Article Text

Download PDFPDF
Letter
Authors' response

Statistics from Altmetric.com

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Footnotes

  • Funding This study was supported by the Norwegian Smelter Industry.

  • Competing interests None.

  • Ethics approval Ethics approval was provided by the Regional Ethics Committee, Eastern Norway.

  • Provenance and peer review Not commissioned; internally peer reviewed.