Lorraine Williamson
Spain is finally breathing easier in its biggest cities. Nitrogen dioxide (NO₂) — the traffic-linked pollutant that defined a decade of bad headlines — has fallen sharply in recent years.
But the next EU target is far tougher than the current one. And on today’s numbers, most Spanish cities are not even close.
Ecologistas en Acción, which has compiled preliminary 2025 readings from official monitoring stations across around 20 large and mid-sized cities, says every city studied still sits above the EU’s incoming annual NO₂ limit of 20 μg/m³. The World Health Organisation’s health-based guideline is stricter again, at 10 μg/m³.
The numbers that tell the story
Start with the good news. Spain’s current legal annual NO₂ limit remains 40 μg/m³. Cities that once breached it routinely are now staying under it.
Now the reality check. In 2025, the highest annual concentrations highlighted by Ecologistas en Acción were recorded at traffic-heavy stations in:
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Madrid (Plaza Elíptica): 32 μg/m³
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Málaga (Avenida Juan XXIII): 31 μg/m³
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Granada (Granada Norte): 30 μg/m³
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Barcelona (Eixample): 29 μg/m³
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Murcia (San Basilio): 29 μg/m³
Cities hovering closest to the new EU line include Valladolid (Arco de Ladrillo: 20 μg/m³) and Santa Cruz de Tenerife (Piscina Municipal: 20 μg/m³) — still fractionally above the target, but in touching distance.
Madrid: compliant, but stalled
Madrid has now remained within the current EU limits for four consecutive years, and the city says it has avoided activating its high-pollution protocol again in 2025. Across its network, no station exceeded 32 μg/m³ last year.
Yet the trend line is no longer falling cleanly. Ecologistas en Acción argues the city is still a long way from 2030 compliance, with 17 of Madrid’s 24 stations above the 20 μg/m³ threshold in 2025, and only a handful below — largely in greener areas.
There is another complication that gets less attention: ozone. The same set of Madrid data shows ozone pollution worsening, a reminder that “cleaner traffic” is not the whole air-quality story.
Why Málaga and Granada matter beyond their city limits
Málaga and Granada being near the top of the NO₂ list matters because they are not outliers. They are a warning sign for fast-growing urban areas where traffic remains the default.
For Andalucia, the message is uncomfortable but clear. Coastal mobility patterns, commuter corridors, and pressure on housing and jobs keep vehicle kilometres rising. Cleaner engines help. But they do not erase congestion.
And in day-to-day life, the most polluted air is often not an abstract citywide average. It is the school run route, the ring road, the bus corridor, the street canyon where fumes linger.
Low-emission zones: law on paper, patchwork on the ground
Since before 2023, Spain has required municipalities with over 50,000 residents (plus islands and smaller towns that exceed limit values) to establish low-emission zones (ZBE)
Ecologistas en Acción says the rollout has been slow and, in many places, ineffective. In short, the legal framework exists, but enforcement and ambition vary widely.
Madrid’s own debate shows how political this can get. The city has extended permission for some resident-owned cars without environmental labels to continue circulating during 2026 — a decision critics say cuts against the direction of travel.
Are cities measuring the worst air?
One of the sharpest criticisms in the 2025 review is not about policy — it is about data.
Ecologistas en Acción argues that some “traffic” monitoring stations are poorly positioned and miss the true hotspots that the new EU rules want captured. If you do not measure the worst air, you can end up congratulating yourself too early.
That matters because the revised EU air rules are designed to tighten not only limits, but also how compliance is assessed, with a stronger emphasis on credible monitoring and early action.
What the EU’s new rules change — and why 2030 is not “far away”
The revised EU Ambient Air Quality Directive is part of the bloc’s wider “zero pollution” push. It raises the bar for multiple pollutants and leans closer to WHO health guidance.
The politics is familiar. Spain was warned in the last decade over repeated breaches in major urban areas, and only serious legal and financial pressure pushed some tougher measures into place.
The difference now is timing. The direction is set, and the limit is clearer. Cities that wait for 2030 may discover the last-minute sprint is brutal — and far more expensive than steady change now.
The 2030 limit is a health deadline, not a bureaucratic one
NO₂ is not just a “traffic number”. It is linked to respiratory harm, and public-health agencies treat urban air as one of Europe’s most persistent environmental health risks.
That is why campaigners argue the right question is not, “Can we hit 2030?” but, “How many years of avoidable exposure are we willing to accept?”
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