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

Abstract

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.

Quantification of environmentally persistent free radicals and reactive oxygen species in atmospheric aerosol particles

“…Concentrations are smaller for particles in the coarse mode with a diameter larger than 1 µm. This is consistent with previous studies, suggesting that particles in the accumulation mode are the most active in the ROS generation (Hung and Wang, 2001;Venkatachari et al, 2007;Saffari et al, 2013Saffari et al, , 2014Wang et al, 2013). The total concentration of radical forms of ROS was measured to be 1.2 × 10 11 spins µg −1 .…”

“…Ambient particles have been found to contain large amounts of ROS (mostly H 2 O 2 ) in the particle phase (Hung and Wang, 2001;Venkatachari et al, 2005Venkatachari et al, , 2007Fuller et al, 2014). Substantial amounts of particle-bound ROS are A. M. Arangio et al: Quantification of environmentally persistent free radicals and reactive oxygen species found on biogenic secondary organic aerosols (SOA) produced from the oxidation of α-pinene, linalool, and limonene (Chen and Hopke, 2010;Chen et al, 2011;Pavlovic and Hopke, 2011;Wang et al, 2011Wang et al, , 2012.…”

Oxidative Potential of Selected PM Components

“…The formed DCF can be easily measured by fluorescence at the excitation and emission wavelengths of 485 and 530 nm. [17][18][19] The ROS concentration may be then calculated in terms of H2O2 equivalent. This assay was widely applied also for the ROS determination in biological cells.…”

Formation Characteristics of Aerosol Particles from Pulverized Coal Pyrolysis in High-Temperature Environments

“…This is because the aforementioned two factors are closely relevant to human health. 20,21 Considering the particle size, for example, it has been illustrated 22 that particle sizes less than or equal to 2.5 m (i.e., particulate matter Յ 2.5 m [PM 2.5 ]) are more harmful to human health than larger particles. On the other hand, the development of aerosol particles has been linked to PAH formation and destruction in the flame, with PAHs forming early, via condensation reactions or reactive coagulation of smaller PAHs.…”