IN the last Globe, Stephen Edwards pointed to NICE guidance promoting physical activity such as walking or cycling children to school.

Outdoor exercise is indeed a good idea BUT only in clean air conditions.

At morning rush hour, as kids travel to school Particulate Matter (PM) and nitrogen dioxide reach peak levels.

Much of urban Wirral near major roads has PMs and NOx well above the WHO limits at these times.

For example while the WHO PM annual mean limit is 10 micrograms per metre cubed, for the whole of April 2019, the Birkenhead / Tranmere mean level was 18.9.

The maximum daily mean in 2019 so far is 52 units at Tranmere and the maximum hourly mean 82 units.

Parents who are moved to follow Mr Edwards' advice might wish to check out the DEFRA UK Air website and the Air Quality England website for daily Tranmere AURN pollution measurements.

Remarkably Tranmere is the only place in Wirral where the council monitors PMs and strangely that is in a park far from a major road.

Planning should 'minimise the exposure of vulnerable groups to air pollution by not siting building in areas where pollution levels will be high.'

Sadly many of our schools are near high pollution roads.

Fewer motorised school runs would indeed reduce air pollution but at morning rush hour would make little overall difference in urban areas.

By the way even if all fossil fuel cars were banned and we went electric, 78% of traffic PMs would remain.

Successive governments have been living in a fantasy land on this issue.

Don't let fantasy misinformation and official misdirection damage your children's health.

Professor D P Gregg, Spital