title: Quantifying missing annual emission sources of heavy metals in the United Kingdom with an atmospheric transport model.
abstract: An atmospheric chemical transport model was adapted to simulate the concentration and deposition of heavy metals (arsenic, cadmium, chromium, copper, lead, nickel, selenium, vanadium, and zinc) in the United Kingdom. The model showed that wet deposition was the most important process for the transfer of metals from the atmosphere to the land surface. The model achieved a good correlation with annually averaged measurements of metal concentrations in air. The correlation with measurements of wet deposition was less strong due to the complexity of the atmospheric processes involved in the washout of particulate matter which were not fully captured by the model. The measured wet deposition and air concentration of heavy metals were significantly underestimated by the model for all metals (except vanadium) by factors between 2 and 10. These results suggest major missing sources of annual heavy metal emissions which are currently not included in the official inventory. Primary emissions were able to account for only 9%, 21%, 29%, 21%, 36%, 7% and 23% of the measured concentrations for As, Cd, Cr, Cu, Ni, Pb and Zn. A likely additional contribution to atmospheric heavy metal concentrations is the wind driven re-suspension of surface dust still present in the environment from the legacy of much higher historic emissions. Inclusion of two independent estimates of emissions from re-suspension in the model was found to give an improved agreement with measurements. However, an accurate estimate of the magnitude of re-suspended emissions is restricted by the lack of measurements of metal concentrations in the re-suspended surface dust layer.
authors.affiliation: Centre for Ecology and Hydrology, UK. Electronic address: todo@ceh.ac.uk.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Dore
authors.affiliation: Centre for Ecology and Hydrology, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Hallsworth
authors.affiliation: Scottish Environment Protection Agency, UK.
authors.forename: Alan G
authors.initials: AG
authors.lastname: McDonald
authors.affiliation: Department of Climatology and Atmosphere Protection, University of Wrocław, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Werner
authors.affiliation: Department of Climatology and Atmosphere Protection, University of Wrocław, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Kryza
authors.affiliation: Ricardo-AEA, Didcot, UK.
authors.forename: John
authors.initials: J
authors.lastname: Abbot
authors.affiliation: Centre for Ecology and Hydrology, UK.
authors.forename: Eiko
authors.initials: E
authors.lastname: Nemitz
authors.affiliation: Aether Ltd., Oxford, UK.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Dore
authors.affiliation: Centre for Ecology and Hydrology, UK.
authors.forename: Heath
authors.initials: H
authors.lastname: Malcolm
authors.affiliation: Centre for Ecology and Hydrology, UK.
authors.forename: Massimo
authors.initials: M
authors.lastname: Vieno
authors.affiliation: Centre for Ecology and Hydrology, UK.
authors.forename: Stefan
authors.initials: S
authors.lastname: Reis
authors.affiliation: Centre for Ecology and Hydrology, UK.
authors.forename: David
authors.initials: D
authors.lastname: Fowler
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D001272:Atmosphere / Q000737:chemistry*; D004784:Environmental Monitoring; D019216:Metals, Heavy / Q000032:analysis*; D008956:Models, Chemical; D006113:United Kingdom
chemical_list: D000393:Air Pollutants; D019216:Metals, Heavy
keywords: Atmospheric transport model; Cadmium; FRAME; Heavy metals; Lead; Re-suspension