Londoners told to reduce physical activity on Friday due to pollution

Government advises older people and those with lung or heart issues to avoid strenuous activity altogether

Londoners should avoid strenuous physical activity on Friday due to very high" levels of pollution, experts have warned.

The poor air quality is the result of an intense area of high pressure covering western Europe. The associated lack of air movement means emissions from vehicles and other pollutants are not blown away as they usually would be.