Is the Clean Air Zone the right solution for Sheffield’s dirty air?

What is the Clean Air Zone?

It’s been just over a year since Sheffield introduced its controversial Clean Air Zone (CAZ) policy, which fines dirty taxis, lorries and buses for driving through the city centre. To drive into the zone, highly polluting taxis and vans must pay £10 a day. For dirty lorries and buses, it’s £50 a day.

In many cities, including Berlin, Birmingham and London, air quality research has shown that Clean Air Zones have reduced pollution.

Why might Sheffield need one?

In the 1960s Sheffield was one of the most polluted cities in Europe. Residents tell stories of only being able to see clear skies once a year – when the steel factories would close for summer holidays. Things have improved significantly since then, but the air quality in parts of the city is still well above the WHO healthy limit.

“Poor air quality kills people,” said Dr Greg Fell, Sheffield Director of Public Health, in a video released by the City Council when the CAZ was first introduced.

“It puts people into hospital for stroke and heart attacks and cardiovascular causes, and it accelerates ageing. So the reason we're doing this work is to reduce illness and reduce deaths.”

Pollution still contributes to the deaths of an estimated 500 people in Sheffield each year. It also contributes to 12% of Sheffield’s childhood asthma cases.

“There’s no universe where [reducing air pollution] isn’t the right path to go to protect the health of our children, our future, but also the health and wellbeing of adults alive today,” said Fell.

Is the CAZ working?

Determining whether the CAZ is improving air quality is not as simple as comparing one year’s air quality readings to the next.

Dr Maria Val Martin, an Atmospheric Scientist at the University of Sheffield who is studying the CAZ air quality data, explained: “We had COVID, which makes it difficult because the air pollution levels from those years aren’t representative of the city. Air pollution can also depend on the weather, so we need to make sure the changes aren’t caused by that.”

While the city has yet to release air quality data showing definitively whether the CAZ has reduced pollution, they have announced intentions to publish results this summer. Dr Val Martin’s team will also publish their CAZ analysis at a similar time.

Despite the absence of this data, the city has already declared a win – and their plan to eventually do away with the CAZ.

On the one year anniversary of the Clean Air Zone in February, the Council announced that the CAZ had been a success, citing data showing that the numbers of dirty vehicles driving through the city centre had decreased by two-thirds. Shortly afterwards, they released plans to eventually decommission the zone if air quality improves substantially, arguing that Sheffield won’t need the CAZ if the city’s vehicles are cleaner.

“We can do more,” said Dr Val Martin. “Any initiative that gives urban spaces back for public use or reduces traffic is good. For these initiatives to work, however, they require a holistic approach, and active involvement of everybody, including residents, businesses and local authorities.”