title: Particulate matter oxidative potential from waste transfer station activity.
abstract: BACKGROUND
  Adverse cardiorespiratory health is associated with exposure to ambient particulate matter (PM). The highest PM concentrations in London occur in proximity to waste transfer stations (WTS), sites that experience high numbers of dust-laden, heavy-duty diesel vehicles transporting industrial and household waste.
  
  
  OBJECTIVE
  Our goal was to quantify the contribution of WTS emissions to ambient PM mass concentrations and oxidative potential.
  
  
  METHODS
  PM with a diameter < 10 microm (PM10) samples were collected daily close to a WTS. PM10 mass concentrations measurements were source apportioned to estimate local versus background sources. PM oxidative potential was assessed using the extent of antioxidant depletion from a respiratory tract lining fluid model. Total trace metal and bioavailable iron concentrations were measured to determine their contribution to PM oxidative potential.
  
  
  RESULTS
  Elevated diurnal PM10 mass concentrations were observed on all days with WTS activity (Monday-Saturday). Variable PM oxidative potential, bioavailable iron, and total metal concentrations were observed on these days. The contribution of WTS emissions to PM at the sampling site, as predicted by microscale wind direction measurements, was correlated with ascorbate (r = 0.80; p = 0.030) and glutathione depletion (r = 0.76; p = 0.046). Increased PM oxidative potential was associated with aluminum, lead, and iron content.
  
  
  CONCLUSIONS
  PM arising from WTS activity has elevated trace metal concentrations and, as a consequence, increased oxidative potential. PM released by WTS activity should be considered a potential health risk to the nearby residential community.
authors.affiliation: Environmental Research Group, MRC-HPA Centre for Environmental Health, School of Biomedical and Health Sciences, King's College London, London, United Kingdom.
authors.forename: Krystal J
authors.initials: KJ
authors.lastname: Godri
authors.forename: Sean T
authors.initials: ST
authors.lastname: Duggan
authors.forename: Gary W
authors.initials: GW
authors.lastname: Fuller
authors.forename: Tim
authors.initials: T
authors.lastname: Baker
authors.forename: David
authors.initials: D
authors.lastname: Green
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Kelly
authors.forename: Ian S
authors.initials: IS
authors.lastname: Mudway
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D004784:Environmental Monitoring; D055904:Meteorology; D052638:Particulate Matter / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D052638:Particulate Matter