is the headline based on a press release by the EEA that became online only this morning after having been taken up by news outlets like the Guardian, DW and Tagesschau. Many newspaper did not respond, so was it just a small experiment which news desk can discriminate fake and real news?

When asking the EEA about the source of their information, they responded by an automated reply. Maybe I am wrong but this looks like a scientific hoax just like the recent news of 6000 deaths by NO2 .
I cannot find any scientific study that allows for such a claim. There are 200 children dying from asthma in the US every year. My estimate for Germany is not higher than 10 and for Europe not more than 100 children per year (see below). The only source given in the press release is leading to a page listing the EEA member countries.

Another reference in the text is made to the GBD Collaborative Network 2020, probably https://ghdx.healthdata.org
As a research institute, we rely primarily on data collected by others, or secondary data…. If a newly-discovered dataset is publicly available, we download it straight from the source. If not, we request access to the data, which may involve entering into a data use agreement with the collector.
But also here deaths by asthma do not exceed N=30.

Even if we add any upper or lower respiratory disease, we are still at N<1000 p.a.
No method is given by the agency so I do not know how they arrived at the conclusion that air pollution is causing over 1,200 premature deaths every year among those under the age of 18.
Maybe the topic is too serious for EU policy makers like Hans Bruyninckx. Until proven otherwise this press release contains fake news.