title: Probabilistic modelling of prospective environmental concentrations of gold nanoparticles from medical applications as a basis for risk assessment.
abstract: BACKGROUND
  The use of gold nanoparticles (Au-NP) based medical applications is rising due to their unique physical and chemical properties. Diagnostic devices based on Au-NP are already available in the market or are in clinical trials and Au-NP based therapeutics and theranostics (combined diagnostic and treatment modality) are in the research and development phase. Currently, no information on Au-NP consumption, material flows to and concentrations in the environment are available. Therefore, we estimated prospective maximal consumption of Au-NP from medical applications in the UK and US. We then modelled the Au-NP flows post-use and predicted their environmental concentrations. Furthermore, we assessed the environment risks of Au-NP by comparing the predicted environmental concentrations (PECs) with ecological threshold (PNEC) values.
  
  
  RESULTS
  The mean annual estimated consumption of Au-NP from medical applications is 540 kg for the UK and 2700 kg for the US. Among the modelled concentrations of Au-NP in environmental compartments, the mean annual PEC of Au-NP in sludge for both the UK and US was estimated at 124 and 145 μg kg(-1), respectively. The mean PEC in surface water was estimated at 468 and 4.7 pg L(-1), respectively for the UK and US. The NOEC value for the water compartment ranged from 0.12 up to 26,800 μg L(-1), with most values in the range of 1000 μg L(-1).
  
  
  CONCLUSIONS
  The results using the current set of data indicate that the environmental risk from Au-NP used in nanomedicine in surface waters and from agricultural use of biosolids is minimal in the near future, especially because we have used a worst-case use assessment. More Au-NP toxicity studies are needed for the soil compartment.
authors.affiliation: School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK. ixm025@bham.ac.uk.
authors.forename: Indrani
authors.initials: I
authors.lastname: Mahapatra
authors.affiliation: Empa-Swiss Federal Laboratories for Materials Science and Technology, Technology and Society Laboratory, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland. tianyin.sun@empa.ch.|Safety and Environmental Technology Group, Institute for Chemical and Bioengineering, ETH-Hoenggerberg, 8093, Zurich, Switzerland. tianyin.sun@empa.ch.
authors.forename: Tian Yin
authors.initials: TY
authors.lastname: Sun
authors.affiliation: School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK. j.r.a.clark@bham.ac.uk.
authors.forename: Julian R A
authors.initials: JR
authors.lastname: Clark
authors.affiliation: The Queen's College, Oxford, OX1 4AW, UK. peter.dobson@queens.ox.ac.uk.|Warwick Manufacturing Group, University of Warwick, Coventry, CV4 7AL, UK. peter.dobson@queens.ox.ac.uk.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Dobson
authors.affiliation: Safety and Environmental Technology Group, Institute for Chemical and Bioengineering, ETH-Hoenggerberg, 8093, Zurich, Switzerland. konrad.hungerbuehler@chem.ethz.ch.
authors.forename: Konrad
authors.initials: K
authors.lastname: Hungerbuehler
authors.affiliation: Business School, University of Exeter, Exeter, EX4 4PU, UK. R.J.Owen@exeter.ac.uk.
authors.forename: Richard
authors.initials: R
authors.lastname: Owen
authors.affiliation: Empa-Swiss Federal Laboratories for Materials Science and Technology, Technology and Society Laboratory, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland. nowack@empa.ch.
authors.forename: Bernd
authors.initials: B
authors.lastname: Nowack
authors.affiliation: School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK. jlead@mailbox.sc.edu.|Department of Environmental Health Sciences, Center for Environmental Nanoscience and Risk, Arnold School of Public Health, University of South Carolina, Columbia, SC, 29208, USA. jlead@mailbox.sc.edu.
authors.forename: Jamie
authors.initials: J
authors.lastname: Lead
mesh_terms: D004785:Environmental Pollutants / Q000032:analysis*; D005618:Fresh Water / Q000737:chemistry*; D006046:Gold / Q000032:analysis*; D006801:Humans; D008452:Maximum Allowable Concentration; D053768:Metal Nanoparticles / Q000032:analysis*; D015233:Models, Statistical; D018570:Risk Assessment; D006113:United Kingdom; D014481:United States
chemical_list: D004785:Environmental Pollutants; D006046:Gold