The term smog derives from the combination of the English words smoke , which means smoke, and fog , which means fog and is a term used to describe visible air pollution, very common in urban areas.
Smog is the result of various chemical reactions between various primary pollutants, which can derive from car emissions, industry emissions, fires, among others, which depend on the climate, since their composition is also influenced by the sun.
This type of air pollution can be harmful to health, as it can cause irritation in the eyes, throat and nose, affect the lungs, cause coughing and aggravate respiratory diseases, such as asthma, for example, besides also harming plants and animals. animals.
What types of smog
The smog can be:
1. Photochemical smog
Photochemical smog , as the name implies, occurs in the presence of light, is common on very hot and dry days and comes from the incomplete burning of fossil fuels, and the emissions of motor vehicles.
In the composition of photochemical smog , primary pollutants, such as carbon monoxide, sulfur and nitrogen dioxides, and secondary pollutants, such as ozone, can be found under the influence of sunlight, which is why photochemical smog forms. usually on drier, hotter days.
2. Industrial, urban or acid smog
Industrial, urban or acid smog occurs mainly in winter, and is composed of a mixture of smoke, fog, ash, soot, sulfur dioxide and sulfuric acid, among other compounds harmful to health, bringing many risks to the population.
This type of smog has a dark color, which is due to the combination of these materials, which come mainly from industrial emissions and from the burning of coal. The main difference between this type of smog and photochemical smog is that the first occurs in winter and the photochemical needs sunlight to form, with more tendency to occur in summer.
Health risks
Smog can cause changes in the immune system, worsening of respiratory diseases, such as asthma, dryness of protective membranes such as nose and throat, eye irritation, headache and lung problems.
Also know the risks of air pollution that are not visible.
What to do
On days when smog is visible in the air, exposure should be avoided, especially near areas with a lot of traffic, restricting hours outdoors, especially when exercising.
To reduce the emission of pollutants, active and sustainable mobility, such as cycling, walking and public transport, increasing green areas, removing old vehicles from circulation, reducing open fires and encouraging industries to use equipment should be preferred. as catalysts and filters to retain smoke and pollutants.
