Could congestion charges help solve Cardiff's pollution?
The average air quality over Cardiff is the fourth worst in the UK, according to the latest research.
So the Welsh capital's council is to bring in a series of measures to tackle the problem.
Among the plans, to be confirmed on 15 January, are improved public transport, taxi licensing changes, re-modelled roads to encourage active travel and 36 electric buses.
Campaigners are hoping congestion charges in the city centre could also be introduced.
"Clean air zones are the most effective way of reducing air pollution in the short-term and working towards clean air levels in the long term," said Huw Cook of Healthy Air Cymru.
15 Jan 2020