The UK has legal air-quality limits for major pollutants at a local and national level, covering pollution from ammonia, particulate matter, nitrogen oxides (NO₂), non-methane volatile organic compounds, sulphur dioxide, and more.

An NAO report assessing the effectiveness of policies designed to tackle these pollutants has found that only sluggish national action has been taken to tackle the challenges on major roads and motorways, which means overall compliance cannot be achieved until after 2030.

This is more than four years later than the government expected when it published its plan for tackling NO₂ in 2017.

Furthermore, the NAO said there is particular concern about the health risks from particulate matter and ammonia.

“Government is not yet clear how it will meet existing 2030 ceiling limits, and expects to set new long-term targets for particulate matter by October 2022,” the report states.

The NAO urged faster action with “robust plans” to meet...