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Title: Source-dependent variation in hydroxyl radical production by airborne particulate matter

Abstract

Epidemiological studies suggest exposure to airborne particles is responsible for a wide range of adverse health effects, potentially arising from particle-induced oxidative stress. A highly sensitive fluorescence method was employed to measure the production of hydroxyl radical by a broad range of particle types including urban dust, diesel particulate matter, coal fly ash, kaolinite, and silica. Little or no production of OH was observed in the absence of an added electron donor or H{sub 2}O{sub 2}. In the presence of a biological electron donor (NADPH, 3 mM), the rate of OH production (R{sub OH}) for 3 mg/mL of these particles varied from 23 nM s{sup -1} for diesel particulate matter (SRM 2975) to 0.20 nM s{sup -1} for coal fly ash (SRM 2689). No detectable OH was produced by kaolinite or silica. Hydroxyl radical formation was eliminated under anaerobic conditions and in the presence of catalase, indicating that O{sub 2} and H{sub 2}O{sub 2} are required for its generation. Partial inhibition of OH formation by superoxide dismutase (SOD) was also observed in some cases, suggesting that superoxide is also involved. The metal chelator deferoxamine mesylate (DFX) in most cases suppressed OH formation, but diethylenetriaminepentaacetic acid (DTPA) generally enhanced it, implicatingmore » metal ion reactions in OH generation as well. The dependence of R{sub OH} on NADPH concentration further implicates particle surface reactions in OH formation. To the authors' knowledge, these measurements provide the first quantitative estimate of ROH for a broad range of particle types. 49 refs., 6 figs., 1 tab.« less

Authors:
;  [1]
  1. University of Maryland, College Park, MD (United States). Department of Chemistry and Biochemistry
Publication Date:
OSTI Identifier:
20885849
Resource Type:
Journal Article
Resource Relation:
Journal Name: Environmental Science and Technology; Journal Volume: 41; Journal Issue: 7; Other Information: neilb@umd.edu
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 54 ENVIRONMENTAL SCIENCES; 02 PETROLEUM; COAL; FLY ASH; PARTICULATES; FLUORESCENCE; KAOLINITE; SILICA; DIESEL FUELS; POLLUTION SOURCES; AIR POLLUTION; EPIDEMIOLOGY; HYDROXYL RADICALS; HEALTH HAZARDS; CHEMICAL REACTION KINETICS; AEROBIC CONDITIONS; LEWIS BASES; HYDROGEN PEROXIDE; QUANTITATIVE CHEMICAL ANALYSIS

Citation Formats

Marjan Alaghmand, and Neil V. Blough. Source-dependent variation in hydroxyl radical production by airborne particulate matter. United States: N. p., 2007. Web. doi:10.1021/es061902o.
Marjan Alaghmand, & Neil V. Blough. Source-dependent variation in hydroxyl radical production by airborne particulate matter. United States. doi:10.1021/es061902o.
Marjan Alaghmand, and Neil V. Blough. Sun . "Source-dependent variation in hydroxyl radical production by airborne particulate matter". United States. doi:10.1021/es061902o.
@article{osti_20885849,
title = {Source-dependent variation in hydroxyl radical production by airborne particulate matter},
author = {Marjan Alaghmand and Neil V. Blough},
abstractNote = {Epidemiological studies suggest exposure to airborne particles is responsible for a wide range of adverse health effects, potentially arising from particle-induced oxidative stress. A highly sensitive fluorescence method was employed to measure the production of hydroxyl radical by a broad range of particle types including urban dust, diesel particulate matter, coal fly ash, kaolinite, and silica. Little or no production of OH was observed in the absence of an added electron donor or H{sub 2}O{sub 2}. In the presence of a biological electron donor (NADPH, 3 mM), the rate of OH production (R{sub OH}) for 3 mg/mL of these particles varied from 23 nM s{sup -1} for diesel particulate matter (SRM 2975) to 0.20 nM s{sup -1} for coal fly ash (SRM 2689). No detectable OH was produced by kaolinite or silica. Hydroxyl radical formation was eliminated under anaerobic conditions and in the presence of catalase, indicating that O{sub 2} and H{sub 2}O{sub 2} are required for its generation. Partial inhibition of OH formation by superoxide dismutase (SOD) was also observed in some cases, suggesting that superoxide is also involved. The metal chelator deferoxamine mesylate (DFX) in most cases suppressed OH formation, but diethylenetriaminepentaacetic acid (DTPA) generally enhanced it, implicating metal ion reactions in OH generation as well. The dependence of R{sub OH} on NADPH concentration further implicates particle surface reactions in OH formation. To the authors' knowledge, these measurements provide the first quantitative estimate of ROH for a broad range of particle types. 49 refs., 6 figs., 1 tab.},
doi = {10.1021/es061902o},
journal = {Environmental Science and Technology},
number = 7,
volume = 41,
place = {United States},
year = {Sun Apr 01 00:00:00 EDT 2007},
month = {Sun Apr 01 00:00:00 EDT 2007}
}