Bibliometric Analysis
for the U.S. Environmental Protection Agency/Office of
Research and Development's Particulate Matter Research
This is a bibliometric analysis of the papers prepared by U.S. Environmental Protection Agency
(EPA) intramural and extramural researchers on particulate matter (PM) research, which is a
component of EPA's Air Research Program. For this analysis, 1,561 papers were reviewed, and
they were published from 1998 to 2007. These publications were cited 27,449 times in the
journals covered by Thomson Scientific's Web of Science1 and Elsevier's Scopus2. Of these
1,561 publications, 1,369 (87.7%) have been cited at least once in a journal.
Searches of Web of Science and Scopus were conducted to obtain times cited data for the PM
journal publications. The analysis was completed using Thomson's Essential Science Indicators
(ESI) and Journal Citation Reports (JCR) as benchmarks. ESI provides access to a unique and
comprehensive compilation of essential science performance statistics and science trends data
derived from Thomson's databases. For this analysis, the ESI highly cited papers thresholds as
well as the hot papers thresholds were used to assess the influence and impact of the PM papers.
JCR is a recognized authority for evaluating journals. It presents quantifiable statistical data that
provide a systematic, objective way to evaluate the world's leading journals and their impact and
influence in the global research community. The two key measures used in this analysis to assess
the journals in which the EPA PM papers are published are the Impact Factor and Immediacy
Index. The Impact Factor is a measure of the frequency with which the "average article" in a
journal has been cited in a particular year. The Impact Factor helps evaluate a journal's relative
importance, especially when compared to other journals in the same field. The Immediacy Index
is a measure of how quickly the "average article" in a journal is cited. This index indicates how
often articles published in a journal are cited within the same year and it is useful in comparing
how quickly journals are cited.
The report includes a summary of the results of the bibliometric analysis, an analysis of the 1,561
PM research papers analyzed by ESI field (e.g., Clinical Medicine, Environment/ Ecology, and
Geosciences), an analysis of the journals in which the PM papers were published, a table of the
highly cited researchers publishing on PM research, and a list of patents that have resulted from
the program.
Thomson Scientific's Web of Science provides access to current and retrospective multidisciplinary
information from approximately 8,830 of the most prestigious, high impact research journals in the world.
Web of Science also provides cited reference searching.
Scopus is a large abstract and citation database of research literature and quality Web sources designed to
support the literature research process. Scopus offers access to 15,000 titles from 4,000 different publishers,
more than 12,850 academic journals (including coverage of 535 Open Access journals, 750 conference
proceedings, and 600 trade publications), 27 million abstracts, 245 million references, 200 million scientific
Web pages, and 13 million patent records.
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SUMMARY OF RESULTS
l. More than one-third of the PM publications are highly cited papers. 578 (37.0%) of the PM
papers qualify as highly cited when using the ESI criteria for the top 10% of highly cited
publications. This is 3.7 times the 10% of papers expected to be highly cited. 96 (6.2%) of the
PM papers qualify as highly cited when using the ES/ criteria for the top 1 %, which is 6.1 times
the number expected. 14 (0.9%) of these papers qualify as very highly cited when using the
criteria for the top 0.1 %, which is 9 times the number anticipated. None of the papers actually
meets the 0.01 % threshold for the most highly cited papers, which is not surprising given that the
expected number for this program is 0.2 papers.
2. The PM papers are more highly cited than the average paper. Using the ESI average
citation rates for papers published by field as the benchmark, in 13 of the 18 fields in which the
1,561 EPA PM papers were published, the ratio of actual to expected cites is greater than 1,
indicating that the PM papers are more highly cited than the average papers in those fields. For
all 18 fields combined, the ratio of total number of cites to the total number of expected cites
(27,449 to 10,856.34) is 2.5, indicating that the PM papers are more highly cited than the
average paper.
3. More than one-third of the PM papers are published in high impact journals. 537 of the
1,561 papers were published in the top 10% of journals ranked by JCf? Impact Factor,
representing 34.4% of EPA's PM papers. This number is 3.4 times higher than the expected 156
papers. Nearly one-half of the papers are published in high impact journals as determined by
JCf? Immediacy Index. 762 of the 1,561 papers appear in the top 10% of journals ranked by
JCf? Immediacy Index, representing 48.8% of EPA's PM papers. This number is 4.9 times higher
than the expected 156 papers.
4. Forty-five of the PM papers qualify as hot papers. Using the hot paper thresholds
established by ESI as a benchmark, 45 hot papers, representing 2.9% of the PM papers, were
identified in the analysis. Hot papers are papers that were highly cited shortly after they were
published. The number of PM hot papers identified is 29 times higher than the expected 2 hot
papers.
5. The authors of the PM papers cite themselves much less than the average author. 1,227
of the 27,449 cites are author self-cites. This 4.5% author self-citation rate is well below the
accepted range of 10-30% author self-citation rate.
6. Forty (1.5%) of the 2,710 authors of the PM papers are included in ISIHighlyCited.com,
which is a database of the world's most influential researchers who have made key contributions
to science and technology during the period from 1981 to 1999.
7. There were 6 patents issued to investigators from 1998 to 2007 for research that was
conducted under EPA's PM research. Two of these patents were cited by a total of 9 other
patents.
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Highly Cited PM Publications
All of the journals covered by ESI are assigned a field, and to compensate for varying citation
rates across scientific fields, different thresholds are applied to each field. Thresholds are set to
select highly cited papers to be listed in ESI. Different thresholds are set for both field and year
of publication. Setting different thresholds for each year allows comparable representation for
older and younger papers for each field.
The 1,561 PM research papers reviewed for this analysis were published in journals that were
assigned to 18 of the 22 ESI fields. The distribution of the papers among these 18 fields and the
number of citations by field are presented in Table 1.
Table 1. PM Papers by £S7 Fields
ESI Field
Biology & Biochemistry
Chemistry
Clinical Medicine
Computer Science
Economics & Business
Engineering
Environment/Ecology
Geosciences
Immunology
Materials Science
Mathematics
Molecular Biology & Genetics
Multidisciplinary
Neuroscience & Behavior
Pharmacology & Toxicology
Physics
Plant & Animal Science
Social Sciences, general
No. of Citations
486
1,056
6,346
6
25
3,628
6,507
5,527
372
1
31
25
389
185
2,642
164
32
27
Total = 27,449
No. of PM Papers
34
78
243
2
3
272
333
350
13
1
6
3
9
11
179
11
5
8
Total = 1,561
Average Cites/Paper
14.3
13.5
26.1
3.0
8.3
13.3
19.5
15.8
28.6
1.0
5.2
8.3
43.2
16.8
14.8
14.9
6.4
3.4
17.6
There are 578 (37.0% of the papers analyzed) highly cited EPA PM papers in 13 of the 18
fields—Biology & Biochemistry, Chemistry, Clinical Medicine, Economics & Business,
Engineering, Environment/Ecology, Geosciences, Immunology, Mathematics, Multidisciplinary,
Pharmacology & Toxicology, Physics, and Social Sciences—when using the ESI criteria for the
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top 10% of papers. Table 2 shows the number of EPA PM papers in those 13 fields that meet
the top 10% threshold in ESI. Ninety-six (6.2%) of the papers analyzed qualify as highly cited
when using the ESI criteria for the top 1% of papers. These papers cover 8 fields—Chemistry,
Clinical Medicine, Economics & Business, Engineering, Environment/ Ecology, Geosciences,
Multidisciplinary, and Pharmacology & Toxicology. Table 3 shows the 96 papers by field that
meet the top 1% threshold in ESI. The citations for these 96 papers are provided in Tables 4
through 11. Table 12 shows the 14 (0.9%) papers by field that meet the top 0.1% threshold in
ESI. These 14 very highly cited PM papers in the fields of Chemistry, Clinical Medicine,
Economics & Business, Engineering, Environment/Ecology, and Geosciences are listed in Table
13. None of the PM papers meet the top 0.01% threshold in ESI, which is not surprising
because the expected number of papers that should meet this threshold for this analysis is 0.2.
