You often don't notice a single breath of polluted air. How clean the air actually is is usually impossible to see with the naked eye, or even smell. The actual health risk you run from inhaling harmful smoke depends on three factors: how toxic the smoke is, how concentrated it is, and how long you inhale it.
If you occasionally breathe in polluted air, you may experience the following symptoms:
The short-term effects of exposure to harmful substances: irritated airways, coughing, sore throat, stinging eyes or nose, itching, faster heart rate, slight increase in blood pressure, headache, nausea, dizziness, fatigue or worsening vision.
However, you can also inhale unhealthy air (even small amounts) for extended periods. This can cause serious, chronic, and often irreversible damage to your health!
The long-term consequences of exposure to harmful substances: chronic bronchitis and other respiratory diseases, reduced lung function, asthma, risk of lung cancer, inflamed mucous membranes, accelerated cognitive decline and Parkinson's-like symptoms, increased risk of cardiovascular disease, heart attack or stroke, and dementia...
Also be aware that polluted air is toxic to your unborn baby. People with respiratory problems like asthma or COPD also experience more symptoms when they breathe in polluted air. The elderly or those with compromised health are particularly vulnerable if they inhale toxic particles.