Advice on the Defra website states that for high levels of pollution “adults and children with lung problems, and adults with heart problems, should reduce strenuous physical exertion, particularly outdoors, and particularly if they experience symptoms.
“People with asthma may find they need to use their reliever inhaler more often. Older people should also reduce physical exertion.”
It adds that “anyone experiencing discomfort such as sore eyes, cough or sore throat should consider reducing activity, particularly outdoors”.
In February, the European Commission launched legal proceedings against the UK for failing to reduce levels of NO2 air pollution.
See on www.bbc.co.uk