The highly cited papers in Tables 4 through 11 are presented in order of year of publication with
the oldest papers appearing first. Within the year of publication, the papers are ordered by
increasing number of times cited.
Table 2. Number of Highl
ESI Field
Biology & Biochemistry
Chemistry
Clinical Medicine
Economics & Business
Engineering
Environment/Ecology
Geosciences
Immunology
Mathematics
Multidisciplinary
Pharmacology & Toxicology
Physics
Social Sciences, general
No. of Citations
179
663
4,954
7
3,159
5,070
3,871
303
25
366
1,588
117
6
Total = 20,308
y Cited PM Papers by Field (top 10%)
No. of Papers
5
21
90
1
123
152
126
5
2
5
44
3
1
Total = 578
Average Cites/Paper
35.8
31.6
55.0
7.0
25.7
33.4
30.7
60.6
12.5
73.2
36.4
39.0
6.0
35.1
% of Papers in Fiek
14.7%
26.9%
37.0%
33.3%
45.2%
45.6%
36.0%
38.5%
33.3%
62.5%
24.6%
27.3%
12.5%
37.0%
Table 3. Number of Highly Cited PM Papers by Field (top 1%)
ESI Field
Chemistry
Clinical Medicine
No. of
Citations
62
1,513
No. of
Papers
2
8
Average
Cites/Paper
31.0
189.1
%ofPM Papers
in Field
2.6%
3.3%
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ESI Field
Economics & Business
Engineering
Environment/Ecology
Geosciences
Multidisciplinary
Pharmacology & Toxicology
No. of
Citations
7
1,746
1,549
1,416
272
259
Total =
6,824
No. of
Papers
1
31
31
19
2
2
Total =
96
Average
Cites/Paper
7.0
56.3
50.0
74.5
136.0
129.5
71.1
%ofPM Papers
in Field
33.3%
11.4%
9.3%
5.4%
22.2%
1.1%
6.2%
Table 4. Highly Cited PM Papers in the Field of Chemistry (top 1%)
No. of
Cites
59
3
ESI
Threshold
43
2
First Author
GaoS
Rudich Y
Paper
Low-molecular-weight and oligomeric components in secondary
organic aerosol from the ozonolysis of cycloalkenes and alpha-pinene.
Journal of Physical Chemistry A 2004;108(46): 10147-10164.
Aging of organic aerosol: bridging the gap between laboratory and
field studies. Annual Review of Physical Chemistry 2007;58:321-352.
Table 5. Highly Cited PM Papers in the Field of Clinical Medicine (top 1%)
No. of
Cites
187
216
249
634
89
131
ESI Threshold
144
133
115
99
54
54
First Author
Abbey DE
Gold DR
Peters A
Pope CA
Peters A
Pope CA
Paper
Long-term inhalable particles and other air pollutants related to
mortality in nonsmokers. American Journal of Respiratory and
Critical Care Medicine 1999;159(2):373-382.
Ambient pollution and heart rate variability. Circulation
2000;101(11): 1267-1273.
Increased particulate air pollution and the triggering of myocardial
infarction. Circulation 2001;103(23):2810-2815.
Lung cancer, cardiopulmonary mortality and long-term exposure to
fine particulate air pollution. Journal of the American Medical
Association 2^2-^1 (9}: 1132-1141.
Exposure to traffic and the onset of myocardial infarction. New
England Journal of Medicine 2004;35 1(17): 1721-1730.
Cardiovascular mortality and long-term exposure to particulate air
pollution: epidemiological evidence of general pathophysiological
pathways of disease. Circulation 2004;109(l):71-77.
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No. of
Cites
2
5
ESI Threshold
2
2
First Author
Baccarelli A
Miller KA
Paper
Effects of exposure to air pollution on blood coagulation. Journal of
Thrombosis and Haemostasis 2007;5(2):252-260.
Long-term exposure to air pollution and incidence of cardiovascular
events in women. New England Journal of Medicine
2007;356(5):447-458.
Table 6. Highly Cited PM Papers in the Field of Economics & Business (top 1%)
No. of
Cites
7
ESI
Threshold
4
First Author
PengRD
Paper
Model choice in time series studies of air pollution and mortality.
Journal of the Royal Statistical Society: Series A (Statistics in Society)
2006;169(2):179-203.
Table 7. Highly Cited PM Papers in the Field of Engineering (top 1%)
No. of
Cites
ESI
Threshold
First Author
Paper
54
46
ZhangY
Simulation of aerosol dynamics: a comparative review of algorithms
used in air quality models. Aerosol Science and Technology
1999;31(6):487-514.
45
44
Wilson WE
Estimating separately personal exposure to ambient and non-ambient
particulate matter for epidemiology and risk assessment; why and how.
Journal of the Air & Waste Management Association 2000;50(7): 1167-
1183.
52
44
Tobias HJ
Real-time chemical analysis of organic aerosols using a thermal
desorption particle beam mass spectrometer. Aerosol Science and
Technology 2000;33(l-2): 170-190.
75
44
Sarnat JA
Assessing the relationship between personal particulate and gaseous
exposures of senior citizens living in Baltimore. Journal of the Air &
Waste Management Association 2000;50(7): 1184-1198.
78
44
Long CM
Characterization of indoor particle sources using continuous mass and
size monitors. Journal of the Air & Waste Management Association
2000;50(7): 1236-1250.
207
44
Jayne JT
Development of an aerosol mass spectrometer for size and composition
analysis of submicron particles. Aerosol Science and Technology
2000;33(l-2):49-70.
209
44
Richter H
Formation of poly cyclic aromatic hydrocarbons and their growth to
soot-
a review of chemical reaction pathways. Progress in Energy and
Combustion Science 2000;26(4-6):565-608.
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No. of
Cites
ESI
Threshold
First Author
Paper
38
37
Vette AF
Characterization of indoor-outdoor aerosol concentration relationships
during the Fresno PM exposure studies. Aerosol Science and
Technology 2QQ\;34(\): 118-126.
42
37
Lewtas J
Comparison of sampling methods for semi-volatile organic carbon
associated with PM25. Aerosol Science and Technology 2001;34(1):9-
22.
57
37
Tolocka MP
East versus West in the US: chemical characteristics of PM2 5 during the
winter of 1999. Aerosol Science and Technology 2001;34(l):88-96.
92
37
WooKS
Measurement of Atlanta aerosol size distributions: Observations of
ultrafine particle events. Aerosol Science and Technology
2001;34(l):75-87.
105
37
Weber PJ
A particle-into-liquid collector for rapid measurement of aerosol bulk
chemical composition. Aerosol Science and Technology
2001;35(3):718-727.
31
31
Cabada JC
Sources of atmospheric carbonaceous particulate matter in Pittsburgh,
Pennsylvania. Journal of the Air & Waste Management Association
2002;52(6):732-741.
34
31
Zhang Z
Cyclic micron-size particle inhalation and deposition in a triple
bifurcation lung airway model. Aerosol Science and Technology
2002;33(2):257-281.
37
31
KimS
Size distribution and diurnal and seasonal trends of ultrafine particles in
source and receptor sites of the Los Angeles basin. Journal of the Air &
Waste Management Association 2002;52(3):297-307.
40
31
Zhang X
A numerical characterization of particle beam collimation by an
aerodynamic lens-nozzle system: Part I. an individual lens or nozzle.
Aerosol Science and Technology 2002;36(5):617-631.
