Using differing modelling approaches, both Imperial College London and King’s College London found that most of the UK will have concentrations of the pollutant below 10 micrograms per cubic metre by 2030. This is so even under a business-as-usual scenario.
The World Health Organization (WHO) recommended that the level is not exceeded in guidelines issued in 2006. But an accompanying note from the advisory Air Quality Expert Group cautions that the “very crude” target was set only according to what was thought possible to be met. There is no evidence that there is a safe concentration below which human health impacts, such as cardiovascular and respiratory disease, may not be encountered.