Spatial and seasonal heterogeneity of atmospheric particles induced reactive oxygen species in urban areas and the role of water-soluble metals

Source apportionment and water solubility of metals in size segregated particles in urban environments

“…Ni and V in the atmosphere were directly related to the respiratory health problems, like irritation, coughing and injection of pharynx and carcinogenic potential (WHO, 2000). Our previous study in Hong Kong has shown Ni and V were strongly associated with the reactive oxygen species formation (Gali et al, 2015). The increased levels of Ni and V from the shipping traffic associated with Table 1) Each site has 8 weeks of every week time integrated data points, 4 for winter and 4 for summer.…”

“…This technique takes concentration and uncertainty as input and several variables such as factor profiles, their contribution and error in modeling are output. More description of the apportionment approach could be found elsewhere (Gali et al, 2015;Paatero and Tapper, 1994;Pakbin et al, 2011). Uncertainty in measurement was estimated following already existing procedure for metals (Barwick and Ellison, 2000;Ellison et al, 2000) which were 11,10,21,15,15,14,24,23,13,22,16,15,17,17,19 and 10% for Ca, Fe, K, Mg, Na, Al, Cd, Cr,Co, Cu, Pb, Mn, Mo, Ni, V, Zn metals, respectively.…”

Dose-dependent intracellular reactive oxygen and nitrogen species (ROS/RNS) production from particulate matter exposure: comparison to oxidative potential and chemical composition

“…Prior studies using the macrophage assay involved normalizing raw fluorescence measurements to a positive control (e.g., zymosan or H2O2) in order to obtain a single value for comparison with 317 DTT activity. 60,66 However, studies involving inflammatory stimulants and cellular endpoints, including IL-6, IL-8, NF-κB, and TNF-α, showed that endpoints generally followed a sigmoidal dose-response curve. 65,67,68 Here, we demonstrated clearly that ROS/RNS production from PM exposure was non-linear, highly dose-dependent, and could not be represented by a single concentration measurement.…”

Investigation on the mechanism of non‐photocatalytically TiO2‐induced reactive oxygen species and its significance on cell cycle and morphology

“…The yellow MTT dye was then added to samples and untreated cell control at a final concentration of 0.45 mg ml À1 and allowed to incubate for 4 h under culture conditions, followed by replacement of 100 μl with DMSO to solubilize the formazan, which was spectrophotometrically (Spectramax M2e; Molecular Devices, Taiwan) recorded at 570 nm and compared with untreated controls (positive control) to determine the percentage cell viability. Nanoparticle suspension along with the dye, served as negative control (Gali et al, 2015). Untreated cell controls were maintained for each interval.…”

“…The change in absorbance of DCF each minute was recorded at the excitation and emission wavelength of 485 and 530 nm, respectively, and the measured light intensity normalized with those from standard H 2 O 2 prepared in the concentration range 50-1500 nmol l À1 , and unit defined as nanomolar H 2 O 2 produced per minute per milliliter of TiO 2 suspension. Nanoparticlefree samples served as the DCFH-DA control (Gali et al, 2015).…”