63
31
McMurray PH
The relationship between mass and mobility for atmospheric particles: A
new technique for measuring particle density. Aerosol Science and
Technology 2002;36(2):227-238.
130
31
ZhuYF
Concentration and size distribution of ultrafine particles near a major
highway. Journal of the Air & Waste Management Association
2002;52(9): 1032-1042.
31
25
Lewis CW
Source apportionment of Phoenix PM2.5 aerosol with the Unmix
receptor model. Journal of the Air & Waste Management Association
2003;53(3):325-338.
23
18
Zhang XF
Numerical characterization of particle beam collimation: Part II
integrated aerodynamic-lens-nozzle system. Aerosol Science and
Technology 2004;38(6):619-638.
23
18
ZhuY
Seasonal trends of concentration and size distribution of ultrafine
particles near major highways in Los Angeles. Aerosol Science and
Technology 2004;38(S1):5-13.
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No. of
Cites
24
25
26
33
34
39
55
13
14
17
ESI
Threshold
18
18
18
18
18
18
18
10
4
4
First Author
Cabada JC
Drewnick F
ChoA
Stanier CO
Drewnick F
Subramanian R
Canagaratna M
KimE
ByunD
Bond TC
Paper
Estimating the secondary organic aerosol contribution to PM2 5 using the
EC tracer method. Aerosol Science and Technology 2004;38(S 1): 140-
155.
Measurement of ambient aerosol composition during the PMTACS-NY
2001 campaign using an aerosol mass spectrometer. Part II: Chemically
speciated mass distribution. Aerosol Science and Technology
2004;38(S1):104-117.
Determination of four quinones in diesel exhaust particles, SRM 1649a
and atmospheric PM2 5. Aerosol Science and Technology
2004;38(S1):68-81.
Nucleation events during the Pittsburgh Air Quality Study: description
and relation to key meteorological, gas phase, and aerosol parameters.
Aerosol Science and Technology 2004;38(Sl):253-264.
Measurement of ambient aerosol composition during the PMTACS-NY
2001 campaign using an aerosol mass spectrometer. Part I: Mass
concentrations. Aerosol Science and Technology 2004;38(S1):92-103.
Positive and negative artifacts in particulate organic carbon
measurements with denuded and undenuded sampler configurations.
Aerosol Science and Technology 2004;38(Sl):27-48.
Chase studies of particulate emissions from in-use New York City
vehicles. Aerosol Science and Technology 2004;38(6):555-573.
Estimation of organic carbon blank values and error structures of the
speciation trends network data for source apportionment. Journal of the
Air & Waste Management Association 2005;55(8): 1190-1 199.
Review of the governing equations, computational algorithms, and other
components of the Models-3 Community Multiscale Air Quality
(CMAQ) modeling system. Applied Mechanics Reviews 2006;59:51-77.
Light absorption by carbonaceous particles: an investigative review.
Aerosol Science and Technology 2006;40(l):27-67.
Table 8. Highly Cited PM Papers in the Field of Environment/Ecology (top 1%)
No. of
Cites
175
208
ESI
Threshold
103
88
First Author
Liao D
Laden F
Paper
Daily variation of particulate air pollution and poor cardiac autonomic
control in the elderly. Environmental Health Perspectives
1999;107(7):521-525.
Association of fine particulate matter from different sources with daily
mortality in six U.S. cities. Environmental Health Perspectives
2000;108(10):941-947.
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No. of
Cites
83
83
94
67
144
34
40
44
45
58
59
17
18
19
22
ESI
Threshold
77
77
77
48
48
34
34
34
34
34
34
17
17
17
17
First Author
Fine PM
Jang M
Dockery DW
ParkK
LiN
Landrigan PJ
Chow JC
XiaT
Zhang Q
Pope CA
GaoS
Reisen F
Delfmo RJ
Dockery DW
Zanobetti A
Paper
Chemical characterization of fine particle emissions from the fireplace
combustion of woods grown in the northeastern United States.
Environmental Science & Technology 2001;35(13):2665-2675.
Atmospheric secondary aerosol formation by heterogeneous reactions of
aldehydes in the presence of a sulfuric acid aerosol catalyst.
Environmental Science & Technology 2001;35(24):4758-4766.
Epidemiologic evidence of cardiovascular effects of particulate air
pollution. Environmental Health Perspectives 2001;109(S4):483-486.
Relationship between particle mass and mobility for diesel exhaust
particles. Environmental Science & Technology 2003;37(3):577-583.
Ultrafine particulate pollutants induce oxidative stress and mitochondrial
damage . Environmental Health Perspectives 2003;111(4):455-460.
Health and environmental consequences of the World Trade Center
disaster. Environmental Health Perspectives 2004; 112(6):73 1-739.
Equivalence of elemental carbon by thermal/optical reflectance and
transmittance with different temperature protocols. Environmental
Science & Technology 2004;38(16):4414-4422.
Quinones and aromatic chemical compounds in particulate matter induce
mitochondrial dysfunction: implications for ultrafine particle toxicity.
Environmental Health Perspectives 2004;! 12(14): 1347-1358.
Insights into the chemistry of new particle formation and growth events
in Pittsburgh based on aerosol mass spectrometry. Environmental
Science & Technology 2004;38(18):4797-4809.
Ambient particulate air pollution, heart rate variability, and blood
markers of inflammation in a panel of elderly subjects. Environmental
Health Perspectives 2004;! 12(3):339-345.
Particle phase acidity and oligomer formation in secondary organic
aerosol. Environmental Science & Technology 2004;38(24):6582-6589.
Atmospheric reactions influence seasonal PAH and nitro-PAH
concentrations in the Los Angeles Basin. Environmental Science &
Technology 2005;39(l):64-73.
Potential role of ultrafine particles in associations between airborne
particle mass and cardiovascular health. Environmental Health
Perspectives 2005;! 13(8):934-946.
Association of air pollution with increased incidence of ventricular
tachyarrhythmias recorded by implanted cardioverter defibrillators.
Environmental Health Perspectives 2005; 1 13 (6): 670-674.
The effect of particulate air pollution on emergency admissions for
myocardial infarction: a multeity case-crossover analysis.
Environmental Health Perspectives 2005;! 13(8):978-982.
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No. of
Cites
23
25
26
27
40
133
6
7
7
7
8
8
9
13
ESI
Threshold
17
17
17
17
17
17
6
6
6
6
6
6
6
6
First Author
LimH
Park SK
Bahrein! R
Lough GC
Zhang Q
Oberdorster G
Selgrade MK
Dubowsky SD
Elder A
Okin GS
Shrivastava
MK
Donahue NM
Presto AA
McConnell R
Paper
Isoprene forms secondary organic aerosol through cloud processing:
model simulations. Environmental Science & Technology
2005;39(12):4441-4446.
Effects of Air Pollution on Heart Rate Variability: The VA Normative
Aging Study. Environmental Health Perspectives 2005;! 13(3):304-309.
Measurements of secondary organic aerosol from oxidation of
cycloalkenes, terpenes, and m-xylene using an Aerodyne aerosol mass
spectrometer. Environmental Science & Technology 2005;39(15):5674-
5688.
Emissions of metals associated with motor vehicle roadways.
Environmental Science & Technology 2005;39(3):826-836.
Deconvolution and quantification of hydrocarbon-like and oxygenated
organic aerosols based on aerosol mass spectrometry. Environmental
Science & Technology 2005;39(13):4938-4952.
Nanotoxicology: an emerging discipline evolving from studies of
ultrafine particles. Environmental Health Perspectives
2005;113(7):823-839.
Induction of asthma and the environment: what we know and need to
know. Environmental Health Perspectives 2006;114(4):615-619.
