Every morning, you might step outside into a soft, white mist or a choking, yellowish haze, and although they look similar, fog and smog arise from completely different processes. Natural fog is nothing more than condensed water droplets, while smog is a complex blend of harmful substances. Most of us know that we should definitely limit our exposure to the latter, but very few people realise that there is a significant difference between fog and smog. Below, we break down the three key discrepancies between these two phenomena and explore how to recognise each of them. Keep reading!
Table of Contents
- Smog and Fog – What Are They?
- What Is the Difference Between Fog and Smog?
- Why Is Smog Dangerous?
- The Takeaway
Smog and Fog – What Are They?
While both phenomena can obscure vision, their underlying causes diverge sharply. Fog is a purely natural element, driven by moisture in the air collapsing into tiny droplets. Smog, on the other hand, represents a dangerous fusion of pollutants, often ejected into the air by factories, power plants, or vehicles, mixed together with the ambient moisture.
The word “smog” was first used at the beginning of the 20th century, and it appeared as a result of combining two terms: smoke and fog. First recorded in London, smog events quickly became synonymous with industrial growth during the early 1900s. As coal combustion in factories ramped up, cities began experiencing prolonged episodes of murky air that not only reduced visibility but also foreshadowed urban air quality challenges.
What Is the Difference Between Fog and Smog?
When seeing a thick cloud that makes it hard to function and observe objects from a distance, very few people wonder whether it’s actually smog or fog. Visually, fog often appears as a uniform white or gray veil. Smog, however, can take on yellowish or brownish hues that reflect its chemical and harmful makeup. The acrid odor and slight irritation in the throat or eyes are telltale signs that you’re breathing pollutant-laden smog rather than harmless fog.
As explained before, fog droplets are simply minute spheres of water, while smog can carry a complex cocktail of different pollutants, which include:
- Sulfur dioxide
- Nitrogen oxides
- Volatile organic compounds (VOCs)
- Fine particulate matter (PM2.5 and PM10).
These contaminants can penetrate deep into the respiratory system, causing both immediate irritation and long-term health effects.
Beyond their color and composition, their formation conditions also diverge. Fog forms on cool, humid nights when dew-point temperatures cause condensation. Smog surges on sunny days as pollutants accumulate in stagnant air layers; temperature inversions can lock these toxic mixtures of nitrogen oxides, VOCs, and particulates at breathing level for days, all the while local residents can’t go about their day without exposing themselves to the harmful effects of these substances.
Why Is Smog Dangerous?
It’s worth taking appropriate steps to minimise your exposure to smog as it may lead to serious health problems and conditions like:
- respiratory and circulatory problems,
- asthma,
- allergies,
- nausea,
- difficulties with concentration,
- heart attacks,
- miscarriages,
- problems with concentration,
- allergies,
- nausea,
- cancer.
Therefore, it’s worth using special tools that allow you to make informed decisions and avoid outdoor activities when the air quality isn’t satisfactory. To be on the safe side, benefit from professional air quality sensors or air pollution maps that help you track the situation in real time.
Beyond personal monitoring, communities can demand stricter factory emission controls. Urban planners can establish green belts around industrial zones to better filter particulates. Employers in areas that often experience smog can offer remote work options to reduce traffic and collective exposure. From prevention to avoidance, there are plenty of strategies – all that is required is awareness and collective action.
The Takeaway
Now you know the difference between fog and smog. Find out how smog is created to ensure that you recognise harmful practices and eliminate them from your daily life.
Read also: 9 Steps You Can Take to Reduce Air Pollution