Extramural Research
Bibliometrics
Grantee Research Project Results
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.
Summary of Results
- 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 ESI 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.
- 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.
- 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 JCR 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 JCR Immediacy Index. 762 of the 1,561 papers appear in the top 10% of journals ranked by JCR Immediacy Index, representing 48.8% of EPA’s PM papers. This number is 4.9 times higher than the expected 156 papers.
- 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.
- 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.
- 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.
- 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.
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 ESI Fields
ESI Field |
No. of Citations |
No. of PM Papers |
Average Cites/Paper |
Biology & Biochemistry |
486 |
34 |
14.3 |
Chemistry |
1,056 |
78 |
13.5 |
Clinical Medicine |
6,346 |
243 |
26.1 |
Computer Science |
6 |
2 |
3.0 |
Economics & Business |
25 |
3 |
8.3 |
Engineering |
3,628 |
272 |
13.3 |
Environment/Ecology |
6,507 |
333 |
19.5 |
Geosciences |
5,527 |
350 |
15.8 |
Immunology |
372 |
13 |
28.6 |
Materials Science |
1 |
1 |
1.0 |
Mathematics |
31 |
6 |
5.2 |
Molecular Biology & Genetics |
25 |
3 |
8.3 |
Multidisciplinary |
389 |
9 |
43.2 |
Neuroscience & Behavior |
185 |
11 |
16.8 |
Pharmacology & Toxicology |
2,642 |
179 |
14.8 |
Physics |
164 |
11 |
14.9 |
Plant & Animal Science |
32 |
5 |
6.4 |
Social Sciences, general |
27 |
8 |
3.4 |
|
Total = 27,449 |
Total = 1,561 |
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 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 Highly Cited PM Papers by Field (top 10%)
ESI Field |
No. of Citations |
No. of Papers |
Average Cites/Paper |
% of Papers in Field |
Biology & Biochemistry |
179 |
5 |
35.8 |
14.7% |
Chemistry |
663 |
21 |
31.6 |
26.9% |
Clinical Medicine |
4,954 |
90 |
55.0 |
37.0% |
Economics & Business |
7 |
1 |
7.0 |
33.3% |
Engineering |
3,159 |
123 |
25.7 |
45.2% |
Environment/Ecology |
5,070 |
152 |
33.4 |
45.6% |
Geosciences |
3,871 |
126 |
30.7 |
36.0% |
Immunology |
303 |
5 |
60.6 |
38.5% |
Mathematics |
25 |
2 |
12.5 |
33.3% |
Multidisciplinary |
366 |
5 |
73.2 |
62.5% |
Pharmacology & Toxicology |
1,588 |
44 |
36.4 |
24.6% |
Physics |
117 |
3 |
39.0 |
27.3% |
Social Sciences, general |
6 |
1 |
6.0 |
12.5% |
|
Total = 20,308 |
Total = 578 |
35.1 |
37.0% |
Table 3. Number of Highly Cited PM Papers by Field (top 1%)
ESI Field |
No. of Citations |
No. of Papers |
Average Cites/Paper |
% of PM Papers in Field |
Chemistry |
62 |
2 |
31.0 |
2.6% |
Clinical Medicine |
1,513 |
8 |
189.1 |
3.3% |
Economics & Business |
7 |
1 |
7.0 |
33.3% |
Engineering |
1,746 |
31 |
56.3 |
11.4% |
Environment/Ecology |
1,549 |
31 |
50.0 |
9.3% |
Geosciences |
1,416 |
19 |
74.5 |
5.4% |
Multidisciplinary |
272 |
2 |
136.0 |
22.2% |
Pharmacology & Toxicology |
259 |
2 |
129.5 |
1.1% |
|
Total = 6,824 |
Total = 96 |
71.1 |
6.2% |
Table 4. Highly Cited PM Papers in the Field of Chemistry (top 1%)
No. of Cites |
ESI Threshold |
First Author |
Paper |
59 |
43 |
Gao S |
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. |
3 |
2 |
Rudich Y |
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 |
ESI Threshold |
First Author |
Paper |
187 |
144 |
Abbey DE |
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. |
216 |
133 |
Gold DR |
Ambient pollution and heart rate variability. Circulation 2000;101(11):1267-1273. |
249 |
115 |
Peters A |
Increased particulate air pollution and the triggering of myocardial infarction. Circulation 2001;103(23):2810-2815. |
634 |
99 |
Pope CA |
Lung cancer, cardiopulmonary mortality and long-term exposure to fine particulate air pollution. Journal of the American Medical Association 2002;287(9):1132-1141. |
89 |
54 |
Peters A |
Exposure to traffic and the onset of myocardial infarction. New England Journal of Medicine 2004;351(17):1721-1730. |
131 |
54 |
Pope CA |
