Secondhand Smoke (SHS)

WHO report

What is Secondhand Smoke (SHS)?

Secondhand smoke is also known as environmental tobacco smoke (ETS) or passive smoke. It is a mixture of 2 forms of smoke that come from burning tobacco: sidestream smoke (smoke that comes from the end of a lighted cigarette, pipe, or cigar) and mainstream smoke (smoke that is exhaled by a smoker). Even though we think of these as the same, they aren't. The sidestream smoke has higher concentrations of cancer-causing agents (carcinogens) than the mainstream smoke because the chemicals are burning at a lower temperature. And, it contains smaller particles than mainstream smoke, which make their way into the body's cells more easily. Secondhand smoke significantly increases a person's risk for:

  • Respiratory infections (like bronchitis and pneumonia)
  • Asthma (secondhand smoke is a risk factor for the development of asthma and can trigger attacks in those who already have it)
  • Coughing, sore throats, sniffling, and sneezing
  • Chronic coughing, phlegm, and wheezing
  • Chest discomfort
  • Lowered lung function
  • Eye and nose irritation
  • Severe and chronic heart disease
  • Middle ear infections in children
  • Sudden infant death syndrome (SIDS)
  • Low birth weight or small size at birth for babies of women exposed to secondhand smoke during pregnancy
  • Cancer
  • Stroke

Secondhand smoke constitutes more than 7,000 chemicals, at least 250 are known to be harmful, and at least 70 of these are carcinogens which include:

  • formaldahyde (embalming fluid)
  • arsenic (heavy metal toxin)
  • benzene (chemical found in gasoline)
  • beryllium (toxic metal)
  • cadmium (metal used in batteries)
  • chromium (metallic element)
  • ethylene oxide (chemical used to sterilize medical devices)
  • nickel (metallic element)
  • polonium-210 (chemical element that is radio active)
  • vinyl chloride (toxic substance used in plastic manufacture)

What are the Health Risks of Secondhand Smoke Exposure?

Smoke can diminish the overall health of a person and can harm almost all of the organs in the body. Smoke has been the cause of serious health problems in millions of people. It is the leading cause of cancers such as bladder, stomach, cervix, pancreas, kidney, mouth, throat and larynx cancer. Smoke can cause acute myeloid leukemia, heart disease, aortic aneurysms, strokes, chronic obstructive pulmonary disease and asthma. Women who are pregnant and either smoke or are exposed to secondhand smoke, have a higher risk of delivering their child prematurely and with a low birth weight. There are many more health issues related to secondhand smoke and exposure should be avoided.

Secondhand smoke causes cancer in nonsmokers. Secondhand smoke is classified as a Class A carcinogen (similar to asbestos) by the US Environmental Protection Agency (EPA), the US National Toxicology Program (NTP), the US Surgeon General, and the International Agency for Research on Cancer (IARC). Approximately 50,000 lung cancer deaths occur each year among adult nonsmokers in the US as a result of exposure to secondhand smoke.

Social Smoking

Social Smoking is smoking less than everyday. A social (or casual) smoker may smoke a few cigarettes one night, then not smoke for days or weeks afterwards.

Reasons why people smoke socially:

  • Many people who smoke socially don’t realize that occasional smoking can be harmful
  • They may not be aware of how easy it is to become addicted
  • If you are around people who smoke, you may be tempted to smoke too.
  • It may seem like smoking makes social situations easier.
  • Some people just have a cigarette when they go out with friends and are drinking.
  • Sometimes you find someone that may have been up all night working and wanted a break or something to help them stay awake, which can resort in chain smoking.

Statistics: Social smokers make up the significant population that do not consider themselves to be smokers, but are at risk of becoming addicted to nicotine.

  • About 60% of students are non-smokers, reporting never smoking cigarettes.
  • About 10% of students are smokers- using cigarettes every day or every other day.
  • This leaves us with about a 1/4 students- 30% who probably do not consider themselves smokers but smoke a couple of times each week or month.
  • A high percentage of smokers- 85-90%- must smoke every day or they start to go through withdrawal
  • In contrast- only about 10% to 15% of people who drink alcohol are problem drinkers; which puts nicotine as probably the most addictive drugs. 

Risks: Even if you are smoking “every now and then” you are still subject to physical consequences.

  • You are still exposed to the 7,000 chemicals such as arsenic, formaldehyde, lead, and mercury.
  • Even after a cigarette or two, smokers will experience a spike in blood pressure
  • 30 minutes of exposure to secondhand smoke can cause heart damage similar to that of an everyday smoker.
  • Addiction could happen within 10 seconds of taking a puff of a cigarette, nicotine reaches the brain and regulates the feeling of pleasure. The thing is within a few minutes the effects wear off, which makes the person crave another cigarette.

Signs of Addiction:

  • You buy your own cigarettes because you feel guilty about bumming from friends so often.
  • You start to smoke alone
  • You think about smoking when you’re not
  • You crave cigarettes when you wake up
  • You don’t feel the dizziness and headaches of a new smoker.

Reducing Secondhand Smoke Exposure

There are ways to reduce exposure to secondhand smoke. Start by making sure there is no smoking allowed inside the home. This can be done by removing ashtrays or placing no smoking signs in easy to see areas. Be sure to inform anyone that enters the home of the no smoking rule as well. Eliminating any smoking inside the vehicle is also essential. When a smoker is noticed, be sure to keep a safe distance to ensure secondhand smoke is not being inhaled. Create, strengthen and inforce a smoke-free policy in workplace environments, child care facilities, and schools and encourage parents to follow the same rules in their cars and homes. Always be supportive of any loved one trying to kick the habit. Smoking is addictive and it is hard for many people to quit regardless of the dangers involved. Below is more information on how nonsmokers can reduce their exposure.

  • Do not allow smoking in your home or in your car.
  • Choose child-care providers and baby sitters who DO NOT EVER smoke around children.
  • Do not expose children to smoking at social occasions, while conducting business, or in public places.
  • Ask school administrators to strengthen and enforce their no-smoking policy and speak to parents about stepping outside the home and the care when they smoke cigarette.
  • Eliminate time spent in businesses that allow smoking.
  • Eliminate time spent indoors with friends who smoke.

It is no secret that smoking cigarettes is dangerous to a person’s health. Secondhand smoke is no different. Passive smoke means that a nonsmoker is still ingesting the dangerous chemicals in tobacco. Nonsmokers are at risk of developing all the same health issues as a smoker. Secondhand smoke should be avoided and can be avoided or at the least reduced by not allowing smoking in the home or in the vehicle. Remove all ashtrays and post no smoking signs if needed. Support and encourage nonsmoking workplaces, schools, restaurants, and other public areas. Encourage smokers trying to quit to stick with it and provide plenty of support.

People will not quit smoking overnight. With proper education they may decide that the related health risks for themselves and their loved ones are more than they are ready to deal with. They may eventually try to quit. In the meantime, non-smoking individuals can protect themselves and their families by reducing their exposure to secondhand smoke as much as possible. It’s not always easy but it can and should be done. Keep yourself and your family safe by not smoking and avoid areas with increased secondhand smoke exposure. Stay healthy and smoke-free!


Secondhand smoke is still a risk in some airports. Read the article here!