Secondhand Smoke

March 22, 2017

Secondhand Smoke

What is secondhand smoke?

Secondhand smoke is the smoke you are exposed to when someone nearby is smoking. It includes the smoke exhaled by the smoker, and the smoke given off directly by the burning tobacco.

In the U.S., cigarettes are the main source of secondhand smoke. Pipes, cigars, and other methods of smoking tobacco can also give off secondhand smoke. A single cigar can create as much secondhand smoke as a whole pack of cigarettes.

If you’re in an area where other people are smoking, you’re being exposed to secondhand smoke. You may breathe in secondhand smoke in bars, restaurants, or other public places. And you may breathe it in at home, at your workplace, or in a car.

Tobacco smoke is a mixture of gases and particles. It is filled with many chemicals that can harm your health. Being exposed to the smoke increases your risk of lung diseases, certain types of cancer, and other health conditions. Even contact with a small amount of secondhand smoke can cause problems.

Millions of Americans are exposed to secondhand smoke every year. This includes many young children. Children are more vulnerable to the effects of secondhand smoke.

In recent years, exposure to secondhand smoke has lessened. This is because smoking has been banned in many public places. Also, fewer people smoke, and more homes have smoke-free rules.

What effects does secondhand smoke have on the body?

No level of secondhand smoke is safe. Even a small amount of contact can cause problems.

Secondhand smoke contains thousands of chemicals. Many of these are known to be harmful, including:

  • Nicotine
  • Ammonia
  • Arsenic
  • Benzene
  • Beryllium
  • Carbon monoxide
  • Formaldehyde
  • Hydrogen cyanide
  • Toluene

Many of these are also known to cause cancer. These chemicals have been found in the blood of nonsmokers who have been in contact with secondhand smoke. The chemicals found in secondhand smoke depend on different factors. These include the type and amount of tobacco, the chemicals added to it, and the way it’s smoked.

These chemicals irritate your airways as soon as you’re in contact with secondhand smoke. The chemicals also have instant harmful effects on your heart and blood vessels. They may increase your blood pressure and lower your HDL (good) cholesterol. The smoke may increase the clotting ability of your blood. This can make it more likely for you to form an abnormal blood clot that can lead to a stroke or heart attack.

What are the risks for secondhand smoke exposure?

You may be at a higher risk of secondhand smoke exposure if you live with a smoker. You may also be at higher risk if you work in a place that allows smoking, such as a bar.

What are the symptoms of secondhand smoke exposure?

Secondhand smoke can cause a number of symptoms right away, such as:

  • Coughing
  • Sneezing
  • Shortness of breath
  • Eye irritation

Many people in contact with secondhand smoke may not have any symptoms right away. But that does not mean the smoke has not caused harm. It can still lead to problems over time, such as chronic bronchitis and scarring of the air passages in the lungs.

How is secondhand smoke exposure measured?

Secondhand smoke exposure can be measured. This is done by testing indoor air for chemicals found in tobacco smoke, such as nicotine. Your healthcare provider can also test your own level of exposure. This is done by measuring the level of cotinine in your blood, saliva, or urine. Cotinine is a chemical created after nicotine enters the body. If you have high levels of cotinine, you likely have high levels of other chemicals from contact with smoke.

But this type of testing is not often needed. If you spend a lot of time in places where people smoke, you likely have high levels of chemicals in your body from the smoke. This is true even if you do not smoke. If you spend only a small amount of time around smoke, your levels are likely lower.

What are the complications of secondhand smoke?

Contact with secondhand smoke greatly raises the risk of some health problems. It may also make certain health problems happen more often, and be more severe. Because of this, secondhand smoke causes thousands of deaths. Health problems linked to secondhand smoke include:

  • Lung cancer
  • Breast cancer
  • Other cancers such as leukemia, lymphoma, brain tumors, and cancers of the larynx, bladder, stomach, and more
  • Heart disease, which may lead to heart attack
  • Peripheral artery disease (PAD)
  • Stroke
  • Ear infections, especially in children
  • Asthma
  • Irreversible lung disease such as chronic obstructive pulmonary disease (COPD)
  • Respiratory infections, such as bronchitis and pneumonia
  • Sudden infant death syndrome (SIDS)
  • Miscarriage, stillborn birth, or babies with low birth weights

What can I do to prevent exposure to secondhand smoke?

It’s important to protect all people, in particular children and those with health problems, from secondhand smoke. You can do this by avoiding places where smoking is allowed. If you live with a smoker, ask that he or she smokes only outside.

Open windows, air filters, and air ventilation systems may lessen contact with secondhand smoke. But they don’t stop contact. Preventing smoking indoors is the only way to protect people from secondhand smoke.

Many towns and cities have taken steps to reduce secondhand smoke. Some cities now ban smoking in public places such as restaurants, bars, hospitals, airports, and schools. Some states have banned smoking in the workplace. Many advocacy groups argue for greater smoking restrictions to protect people from secondhand smoke.

Key points

  • Secondhand smoke is the smoke you are exposed to when someone nearby is smoking. You breathe in the harmful chemicals in tobacco smoke, even if you don’t smoke.
  • Secondhand smoke causes instant harm to the lungs, heart, and blood vessels.
  • Secondhand smoke can lead to many health problems. These include cancer, heart disease, stroke, lung infections, and asthma.
  • No level of contact with secondhand smoke is safe. Your risk of health problems may increase with the amount of smoke you are exposed to.
  • Millions of Americans are exposed to secondhand smoke. This includes people who may be harmed the most by it, such as children and people with health problems.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.
  • Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
  • Ask if your condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if you do not take the medicine or have the test or procedure.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.



March 22, 2017

Reviewed By:  

Holloway, Beth Greenblatt, RN, M.Ed.,Perez, Eric, MD