title: Air pollution exposure affects circulating white blood cell counts in healthy subjects: the role of particle composition, oxidative potential and gaseous pollutants - the RAPTES project.
abstract: Studies have linked air pollution exposure to cardiovascular health effects, but it is not clear which components drive these effects. We examined the associations between air pollution exposure and circulating white blood cell (WBC) counts in humans. To investigate independent contributions of particulate matter (PM) characteristics, we exposed 31 healthy volunteers at five locations with high contrast and reduced correlations amongst pollutant components: two traffic sites, an underground train station, a farm and an urban background site. Each volunteer visited at least three sites and was exposed for 5 h with intermittent exercise. Exposure measurements on-site included PM mass and number concentration, oxidative potential (OP), elemental- and organic carbon, metals, O3 and NO2. Total and differential WBC counts were performed on blood collected before and 2 and 18 h post-exposure (PE). Changes in total WBC counts (2 and 18 h PE), number of neutrophils (2 h PE) and monocytes (18 h PE) were positively associated with PM characteristics that were high at the underground site. These time-dependent changes reflect an inflammatory response, but the characteristic driving this effect could not be isolated. Negative associations were observed for NO2 with lymphocytes and eosinophils. These associations were robust and did not change after adjustment for a large suite of PM characteristics, suggesting an independent effect of NO2. We conclude that short-term air pollution exposure at real-world locations can induce changes in WBC counts in healthy subjects. Future studies should indicate if air pollution exposure-induced changes in blood cell counts results in adverse cardiovascular effects in susceptible individuals.
authors: Division of Toxicology and Division of Environmental Epidemiology, Institute for Risk Assessment Sciences (IRAS), Utrecht University , Utrecht , The Netherlands .
authors: Maaike
authors: M
authors: Steenhof
authors: Nicole A H
authors: NA
authors: Janssen
authors: Maciej
authors: M
authors: Strak
authors: Gerard
authors: G
authors: Hoek
authors: Ilse
authors: I
authors: Gosens
authors: Ian S
authors: IS
authors: Mudway
authors: Frank J
authors: FJ
authors: Kelly
authors: Roy M
authors: RM
authors: Harrison
authors: Raymond H H
authors: RH
authors: Pieters
authors: Flemming R
authors: FR
authors: Cassee
authors: Bert
authors: B
authors: Brunekreef
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000737:chemistry / Q000633:toxicity*; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects / Q000032:analysis; D007958:Leukocyte Count; D007962:Leukocytes / Q000187:drug effects*; D008297:Male; D009426:Netherlands; D009585:Nitrogen Dioxide / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects; D010126:Ozone / Q000633:toxicity*; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry / Q000633:toxicity*; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter; D010126:Ozone; D009585:Nitrogen Dioxide