Exposure to diesel exhaust induces changes in EEG in human volunteers

Björn Crüts¹ , Ludo van Etten¹ , Håkan Törnqvist² , Anders Blomberg² , Thomas Sandström² , Nicholas L Mills³ and Paul JA Borm¹

¹Centre of Expertise in Life Sciences, Zuyd University, Heerlen, The Netherlands

²Department of Respiratory Medicine and Allergy, University of Umeå, Sweden

³Centre for Cardiovascular Sciences, The University of Edinburgh, UK

author email corresponding author email

Particle and Fibre Toxicology 2008, 5:4doi:10.1186/1743-8977-5-4


Published:	11 March 2008

Abstract

Background

Ambient particulate matter and nanoparticles have been shown to translocate to the brain, and potentially influence the central nervous system. No data are available whether this may lead to functional changes in the brain.

Methods

We exposed 10 human volunteers to dilute diesel exhaust (DE, 300 μg/m³) as a model for ambient PM exposure and filtered air for one hour using a double blind randomized crossover design. Brain activity was monitored during and for one hour following each exposure using quantitative electroencephalography (QEEG) at 8 different sites on the scalp. The frequency spectrum of the EEG signals was used to calculate the median power frequency (MPF) and specific frequency bands of the QEEG.

Results

Our data demonstrate a significant increase in MPF in response to DE in the frontal cortex within 30 min into exposure. The increase in MPF is primarily caused by an increase in fast wave activity (β2) and continues to rise during the 1 hour post-exposure interval.

Conclusion

This study is the first to show a functional effect of DE exposure in the human brain, indicating a general cortical stress response. Further studies are required to determine whether this effect is mediated by the nanoparticles in DE and to define the precise pathways involved.