Se in inverno a preoccupare sono le polveri fini, in estate è l'ozono a creare grattacapi, soprattutto nelle giornate soleggiate e calde.
Oggi, infatti, le concentrazioni di questo gas in Ticino hanno superato la soglia di 180 microgrammi per metro cubo, un valore di 1,5 volte superiore al limite previsto dall'ordinanza contro l'inquinamento atmosferico.
Tenuto conto che anche la giornata di domani sarà caratterizzata dal bel tempo, i tassi di inquinamento rimarranno alti e verrà superata nuovamente la soglia d'informazione. I consigli sono sempre gli stessi: evitare sport durante le ore più calde e ripararsi dal sole.
Nel corso degli ultimi venti anni, la Confederazione, i cantoni e i comuni hanno adottato diverse misure e ridotto di circa la metà i precursori dell’ozono. In linea di massima, il problema dello smog estivo può essere risolto soltanto mediante l’adozione, a livello nazionale e internazionale, di misure durature. Fra queste vanno ad esempio annoverate misure tecniche come il miglioramento delle tecnologie di riduzione dei gas di scarico o la promozione dei trasporti pubblici.
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