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maitem Jul 09, 2018 05:53 PM
Dear EEA,

At the moment, I'm writing my master thesis about the enforcement of European Commission's Air Quality Standards, with a particular focus on PM.
There are three things that remain unclear for me, and that I find difficult to find online. I hope you can maybe help me with answering them.
1) Why are there no daily limits for PM2.5 concentration?
2) I cannot find the emission ceilings for PM.Is there a difference between the air quality standards for PM, and the PM Emissions Ceiling? Or do the Air Quality Standards refer to the emissions as well?
3) Directive 2008 mentions after stating the limit values how the 'tresholds do not apply to the measurements to assess compliance with the PM2.5 exposure reduction target for the protection of human health' ([…]/?uri=CELEX:32008L0050&from=en , pg. 152/16)
If these tresholds are not being used (or at least not only these tresholds), how is compliance with the PM2.5 value (and PM10 as well) measured

If you would have the knowledge, it would be great if someone would be willing to provide me with answers to these questions,
Thank you very much in advance,

Maite (Maastricht University, the Netherlands)
Replies (1)
EEA Jul 11, 2018 03:19 PM
here are the answer for each of your questions:
1) The European legislation is the result of a negotiation process involving the European Commission and the European Parliament together with the Member States. When negotiating the Air Quality Directive 2008/50/EC, instead of including a daily limit value for PM2.5 (probably due to the fact that long-term exposure to PM implies more serious impacts, see for instance the WHO Air quality guidelines for particulate matter, ozone, nitrogen dioxide and sulfur dioxide - Global update 2005) it was decided to include new standards as the average exposure indicator and new obligations as the National exposure reduction target or the Exposure concentration obligation (see annex XIV to the AQ Directive 2008/50/EC). In any case, for further information on the process that led to the approval of the AQ Directive 2008/50/EC, we would propose you to contact the European Commission (see, for instance,

2) The air quality standards defined in the AQ Directive 2008/50/EC refer to maximum values of concentration of pollutants in ambient air. On the contrary, the National Emissions Ceilings Directive (NECD) sets national reduction commitments for the emissions of, among others, PM2.5 (see Annex II to the NECD). You can find more information at

3) You refer here to the upper and lower assessment thresholds, used to define the air quality assessment method (fixed measurements, indicative measurements, modelling, etc) and the minimum number of sampling points. What is said in Annex II is that these criteria of the upper and lower assessment thresholds do not apply to the measurements related to the exposure reduction target, which is regulated under Annex XIV (see previous point 1).
I hope this information will be useful to you.
Best regards