Characterization of Urban Particulate Air Pollution over
Metropolitan Newark in New Jersey
on the US East Coast
Yuan Gao, Lily Xia, Dawn Roberts-Semple, Rafael Jusino-Astresino, Chris Thuman,
Lu Wang, Nathi Kijpatanasilp
Department of Earth and Environmental Sciences
Rutgers University
Newark, New Jersey USA
.
Objectives:
• To characterize mass-size distributions of ambient aerosol
particles in the polluted urban environment
•To investigate the interactions of chemical species
•To explore the impact of air pollution on biogeochemistry
Methodology:
•Micro-Orifice Uniform Deposit Impactor (MOUDI)
•Inductively coupled plasma mass spectrometry (ICPMS)
•Scanning electron microscope (SEM)
•Ion chromatography (IC)
Air Measurement Sites
n
Lo
Newark
n
sla
I
g
d
New
Yo
rk C
ity
Atlantic ocean
Aerosol Mass Size Distributions: Unban Newark
dC/dlog(dDp) (µm m-3)3)
40
7/13-7/14
7/24-7/27
8/15-8/18
8/18-8/21
8/21-8/24
8/24-8/27
9/6-9/9
9/9-9/12
9/20-9/22
9/25-9/27
10/12-10/16
12/14-12/18
2006
30
20
10
0
0.01
0.1
1
Dp (µm)
(Zhao and Gao, Atmospheric Environment, 2008)
10
100
Mass Size Distributions at Coastal Site
(Xia and Gao, Marine Chemistry, 2010)
Mass Size Distributions at High-Traffic Site
2009
Size Distributions: Selected Trace
Elements
Vanadium
Nickle
Size Distributions: Water-Soluble Inorganic and Organic Species
Sulfate and oxalate:
- Dominant peaks are in
submicron meter size ranges
for both,
- positively correlated,
- Consistent with Yu et al,
(2005).
- Both can come from
pollution emissions.
- Both may play important
roles in dust geochemistry;
dust is a source of Fe, a
limiting nutrient in open
ocea.
Evidence of interactions of
soil particles with acific air
pollutants.
(Gao and Anderson,
JGR-Atmospheres, 2001)
Dissolved iron amount (µmol g-1)
Hematite Dissolution in Oxalate Solutions
10
10
a)
b)
Coated with 25mMoxalate
Non-coated
8
8
6
6
4
4
2
2
0
0
0
10
20
30
40
50
In 25µM oxalate
In background eletrolyte
60
0
10
20
30
Dissolution Time (hours)
pH = 2.4 ± 0.1
(Xu and Gao, Applied Geochemistry, 2008)
40
50
60
Inner sphere
coordinated oxygen
Fe
HO – C = O
HO – C = O
Fe
Solution
Hematite
Molecular structure of inner-sphere surface
complexation of Fe(III)-oxalate
Oxygen
C
H+
Implementation of the field/laboratory results from air
pollution studies into global models to gain better
understanding of biogeochemical cycles:
“Aeolian Iron Mobilization by Dust-Acids Interactions and
Its Implication for Soluble Iron Deposition to the Ocean: A
Test Involving Potential Anthropogenic Organic Acidic
Species”
(Luo and Gao, Environmental Chemistry, 2010)
Conclusions:
1. Ambient particulate mass in this region is
dominated by submicron meter particles, likely
formed through heterogeneous reactions,
2. Particulate matter is highly enriched with
chemical elements of non-crustal source,
indicating the level of air pollution,
3. Acidic air pollutants may interact with dust and
then iron, affecting global biogeochemical cycles.
Thank You.