Persons with health problems

Tissues that are already weakened and an impaired immune system react much more sensitively to the harmful substances found in tobacco smoke. The result: the progression of diseases can worsen, and new health problems may arise..

Who is particularly at risk​?

People with respiratory diseases (asthma, chronic obstructive pulmonary disease – COPD) or cardiovascular conditions are particularly vulnerable to secondhand smoke. Exposure to smoke increases :

  • the frequency and severity of crises in people with asthma
  • decline in lung function in people with COPD
  • the risk of heart attack and stroke in people with pre-existing cardiovascular disease
  • systemic inflammation, making people with respiratory or cardiovascular diseases more susceptible to other pathogens (e.g. COVID).

These effects are attributable to the presence of numerous toxic and irritating substances in tobacco smoke, such as benzene, formaldehyde, fine particles, acrolein, tobacco-specific nitrosamines (TSNAs), and polycyclic aromatic hydrocarbons (PAHs). These substances are irritants, promote inflammation, and—in some cases—are carcinogenic. In individuals with pre-existing tissue damage—for instance, in the airways or blood vessels—they can penetrate more easily and cause even more severe damage.

Clear scientific evidence

  • A study by OHSU (Oregon Health & Science University, US) shows that mice chronically exposed to secondhand smoke develop cognitive impairments, metabolic changes in the brain, and weight loss—particularly in males. This suggests heightened sensitivity among individuals already suffering from neurological disorders (Raber et al., 2021).
  • A US cohort study involving over 70,000 never-smokers shows that those with long-term exposure to secondhand smoke during childhood have a 31% higher risk of death from COPD in adulthood (Diver et al., 2018).

For people with pre-existing conditions, secondhand smoke is particularly dangerous.

Even small amounts of tobacco smoke can:

  • aggravate existing conditions
  • further weaken the immune system
  • significantly increase the risk of serious secondary illnesses

Avoiding all exposure to tobacco smoke protects people and is an essential step towards better health and a better quality of life.

Learn more

To learn more:

  • Costantino, S. et al. (2024). Association between Second-Hand Exposure to E-Cigarettes at Home and Exacerbations in Children with Asthma. Children, 11(3), 356. https://doi.org/10.3390/children11030356
  • Diver, W. R., Jacobs, E. J., & Gapstur, S. M. (2018). Secondhand Smoke Exposure in Childhood and Adulthood in Relation to Adult Mortality Among Never Smokers. American journal of preventive medicine, 55(3), 345–352. https://doi.org/10.1016/j.amepre.2018.05.005
  • Öberg, M. et al. (2010). Global estimate of the burden of disease from second-hand smoke. Weltgesundheitsorganisation. WHO-Link
  • Raber, J., Perez, R., Torres, E. R. S., Krenik, D., Boutros, S., Patel, E., Chlebowski, A. C., … Kisby, G. (2021). Effects of chronic secondhand smoke (SHS) exposure on cognitive performance and metabolic pathways in the hippocampus of wild‑type and human tau mice. Environmental Health Perspectives, 129(5), Article 057009. https://doi.org/10.1289/EHP8428