As expected a rise in PM10 particulate concentrations started overnight across the London and neighbouring air quality monitoring networks. Increased PM10 at background locations and the increased in semi-volatile particles are indicating imported pollution from continental Europe. The air feed from Europe is expected to continue and strengthen leading to widespread ‘moderate’ air pollution at roadside locations and breaches of the EU limit value at background locations.

Around Friday a frontal system is expected to introduce fresher Atlantic air and give a temporary clearance. Medium range weather forecasts indicate the possibility of another PM10 particulate episode building from the weekend onwards.

Item date 16/03/2011 14:00:00