Diabetes, obesity, and hypertension may enhance associations between
air pollution and markers of systematic inflammation. Environmental
Health Perspectives 2006;! 14(7):992-998.
Translocation of inhaled ultrafine manganese oxide particles to the
central nervous system. Environmental Health Perspectives
2006;! 14(8): 1172-1 178.
Multi-scale controls on and consequences of aeolian processes in
landscape change in arid and semi -arid environments. Journal of Arid
Environments 2006;65(2):253-275.
Modeling semivolatile organic aerosol mass emissions from combustion
systems. Environmental Science & Technology 2006;40(8):2671-2677.
Coupled partitioning, dilution, and chemical aging of semivolatile
organics. Environmental Science & Technology 2006;40(8):2635-2643.
Investigation of a-pinene + ozone secondary organic aerosol formation
at low total aerosol mass. Environmental Science & Technology
2006;40(ll):3536-3543.
Traffic, susceptibility, and childhood asthma. Environmental Health
Perspectives 2006;! 14(5):766-772.
10
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Table 9. Highly Cited PM Papers in the Field of Geosciences (top 1%)
No. of Cites
149
166
170
188
92
178
121
42
53
85
29
31
31
27
ESI
Threshold
114
98
98
98
69
69
54
41
41
41
29
29
29
18
First Author
Nenes A
Griffin RJ
YuJ
Simoneit BRT
Sokolik IN
Huser RB
ZhuY
Binkowski FS
Orsini DA
Jiminez JL
Zhang KM
Wittig AE
KimE
Edney EO
Paper
ISORROPIA: a new thermodynamic equilibrium model for multiphase
multicomponent inorganic aerosols. Aquatic Geochemistry 1998;4:123-
152.
Organic aerosol formation from the oxidation of biogenic hydrocarbons.
Journal of Geophysical Research-Atmospheres 1999;104(D3):3555-
3567.
Gas-Phase ozone oxidation of monoterpenes: gaseous and particulate
products. Journal of Atmospheric Chemistry 1999;34(2):207-258.
Levoglucosan, a tracer for cellulose in biomass burning and atmospheric
particles. Atmospheric Environment 1999;33(2): 173-182.
Introduction to special section: outstanding problems in quantifying the
radiative impact of mineral dust. Journal of Geophysical Research-
Atmospheres 2001;106(D16): 18015-18027.
Asian dust events of April 1998. Journal of Geophysical Research-
Atmospheres 2001;106(D16): 18317-18330.
Study of ultrafine particles near a major highway with heavy-duty diesel
traffic. Atmospheric Environment 2002;36(27):4323-4335.
Models-3 Community Multiscale Air Quality (CMAQ) model aerosol
component. 1. Model description. Journal of Geophysical Research-
Atmospheres 2003;108(D6):4183.
Refinements to the particle -into-liquid sampler (PILS) for ground and
airborne measurements of water soluble aerosol composition.
Atmospheric Environment 2003;37(9-10):243-1259.
Ambient aerosol sampling using the Aerodyne Aerosol Mass
Spectrometer. Journal of Geophysical Research-Atmospheres
2003;108(D7):8425.
Evolution of particle number distribution near roadways: Part II: The
"road-to-ambient" process. Atmospheric Environment
2004;38(38):6655-6665.
Pittsburgh Air Quality Study overview. Atmospheric Environment
2004;38(20):3 107-3 125.
Improving source identification of Atlanta aerosol using temperature
resolved carbon fractions in positive matrix factorization. Atmospheric
Environment 2004;38(20):3349-3362.
Formation of 2-methyl tetrols and 2-methylgly eerie acid in secondary
organic aerosol from laboratory irradiated isoprene/NOx/SO2/air
mixtures and their detection in ambient PM2 5 samples collected in the
eastern United States. Atmospheric Environment 2005;39(29):5281-
5289.
11
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No. of Cites
32
8
8
3
3
ESI
Threshold
18
7
7
3
3
First Author
Zhang Q
Offenberg JH
Takegawa N
Kondo Y
Pathak RK
Paper
Hydrocarbon-like and oxygenated organic aerosols in Pittsburgh:
insights into sources and processes or organic aerosols. Atmospheric
Chemistry and Physics 2QQ5;5(l2):3289-33ll.
Thermal properties of secondary organic aerosols. Geophysical
Research Letters 2006;33(3):L03816.
Seasonal and diurnal variations of submicron organic aerosol in Tokyo
observed using the Aerodyne aerosol mass spectrometer. Journal of
Geophysical Research-Atmospheres 2006;! 1 1(D1 1206).
Oxygenated and water-soluble organic aerosols in Tokyo. Journal of
Geophysical Research-Atmospheres 2007;! 12(D1):DO 1203.
Ozonolysis of a-pinene at atmospherically relevant concentrations:
Temperature dependence of aerosol mass fractions (yields). Journal of
Geophysical Research-Atmospheres 2007; 1 12(D3):D0320 1 .
Table 10. Highly Cited PM Papers in the Field of Multidisciplinary (top 1%)
No. of Cites
117
155
ESI
Threshold
55
93
First Author
Gard EE
Jang M
Paper
Direct Observation of Heterogeneous Chemistry in the Atmosphere.
Science 1998;279(5354): 1 184-1 187.
Heterogeneous Atmospheric Aerosol Production by Acid-Catalyzed
Particle-Phase Reactions. Science 2002;298(5594):814-817.
Table 11. Highly Cited PM Papers in the Field of Pharmacology & Toxicology (top 1%)
No. of Cites
157
102
ESI
Threshold
99
44
First Author
Oberdorster G
Oberdorster G
Paper
Pulmonary effects of inhaled ultrafine particles. International Archives
of Occupational and Environmental Health 2001;74(1): 1-8.
Translocation of inhaled ultrafine particles to the brain. Inhalation
rox/co/ogj2004;16(6-7):437-445.
Table 12. Number of Very Highly Cited Papers by Field (Top 0.1%)
ESI Field
Chemistry
Clinical Medicine
No. of
Citations
3
639
No. of
Papers
1
2
Average
Cites/Paper
3.0
319.5
%ofPM
Papers in Fielt
1.3%
0.8%
12
-------
ESI Field
Economics & Business
Engineering
Environment/Ecology
Geosciences
No. of
Citations
7
671
277
178
Total =
1,775
No. of
Papers
1
7
2
1
Total =
14
Average
Cites/Paper
7.0
95.8
138.5
178.0
126.8
%ofPM
Papers in Fielt
33.3%
2.6%
0.6%
0.3%
0.9%
Table 13. Very Highly Cited PM Papers (top 0.1%)
ESI Field
Chemistry
Clinical
Medicine
Economics &
Business
Engineering
ESI
Threshold
3
288
4
7
116
116
76
39
No. of
Cites
3
634
5
7
207
209
130
39
First Author
Rudich Y
Pope CA
Miller KA
PengRD
Jayne JT
Richter H
ZhuYF
Subramanian R
Paper
Aging of organic aerosol: bridging the gap between
laboratory and field studies. Annual Review of Physical
Chemistry 2007;58:321-352.
Lung cancer, cardiopulmonary mortality and long-term
exposure to fine particulate air pollution. Journal of the
American Medical Association 2002;287(9): 1 132-1 141 .
Long-term exposure to air pollution and incidence of
cardiovascular events in women. New England Journal of
Medicine 2007;356(5):447-458.
Model choice in time series studies of air pollution and
mortality. Journal of the Royal Statistical Society: Series A
(Statistics in Society) 2006;169(2): 179-203.
Development of an aerosol mass spectrometer for size and
composition analysis of submicron particles. Aerosol
Science and Technology 2000;33(l-2):49-70.
