Secondhand smoke or environmental tobacco smoke (ETS) is a direct cause of lung disease in both children and adults. In children, ETS increases the risk of lower respiratory tract infections such as bronchitis and pneumonia. In the United States, the problem is still significant, affecting up to 300,000 children under eighteen each year.
ETS causes increased fluid in the middle ear, upper respiratory tract infections, and diminished lung function. ETS is associated with both the development of asthma and the increased severity of asthma in children. Children who live in a household with a smoker are one-third more likely to be diagnosed with asthma than those who do not live with a smoker.
What does ETS do to a child’s airways and lungs?
The physiologic response in children to ETS can be the same as if the child were smoking himself or herself, but with a diminished effect. The changes to the airways include:
- Increased mucus production (up to seven times more).
- Decreased ciliary (small hair cells) movement.
- Decreased ciliary beat frequency and transport.
- Increased white blood cell production and movement to the airway lumen.
- Increased mucosal permeability to allergens.
- Increased total and specific immunoglobulin E (IgE) levels.
- Increased blood eosinophil counts.
What this all means is that children who are exposed to ETS can experience acute and long-term structural changes in the airways and the lungs. In children as young as two weeks of age who are around mothers who smoke, their infant lungs can show increased compliance. Changes in compliance and elasticity may predispose children to developing emphysema as adults.
The effects of ETS on children, infants and even fetuses continue to be studied. The effects are all deleterious.
How many people still smoke?
The problem is still widespread worldwide. Twenty-six percent of the adult population still smoke, consuming more than 500 billion cigarettes each year.
Data is not available for the prevalence of ETS exposure, but in places such as Asia, South America, and Africa, the increase in tobacco consumption will increase diseases related to ETS.
It makes sense that mothers who smoke have a greater effect on children and the risk of ETS. This is likely because of the closer contact.
It turns out that the risk of ETS to children is greater in the younger age groups. It is not clear why, but it may be because of the general decrease in illnesses as children get older and their immune systems get stronger, or their lungs begin to mature.
Does it have an effect if children are no longer exposed to ETS?
Yes, improvements appear to be immediately apparent. Children tend to have fewer problems with asthma, upper respiratory conditions, or ear infections.
The principal goal is prevention. By both the parents and family stopping smoking and the cessation of exposure to anyone smoking, the benefits can be short and long term for the children. In fact, it is a great motivating factor for smoking cessation in many families. It has taken many years, but finally most buildings, including restaurants are smoke-free zones.
How is passive smoke exposure diagnosed?
The simplest way is by asking. Parent history, honest admission, is the best. The degree of exposure can usually be determined by what the parents describe. Being in a car with a smoker may be different than the child being around someone who smokes out in the family’s backyard.
Any child who has persistent or recurrent upper respiratory issues or asthma may be subject to being around ETS. A good clinician will also have a heightened sense of awareness to children who frequently visit their office with the following:
- Recurrent pneumonia.
- Upper respiratory tract infections (URTIs).
- Ear infections.
- Sinus infections.
What is the treatment?
Besides the obvious of removing the child from any and all environments with smoking, there are other measures that can be taken.
It is also important to consider the importance of avoidance of smoking at all times, not just when the child is at home. The issues are twofold.
First, smoking in a distant area of the home still does not solve the problem. The analogy best used by many clinicians is that smoking in only one part of the home is like having a flood only in the basement. Eventually, the water affects everything upstairs.
Next, there is the issue of thirdhand smoke. Thirdhand smoke refers to the residual smoke, odor of smoke in the home or clothing and the toxins that are left behind.
Children are particularly susceptible to these noxious chemicals on contaminated surfaces or breathing in the off-gassing from these surfaces. As we all know, thirdhand smoke leaves its signature on drapes, walls, bedding, dust, vehicles, and even our dogs and cats.
Thirdhand smoke and its effects are a relatively new concept. The residual nicotine and noxious chemicals pose significant, real risks. The tobacco chemicals remain, re-emit, and are resuspended (the 3 Rs) long after the smoker is gone.
A final word
Over the past half century, the culture of smoking has changed. This has led to effectively banning smoking in many environments. It was not that long ago that I can remember being asked if I wanted a non-smoking seat on an airplane or coming home after being in a restaurant with my clothing smelling of secondhand and thirdhand smoke.
The problem with nicotine addiction is that it is unique in how it affects the central nervous system. Nicotine is thought to be the only drug that stimulates, causing increased mental acuity or alertness, but at the same time, soothing the peripheral nervous system. In comparison to typical stimulants like amphetamines, nicotine does not cause tremor or nervousness and they do not cause sleepiness.
Fortunately, our children continue to be exposed less to secondhand and thirdhand smoke. This can make the pediatrician’s job a lot easier when he or she is trying to figure out why a child’s lungs are just not getting better with standard treatment.
Cleveland Clinic. Secondhand Smoke Dangers.
Xie, L., Atem, F., Gelfand, A., Bauer, C., Messiah, S.E. (April 2021). United States prevalence of pediatric asthma by environmental tobacco smoke exposure, 2016-2017. Journal of Asthma.
US Department of Health and Human Services. (2004). The health consequences of smoking: a report of the surgeon general. US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health.