Final answer:
Smog is a noxious mixture of air pollutants that often accumulates over urban areas due to fossil fuel combustion. It poses significant health risks, particularly for individuals with respiratory conditions. Addressing both outdoor and indoor air pollution requires emissions controls and sustainable practices.
Step-by-step explanation:
Smog is a form of air pollution characterized by a mixture of air pollutants that include sulfur dioxide, nitrogen oxides, ozone, and particulates. These pollutants often accumulate over urban areas as the result of fossil fuel combustion. Photochemical smog, a common type found in cities, is produced when nitrogen oxides and volatile organic compounds (VOCs) react under the influence of sunlight, leading to a brownish haze that impacts air quality and visibility. Smog is not only a visual issue but also a health hazard, causing problems for people with respiratory conditions and impacting the overall quality of life.
Outdoor air pollution can be severe in large cities, particularly where industrial activities and high volumes of traffic contribute to the concentration of harmful substances. However, indoor air pollution can also pose significant health risks, containing contaminants such as mold, bacteria, radon, and carbon monoxide—an odorless, colorless gas that can be deadly if inhaled.
Emissions controls and green practices are required to tackle the issue, with measures like catalytic converters in vehicles and green chemistry principles being employed to reduce the production of pollutants. Nevertheless, air quality remains a significant concern in many areas around the world, with citizens and governments alike seeking solutions to this persistent environmental and health challenge.