title: Corona ions from powerlines and increased exposure to pollutant aerosols.
abstract: OBJECTIVE
  To investigate corona ions emitted from high-voltage powerlines and assess their effects on exposure to environmental pollutant aerosols.
  
  
  METHODS
  The charge density of ions in air required to produce a given change in the observed DC field at ground level was calculated. A DC field mill meter was used to map the DC fields near 132, 275 and 400 kV powerlines.
  
  
  RESULTS
  The Earth's natural DC field of around approximately 100 Vm(-1) was significantly modified near powerlines in 8 out of 14 cases. Typically, downwind of the powerlines the field direction was reversed giving values to -340 V m(-1). In one case, the effect extended more than 500 m from a 275 kV line.
  
  
  CONCLUSIONS
  These results can be analysed in terms of the charge density present. This analysis suggests that typically 2000 excess negative charges per cm3 are required to match the measured DC fields. Such space charge will result in unipolar aerosol charging in excess of the normal bipolar steady state charge distribution of pollutant aerosols. This may lead to increased lung deposition on inhalation.
authors.affiliation: H. H. Wills Physics Laboratory, University of Bristol, UK. Peter.Fews@bristol.ac.uk
authors.forename: A P
authors.initials: AP
authors.lastname: Fews
authors.forename: D L
authors.initials: DL
authors.lastname: Henshaw
authors.forename: R J
authors.initials: RJ
authors.lastname: Wilding
authors.forename: P A
authors.initials: PA
authors.lastname: Keitch
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000009:adverse effects* / Q000737:chemistry*; D001272:Atmosphere; D018534:Earth, Planet; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004781:Environmental Exposure; D006801:Humans; D019570:Inhalation Exposure; D007477:Ions; D008168:Lung / Q000378:metabolism; D001335:Vehicle Emissions; D014919:Wind
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D007477:Ions; D001335:Vehicle Emissions