Smog: What is it and Where Does it Come From?

You could probably work out for yourself that smog is a combination of smoke and fog, but after that do you know what it is? The emissions from the internal combustion engines of vehicles and industrial smokes cause the air pollution known as smog, which affects the wellbeing of those in cities with sunny, warm, dry climates and a large number of vehicles.

So what is it made of? Many fine particles form smog, including gases like carbon monoxide (CO), carbon dioxide (CO2), sulfur dioxide (SO2) and nitrogen oxides (NO2), as well as the harmful pollutant of ground level ozone. These chemicals exist in polluted air and are highly oxidising and reactive. When they react in the atmosphere with sunlight, they form secondary pollutants. For example, photochemical smog is formed by the combination of primary emissions and secondary pollutants.

When the weather is warmer and sunnier, smog levels increase. This is because during these times the upper air is warm and inhibits vertical circulation. When smog stays for extended periods of time over densely populated areas, it can build up to dangerous levels. And it’s not just those in crowded areas at risk. Smog can travel with the wind and affect sparsely populated areas as well.

So how exactly does smog threaten your wellness? Smog is a serious health problem, especially for those with heart and lung conditions like asthma and bronchitis, as well as children and the elderly. Smog can cause eye and nose irritation, dryness of your nose and throat, inflammation of your breathing passages, shortness of breath, wheezing, coughing, decreased working capacity of your lungs, pain during deep inhalation, decreased ability of your body to fight infection (which increases your susceptibility to illness), worse and more frequent asthma attacks and even lung cancer.

Then, how do you avoid smog when you live in, or visit, affected areas? Firstly, avoid exercising near heavy traffic areas, especially during peak times. When smog levels are high, particularly in the afternoon, avoid outdoor activities. When possible, walk, ride your bicycle or use public transportation instead of your car and, if you’re concerned about your wellbeing, consult your doctor about more ways you can protect your health against smog.