Asthma and passive smoking

Passive smoking occurs when a non-smoker involuntarily breathes in the smoke exhaled by smokers or the smoke emitted from burning tobacco products¹. It’s important to note that passive smoking is not limited to just the visible smoke from a cigarette; it includes the invisible toxins released into the air as well. Passive smoke exposure can happen in various settings, such as homes, cars, public places, and workplaces, making it a pervasive health concern².

Second-hand smoke is a toxic mixture of over 7,000 chemicals, including at least 250 that are known to be harmful, with more than 60 being recognised as carcinogens³. These chemicals are divided into two categories: side stream smoke (the smoke from the burning end of a cigarette) and mainstream smoke (the smoke exhaled by the smoker)⁴. Both types contain harmful substances like nicotine, carbon monoxide, formaldehyde, and benzene, among others⁵.

Now, let’s focus on how passive smoking affects individuals with asthma, a chronic respiratory condition characterised by airway inflammation and hyperreactivity⁹. Asthmatics are particularly vulnerable to the harmful effects of second-hand smoke, as their already sensitive airways are further irritated and compromised.

1. Increased Asthma Symptoms: Passive smoking can trigger or worsen asthma symptoms in asthmatic individuals. When exposed to second-hand smoke, they may experience increased coughing, wheezing, shortness of breath, and chest tightness¹⁰.
2. Exacerbation of Asthma Attacks: Asthmatics exposed to second-hand smoke are at a higher risk of having severe asthma attacks¹¹. These attacks can be life-threatening, requiring emergency medical intervention.
3. Reduced Medication Efficacy: Smoking in the vicinity of asthmatic individuals can reduce the effectiveness of their asthma medications¹². This means that even if they are diligently following their treatment plan, exposure to second-hand smoke can undermine its benefits.
4. Long-Term Lung Damage: Chronic exposure to passive smoke can lead to long-term lung damage in asthmatics. It may increase the risk of reduced lung function over time, making it harder for them to breathe and manage their asthma¹³.

^{Last reviewed : 5 January 2024}