Smog: what is it?

The word "smog" derives from two English words: "smoke" and "fog". Smog is an artificial atmospheric phenomenon, dangerous for our health. It occurs when two factors – specific atmospheric conditions – are present simultaneously: fog in windless weather, and air pollution associated directly with human activity. Smog contains harmful chemical compounds, e.g. sulphur oxides, nitrogen oxide and so-called suspended particulate matter, that is solid particles which can easily penetrate into the respiratory system. There are two types of smog. The first one, London smog, contains sulphur oxide, nitrogen oxides, carbon oxides and soot. The other type is referred to as Los Angeles smog, and it is produced primarily in subtropical areas. It contains carbon oxides, nitrogen oxides and hydrocarbons which undergo chemical reactions, whose products include aldehydes and ozone.

Three main causes of smog

Doubtlessly, the cause of smog formation is human activity, closely related to air pollution. House heating, transport and industrial plants are the major sources of air pollution, and thus of smog. One of the most pressing problems is low emission, related to house heating. It involves burning coal, coke, wood, and even rubbish in household furnaces, heaters and fireplaces. In Poland, there are no standards regarding pollutant emissions from the furnaces available on the market, and social awareness in this area is still very limited. Heavy traffic is another source of pollution. This is mostly caused by diesel-powered vehicles, but also by the particulate matter formed due to tyre and brake block wear. The activity of industrial plants also plays a part in the problem. Iron works, heating power stations and coal-based power generation are significant sources of pollution.

How does smog affect our health?

Smog induces respiratory diseases and neoplasms, intensifies allergic reactions, and increases the risk of asthma. Children of women exposed to smog during pregnancy have lower birth weight. Smog is also a serious hazard to the environment. It may cause acid rain, which contains poisonous acids that damage forests, and increase the acidity of soil and water. Children, pregnant women and seniors are particularly exposed to the risks associated with smog.

Smog in Poland

Poland is among the countries with the worst air quality, and the highest concentrations of harmful substances. The most dangerous are benzo(a)pyrene and particulate matter PM2.5 and PM10. The most polluted air is found in małopolskie, śląskie, łódzkie and mazowieckie voivodeships. However, the problem concerns the entire country. Smog is a common phenomenon in Poland, especially in autumn and winter.