Formation of poly cyclic aromatic hydrocarbons and their
growth to soot - a review of chemical reaction pathways.
Progress in Energy and Combustion Science 2000;26(4-
6):565-608.
Concentration and size distribution of ultrafine particles
near a major highway. Journal of the Air & Waste
Management Association 2002;52(9): 1032-1042.
Positive and negative artifacts in particulate organic carbon
measurements with denuded and undenuded sampler
configurations. Aerosol Science and Technology
2004;38(Sl):27-48.
13
-------
ESI Field
Engineering
Environment/
Ecology
Geosciences
ESI
Threshold
39
9
9
116
43
176
No. of
Cites
55
14
17
144
133
178
First Author
Canagaratna M
ByunD
Bond TC
LiN
Oberdorster G
Huser RB
Paper
Chase studies of particulate emissions from in-use New
York City vehicles. Aerosol Science and Technology
2004;38(6):555-573.
Review of the governing equations, computational
algorithms, and other components of the Models-3
Community Multiscale Air Quality (CMAQ) modeling
system. Applied Mechanics Reviews 2006;59:51-77.
Light absorption by carbonaceous particles: an
investigative review. Aerosol Science and Technology
2006;40(l):27-67.
Ultrafine particulate pollutants induce oxidative stress and
mitochondrial damage. Environmental Health Perspectives
2003;111(4):455-460.
Nanotoxicology: an emerging discipline evolving from
studies of ultrafine particles. Environmental Health
Perspectives 2QQ5;ll3(7):823-839.
Asian dust events of April 1998. Journal of Geophysical
Research-Atmospheres 2QQ\;\Q6(D\6): 183 17-18330.
Ratio of Actual Cites to Expected Citation Rates
The expected citation rate is the average number of cites that a paper published in the same
journal in the same year and of the same document type (article, review, editorial, etc.) has
received from the year of publication to the present. Using the ESI average citation rates for
papers published by field as the benchmark, in 13 of the 18 fields in which the EPA PM papers
were published, the ratio of actual to expected cites is greater than 1, indicating that the PM
papers are more highly cited than the average papers in those fields (see Table 14). For one field,
the ratio is equal to 1, indicating that the papers in that ESI field are cited the same as the average
paper. For all 18 fields combined, the ratio of total number of cites to the total number of
expected cites (27,449 to 10,856.34) is 2.5, indicating that the PM papers are more highly cited
than the average paper.
Table 14. Ratio of Actual Cites to Expected Cites for PM Papers by Field
ESI Field
Biology & Biochemistry
Chemistry
Clinical Medicine
Total
Cites
486
1,056
6,346
Expected
Cite Rate
497.14
642.11
2,274.10
Ratio
1.0
1.6
2.8
14
-------
ESI Field
Computer Science
Economics & Business
Engineering
Environment/Ecology
Geosciences
Immunology
Materials Science
Mathematics
Molecular Biology & Genetics
Multidisciplinary
Neuroscience & Behavior
Pharmacology & Toxicology
Physics
Plant & Animal Science
Social Sciences, general
TOTAL
Total
Cites
6
25
3,628
6,507
5,527
372
1
31
25
389
185
2,642
164
32
27
27,449
Expected
Cite Rate
5.14
7.29
815.40
2,250.50
2,091.43
213.76
3.20
11.07
82.44
39.00
220.51
1,542.98
100.75
38.05
21.47
10,856.34
Ratio
1.2
3.4
4.4
2.9
2.6
1.7
0.3
2.8
0.3
10.0
0.8
1.7
1.6
0.8
1.2
2.5
JCR Benchmarks
Impact Factor. The JCR Impact Factor is a well known metric in citation analysis. It is a
measure of the frequency with which the "average article" in a journal has been cited in a
particular year. The Impact Factor helps evaluate a journal's relative importance, especially when
compared to others in the same field. The Impact Factor is calculated by dividing the number of
citations in the current year to articles published in the 2 previous years by the total number of
articles published in the 2 previous years.
Table 15 indicates the number of PM papers published in the top 10% of journals, based on the
JCR Impact Factor. Five hundred thirty-seven (537) of 1,561 papers were published in the top
10% of journals, representing 34.4% of EPA's PM papers. This indicates that more than one-third
of the PM papers are published in the highest quality journals as determined by the JCR Impact
Factor, which is 3.4 times higher than the expected percentage.
15
-------
Table 15. PM Papers in Top 10% of Journals by JCR Impact Factor
EPAPM
Papers in that
Journal
2
6
3
4
1
1
10
1
2
27
6
1
2
1
1
1
5
5
1
117
4
12
5
1
12
1
4
1
Journal
New England Journal of Medicine
Science
Lancet
JAMA — Journal of the American Medical Association
Journal of Clinical Investigation
Annual Review of Physical Chemistry
Circulation
Nano Letters
Proceedings of the National Academy of Sciences of the Unitec
States of America
American Journal of Respiratory and Critical Care Medicine
Journal of Allergy and Clinical Immunology
Advanced Drug Delivery Reviews
Cancer Research
Journal of Neuroscience
FASEB Journal
Critical Care Medicine
Journal of Immunology
Thorax
American Journal of Pathology
Environmental Health Perspectives
Journal of Biological Chemistry
Analytical Chemistry
Free Radical Biology & Medicine
Stroke
American Journal of Epidemiology
Journal of Thrombosis and Haemostasis
European Respiratory Journal
TrAC - Trends in Analytical Chemistry
Impact
Factor
(IF)
51.296
30.028
25.800
23.175
15.754
11.250
10.940
9.960
9.643
9.091
8.829
7.977
7.656
7.453
6.721
6.599
6.293
6.064
5.917
5.861
5.808
5.646
5.440
5.391
5.241
5.138
5.076
5.068
JCR IF
Rank
2
9
18
23
42
83
88
110
116
131
136
156
172
177
206
211
223
237
249
255
260
276
289
293
308
325
335
337
16
-------
EPAPM
Papers in that
Journal
1
1
25
16
1
1
1
1
2
23
2
1
34
2
120
2
3
1
1
1
1
1
1
2
31
1
3
11
Journal
Cellular Signalling
Faraday Discussions
Toxicology and Applied Pharmacology
American Journal of Respiratory Cell and Molecular Biology
Journal of Leukocyte Biology
Journal of Catalysis
International Journal of Epidemiology
Antioxidants & Redox Signaling
Atmospheric Chemistry and Physics
Epidemiology
American Journal of Physiology - Cell Physiology
Progress in Energy and Combustion Science
American Journal of Physiology - Lung Cellular and Molecular
Physiology
Journal of Physical Chemistry B
Environmental Science & Technology
Applied Catalysis B: Environmental
Chest
Experimental Cell Research
Human Reproduction
Bulletin of the American Meteorological Society
American Journal of Physiology - Heart and Circulatory
Physiology
American Journal of Public Health
Journal of Cellular Physiology
Clinical Immunology
Toxicological Sciences
Journal of Chromatography A
Journal of Neuroscience Research
Journal of Applied Physiology
Impact
Factor
(IF)
4.887
4.731
4.722
4.593
4.572
4.533
4.517
4.491
4.362
4.339
4.334
4.333
4.250
4.115
4.040
3.942
3.924
3.777
3.769
3.728
3.724
3.698
3.638
3.606
3.598
3.554
3.476
3.178
JCR IF
Rank
363
393
397
412
415
418
424
431
449
452
455
456
472
501
518
548
552
596
599
614
616
626
646
659
662
678
704
807
17
-------
EPAPM
Papers in that
Journal
1
3
1
4
1
Total = 537
Journal
Journal of Chemical Physics
Chemical Research in Toxicology
Remote Sensing of Environment
Journal of Physical Chemistry A
American Journal of Cardiology
Impact
Factor
(IF)
3.166
3.162
3.064
3.047
3.015
JCR IF
Rank
814
818
855
863
876
Immediacy Index. The JCR Immediacy Index is a measure of how quickly the average article in
a journal is cited. It indicates how often articles published in a journal are cited within the year
they are published. The Immediacy Index is calculated by dividing the number of citations to
articles published in a given year by the number of articles published in that year.