Cardiovascular mortality and long-term exposure to particulate air pollution: epidemiological evidence of general pathophysiological pathways of disease. Circulation 2004;109(1):71-77. |
2 |
2 |
Baccarelli A |
Effects of exposure to air pollution on blood coagulation. Journal of Thrombosis and Haemostasis 2007;5(2):252-260. |
5 |
2 |
Miller KA |
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 |
ESI Threshold |
First Author |
Paper |
7 |
4 |
Peng RD |
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 |
Zhang Y |
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(1-2):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(1-2):49-70. |
209 |
44 |
Richter H |
Formation of polycyclic aromatic hydrocarbons and their growth to soot– |
38 |
37 |
Vette AF |
Characterization of indoor-outdoor aerosol concentration relationships during the Fresno PM exposure studies. Aerosol Science and Technology 2001;34(1):118-126. |
42 |
37 |
Lewtas J |
Comparison of sampling methods for semi-volatile organic carbon associated with PM2.5. 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(1):88-96. |
92 |
37 |
Woo KS |
Measurement of Atlanta aerosol size distributions: Observations of ultrafine particle events. Aerosol Science and Technology 2001;34(1):75-87. |
105 |
37 |
Weber RJ |
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 |
Kim S |
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 |
Zhu YF |
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 |
Zhu Y |
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. |
24 |
18 |
Cabada JC |
Estimating the secondary organic aerosol contribution to PM2.5 using the EC tracer method. Aerosol Science and Technology 2004;38(S1):140-155. |
25 |
18 |
Drewnick F |
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. |
26 |
18 |
Cho A |
Determination of four quinones in diesel exhaust particles, SRM 1649a and atmospheric PM2.5. Aerosol Science and Technology 2004;38(S1):68-81. |
33 |
18 |
Stanier CO |
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(S1):253-264. |
34 |
18 |
Drewnick F |
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. |
39 |
18 |
Subramanian R |
Positive and negative artifacts in particulate organic carbon measurements with denuded and undenuded sampler configurations. Aerosol Science and Technology 2004;38(S1):27-48. |
55 |
18 |
Canagaratna M |
Chase studies of particulate emissions from in-use New York City vehicles. Aerosol Science and Technology 2004;38(6):555-573. |
13 |
10 |
Kim E |
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):1190-1199. |
14 |
4 |
Byun D |
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. |
17 |
4 |
Bond TC |
Light absorption by carbonaceous particles: an investigative review. Aerosol Science and Technology 2006;40(1):27-67. |
Table 8. Highly Cited PM Papers in the Field of Environment/Ecology (top 1%)
No. of Cites |
ESI Threshold |
First Author |
Paper |
175 |
103 |
Liao D |
Daily variation of particulate air pollution and poor cardiac autonomic control in the elderly. Environmental Health Perspectives 1999;107(7):521-525. |
208 |
88 |
Laden F |
Association of fine particulate matter from different sources with daily mortality in six U.S. cities. Environmental Health Perspectives 2000;108(10):941-947. |
83 |
77 |
Fine PM |
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. |
83 |
77 |
Jang M |
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. |
94 |
77 |
Dockery DW |
Epidemiologic evidence of cardiovascular effects of particulate air pollution. Environmental Health Perspectives 2001;109(S4):483-486. |
67 |
48 |
Park K |
Relationship between particle mass and mobility for diesel exhaust particles. Environmental Science & Technology 2003;37(3):577-583. |
144 |
48 |
Li N |
Ultrafine particulate pollutants induce oxidative stress and mitochondrial damage. Environmental Health Perspectives 2003;111(4):455-460. |
34 |
34 |
Landrigan PJ |
Health and environmental consequences of the World Trade Center disaster. Environmental Health Perspectives 2004;112(6):731-739. |
40 |
34 |
Chow JC |
Equivalence of elemental carbon by thermal/optical reflectance and transmittance with different temperature protocols. Environmental Science & Technology 2004;38(16):4414-4422. |
44 |
34 |
Xia T |
