Should you protect yourself against air pollution during sunny days?

Air pollution during sunny days

Why check the quality of the air we breathe every day? According to research carried out by the European Environment Agency, in medium and large Polish cities the acceptable level of PM10 dust exceeds the norm for over 100 days a year.

We are exposed to air pollution not only during bad, autumn-winter weather, but also when the sun is shining and the wind is not blowing. In the article, we present the reasons for the formation of pollution during nice weather, which theoretically should improve air quality, and practically contributes to its deterioration.

photo: Shutterstock

Weather conditions that leads to the formation of smog

Polluted air is created as a result of heating buildings with coal-powered furnaces, exhaust emissions from transport and the release of pollutants emitted by factories into the atmosphere. Weather conditions also have a direct impact on the appearance of smog:

  • no wind or light wind,
  • high temperature and high sunlight,
  • no snow or rain,
  • low temperature.

One of the reasons for the appearance of smog is the lack of wind. Due to the lack of air traffic, polluted air accumulates in a given area - usually in medium and large cities. 

High exhaust emissions from transport, industry and the heating season result in accumulation of dust particles and fumes, have negative impact on human body by weakening immunity system, affecting well-being, and in the long run cause respiratory and cardiovascular diseases.

The cloudless sky during the day reasons in a cool night. Heating of houses and flats at night causes the accumulation of large amounts of dust as households are responsible for the emission of almost 50-60% of pollution (outdated heating systems, low-quality heating fuels, coal and garbage).

By far the worst air quality occurs in the evening, after the sunset when changes of temperature cause "inversion" and pulling the polluted air close to the ground. This phenomenon can last till the sunrise when the sunlight warms the polluted air and makes it float higher.

It is also not recommended to go jogging or cycling during the first spring days. Oxygen intake during exercise is 3-4 times higher than at rest - hence, we are exposed to absorbing larger amounts of pollution that can get into our airways.

source: (as of 08.02.2019)

Impact of transport on air quality

The number of cars per capita has increased significantly in recent years. For example, in Katowice the number of cars per 1000 inhabitants increased by over 13% comparing to the last 5 years, (to over 700 cars).

It means that around 210,000 cars are moving around the city with a population of 300,000 people, which emit health-threatening exhaust fumes. Nitrogen oxides and hydrocarbons emanating from the tailpipes of motor vehicles oxidize, forming ozone, which is very dangerous to health.

Some cities in Europe (e.g. Paris, Madrid, Athens) due to the scale of pollution caused by exhaust emissions introduced restrictions on diesel cars - in some cases, authorities created zones were into which these vehicles cannot enter.

In addition, people are less likely to travel by public transport, choosing private means of transport. In Wrocław, the number of people using public transport dropped from 35% to 28% compared to 2011.


Nice weather does not mean clean air

We are exposed to the harmful effects of smog not only in the autumn and winter. In larger cities, the acceptable norm for PM2.5 and PM10 dust concentrations is exceeded for over 100 days a year.

Let's verify the level of polluted air every day and prevent smog exposure by using health protection measures, such as masks or anti-smog scarves. Even during sunny, windless days we are exposed to low quality air. If possible, let's stay at home, and if necessary let's move around the city by public transport instead of by car.