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Thu 9/19/2019 11:00AM - 12:00PM
EOH Journal Club
Particle Depletion Does Not Remediate Acute Effects of Traffic-related Air Pollution and Allergen EOH Journal Club
Particle Depletion Does Not Remediate Acute Effects of Traffic-related Air Pollution and Allergen
Thu 9/19/2019 11:00AM - 12:00PM
4140 Public Health, Young Seminar Room

Presenter: Brandy Hill

Paper: Particle Depletion Does Not Remediate Acute Effects of Traffic-related Air Pollution and Allergen. A Randomized, Double-Blind Crossover Study

Authors: Denise J. Wooding, Min Hyung Ryu, Anke Huls, Andrew D. Lee, David T. S. Lin, Christopher F. Rider, Agnes C. Y. Yuen, and Chris Carlsten

Rationale: Diesel exhaust (DE), an established model of trafficrelated
air pollution, contributes significantly to the global burden of
asthma and may augment the effects of allergen inhalation. Newer
diesel particulate-filtering technologies may increaseNO2 emissions,
raising questions regarding their effectiveness in reducing harm from
associated engine output.

Objectives: To assess the effects of DE and allergen coexposure on
lung function, airway responsiveness, and circulating leukocytes, and
determine whether DE particle depletion remediates these effects.

Methods: In this randomized, double-blind crossover study, 14
allergen-sensitized participants (9 with airway hyperresponsiveness)
underwent inhaled allergen challenge after 2-hour exposures to DE,
particle-depleted DE (PDDE), or filtered air. The control condition
was inhaled saline after filtered air. Blood sampling and spirometry
were performed before and up to 48 hours after exposures. Airway
responsiveness was evaluated at 24 hours.

Measurements and Main Results: PDDE plus allergen
coexposure impaired lung function more than DE plus allergen,
particularly in those genetically at risk. DE plus allergen and PDDE
plus allergen each increased airway responsiveness in normally
responsive participants.DEplus allergen increased blood neutrophils
and was associated with persistent eosinophilia at 48 hours. DE and
PDDE each increased total peripheral leukocyte counts in a manner
affected by participant genotypes. Changes in peripheral leukocytes
correlated with lung function decline.

Conclusions: Coexposure to DE and allergen impaired lung
function, which was worse after particle depletion (which increased
NO2). Thus, particulates are not necessarily the sole or main
culprit responsible for all harmful effects of DE. Policies and
technologies aimed at protecting public health should be scrutinized
in that regard.
Clinical trial registered with www.clinicaltrials.gov (NCT02017431).

Keywords: diesel exhaust; asthma; filter; genetic susceptibility

4140 Public Health, Young Seminar Room

Recent Events

EOH Journal Club

Ambient air pollution and thrombosis - Omar Tahtamooni

Thursday 2/8 11:00AM - 12:00PM
EOH Journal Club Seminar - Spring 2018

Date: Thursday February 8, 2018

Time: 11am - 12pm

Presenter: Omar Tahtamooni

Paper: Ambient air pollution and thrombosis

Authors: Robertson S1, Miller MR

Abstract: Air pollution is a growing public health concern of global significance. Acute and chronic exposure is known to impair cardiovascular function, exacerbate disease and increase cardiovascular mortality. Several plausible biological mechanisms have been proposed for these associations, however, at present, the pathways are incomplete. A seminal review by the American Heart Association (2010) concluded that the thrombotic effects of particulate air pollution likely contributed to their effects on cardiovascular mortality and morbidity. The aim of the current review is to appraise the newly accumulated scientific evidence (2009-2016) on contribution of haemostasis and thrombosis towards cardiovascular disease induced by exposure to both particulate and gaseous pollutants.Seventy four publications were reviewed in-depth. The weight of evidence suggests that acute exposure to fine particulate matter (PM2.5) induces a shift in the haemostatic balance towards a pro-thrombotic/pro-coagulative state. Insufficient data was available to ascertain if a similar relationship exists for gaseous pollutants, and very few studies have addressed long-term exposure to ambient air pollution. Platelet activation, oxidative stress, interplay between interleukin-6 and tissue factor, all appear to be potentially important mechanisms in pollution-mediated thrombosis, together with an emerging role for circulating microvesicles and epigenetic changes.Overall, the recent literature supports, and arguably strengthens, the contention that air pollution contributes to cardiovascular morbidity by promoting haemostasis. The volume and diversity of the evidence highlights the complexity of the pathophysiologic mechanisms by which air pollution promotes thrombosis; multiple pathways are plausible and it is most likely they act in concert. Future research should address the role gaseous pollutants play in the cardiovascular effects of air pollution mixture and direct comparison of potentially susceptible groups to healthy individuals.

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Last Updated On Monday, January 29, 2018 by Temp, GSPH Marketing & Development
Created On Friday, January 12, 2018

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