Quinones and aromatic chemical compounds in particulate matter induce mitochondrial dysfunction: implications for ultrafine particle toxicity. Environmental Health Perspectives 2004;112(14):1347-1358. |
45 |
34 |
Zhang Q |
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. |
58 |
34 |
Pope CA |
Ambient particulate air pollution, heart rate variability, and blood markers of inflammation in a panel of elderly subjects. Environmental Health Perspectives 2004;112(3):339-345. |
59 |
34 |
Gao S |
Particle phase acidity and oligomer formation in secondary organic aerosol. Environmental Science & Technology 2004;38(24):6582-6589. |
17 |
17 |
Reisen F |
Atmospheric reactions influence seasonal PAH and nitro-PAH concentrations in the Los Angeles Basin. Environmental Science & Technology 2005;39(1):64-73. |
18 |
17 |
Delfino RJ |
Potential role of ultrafine particles in associations between airborne particle mass and cardiovascular health. Environmental Health Perspectives 2005;113(8):934-946. |
19 |
17 |
Dockery DW |
Association of air pollution with increased incidence of ventricular tachyarrhythmias recorded by implanted cardioverter defibrillators. Environmental Health Perspectives 2005;113(6):670-674. |
22 |
17 |
Zanobetti A |
The effect of particulate air pollution on emergency admissions for myocardial infarction: a multicity case-crossover analysis. Environmental Health Perspectives 2005;113(8):978-982. |
23 |
17 |
Lim H |
Isoprene forms secondary organic aerosol through cloud processing: model simulations. Environmental Science & Technology 2005;39(12):4441-4446. |
25 |
17 |
Park SK |
Effects of Air Pollution on Heart Rate Variability: The VA Normative Aging Study. Environmental Health Perspectives 2005;113(3):304-309. |
26 |
17 |
Bahreini R |
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. |
27 |
17 |
Lough GC |
Emissions of metals associated with motor vehicle roadways. Environmental Science & Technology 2005;39(3):826-836. |
40 |
17 |
Zhang Q |
Deconvolution and quantification of hydrocarbon-like and oxygenated organic aerosols based on aerosol mass spectrometry. Environmental Science & Technology 2005;39(13):4938-4952. |
133 |
17 |
Oberdorster G |
Nanotoxicology: an emerging discipline evolving from studies of ultrafine particles. Environmental Health Perspectives 2005;113(7):823-839. |
6 |
6 |
Selgrade MK |
Induction of asthma and the environment: what we know and need to know. Environmental Health Perspectives 2006;114(4):615-619. |
7 |
6 |
Dubowsky SD |
Diabetes, obesity, and hypertension may enhance associations between air pollution and markers of systematic inflammation. Environmental Health Perspectives 2006;114(7):992-998. |
7 |
6 |
Elder A |
Translocation of inhaled ultrafine manganese oxide particles to the central nervous system. Environmental Health Perspectives 2006;114(8):1172-1178. |
7 |
6 |
Okin GS |
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. |
8 |
6 |
Shrivastava MK |
Modeling semivolatile organic aerosol mass emissions from combustion systems. Environmental Science & Technology 2006;40(8):2671-2677. |
8 |
6 |
Donahue NM |
Coupled partitioning, dilution, and chemical aging of semivolatile organics. Environmental Science & Technology 2006;40(8):2635-2643. |
9 |
6 |
Presto AA |
Investigation of α-pinene + ozone secondary organic aerosol formation at low total aerosol mass. Environmental Science & Technology 2006;40(11):3536-3543. |
13 |
6 |
McConnell R |
Traffic, susceptibility, and childhood asthma. Environmental Health Perspectives 2006;114(5):766-772. |
Table 9. Highly Cited PM Papers in the Field of Geosciences (top 1%)
No. of Cites |
ESI Threshold |
First Author |
Paper |
149 |
114 |
Nenes A |
ISORROPIA: a new thermodynamic equilibrium model for multiphase multicomponent inorganic aerosols. Aquatic Geochemistry 1998;4:123-152. |
166 |
98 |
Griffin RJ |
Organic aerosol formation from the oxidation of biogenic hydrocarbons. Journal of Geophysical Research–Atmospheres 1999;104(D3):3555-3567. |
170 |
98 |
Yu J |
Gas-Phase ozone oxidation of monoterpenes: gaseous and particulate products. Journal of Atmospheric Chemistry 1999;34(2):207-258. |
188 |
98 |
Simoneit BRT |
