Concentrated ambient air particles cause pulmonary inflammation in a dose-dependent manner in both normal and chronic bronchitic rats
Year: 1998
Type: article
Abstract: To estimate the significance of temporal changes in RH on dry deposition to a water surface, size-segregated particulate aerosol samples were collected with nine-stage micro-orifice impactors at average RH ranging from <60 to 95% at a shoreline site along the Chesapeake Bay. These were analyzed by instrumental neutron activation for up to 44 elements including Al, As, Br, Cd, Cr, Cu, Fe, Mn, S, Sb, Se, V, and Zn. Distribution parameters, e.g., mass median aerodynamic diameters (mmad) were calculated from the resulting size spectra for each element and used to characterize particle growth as a function of RH. The spectra were used in an adaptation of the Williams (1982)’ model along with half-hourly meteorological observations made over a nine-month period at a northern Bay Buoy station to investigate the effects of temporal variations in RH on the deposition fluxes of important elemental aerosol constituents. Additional modeling was done using the hygroscopic growth equation of Koutrakis et al. (1989) developed for atmospheric sulfate. At 60% RH, mmads for fine-particle components of As, Sb, Se, V, and Zn aerosols were: 0.29, 0.33, 0.30, 0.27, and 0.4 μm, i.e. comparable to those measured previously in College Park, MD Ondov and Divita, 1993. These increased from 50 to 300% at RH=95±4%. Modeling results suggest that temporal RH effects account for from 1.5- to>four-fold increase in the deposition of fine particle fractions which bear the bulk of many these elements.
Source: Pathophysiology
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,689
OpenAlex ID: W2062683917