The effect of fog has multifarious impacts on human life and the environment encompassing air quality, transportation, economy, ecology, and agriculture. These wide-ranging impacts require adjustments in daily routine and lifestyle at the individual level and initiatives at the Government level. Individually one has to plan travelling according to fog weather conditions and take measures to avoid the negative effects of fog on health. At the government level, provision and regulation of facilities and infrastructure according to the dictates of foggy conditions is a surmounting challenge.
There is 0.001% water in the atmosphere, a critical component in determining the earth’s heat budget and driving climate phenomena. Clouds at altitude and fog close to the surface are evident manifestations of water as a component of the atmosphere. Altitude being the only difference, the fog is also called stratus cloud – just above the ground.
How is fog formed?
Understanding the formation of fog is imperative to comprehending its various effects. A combination of factors ranging from chemical and physical properties of cloud condensation nuclei, the topography of the region, and changes in the atmosphere or winter teleconnections influence the formation of fog.
Fog is a phenomenon of visible air condensation at or near ground level – which forms when the air layer temperature drops to its dew point.
The dew point temperature is key to the concept of fog formation. It is the temperature at which air becomes 100 per cent saturated, incapable of holding more water molecules in gaseous form. Any further addition of water molecules or air cooling will cause the water vapours to condense and form water droplets.
Effect of Fog
Does fog affect AQI?
If the air contains more pollutants, there are more chances of fog formation. Air pollutants act as cloud condensation nuclei enhancing the fog probability due to favourable meteorological conditions. The most adverse manifestation of the interaction between fog and air pollutants is “Smog”!
However, it doesn’t affect the atmosphere in a harmful manner only; it can act as an agent for removing air pollutants from the atmosphere. It is imperative to reduce air pollutants from the atmosphere to accrue the positive effects of fog.
Fog has a significant role in maintaining the ecosystem of all strata, ranging from deserts to alpine and inland to coastal systems. It acts as a vector, medium, and connector for the ecosystem, providing it with critical water and nutrient subsidies. As a vector and medium, fog regulates, delivers, and supplies the flow of “critical limiting resources” – water, elements, and light – to the ecosystem. Fog droplets have more chemical concentration, transporting nutrients and pollutants incorporated in these droplets during fog formation.
Fog impacts the light climate of the ecosystem; total shortwave radiations tend to reduce as much as 75% under foggy conditions.
In short, on the one hand, fog is valuable in extending or sustaining ecosystem processes, which would have been otherwise slowed down or ceased due to water deficits or lack of elements. On the other hand, ecosystem processes may be slowed down or impaired due to water saturation or excessive pollutants.
Effect of fog on Human Health
Fog is not harmful to the human body as it’s devoid of any chemicals or air pollutants and consists of only water droplets. It’s the amount of particulate matter that makes inhaling fog dangerous. The air quality index, especially in urban areas, has deteriorated to dangerous levels due to increased particulate matter in the atmosphere. People suffering from respiratory diseases have experienced deteriorated health during foggy conditions, especially patients with asthma. It is noteworthy that the phenomenon is not dangerous to humans. However, the effect of fog exacerbates the impacts of air pollution.
Is fog bad for your lungs? Inhaling fog exposes your lungs to cold and watery air, which can be damaging and may cause cough, irritation, or chills. People with low immunity or vitality may suffer from bronchitis if these conditions deteriorate.
Inhaling foggy air is also likely to reduce oxygen intake due to more saturated water droplets. It will put more pressure on the body, requiring more sleep or repairing time.
Patients of rheumatism and arthritis experience excruciating pain during foggy weather. Argument dilates that low air pressure on fog days causes inflamed tissues to expand and aggravate the pain. In addition, lower activity and inclination to hibernate during fog weather results in joint stiffening and extreme pain in case of movement.
The most pronounced effect of fog is the loss and delay caused to transportation infrastructure. Its impacts are not only confined to land travel and air operations; marine traveling is also severely affected. Fog reduces visibility causing accidents and loss of life, especially on motorways and highways. Visibility of less than 200 ms is attributed to dense fog and is dangerous for driving. On average, 10 percent of accidents in fog-prone areas, especially multiple crashes, are because of fog. It causes inconvenience for air passengers and considerable economic loss due to cancellations, delays, and diversions of flights if visibility reduces from 1.2 km. The fog may cause the termination of shipping operations if visibility reduces from 0.5 km.
Dense foggy conditions on roads disrupt vision and make it difficult for drivers to see the road, signs, pedestrians, and other vehicles or objects, threatening the life of passengers.
How to avoid the negative effect of fog?
Keep the air clean. The quantity of particulate matter and pollutants in the air tend to exacerbate the negative effect of fog. Government has to take long-term measures to minimize carbon emissions and regulate the lifestyle of the population, like the timings of industry and traffic on the roads to lower the pollutants in the air.
Ensure personal protective measures like wearing masks/ full sleeves clothes and staying hydrated.
Drive Safely. The most pronounced effect of fog is the dangers associated with driving. Adhere to the following safety tips for driving in fog:-
- Drive slowly and keep a sufficient distance from the front vehicle.
- Keep the headlights and taillights on to be visible.
- Use low beam; high beam light will reflect from the fog, further impairing the vision.
- Use the left edge or lines on the roads as navigation aids.
- Never apply sudden breaks to avoid being bumped by an oncoming rear vehicle.
- Use the defroster to keep your windows clear from fog.