Effect of fog and mist in winter
In winter, the mist and fog become so dense in the morning that at times it becomes difficult to understand what is in the air. However, it is not correct to consider every mist as fog, because sometimes it can also be the result of pollution. Fog, mist and smog may seem similar to each other, but there are important differences between them. Let us understand in simple language how these three are formed and which one is more worrying for health.
What is fog?
Fog is formed when moisture in the air cools and turns into water droplets. These drops keep floating close to the ground. It can be considered a type of cloud that occurs near the ground. According to the Meteorological Department, when it becomes difficult to see more than 1,000 meters away at a place, it is called fog.
Fog usually forms more often at night when the air is calm and humidity is high. As the cold increases, the moisture in the air turns into water droplets, causing dense fog to appear in the morning. This may hamper road driving and air travel, but that does not mean there is more pollution.
definition of haze
Haze appears when small particles in the air scatter sunlight, preventing distant objects from being seen clearly. This may include dust, smoke and pollution. An excess of small particles in the air can increase the amount of smog. Smog is not limited to a small area only, but these particles can spread far away.
What is smog?
Smog can be called pollution mist. This is related to polluted air. The word smog is a combination of smoke and fog, but nowadays smog does not have to be fog. This may include small pollution particles present in the air and gases like ozone.
Some types of smog form when pollutants react when exposed to sunlight. At the same time, in some cases, the pollution emitted from vehicles remains deposited near the ground.
Coexistence of fog and smog in winter
Why do fog and smog appear together in winter? In North India the temperature drops in winter and the wind blows slowly. Cold and humidity help fog form, while slow winds prevent pollution from spreading.
When there is both moisture and pollution in the air, a thick gray layer may appear over the sky. In this situation it becomes difficult to identify whether there is fog, mist or pollution. Keep in mind that fog is related to weather, while smog is related to pollution.
Are smog, fog and mist more dangerous?
It depends on what is present in the air and its quantity. The main problem with fog is lack of visibility, while the haze created by pollution can be harmful to health. Small particles like PM 2.5 can cause respiratory and heart problems.
According to the US Environmental Protection Agency, exposure to these particles can have serious health effects. People who already have asthma or heart problems may suffer more from such pollution.
accurate assessment of air quality
One cannot tell whether the air is safe to breathe or not just by the color of the sky. If you want to know how clean the air is in your area, check the Air Quality Index (AQI) of the Central Pollution Control Board. Follow the advisories issued by the local administration in case of increase in pollution.
Remember, fog is made up of water droplets, mist is made up of small particles and smog is related to pollution. These three can sometimes be seen together. Therefore, it is more advisable to check AQI along with weather information.