“Let’s go outside,” many say to themselves when the sun beckons. But some people experience a nasty surprise when they get on their bikes in beautiful summer weather: headaches, watery eyes or coughing – the range of problems triggered by increased ozone levels is broad. After all, about ten to 15 percent of the population is sensitive to elevated ozone concentrations. “In particular, people with hay fever or asthma must expect more severe respiratory problems when ozone levels are high,” says Professor Johannes Ring of the German Society for Allergology and Clinical Immunology (DGAI). In this case, a specialist trained in allergology can improve the acute symptoms with anti-allergic medication. Specific immunotherapy with modern molecularly standardized allergens (allergy vaccination) even achieves long-term relief of symptoms in most cases.
Ozone triggers inflammatory processes
Ozone has already made negative headlines several times. In the upper layers of the air, the ozone concentration continues to decrease. The result is the notorious ozone holes. Near the ground, however, average ozone concentrations increase from summer to summer. Here, ozone is the main component of the so-called summer smog, which is composed of many pollutants.
Intense solar radiation, general vegetation, air pollution and a certain weather condition lead to the formation of ozone near the ground and at the same time prevent the removal of this irritant gas. The sad result of the beautiful but ozone-laden weather is that one-third more asthmatics come to emergency outpatient clinics than on days with low ozone levels.
Ozone may exacerbate hay fever and asthma
Ozone and other components of summer smog cause the increased release of allergens. The main problem, however, is that ozone is not retained by the mucous membranes of the upper respiratory tract, but penetrates deep into the bronchi. There it breaks down into aggressive oxygen radicals that can cause inflammation in the surrounding tissue. If allergens are then inhaled, they can have a much more immediate effect.
Summer smog is therefore doubly bad for the person affected. There are more allergens in the air and ozone promotes allergic reactions by damaging lung tissue. Ozone not only aggravates existing respiratory diseases, but may even promote the development of new asthma.
This was the conclusion of an American study of 3,500 children last year. The more outdoor sports are played at high ozone concentrations, the higher the risk of developing a respiratory disease, the study found. Nevertheless, there is no need to raise your children to be couch potatoes. If they refrain from major outdoor exertion when ozone levels are high, there is no increased risk, the American scientists said.
No exertion at peak ozone levels
How often should we expect elevated ozone levels in the summer? The German Federal Environment Agency receives data from more than 360 measuring stations and shows that dangerous ozone peak values are now reached less frequently. Nevertheless, average ozone levels continue to rise. In 2001, ozone concentrations at individual measuring stations exceeded 180 micrograms per cubic meter of air (mu)g/m3 on 33 days and even exceeded 240 (mu)g/m3 on seven days. Above 180 (mu)g/m3 the population is informed about the ozone danger. Allergy and asthma sufferers in particular must then expect health problems. If 360 (mu)g/m3 of ozone in the air is exceeded, there is also an acute danger for healthy people.
At high ozone levels, people should refrain from physical exertion outdoors. This is because exertion or exercise makes us breathe more deeply, consequently more ozone penetrates much further into the lungs.
