A comment on 'Theegarten et al.: Submesothelial deposition of carbon nanoparticles after toner exposition: Case report. Diagnostic Pathology 2010, 5:77'

  • Michael Wensing1,

    Affiliated with

    • Tobias Schripp1,

      Affiliated with

      • Erik Uhde1 and

        Affiliated with

        • Tunga Salthammer1, 2Email author

          Affiliated with

          Diagnostic Pathology20116:20

          DOI: 10.1186/1746-1596-6-20

          Received: 9 February 2011

          Accepted: 17 March 2011

          Published: 17 March 2011

          A comment on 'Theegarten et al.: Submesothelial deposition of carbon nanoparticles after toner exposition: Case report. Diagnostic Pathology 2010, 5:77'

          We read with interest the article by Theegarten et al. [1] which reports on the case of a patient in whose peritoneum were found submesothial aggregates of carbon nanoparticles (CNPs) with a diameter of 31-67 nm. From their literature study and results the authors conclude that these CNPs must be particles emitted by a laser printer in an office environment and inhaled by the patient. In addition the abstract for [1] states: "Inhalation of CNP from toner dust has been shown to have impact on the respiratory health of persons exposed". Other possible exposure and uptake paths for CNPs are not discussed in [1].

          The paper by Theegarten et al. [1] includes experimental data on the morphology and on the constituents of the toner powder of a laser printer. This toner consists of particles with a diameter of 5-9 μm on whose surface " some small elevations" of metal oxides are found. The CNPs detected in the patient's peritoneum were not, however, identified as toner constituents.

          In fact the assumption by Theegarten et al. that the CNPs detected in the patient's peritoneum come from a laser printer is based solely on a reference to a study by Wensing et al. [2]. Theegarten et al. refer to [2] as follows: "Office printers were detected to emit carbon nanoparticles (CNP) in a variable extend". As the authors of [2] we should like to note at this point that this statement is not correct. Our publication [2] does not contain any data which would point to CNPs being possible constituents of ultra-fine particles released from laser printers.

          Our chamber experiments were carried out in a clean and particle-free atmosphere. Therefore we can exclude influences from other sources and outdoor air. Indeed our article [2] states that the ultra-fine particles (UFPs) emitted from laser printers are volatile and are not original toner constituents ("toner dust"). The UFPs are rather formed by the nucleation and condensation processes of hydrophobic SVOCs (semi-volatile organic compounds) such as, for example, semi-volatile organic silicon compounds and higher aliphatic hydrocarbons [3, 4]. The volatility of the UFPs - which is also inconsistent with CNP as constituents of the UFPs - was confirmed by VH-TDMA (volatilization and humidification tandem differential mobility analyzer) [4] and thermo denuder [3] measurements. We have never found CNPs in connection with laser printer experiments. Paper [4] is also cited in Theegarten et al. [1].

          To sum up, it can be stated that our experimental data published in [2] and also in our later publications [3] and [4] do not in any way support the proposition that the patient in the present case was exposed to CNPs from laser printers.


          Authors’ Affiliations

          Department of Material Analysis and Indoor Chemistry, Fraunhofer WKI
          International Laboratory for Air Quality and Health, Queensland University of Technology (QUT)


          1. Theegarten D, Boukercha S, Philippou S, Anhenn O: Submesothelial deposition of carbon nanoparticles after toner exposition: Case report. Diagnostic Pathology 2010, 5: 77.PubMedView Article
          2. Wensing M, Schripp T, Uhde E, Salthammer T: Ultra-fine particles release from hardcopy devices: sources, real room measurements and efficiency of filter accessories. Sci Total Environ 2008, 407: 418–427.PubMedView Article
          3. Wensing M, Delius W, Omelan A, Uhde E, Salthammer T, He C, Wang H, Morawska L: Ultra-fine particles (UFP) from laser printers: chemical and physical characterization. In Proceedings of the 9th International Conference on Healthy Buildings: 13 - 17 September 2009; Syracuse Edited by: Santanam S, Bogucz EA, Peters C, Benson T. 2009. Paper ID 171
          4. Morawska L, He C, Johnson G, Jayaratne R, Salthammer T, Wang H, Uhde E, Bostrom T, Modini R, Ayoko G, McGarry P, Wensing M: An investigation into the characteristics of particles originating from the operation of laser printers. Environ Sci Technol 2009, 43: 1015–1022.PubMedView Article


          © Wensing et al; licensee BioMed Central Ltd. 2011

          This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://​creativecommons.​org/​licenses/​by/​2.​0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.