Table 16 indicates the number of PM papers published in the top 10% of journals, based on the
JCR Immediacy Index. Seven hundred sixty-two (762) of the 1,561 papers appear in the top 10%
of journals, representing 48.8% of the PM papers. This indicates that nearly one-half of the PM
papers are published in the highest quality journals as determined by the JCR Immediacy Index,
which is 4.9 times higher than the expected percentage.
Table 16. PM Papers in Top 10% of Journals by JCR Immediacy Index
EPAPM
Papers in that
Journal
2
4
3
6
1
1
10
1
27
6
1
Journal
New England Journal of Medicine
JAMA - Journal of the American Medical Association
Lancet
Science
Journal of Clinical Investigation
Faraday Discussions
Circulation
International Journal of Epidemiology
American Journal of Respiratory and Critical Care Medicine
Journal of Allergy and Clinical Immunology
Annual Review of Physical Chemistry
Immediacy
Index
(II)
12.743
7.781
7.419
5.555
3.911
2.766
2.674
2.200
2.006
1.790
1.762
JCRU
Rank
2
4
6
16
29
59
63
84
98
118
124
18
-------
EPAPM
Papers in that
Journal
2
1
4
1
5
23
1
1
1
1
2
1
1
4
3
4
12
11
2
117
1
16
2
5
1
1
1
34
Journal
Proceedings of the National Academy of Sciences of the
United States of America
Critical Care Medicine
Philosophical Transactions of the Royal Society of London
Series A: Mathematical and Physical Sciences
Nano Letters
Thorax
Epidemiology
Journal of Thrombosis and Haemostasis
Journal of Neuroscience
Stroke
FASEB Journal
Cancer Research
Cellular Signalling
Antioxidants & Redox Signaling
Journal of Biological Chemistry
Chest
European Respiratory Journal
American Journal of Epidemiology
Journal of Applied Physiology
Atmospheric Chemistry and Physics
Environmental Health Perspectives
Environmental Science and Pollution Research
American Journal of Respiratory Cell and Molecular Biology
American Journal of Physiology - Cell Physiology
Journal of Immunology
Journal of Cellular Physiology
Physical Chemistry Chemical Physics
American Journal of Pathology
American Journal of Physiology - Lung Cellular and
Molecular Physiology
Immediacy
Index
(II)
1.758
1.641
1.534
1.485
1.460
1.437
1.397
1.319
1.242
1.241
1.220
1.213
1.131
1.110
1.110
1.108
1.091
1.026
1.015
0.994
0.982
0.925
0.906
0.886
0.867
0.866
0.833
0.832
JCRU
Rank
126
146
166
177
184
187
194
216
237
238
246
249
281
291
291
294
306
343
350
373
376
404
417
435
453
454
487
493
19
-------
EPAPM
Papers in that
Journal
12
1
1
5
1
1
1
31
4
1
103
1
1
3
120
1
1
2
4
1
1
2
6
6
132
Total = 762
Journal
Analytical Chemistry
American Journal of Physiology - Heart and Circulatory
Physiology
TrAC - Trends in Analytical Chemistry
Free Radical Biology & Medicine
Journal of Catalysis
American Journal of Public Health
Human Reproduction
Toxicological Sciences
Journal of Physical Chemistry A
Journal of Chemical Physics
Journal of Geophysical Research
Agricultural and Forest Meteorology
Journal of Leukocyte Biology
Chemical Research in Toxicology
Environmental Science & Technology
Bulletin of the American Meteorological Society
Journal of Environmental Pathology, Toxicology and
Oncology
Journal of Physical Chemistry B
Boundary -Layer Meteorology
American Journal of Cardiology
Equine Veterinary Journal
Clinical Immunology
Journal of Exposure Science and Environmental
Epidemiology
Environmental Research
Aerosol Science and Technology
Immediacy
Index
(II)
0.795
0.777
0.752
0.751
0.751
0.740
0.734
0.734
0.730
0.721
0.684
0.669
0.668
0.663
0.646
0.646
0.639
0.637
0.629
0.615
0.611
0.604
0.596
0.583
0.571
JCRll
Rank
524
547
578
580
580
588
597
597
602
616
673
690
691
703
729
729
742
746
758
781
790
804
821
844
872
20
-------
Hot Papers
ESI establishes citation thresholds for hot papers, which are selected from the highly cited papers
in different fields, but the time frame for citing and cited papers is much shorter—papers must be
cited within 2 years of publication and the citations must occur in a 2-month time period. Papers
are assigned to 2-month periods and thresholds are set for each period and field to select 0.1% of
papers. There were no hot papers identified for the current 2-month period (i.e., March-April
2007), but there were a number of hot papers identified from previous periods.
Using the hot paper thresholds established by ESI as a benchmark, 45 hot papers, representing
2.9% of the PM papers, were identified in six fields—Clinical Medicine, Engineering,
Environment/Ecology, Geosciences, Multidisciplinary, and Pharmacology & Toxicology. The
number of PM hot papers is 29 times higher than expected. The hot papers are listed in Table 17.
Table 17. Hot Papers Identified Using ESI Thresholds
Field
Clinical Medicine
Engineering
ESI Hot
Papers
Threshold
7
12
10
13
4
4
3
No. of Cites
in 2-Month
Period
7 cites in
March-April
2002
21 cites in
August-
September
2003
1 1 cites in
November-
December
2005
19 cites in
November-
December
2005
4 cites in
October-
November
2001
4 cites in July
2001
3 cites in
May 2001
Paper
Peters A, et al. Increased particulate air pollution and the
triggering of myocardial infarction. Circulation
2001;103(23):2810-2815.
Pope CA, et al. Lung cancer, cardiopulmonary mortality
and long-term exposure to fine particulate air pollution.
Journal of the American Medical Association
2002;287(9):1132-1141.
Peters A, et al. Exposure to traffic and the onset of
myocardial infarction. New England Journal of Medicine
2004;351(17):1721-1730.
Pope CA, et al. Cardiovascular mortality and long-term
exposure to particulate air pollution: epidemiological
evidence of general pathophysiological pathways of
disease. Circulation 2004;109(l):71-77.
Christoforou CS, et al. Trends in fine particle
concentration and chemical composition in southern
California. Journal of the Air & Waste Management
Association 2000;50(l):43-53.
Richter H, Howard JB. Formation of poly cyclic aromatic
hydrocarbons and their growth to soot - a review of
chemical reaction pathways. Progress in Energy and
Combustion Science 2000;26(4-6):565-608.
Vanderpool RW, et al. Evaluation of the loading
characteristics of the EPA WINSPM 2.5 separator.
Aerosol Science and Technology 2001;34(5):444-456.
21
-------
Field
ESI Hot
Papers
Threshold
No. of Cites
in 2-Month
Period
Paper
Engineering
5 cites in
May 2001
Peters TM, et al. Design and calibration of the EPA PM2 5
well impactor ninety-six (WINS). Aerosol Science and
Technology 2001;34(5):389-397.
5 cites in
March- April
2003
Weber RJ, et al. A particle-into-liquid collector for rapid
measurement of aerosol bulk chemical composition.
Aerosol Science and Technology 2001;35(3):718-727.
4 cites in
November-
December
2005
McMurry PH, et al. The relationship between mass and
mobility for atmospheric particles: A new technique for
measuring particle density. Aerosol Science and
Technology 2002;36(2):227-238.
