It has been a misnomer among several people that direct smoking only causes ill health, but not secondhand smoke. To define Secondhand smoking is the involuntary inhalation of smoke from burning tobacco products. For example, when a husband is smoking in front of his wife without her knowledge, she will be a passive smoker or second-hand smoker. Similarly, when four people are traveling in an air-conditioned car, if one of them smokes, the remaining persons are all forced to inhale the smoke released by the primary smoker. Secondhand smoke is a mix of smoke exhaled by a smoker and smoke from the lit end of the product, and it is also called passive or environmental tobacco smoke. This smoke is harmful to both smokers and non-smokers and is linked to various health problems like cancer, heart disease, and stroke.
Secondhand smoke exposure is linked to a wide range of serious health problems in non-smokers, including heart disease, stroke, and lung cancer, as well as increased risks of respiratory infections, asthma attacks. When a father smokes in front of children innocently the children are exposed to various lung diseases and ear infections in children. Research studies have established a clear causal relationship between secondhand smoke exposure and these diseases, showing that even brief exposure can damage blood vessels and increase the risk of heart attack and stroke. Studies also highlight that children are particularly vulnerable due to their developing bodies, leading to higher rates of respiratory illnesses and SIDS. SIDS can stand for sudden infant death syndrome, which is the unexplained death of a seemingly healthy baby under one year of age.
According to a research article published in the “European Journal of Cancer Prevention” p 415-425, September 2025, Studies on the association between passive smoking and head and neck cancer (HNC) are controversial. Passive smoking was significantly associated with an increased risk of HNC. The association was particularly strong for oral cancer, oropharyngeal cancer, laryngeal cancer, and hypopharyngeal cancer. No significant association was observed for nasopharyngeal carcinoma. Geographically, the risk was elevated among both Asian and European populations. Passive smoking is associated with an increased risk of HNC, particularly for subtypes such as oral, oropharyngeal, laryngeal, and hypopharyngeal cancers. These findings underscore the importance of justifying exposure to passive smoking as a public health measure.
Health effects on adults
Focusing on cardiovascular disease, exposure increases the risk of coronary heart disease by 25–30% and stroke by 20–30%. Research indicates that secondhand smoke can cause immediate damage to blood vessels and increase blood platelet stickiness, increasing the risk of a heart attack. Secondhand smoke is a known cause of lung cancer, and studies show a 20–30% increased risk for non-smokers exposed to it.
Other health issues, such as adults may experience eye irritation, headaches, nasal symptoms, and other respiratory issues like coughing and allergic attacks.
Health effects on children
Children are more susceptible to acute respiratory infections, such as bronchitis and pneumonia. Asthma exposure can lead to more frequent and severe asthma attacks, ear infections. Children exposed to secondhand smoke have a higher risk of ear infections—also, as well as sudden Infant Deaths. Further, increased risk of brain tumors, damage to eyes and teeth, and frequent coughing or wheezing are also linked to secondhand smoke exposure in children.
Ongoing Research
Numerous studies, including prospective and cross-sectional studies, have assessed exposure levels at home and in the workplace to link them to health outcomes. Some research suggests a dose-response relationship, meaning that the risk of harm increases with the duration and intensity of exposure. To explain the mechanism of action that the studies have identified that secondhand smoke contains numerous carcinogens and that its components can negatively affect the cardiovascular system, leading to inflammation and blood clot formation.
Diabetic Retinopathy
Smoking can exacerbate the effects of diabetes on the eyes, increasing the risk of diabetic retinopathy, a condition that damages blood vessels in the retina. Smoking can speed up optic nerve damage, a key factor in developing glaucoma.
Smoking cigarettes can cause eye diseases that can lead to vision loss and blindness. Smoking cigarettes can put you at greater risk of developing two serious eye diseases, Cataracts, which in clouding of the eye’s normally clear lens, causing loss of vision. Gradual destruction of the eye’s macula, which can lead to loss of vision in the center of the eye. The Age-related macular degeneration (AMD) People who smoke cigarettes are two to three times more likely to develop cataracts and up to four times more likely to develop AMD than people who don’t smoke.
Quit smoking:
Quitting smoking is the most important step to protect the eyes from further damage. Also, if anyone experiences sudden blurred vision, double vision, or other vision problems, they should consult an eye specialist immediately. Prompt treatment may help recover some vision. Regular eye check-ups can help detect and manage smoking-related eye conditions before they lead to permanent vision loss. Avoid exposure to secondhand smoke, as it can also harm the eyes. Increasing mortality and morbidity among infants due to smoking by their parents will be discussed in the next issue.
