Respirable Fraction of Airborne Dust: Quantitative Descriptions, Formal Definitions, and Performance Characteristics of Samplers Matched to Them

The current study was based on annual ambient air quality monitoring data and corresponding meteorological observation data of Xi'an in 2011. Distribution models on hourly concentrations of PM10, SO2, and NO2 were studied, and the results showed that statistical distribution functions varied from seasons and from pollutants. The optimal distribution models of PM10 concentrations in the four seasons (spring, summer, autumn, and winter) were generalized extreme value distribution (GEVD), Weibull, Weibull, and GEVD, respectively; those of SO2 were lognormal, log-logistic, log-logistic, and GEVD, respectively; and those of NO2 were Weibull, lognormal, GEVD, and GEVD, respectively. The concentrations ranges were 0.03 ∼ 0.20 mg/m3 for PM10, 0.008 ∼ 0.17 mg/m3 for SO2, and 0.01 ∼ 0.12 mg/m3 for NO2, and the probabilities of concentrations in the ranges for accordingly pollutants were up to 85 %. Effects of the meteorological parameters on concentrations of PM10, SO2, and NO2 were studied with linear correlation analysis method for Xi'an city. The results indicated that pollutant concentrations had a negative correlation with wind speed, temperature, and mixing height (MH), whereas it had a positive correlation with atmospheric pressure and atmospheric stability. Both temperature and atmospheric pressure were the most obvious correlation with SO2 concentration with r value of −0.7916 and 0.7032, respectively. Wind speed and MH had the most obvious correlation with NO2 concentration with r value of −0.4423 and −0.3997, respectively. SO2 had the best correlation with meteorological parameters. Analyzing the statistical characteristics of urban air pollution concentration and their relationships with meteorological parameters are of great importance to study urban air pollution problems and corresponding prevention measure.

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Altered Clearance of Inhaled^99mTc-Pentetate Aerosols following Exposure to Cadmium Chloride Aerosols in Ferrets

Platner

Morrow

1989

Experimental Lung Research

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The rate of clearance of inhaled 99mTc-pentetate aerosols has been used as an indicator of pulmonary epithelial "permeability" in human and animal studies. In order to evaluate this technique further, groups of eight male ferrets (Mustela putorius furo) were given acute exposures to aerosols of CdCl2 or NaCl via endotracheal tube. Serial evaluations of the thoracic clearance rate of inhaled 99mTc-pentetate aerosols (MMAD = 0.6 microns, sigma g = 1.6) were made before exposure and at fixed time points after toxicant exposure (3 or 6, 24, 48 h, and 5 days after CdCl2). These serial evaluations of 99mTc-pentetate thoracic clearance were conducted at three cadmium intake levels (3, 10, and 30 min exposure to 10 mg/m3 CdCl2) in order to evaluate possible dose-related response relationships. The rate of thoracic clearance of Tc-pentetate was observed to be slowed at 3 h after exposure to CdCl2 aerosol and subsequently increased to well above control rates. The time sequence observed strongly suggests that increased Tc-pentetate clearance rates are indicative of a tissue response or repair process, rather than acute lung injury. Tracheal epithelial penetration of macromolecular tracers was not observed to increase in histological evaluations following serial sacrifice.

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Respirable Fraction of Airborne Dust: Quantitative Descriptions, Formal Definitions, and Performance Characteristics of Samplers Matched to Them

Cited by 4 publications

References 32 publications

Particle Size Distribution of Particulate Matter Emitted from a Layer Operation in Southeast U.S.

Particle Size Distribution of Particulate Matter Emitted from a Layer Operation in Southeast U.S.

Analysis for the Relationship Between Concentrations of Air Pollutants and Meteorological Parameters in Xi'an, China

Altered Clearance of Inhaled^99mTc-Pentetate Aerosols following Exposure to Cadmium Chloride Aerosols in Ferrets

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Respirable Fraction of Airborne Dust: Quantitative Descriptions, Formal Definitions, and Performance Characteristics of Samplers Matched to Them

Cited by 4 publications

References 32 publications

Particle Size Distribution of Particulate Matter Emitted from a Layer Operation in Southeast U.S.

Particle Size Distribution of Particulate Matter Emitted from a Layer Operation in Southeast U.S.

Analysis for the Relationship Between Concentrations of Air Pollutants and Meteorological Parameters in Xi'an, China

Altered Clearance of Inhaled99mTc-Pentetate Aerosols following Exposure to Cadmium Chloride Aerosols in Ferrets

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Product

Resources

About

Altered Clearance of Inhaled^99mTc-Pentetate Aerosols following Exposure to Cadmium Chloride Aerosols in Ferrets