Question

what is smog? why it is harmful

Answer 1

Smog is a mixture of smoke and fog in air which causes air pollution.
Smog can cause or aggravate health problems such as asthma, emphysema, chronic bronchitis and other respiratory problems as well as eye irritation and reduced resistance to colds and lung infections.

Answer 2

smog is a mixture of air pollutants nitrogen oxide and volatile organic compound that combined with sunlight to form ozone Ozone can be beneficial or harmful good or bad depending on its location Ozone in the stratosphere high above the earth acts as a barrier that protect human health and the environment from excessive amount of solar ultraviolet radiation this is the good kind of ozone