3 cites in
March- April
2003
Weber R, et al. Short-term temporal variation in PM2 5
mass and chemical composition during the Atlanta
Supersite Experiment, 1999. Journal of the Air & Waste
Management Association 2003;53(1): 84-91.
3 cites in
November-
December
2003
Lewis CW, et al. Source apportionment of Phoenix PM25
aerosol with the Unmix receptor model. Journal of the Air
& Waste Management Association 2003;53(3):325-338.
3 cites in
February 2004
Vette A, et al. Environmental research in response to 9/11
and homeland security. EM: Air & Waste Management
Association's Magazine for Environmental Managers
2004;Feb: 14-22.
4 cites in
March-April
2005
Russell M, et al. Daily, seasonal, and spatial trends in
PM2 5 mass and composition in Southeast Texas. Aerosol
Science and Technology 2004;38(S1): 14-26.
4 cites in
March-April
2005
Zhu YF, et al. Seasonal trends of concentration and size
distribution of ultrafine particles near major highways in
Los Angeles. Aerosol Science and Technology
2004;38(S1):5-13.
3 cites in
September-
October 2004
Cho AK, et al. Determination of four quinones in diesel
exhaust particles, SRM 1649a and atmospheric PM2 5.
Aerosol Science and Technology 2004;38(S1):68-81.
4 cites in
November-
December
2004
Drewnick F, et al. Measurement of ambient aerosol
composition during the PMTACS-NY 2001 campaign
using an aerosol mass spectrometer. Part I: Mass
concentrations. Aerosol Science and Technology
2004;38(S1):92-103.
4 cites in
November-
December
2005
Canagaratna MR, et al. Chase studies of particulate
emissions from in-use New York City vehicles. Aerosol
Science and Technology 2004;38(6):555-573.
22
-------
Field
ESI Hot
Papers
Threshold
No. of Cites
in 2-Month
Period
Paper
Environment/
Ecology
3 cites in
March-April
2001
Lumley T, Levy D. Bias in the case-crossover design:
implications for studies of air pollution. Environmetrics
2000;11(6):689-704.
3 cites in
August 2000
Stolzenburg MR, Hering SV. Method for the automated
measurement of fine particle nitrate in the atmosphere.
Environmental Science & Technology 2000;34(5):907-
914.
6 cites in
September-
October 2001
Schwartz J. Assessing Confounding, Effect modification,
and thresholds in the association between ambient
particles and daily deaths. Environmental Health
Perspectives 2000;108(6):563-568.
6 cites in
September-
October 2003
Jang MS, et al. Atmospheric secondary aerosol formation
by heterogeneous reactions of aldehydes in the presence of
a sulfuric acid aerosol catalyst. Environmental Science &
Technology 2QQl;35(24y.4758-4766.
5 cites in
November-
December
2004
Jang MS, et al. Particle growth by acid-catalyzed
heterogeneous reactions of organic carbonyls on pre-
existing aerosols. Environmental Science & Technology
2003;37(17):3828-3837.
7 cites in May-
June 2004
Li N, et al. Ultrafine particulate pollutants induce
oxidative stress and mitochondrial damage.
Environmental Health Perspectives 2003 ;111(4) :455-
460.
2 cites in
August 2004
Landrigan PJ, et al. Health and environmental
consequences of the World Trade Center Disaster.
Environmental Health Perspectives 2004; 112(6):731-739.
9 cites in June-
July 2006
Gao S, et al. Particle Phase Acidity and Oligomer
Formation in Secondary Organic Aerosol. Environmental
Science & Technology 2004;38(24):6582-6589.
4 cites in May-
June 2006
Thurston GD, et al. Workgroup report: workshop on
source apportionment of particulate matter health
effects—intercomparison of results and implications.
Environmental Health Perspectives 2005; 113(12): 1768-
1774.
3 cites in
September
2005
Koenig JQ, et al. Pulmonary effects of indoor- and
outdoor-generated particles in children with asthma.
Environmental Health Perspectives 2005;! 13(4):499-503.
4 cites in
March-April
2006
Presto AA, et al. Secondary organic aerosol production
from terpene ozonolysis. 1. Effect of UV radiation.
Environmental Science & Technology 2005;39(18):7036-
7045.
23
-------
Field
ESI Hot
Papers
Threshold
No. of Cites
in 2-Month
Period
Paper
Environment/
Ecology
10
6 cites in
August-
September
2006
Dockery DW, et al. Association of air pollution with
increased incidence of ventricular tachyarrhythmias
recorded by implanted cardioverter defibrillators.
Environmental Health Perspectives 2005; 113 (6): 670-674.
7 cites in
December
2005-January
2006
Zanobetti A, Schwartz J. The effect of particulate air
pollution on emergency admissions for myocardial
infarction: a multicity case-crossover analysis.
Environmental Health Perspectives 2005;! 13(8):978-982.
6 cites in July-
August 2006
Park SK, et al. Effects of air pollution on heart rate
variability: The VA Normative Aging Study.
Environmental Health Perspectives 2005;! 13(3):304-309.
6 cites in
March-April
2006
Bahreini R, et al. Measurements of secondary organic
aerosol from oxidation of cycloalkenes, terpenes, and m-
xylene using an Aerodyne Aerosol Mass Spectrometer.
Environmental Science & Technology 2005;39(15):5674-
5688.
5 cites in
March-April
2006
Lough GC, et al. Emissions of metals associated with
motor vehicle roadways. Environmental Science &
Technology 2005;39(3):826-836.
12 cites in
December-
2006-January
2007
Zhang Q, et al. Deconvolution and quantification of
hydrocarbon-like and oxygenated organic aerosols based
on aerosol mass spectrometry. Environmental Science &
7ec/w70/ogy2005;39(13):4938-4952.
24 cites in
March-April
2007
Oberdorster G, et al. Nanotoxicology: an emerging
discipline evolving from studies of ultrafine particles.
Environmental Health Perspectives 2005;! 13(7): 823-839.
4 cites in
February-
March 2007
Elder A. Translocation of inhaled ultrafine manganese
oxide particles to the central nervous system.
Environmental Health Perspectives 2006; 114(8): 1172-
1178.
Geosciences
5 cites in June-
July 2003
Huser RB, et al. Asian dust events of April 1998. Journal
of Geophysical Research-Atmospheres
2001;106(D16):18317-18330.
10
10 cites in
June-July 2004
Orsini DA, et al. Refinements to the particle-into-liquid
sampler (PILS) for ground and airborne measurements of
water soluble aerosol composition. Atmospheric
Environment 2003;37(9-10): 1243-1259.
4 cites in June-
July 2006
Grell GA, et al. Fully coupled "online" chemistry within
the WRF model. Atmospheric Environment
2005;39(37):6957-6975.
24
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Field
ESI Hot
Papers
Threshold
No. of Cites
in 2-Month
Period
Paper
Multidisciplinary
10 cites in
May-June
2004
Jang MS, et al. Heterogeneous atmospheric aerosol
production by acid-catalyzed particle-phase reactions.
Science 2002;298(5594):814-817.
Pharmacology &
Toxicology
6 cites in
April 2005
Lippmann M, et al. Effects of subchronic exposures to
concentrated ambient particles (CAPs) in mice: I.
Introduction, objectives, and experimental plan.
Inhalation Toxicology 2005;17(4-5):177-187.
7 cites in April
2005
Maciejczyk P, et al. Effects of subchronic exposures to
concentrated ambient particles (CAPs) in mice: II. The
design of a CAPs exposure system for biometric telemetry
monitoring. Inhalation Toxicology 2005;17(4-5):189-197.
