Smog is a combination of various gases with water vapour and dust. A large part of the gases that form smog is produced when fuels are burnt. Smog forms when heat and sunlight react with these gases and fine particles in the air. In fact the word smog has been coined from a combination of the words smoke and fog.

Its occurrences are often  linked to heavy traffic,  high temperatures, and  calm winds. During the winter,  wind speeds are low and  cause the smoke and fog to stagnate; hence pollution levels can increase near ground level. This keeps the pollution close to the ground, right where people are breathing.

 It hampers visibility and harms the environment.  Heavy smog is greatly decreases ultraviolet radiation.  Smog causes a misty haze similar to fog, but very different in composition.

 The effects of smog on human health were evident, particularly when smog persisted for several days.  Many people suffered respiratory problems and increased deaths were recorded, notably those relating to bronchial causes.  It can aggravates the ground level ozone too which affects health of infants and senior citizens.

Ground-level ozone  Ground-level ozone is formed by smog through a complex reaction involving hydrocarbons, nitrogen oxides, and sunlight.  It is especially harmful for senior citizens, children, asthmatics, and people with heart and lung conditions.  It aggravates respiratory symptoms and further impairs the ability of these individuals to perform normal activities.  It can inflame breathing passages, decreasing the lung's working capacity, and causing shortness of breath, pain when inhaling deeply, wheezing, and coughing.  It can cause eye and nose irritation and dry out the protective membranes of the nose and throat and interfere with the body's ability to fight infection, increasing susceptibility to illness.

The Legislation to control pollution emissions and cleaner emission technology alone can help us from the perils of Smog and Air Pollution The End