Measurement of Particle-Bound Reactive Oxygen Species in Rubidoux Aerosols

Venkatachari, Prasanna; Hopke, Philip K.; Grover, Brett D.; Eatough, Delbert J.

doi:10.1007/s10874-005-1662-z

Cited by 128 publications

(158 citation statements)

References 17 publications

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“…Lower concentrations of ROS were found in this study when compared to the study conducted in Rubidoux (Venkatachari et al 2005). The lower concentrations can be attributed to any of the following: the study was conducted in winter when the temperatures and the intensity and duration of the solar flux was not conducive for photochemical reactions to produce free radicals.…”

Section: Ros Concentrationscontrasting

confidence: 70%

“…Previously, Venkatachari et al (2005) examined the particle-bound ROS in the various size fractions of the ambient aerosols in Rubidoux, California and found that ROS concentrations correlated moderately with the intensity of photochemical reactions, smaller particles were observed to have higher ROS concentrations, and the general magnitude of ROS concentrations were found to be at least an order of magnitude higher than observed in Taipei (Hung and Wang 2001). This study examines the diurnal variation of ROS concentrations in the winter.…”

Section: Introductionmentioning

confidence: 96%

“…Earlier studies looking at atmospheric ROS have focused mainly on ROS in the gas phase and in rainwater and cloud droplets (Sakugawa et al 1993;Tsai et al 1991). However, concentration data on ROS in the particulate phase is limited (Hung and Wang 2001;Hasson and Paulson 2003;Venkatachari et al 2005). Hasson and Paulson (2003) suggested that most of the particle-bound ROS is H 2 O 2 , but observe greater ROS than would be present based on a Henry's Law model of uptake by the particles.…”

Section: Introductionmentioning

confidence: 99%

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Characterization of Wintertime Reactive Oxygen Species Concentrations in Flushing, New York

Venkatachari

Hopke

Brune

et al. 2007

Aerosol Science and Technology

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One of the main hypotheses for the species causing the observed health effects of ambient particulate matter is peroxides and other reactive oxygen species (ROS). However, there is currently very little data available on the concentrations of particle-bound ROS or their behavior in different physical locations and seasons. The concentrations of particle-bound ROS were determined for various size fractions of the aerosol, ranging from 10 nm to 18 μm, in Flushing, New York during the period of January and early February 2004. Sampling was carried out at 3-hour intervals using a MOUDI TM cascade impactor. The collected particles were treated with the non-fluorescent probe dichlorofluorescin (DCFH) that fluoresces when oxidized by the presence of ROS. The measured fluorescent intensities were converted into equivalent hydrogen peroxide concentrations, which were used as indicators of ROS reactivity, by calibrations using H 2 O 2 standards. Diurnal profiles of the ROS concentrations were obtained. Correlations of the particulate ROS concentrations with the intensity of photochemical reaction, estimated secondary organic carbon (SOC) and gas phase OH and HO 2 radical concentrations were explored. The intensity of photochemical reactions and gas phase radical concentrations were found to be moderate factors affecting particulate ROS concentrations. The concentrations of ROS were found to be higher in the submicron size particles of the ambient aerosol.

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Section: Ros Concentrationscontrasting

confidence: 70%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

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Characterization of Wintertime Reactive Oxygen Species Concentrations in Flushing, New York

Venkatachari

Hopke

Brune

et al. 2007

Aerosol Science and Technology

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“…ROS refers to a class of compounds with strong oxidizing ability and they have been implicated in causing several adverse biological effects (Venkatachari et al 2005;Xia et al 2006). The ability of nanoparticles to generate ROS was measured by using a fluorescent dye, 2′,7′-dichlorofluorescein diacetate (DCFH-DA).…”

Section: Nanoparticle Oxidant Generating Capacity Measurementsmentioning

confidence: 99%

“…While toxicological effects are usually evaluated by in vitro and in vivo studies, a rapid cellfree pre-screening assay to determine the intrinsic potential of particles to generate reactive oxygen species (ROS) could be informative as well (Venkatachari et al 2005). Both in vitro and in vivo tests of engineered nanoparticles (e.g.…”

Section: Introductionmentioning

confidence: 99%

Does nanoparticle activity depend upon size and crystal phase?

et al. 2008

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A method to investigate the dependence of the physicochemical properties of nanoparticles (e.g. size, surface area and crystal phase) on their oxidant generating capacity is proposed and demonstrated for TiO 2 nanoparticles. Gas phase synthesis methods that allow for strict control of size and crystal phase were used to prepare TiO 2 nanoparticles. The reactive oxygen species (ROS) generating capacity of these particles was then measured. The size dependent ROS activity was established using TiO 2 nanoparticles of 9 different sizes (4 -195 nm) but the same crystal phase. For a fixed total surface area, an S-shaped curve for ROS generation per unit surface area was observed as a function of particle size. The highest ROS activity per unit area was observed for 30 nm particles, and observed to be constant above 30 nm. There was a decrease in activity per unit area as size decreased from 30 nm to 10 nm; and again constant for particles smaller than 10 nm. The correlation between crystal phase and oxidant capacity was established using TiO 2 nanoparticles of 11 different crystal phase combinations but similar size. The ability of different crystal phases of TiO 2 nanoparticles to generate ROS was highest for amorphous, followed by anatase, and then anatase/rutile mixtures, and lowest for rutile samples. Based on evaluation of the entire dataset, important dose metrics for ROS generation are established. Their implications of these ROS studies on biological and toxicological studies using nanomaterials are discussed.

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Particle Characterization

Kuhlbusch¹,

Asbach²

2011

Cardiovascular Effects of Inhaled Ultrafine and Nanosized Particles

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Measurement of Particle-Bound Reactive Oxygen Species in Rubidoux Aerosols

Cited by 128 publications

References 17 publications

Characterization of Wintertime Reactive Oxygen Species Concentrations in Flushing, New York

Characterization of Wintertime Reactive Oxygen Species Concentrations in Flushing, New York

Does nanoparticle activity depend upon size and crystal phase?

Particle Characterization

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