Direct Identification of Trace Metals in Fine and Ultrafine Particles in the Detroit Urban Atmosphere
Journal
Environmental Science & Technology
Journal Volume
38
Journal Issue
8
Start Page
2289
End Page
2297
ISSN
0013-936X
1520-5851
Date Issued
2004-03-17
Author(s)
Abstract
Exposure to airborne particulates containing low concentrations of heavy metals, such as Pb, As, and Se, may have serious health effects. However, little is known about the speciation and particle size of these airborne metals. Fine- and ultrafine particles with heavy metals in aerosol samples from the Detroit urban area, Michigan, were examined in detail to investigate metal concentrations and speciation. The characterization of individual particles was completed using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) combined with conventional high-resolution TEM techniques. The trace elements, Pb, As, La, Ce, Sr, Zn, Cr, Se, Sn, Y, Zr, Au, and Ag, were detected, and the elemental distributions were mapped in situ at the nanoscale. The crystal structures of the particles containing Pb, Sr, Zn, and Au were determined from their electron diffraction patterns. Based on the characterization of the representative trace element particles, the potential health effects are discussed. Most of the trace element particles detected in this study were within a range of 0.01-1.0 μm in size, which has the longest atmospheric residence time (∼100 days). Increased chemical reactivity owing to the size of nanoparticles may be expected for most of the trace metal particles observed.
Subjects
Aerosols
Air Pollutants
Cities
Environmental Monitoring
Metals
Heavy
Michigan
Particle Size
Trace Elements
Detroit
North America
United States
Diffraction
Heavy metals
Identification (control systems)
Particulate emissions
Trace elements
Transmission electron microscopy
arsenic
barium
cerium
chromium
gold
heavy metal
lanthanide
lanthanum
lead
nanoparticle
selenium
silver
strontium
tin
trace metal
yttrium
zinc
zirconium
aerosol
atmospheric chemistry
health impact
particulate matter
speciation (chemistry)
urban atmosphere
air pollution
airborne particle
article
chemical reaction
crystal structure
electron diffraction
particle size
scanning electron microscopy
transmission electron microscopy
urban area
Chemical reactivity
Nanoparticles
Upper atmosphere
Publisher
American Chemical Society (ACS)
Type
journal article