The Spatial Distribution of Characterised Fly-Ash Particles and Trace Metals in Lake Sediments and Catchment Mosses in the United Kingdom

Abstract

Spheroidal carbonaceous particles (SCP) and trace metals (Cd, Cu, Pb, Ni, V and Zn) were analysed from 75 lake surface sediments across the UK. Trace metals were additionally analysed from catchment mosses (Hylocomium splendens and Pleurozium schreberi) from 43 of the sites but were absent from the remainder. Spatial distribution of SCP concentration and trace metal concentrations in sediments and mosses showed good agreement with each other and with known emission sources. Particles were allocated to their fuel-type and spatial trends in these data showed good agreement with potential sources. High areas of oil particle deposition were identified in the south-east of England, Merseyside, Galloway / Northern Ireland, the Firth of Forth and eastern Scotland. Oil SCP concentrations showed good agreement with Ni and V concentrations in mosses suggesting an atmospheric source for these metals from the combustion of this fuel. Characterised SCP trends also showed good agreement with predictions from models such as HARM and EMEP. Most high deposition areas of metals and particles were found to coincide with population centres suggesting a possible impact on human health.