Vulnerable groups at risk: ozone levels in Bavaria are constantly increasing – how dangerous is the gas really?
Created: 2022-08-02 19:29
By: Thomas Eldersch
The ozone pollution in inner cities - like here in Munich - is often lower than on the outskirts or in the country.
© Sven Hoppe/dpa
In Bavaria, the average ozone value has been increasing for years.
This can have health consequences – especially for vulnerable groups.
Munich – The slightly older generation still knows them.
The 1980s and 1990s warnings about the ozone hole.
The consequence at that time was the ban on harmful chlorofluorocarbons, CFCs for short.
Now the ozone is back.
But not in the form of a hole in the stratosphere.
This time there is also danger at ground level, as ozone levels have been rising steadily in recent years.
Ozone can be dangerous for certain population groups
Meteorologists like Jörg Kachelmann are now warning of the dangers of the odorless gas more frequently in the hottest time of the year.
Because ozone is not to be trifled with.
The gas can be dangerous, especially for vulnerable groups.
So babies, children, the elderly and people with lung diseases (asthma, COPD) should be careful when the concentration reaches or even exceeds certain limits.
These are set by the Federal Environment Agency.
The information threshold is reached from a value of 180 µg/m3 (1-hour value).
This means that recommendations for behavior are issued to the population.
If a value of 240 µg/m3 (1-hour value) is reached, the alarm threshold has been reached.
The Federal Environment Agency further states:
A target value has been set to protect human health: the maximum 8-hour value per day may exceed the value of 120 µg/m3 on a maximum of 25 days per calendar year, averaged over 3 years.
In the long term, the maximum 8-hour average should no longer exceed the value of 120 µg/m3.
To protect the vegetation, a target value of 18,000 µg/m3 applies in the 5-year mean as the sum of the difference between one-hour mean values over 80 µg/m3 and 80 µg/m3 during daylight hours (8 a.m. to 8 p.m.) of the main vegetation period from May to July (AOT 40) .
Risks of excessive ozone pollution
But what are the risks if the load is too high?
The gas attacks the lungs and can impair their function.
It can cause breathing difficulties and cause inflammation in the airways.
About 15 percent of the population across all walks of life are particularly sensitive to the gas.
Since ozone is a very reactive gas, it is even suspected of being carcinogenic.
The MAK Commission (MAK = Maximum Workplace Concentration) of the German Research Foundation (DFG) assessed ozone as a substance that "is suspected of causing cancer in humans".
Ozone is also harmful to plants.
On the website of the Federal Environment Agency it says: "Ozone is absorbed by plants through the stomata of the leaf organs.
This can cause damage to leaf organs in plants.
Prolonged exposure poses a risk to plant growth, crop yields and agricultural product quality.”
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How can you protect yourself from excessive ozone pollution?
How is ozone actually formed near the ground?
The gas is formed when the solar radiation is particularly high.
Then complex photochemical processes from precursor pollutants take place.
These include mainly nitrogen oxides.
Around half of all nitrogen oxides are generated by road traffic.
However, paints, varnishes and cleaning agents with solvents can also generate ozone.
In order to avoid the formation of ozone, you should leave your car on hot days if possible or use solvent-free products.
To protect yourself from possible damage from ozone, you should move exercise to the morning hours on hot days.
Then the load is at its lowest.
Ventilation should also be provided here so that the windows can remain closed in the afternoon and evening.
In addition, the pollution on the outskirts is usually higher than directly in the city center - although there is more traffic there.
The Federal Environment Agency says: "That sounds paradoxical, but it's because the nitrogen monoxide (NO) contained in car exhaust gases reacts with ozone.
In the process, ozone is broken down, so that the ozone pollution in inner cities is significantly lower.
On the other hand, the precursor substances are transported out of the cities with the wind and thus contribute to ozone formation at a distance from their actual sources.”
Ozone hole over Antarctica reaches one of largest in 15 years (video)
Despite warmer summers in Bavaria, the maximum ozone load is decreasing
With the increasingly warmer summers due to climate change, one might think that the limit values would have to be exceeded much more frequently these days.
But this is not the case.
According to the Bavarian State Office for the Environment, the information threshold was regularly exceeded in Bavaria in the 1990s.
The last time the alert threshold was exceeded was in 2003. But how can that be?
The graphic shows on how many days per year the limit of 120 µg/m3 was exceeded.
© Federal Environment Agency
Although temperatures are more and more often above 35 degrees, the conditions for the formation of ozone have changed in recent years and decades.
Precursor substances such as NOx are produced less - keyword fine dust.
The Federal Environment Agency states:
"If the high emissions of 2003 had still been released in July 2013, this would have led to higher ozone levels in large parts of Germany [...].
If the meteorological conditions of July 2003, which were somewhat less favorable for ozone formation, had prevailed in July 2013, this would have led to lower ozone values in large parts of Germany […].
The conditions for ozone formation were therefore more favorable in July 2013 than in July 2003;
nevertheless, in July 2013 there were lower ozone concentrations and thus fewer target values and the information and alarm thresholds were exceeded.”
A reason to be happy, isn't it?
Not quite.
The peaks in ozone levels have decreased.
However, mean ozone pollution has increased in recent years.
"The target value for health protection - 120 µg/m³ as an 8-hour average, may be exceeded on a maximum of 25 days per calendar year, averaged over 3 years - is not met in many places in Germany.
The long-term goal - 120 µg/m³ as an 8-hour average - is currently missed across the board in Germany," according to the Federal Environment Agency.
However, this constant increase can only be stopped globally by further reducing precursor emissions.
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Here you can track the ozone pollution and other air values for Bavaria and your region.
