Reacción a "Most deaths attributable to ground-level ozone in European countries are associated with ozone from outside their borders"

This article presents the relationship between ozone concentrations and mortality. Key points, which determine the publication of the analysis, are the continental scope of the study, as it includes almost all European countries, and also the impact of ozone transport. This is a point that the article stresses, as ozone can be transported and impact in places far away from the source sites. Indeed, one of the most striking results is that the highest levels of mortality do not occur in the areas of highest concentrations.  

Weaknesses include the period analysed, 2015-2017, which may not correspond to the current situation, and the uncertainty associated with the data, especially deaths, in the sense of whether the numbers actually correspond to deaths whose only origin is high ozone concentrations or whether additional causes are present. In general, the results are presented according to administrative geographical boundaries, which can be very uneven, so this is an article aimed at pollution managers or the general public. Finally, the analysis suggests the need to control ozone precursor emissions and the need for international collaboration to achieve satisfactory results.