Comparison of estimated annual emissions and measured annual ambient concentrations of metals in the UK 1980-2007.

The estimated annual emissions and measured ambient concentrations of metals (Cd, Cr, Cu, Ni, Pb, V and Zn) in the UK 1980-2007 have been compared. Both quantities show decreases over this time period and exhibit a broad correlation, although many obfuscating factors impose significant noise on this relationship. A generalised least squares regression analysis has been performed for each metal to estimate the sensitivity of measured ambient concentrations to emissions, and to predict ambient concentrations in the absence of emissions. This process has shown that metals emitted mainly from diffuse sources, such as transport, show the highest sensitivities of ambient concentrations to emissions. The results also provide some evidence to suggest that vanadium emissions may be overestimated.