2 cites in
September-
October 2006
Costa DL, et al. Comparative pulmonary toxicological
assessment of oil combustion particles following
inhalation or instillation exposure. Toxicological Sciences
2006;91(l):237-246.
2 cites in July
2003
Kodavanti UP, et al. Inhaled environmental combustion
particles cause myocardial injury in the Wistar Kyoto rat.
Toxicological Sciences 2003;71(2):237-245.
Author Self-Citation
Self-citations are journal article references to articles from that same author (i.e., the first author).
Because higher author self-citation rates can inflate the number of citations, the author self-
citation rate was calculated for the PM papers. Of the 27,449 total cites, 1,227 are author self-
cites—a 4.5% author self-citation rate. Garfield and Sher3 found that authors working in
research-based disciplines tend to cite themselves on the average of 20% of the time. MacRoberts
and MacRoberts4 claim that approximately 10% to 30% of all the citations listed fall into the
category of author self-citation. Kovacic and Misak5 recently reported a 20% author self-citation
rate for medical literature. Therefore, the 4.5% self-cite rate for the PM papers is well below the
range for author self-citation.
Highly Cited Researchers
A search of Thomson's ISIHighlyCited. com revealed that 40 (1.5%) of the 2,710 authors of the
PM papers are highly cited researchers. ISIHighlyCited.com is a database of the world's most
3 Garfield E, Sher IH. New factors in the evaluation of scientific literature through citation indexing. American
Documentation 1963;18(July):195-210.
4 MacRoberts MH, MacRoberts BR. Problems of citation analysis: a critical review. Journal of the American
Society of Information Science 1989;40(5):342-349.
5 Kavaci N, Misak A. Author self-citation in medical literature. Canadian Medical Association Journal
2004;170(13):1929-1930.
25
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influential researchers who have made key contributions to science and technology during the
period from 1981 to 1999. The highly cited researchers identified during this analysis of the PM
publications are presented in Table 18.
Table 18. Highly Cited Researchers Authoring PM Publications
Highly Cited
Researcher
Arey, Janet
Atkinson, Roger
Cass, Glen R.
Corey, Lawrence
Dickey, David A.
Dockery, Douglas W.
Fehsenfeld, Fred C.
Folsom, Aaron R.
Fuster, Valentin
Garcia, Rolando R.
Giorgi, Filippo
Holben, Brent N.
Jacob, Daniel J.
Karl, Thomas R.
Kaufman, Yoram J.
Kawachi, Ichiro
Kloner, Robert A.
Koutrakis, Petros
Likens, Gene E.
Liotta, Lance A.
Lioy, Paul J.
Lippmann, Morton
Madronich, Sasha
Affiliation
University of California-Riverside
University of California-Riverside
Georgia Institute of Technology
University of Washington
North Carolina State University
Harvard University
National Oceanic and Atmospheric
Administration
University of Minnesota
Mount Sinai Medical Center
National Center for Atmospheric
Research
Abdus Salam International Centre for
Theoretical Physics (Trieste, Italy)
National Air and Space Administration
Goddard Space Flight Center
Harvard University
National Oceanic and Atmospheric
Administration
National Air and Space Administration
Goddard Space Flight Center
Harvard School of Public Health
Good Samaritan Hospital
Harvard School of Public Health
Institute of Ecosystem Studies
National Cancer Institute
University of Medicine & Dentistry of
New Jersey
New York University School of
Medicine
National Center for Atmospheric
Research
ESI Field
Environment/Ecology
Environment/Ecology
Environment/Ecology
Clinical Medicine
Mathematics
Economics & Business
Environment/Ecology
Geosciences
Clinical Medicine
Clinical Medicine
Geosciences
Geosciences
Geosciences
Geosciences
Geosciences
Geosciences
Social Sciences, general
Clinical Medicine
Environment/Ecology
Environment/Ecology
Clinical Medicine
Environment/Ecology
Environment/Ecology
Geosciences
26
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Highly Cited
Researcher
Mannucci, Pier M.
Mazurek, Monica A.
Pankow, James F.
Richards, James H.
Rogge, Wolfgang F.
Schwartz, Joel D.
Schwartz, Stephen E.
Seinfeld, John H.
Simoneit, Bernd R.T.
Speizer, Frank E.
Spengler, John D.
Turco, Richard P.
Wang, Jun
Watson, John G.
Winer, Arthur M.
Wolff, George T.
Zeger, Scott L.
Total = 40
Affiliation
Universita degli Studi di Milano
Rutgers University
Oregon Health and Science University
University of California-Davis
Florida International University
Harvard School of Public Health
Brookhaven National Laboratory
California Institute of Technology
Oregon State University
Harvard Medical School
Harvard University
University of California-Los Angeles
National Centers for Environmental
Prediction, National Oceanic and
Atmospheric Administration
Desert Research Institute
University of California-Los Angeles
General Motors Corporation
Johns Hopkins University
ESI Field
Clinical Medicine
Environment/Ecology
Environment/Ecology
Environment/Ecology
Environment/Ecology
Environment/Ecology
Pharmacology
Geosciences
Geosciences
Environment/Ecology
Engineering
Environment/Ecology
Engineering
Clinical Medicine
Environment/Ecology
Geosciences
Geosciences
Environment/Ecology
Environment/Ecology
Environment/Ecology
Mathematics
Patents
There were 6 patents issued by investigators from 1998 to 2007 for PM research that was
conducted by EPA intramural and extramural researchers. The patents are listed in Table 19. Two
of the 6 patents (33.3%) were referenced by a total of 9 other patents.
27
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Table 19. Patents Resulting From PM Research (1998-2007)
Patent or
Patent
Application
No.
U.S. Patent No.
6,890,372
U.S. Patent No.
5,763,360
U.S. Patent No.
6,226,852
U.S. Patent No.
6,780,818
U.S. Patent No.
7,168,292
Inventor(s)
Dasgupta PK
Morris KJ
LiJ
Gundel L
Daisey JM
Stevens RK
Gundel L
Daisey JM
Stevens RK
Gundel L
Daisey JM
Stevens RK
Gundel LA
Apte MG
Hansen AD
Black DR
Title
Denuder assembly for collection
and removal of soluble
atmospheric gases
Quantitative organic vapor-
particle sampler
Method for fabricating a
quantitative integrated diffusion
vapor-particle sampler for
sampling, detection and
quantitation of semi -volatile
organic gases, vapors and
particulate components
Quantitative organic vapor-
particle sampler
Apparatus for particulate matter
analysis
Patent/Patent
Application
Date
May 2005
June 1998
May 2001
August 2004
January 2007
Patents that Referenced
This Patent
None
Referenced by 6 patents:
(1)7,122,065 Adapter for
low volume air sampler
(2) 6,604,406 Human
portable preconcentrator
system
(3) 6,523,393 Human
portable preconcentrator
system
(4) 6,502,450 Single
detector differential
particulate mass monitor
with intrinsic correction
for volatilization losses
(5) 6,403,384 Device and
method for analyzing a
biologic sample
(6) 6,035,701 Method and
system to locate leaks in
subsurface containment
structures using tracer
gases
Referenced by 3 patents:
(1)7,159,475 Apparatus
and method of sampling
semivolatile compounds
(2) 7, 122,065 Adapter for
low volume air sampler
(3) 7,089,747 Pressure
reduction apparatus and
method
None
None
28
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Patent or
Patent
Application
No.
U.S. Patent No.
7,168,292
Inventor(s)
Gundel LA
Apte MG
Hansen AD
Black DR
Title
Apparatus for participate matter
analysis
Patent/Patent
Application
Date
January 2007
Patents that Referenced
This Patent
None
This bibliometric analysis was prepared by
Beverly Campbell, The Scientific Consulting Group, Inc.
under EPA Contract No. EP-C-05-015
29
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