Strong evidence for the continued contribution of lead deposited during the 20th century to the atmospheric environment in London of today

Research output: Contribution to journalArticlepeer-review

Authors

  • Eléonore Resongles
  • Volker Dietze
  • David C. Green
  • Raquel Ochoa-Gonzalez
  • Anja H. Tremper
  • Dominik J. Weiss

Colleges, School and Institutes

External organisations

  • Imperial College London
  • University of Montpellier
  • Deutscher Wetterdienst
  • King Abdulaziz University
  • Foundation for the Promotion of Applied Scientific Research and Technology of Asturias
  • Princeton University

Abstract

Although leaded gasoline was banned at the end of the last century, lead (Pb) remains significantly enriched in airborne particles in large cities. The remobilization of historical Pb deposited in soils from atmospheric removal has been suggested as an important source providing evidence for the hypothetical longterm persistency of lead, and possibly other pollutants, in the urban environment. Here, we present data on Pb isotopic composition in airborne particles collected in London (2014 to 2018), which provide strong support that lead deposited via gasoline combustion still contributes significantly to the lead burden in present-day London. Lead concentration and isotopic signature of airborne particles collected at a heavily trafficked site did not vary significantly over the last decade, suggesting that sources remained unchanged. Lead isotopic composition of airborne particles matches that of road dust and topsoils and can only be explained with a significant contribution (estimate of 32 ± 10 to 43 ± 9% based on a binary mixing model) of Pb from leaded gasoline. The lead isotopes furthermore suggest significant contributions from nonexhaust traffic emissions, even though isotopic signatures of anthropogenic sources are increasingly overlapping. Lead isotopic composition of airborne particles collected at building height shows a similar signature to that collected at street level, suggesting effective mixing of lead within the urban street canyon. Our results have important implications on the persistence of Pb in urban environments and suggest that atmospheric Pb reached a baseline in London that is difficult to decrease further with present policy measures.

Bibliographic note

Funding Information: ACKNOWLEDGMENTS. We thank Katharina Kreissig and Barry Coles for valuable assistance in the MAGIC laboratories and Rémi Freydier for ICP-MS analysis at the AETE-ISO platform of the OSU OREME/University of Montpel-lier. We thank Nurhijjah Mahyudin for helping during sample collection and processing. This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodow-ska-Curie Grant 702916. E.R. acknowledges the Department of Earth Science and Engineering at Imperial College London for financial support through internal funding (Arthur Holmes Centenary Research Grant). R.O.-G. thanks the European Commission (FP7-PEOPLE-2012-IEF) for funding the project ISOTRACE through Grant 329878. We thank anonymous reviewers for their constructive reviews of this manuscript.

Details

Original languageEnglish
Article numbere2102791118
Number of pages9
JournalProceedings of the National Academy of Sciences of the United States of America
Volume118
Issue number26
Early online date21 Jun 2021
Publication statusPublished - 29 Jun 2021

Keywords

  • Aerosols, Contaminant persistence, Lead isotopes, Source tracing, Urban air pollution

ASJC Scopus subject areas

Sustainable Development Goals