence that<unk>  moderately increased the risk of breast cancer had become "more substantial than a few years ago". * Pancreatic cancer: A 2012 meta-analysis found no evidence that<unk>  was associated with an increased risk of pancreatic cancer. * Cervical cancer: A 2015 overview of systematic reviews found that exposure to secondhand smoke increased the risk of cervical cancer. * Bladder cancer: A 2016 systematic review and meta-analysis found that secondhand smoke exposure was associated with a significant increase in the risk of bladder cancer. * Circulatory system: risk of heart disease, reduced heart rate variability. * Epidemiological studies have shown that both active and<unk>  cigarette<unk>  increase the risk of atherosclerosis. *<unk>  is strongly associated with an increased risk of stroke, and this increased risk is disproportionately high at low levels of exposure. * Lung problems: * Risk of asthma. * Risk of chronic obstructive pulmonary disease (COPD) * According to a 2015 review,<unk>  may increase the risk of tuberculosis infection and accelerate the progression of the disease, but the evidence remains weak. * The majority of studies on the association between secondhand smoke exposure and sinusitis have found a significant association between the two. * Cognitive impairment and dementia: Exposure to secondhand smoke may increase the risk of cognitive impairment and dementia in adults 50 and over. Children exposed to secondhand smoke show reduced vocabulary and reasoning skills when compared with non-exposed children as well as more general cognitive and intellectual deficits. * Mental health: Exposure to secondhand smoke is associated with an increased risk of depressive symptoms. * During pregnancy: * Miscarriage: a 2014 meta-analysis found that maternal secondhand smoke exposure increased the risk of miscarriage by 11%. * Low birth weight, part B, ch. 3. * Premature birth, part B, ch. 3 (Note that evidence of the causal link is described only as "suggestive" by the US Surgeon General in his 2006 report.) Laws limiting<unk>  decrease premature births. * Stillbirth and congenital malformations in children * Recent studies comparing females exposed to Environmental Tobacco Smoke and non-exposed females, demonstrate that females exposed while pregnant have higher risks of delivering a child with congenital abnormalities, longer lengths, smaller head circumferences, and low birth weight. * General: * Worsening of asthma, allergies, and other conditions. A 2014 systematic review and meta-analysis found that<unk>  was associated with a slightly increased risk of allergic diseases among children and adolescents; the evidence for an association was weaker for adults. * Type 2 diabetes. It remains unclear whether the association between<unk>  and diabetes is causal. *Risk of carrying Neisseria meningitidis or Streptococcus pneumoniae. *A possible increased risk of periodontitis. * Overall increased risk of death in both adults, where it is estimated to kill 53,000 nonsmokers per year, making it the third leading cause of preventable death in the U.S, and in children. The World Health Organization states that<unk>  causes about 600,000 deaths a year, and about 1% of the global burden of disease. As of 2017,<unk>  causes about 900,000 deaths a year, which is about 1/8 of all deaths caused by<unk> . * Skin conditions: A 2016 systematic review and meta-analysis found that<unk>  was associated with a higher rate of atopic dermatitis. Risk to children * Sudden infant death syndrome (SIDS). In his 2006 report, the US Surgeon General concludes: "The evidence is sufficient to infer a causal relationship between exposure to secondhand smoke and sudden infant death syndrome." Secondhand<unk>  has been estimated to be associated with 430 SIDS deaths in the United States annually. * Asthma. Secondhand smoke exposure is also associated with an almost doubled risk of hospitalization for asthma exacerbation among children with asthma. * Lung infections, also including more severe illness with bronchiolitis and bronchitis, and worse outcome, as well as increased risk of developing tuberculosis if exposed to a carrier. In the United States, it is estimated that secondhand smoke has been associated with between 150,000 and 300,000 lower respiratory tract infections in infants and children under 18 months of age, resulting in between 7,500 and 15,000 hospitalizations each year. * Impaired respiratory function and slowed lung growth * Allergies * Maternal<unk>  increases the risk of non-syndromic orofacial clefts by 50% among their children. * Prenatal and childhood<unk>  smoke exposure does not appear to increase the risk of inflammatory bowel disease. * Learning difficulties, developmental delays, executive function problems, and neurobehavioral effects. Animal models suggest a role for nicotine and carbon monoxide in neurocognitive problems. * An increase in tooth decay (as well as related salivary biomarkers) has been associated with<unk>  in children. * Increased risk of middle ear infections. * Invasive meningococcal disease. * Maternal exposure to secondhand smoke exposure during pregnancy is associated with an increased risk of neural tube defects. * Anesthesia complications and some negative surgical outcomes. * Sleep disordered breathing: Most studies have found a significant association between<unk>  and sleep disordered breathing in children, but further studies are needed to determine whether this association is causal. * Adverse effects on the cardiovascular system of children.
Passive smoking
Tobacco smoking
Sedentary lifestyle
Smoking
Modified risk tobacco product
Premorbidity
Occupational noise
Third-hand smoke