Reacción a "Reactions: exposure to pollution may increase stroke risk also in the short term"

In this study, the authors conduct a systematic review and meta-analysis of the relationship between exposure to different air pollutants and the occurrence of ischaemic stroke. The study draws on more than 100 published observational studies and a total of more than 18 million cases from large clinical databases such as MEDLINE, Scopus, Cochrane Central and Web of Science, and finds a positive correlation between the incidence of cerebral ischaemia and exposure to numerous compounds from environmental pollution. These include sulphur dioxide (SO₂), nitrogen dioxide (NO₂) and PM2.5 and PM10 particles (derived from the combustion of fossil fuels and classified according to their size), which are associated with an increased risk of mortality due to these neurological accidents.  

The importance and significance of this study lies not only in the enormous size of the population sample analysed and the studies included, but also in the fact that it analyses the effect of individual chemical components. Moreover, it has the novelty of analysing the short-term effect between exposure and the onset of neurological problems, as until now most studies have analysed the long-term effect (chronic exposure).  

The study has certain methodological limitations, such as the inclusion of a population mostly from developed countries; data from developing countries such as those in Africa are missing. Nevertheless, this study warns of the significant risk of stroke following recent (and not just chronic) exposure to air pollution, and should be taken into account when establishing measures to curb pollution, especially in cities and industrial areas.