Smoke fog, more commonly known as smog, is a type of intense air pollution.
Smog is formed by a combination of smoke and fog. The term itself is a portmanteau, blending the words "smoke" and "fog," reflecting its composition and characteristics: a visible, often odorous, haze that reduces visibility. This phenomenon typically occurs in urban or industrial areas with high levels of air pollutants, especially during periods of calm weather conditions.
Here's a breakdown of the key components:
- Smoke: This refers to particulate matter released from combustion processes. Sources include burning fossil fuels (coal, oil, and gas) in power plants, vehicles, and industrial facilities, as well as wood burning.
- Fog: This is a cloud of water droplets suspended in the air at or near the Earth's surface. It reduces visibility, similar to a ground-level cloud.
When smoke mixes with fog, particularly under stable atmospheric conditions (like temperature inversions, where warm air traps cooler air near the ground), the pollutants become concentrated, creating smog.
Different types of smog exist:
- London Smog (Classical Smog): Characterized by high concentrations of sulfur dioxide (SO2) and particulate matter, usually associated with coal burning.
- Los Angeles Smog (Photochemical Smog): Primarily caused by emissions from motor vehicles, this type of smog is characterized by high levels of ozone (O3), nitrogen oxides (NOx), and volatile organic compounds (VOCs), which react in the presence of sunlight.
Smog has significant negative impacts on human health, including respiratory problems (asthma, bronchitis), cardiovascular issues, and increased mortality rates. It also damages ecosystems and materials. Efforts to reduce smog focus on controlling emissions from various sources and promoting cleaner technologies.
