New research by KCL suggests that primary PM10 in London increased between 1998 and 2003.

Annual mean concentrations of PM10 in and around London reduced during the 1990s, however, concentrations have been relatively stable since, with small increases during 2001-2003. Source apportionment of PM10 was undertaken to understand the reasons for these changes in measured concentrations.

It was found that the annual mean concentration of PM10 from primary sources reached a minimum during 1998. Between 1998 and 2003 the greatest increase in the annual mean concentration of primary PM10 occurred at sites adjacent to busy roads: The smallest change in the concentration of PM10 from primary sources occurred at background locations in towns outside London. It is therefore likely that the additional primary PM10 arose from road traffic.

These increases in PM10 from primary sources contradict emissions inventory estimates that indicate consistent reductions in primary PM10.

The research is published in Atmospheric Environment:
Fuller, G.W and Green, D., 2006. Evidence for increasing primary PM10 in London. Atmospheric Environment 40, 6134 - 6145

Item date 06/10/2006