Spain sees sharp rise in ozone pollution as heat wave intensifies

A prolonged heat wave has pushed tropospheric ozone levels to hazardous thresholds across several Spanish regions. In Valladolid, the city’s low‑emission zone (ZBE) was temporarily closed and traffic restrictions imposed after ozone concentrations exceeded the health limit of 120 µg/m³. Ecologistas en Acción criticised the measures as too late and called for the ZBE’s expansion to the city’s inner ring, alongside broader actions such as electric public transport and tighter controls on industrial solvents.

The same heat‑driven ozone spike was recorded in the Cantabrian coast – Galicia, Asturias, Cantabria and the Basque Country – where alerts were rarely needed. Authorities in those northern communities were accused of insufficient warning, while the European Environment Agency estimates 6,000‑7,000 premature deaths each year in Spain from ozone exposure. Health officials warned vulnerable groups – children, the elderly, pregnant women and people with respiratory or cardiovascular disease – to limit outdoor activity.

Ecologistas en Acción highlighted the unusual nature of the episode for the north, noting that ozone formation typically requires strong solar radiation and is more common in Mediterranean areas. The organization urged faster, broader mitigation measures to protect both public health and vegetation.