Reacción a "Extreme heat and air pollution expose nearly 40 per cent of the world’s population to dangerous levels of tropospheric ozone"

This study highlights a reality that is becoming increasingly evident: that global warming and its consequences have a distinctly cross-border nature.

The increase in tropospheric ozone concentrations caused by the emission of its precursors in cities from traffic and energy production, high temperatures and the forest fires themselves – with their emissions of volatile organic compounds – is leading to ever-increasing exposure of the population to this secondary pollutant. These forest fires, whose smoke can travel hundreds of kilometres from the source of the blaze, also carry particulate matter whose impact on health is more harmful than that of the particles emitted in urban environments.

On numerous occasions, in addition to heatwaves and forest fires, emissions of particulate matter of desert origin must also be taken into account. These not only impair air quality due to the increased concentrations of these particles in the air, but have also been shown to be linked to increased levels of other pollutants such as nitrogen dioxide or ozone itself.

We are therefore faced with a problem whose impact on health is not limited solely to the high temperatures associated with heatwaves, but also encompasses the impact of air pollution, the health effects of which, in some circumstances, may be greater than those of the temperature itself.

It is clear that the public health response to minimise the impact on the population must not be limited to measures targeting just one of these factors; rather, it must consist of integrated plans that bring together measures to protect public health in relation to both heat and air pollution as a whole. The cross-border nature of the naturally occurring pollution problems addressed here does not exempt the relevant authorities from taking local action to reduce anthropogenic emissions.