Levoglucosan, a tracer for cellulose in biomass burning and atmospheric particles. Atmospheric Environment 1999;33(2):173-182. |
92 |
69 |
Sokolik IN |
Introduction to special section: outstanding problems in quantifying the radiative impact of mineral dust. Journal of Geophysical Research–Atmospheres 2001;106(D16):18015-18027. |
178 |
69 |
Huser RB |
Asian dust events of April 1998. Journal of Geophysical Research– Atmospheres 2001;106(D16):18317-18330. |
121 |
54 |
Zhu Y |
Study of ultrafine particles near a major highway with heavy-duty diesel traffic. Atmospheric Environment 2002;36(27):4323-4335. |
42 |
41 |
Binkowski FS |
Models-3 Community Multiscale Air Quality (CMAQ) model aerosol component. 1. Model description. Journal of Geophysical Research– Atmospheres 2003;108(D6):4183. |
53 |
41 |
Orsini DA |
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. |
85 |
41 |
Jiminez JL |
Ambient aerosol sampling using the Aerodyne Aerosol Mass Spectrometer. Journal of Geophysical Research–Atmospheres 2003;108(D7):8425. |
29 |
29 |
Zhang KM |
Evolution of particle number distribution near roadways: Part II: The “road-to-ambient” process. Atmospheric Environment 2004;38(38):6655-6665. |
31 |
29 |
Wittig AE |
Pittsburgh Air Quality Study overview. Atmospheric Environment 2004;38(20):3107-3125. |
31 |
29 |
Kim E |
Improving source identification of Atlanta aerosol using temperature resolved carbon fractions in positive matrix factorization. Atmospheric Environment 2004;38(20):3349-3362. |
27 |
18 |
Edney EO |
Formation of 2-methyl tetrols and 2-methylglyceric 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. |
32 |
18 |
Zhang Q |
Hydrocarbon-like and oxygenated organic aerosols in Pittsburgh: insights into sources and processes or organic aerosols. Atmospheric Chemistry and Physics 2005;5(12):3289-3311. |
8 |
7 |
Offenberg JH |
Thermal properties of secondary organic aerosols. Geophysical Research Letters 2006;33(3):L03816. |
8 |
7 |
Takegawa N |
Seasonal and diurnal variations of submicron organic aerosol in Tokyo observed using the Aerodyne aerosol mass spectrometer. Journal of Geophysical Research–Atmospheres 2006;111(D11206). |
3 |
3 |
Kondo Y |
Oxygenated and water-soluble organic aerosols in Tokyo. Journal of Geophysical Research–Atmospheres 2007;112(D1):D01203. |
3 |
3 |
Pathak RK |
Ozonolysis of a-pinene at atmospherically relevant concentrations: Temperature dependence of aerosol mass fractions (yields). Journal of Geophysical Research–Atmospheres 2007;112(D3):D03201. |
Table 10. Highly Cited PM Papers in the Field of Multidisciplinary (top 1%)
No. of Cites |
ESI Threshold |
First Author |
Paper |
117 |
55 |
Gard EE |
Direct Observation of Heterogeneous Chemistry in the Atmosphere. Science 1998;279(5354):1184-1187. |
155 |
93 |
Jang M |
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 |
ESI Threshold |
First Author |
Paper |
157 |
99 |
Oberdorster G |
Pulmonary effects of inhaled ultrafine particles. International Archives of Occupational and Environmental Health 2001;74(1):1-8. |
102 |
44 |
Oberdorster G |
Translocation of inhaled ultrafine particles to the brain. Inhalation Toxicology 2004;16(6-7):437-445. |
Table 12. Number of Very Highly Cited Papers by Field (Top 0.1%)
ESI Field |
No. of Citations |
No. of Papers |
Average Cites/Paper |
% of PM Papers in Field |
Chemistry |
3 |
1 |
3.0 |
1.3% |
Clinical Medicine |
639 |
2 |
319.5 |
0.8% |
Economics & Business |
7 |
1 |
7.0 |
33.3% |
Engineering |
671 |
7 |
95.8 |
2.6% |
Environment/Ecology |
277 |
2 |
138.5 |
0.6% |
Geosciences |
178 |
1 |
178.0 |
0.3% |
|
Total = 1,775 |
Total = 14 |
126.8 |
0.9% |
Table 13. Very Highly Cited PM Papers (top 0.1%)
ESI Field |
ESI Threshold |
No. of Cites |
First Author |
Paper |
Chemistry |
3 |
3 |
Rudich Y |
Aging of organic aerosol: bridging the gap between laboratory and field studies. Annual Review of Physical Chemistry 2007;58:321-352. |
Clinical Medicine |
288 |
634 |
Pope CA |
Lung cancer, cardiopulmonary mortality and long-term exposure to fine particulate air pollution. Journal of the American Medical Association 2002;287(9):1132-1141. |
|
4 |
5 |
Miller KA |
Long-term exposure to air pollution and incidence of cardiovascular events in women. New England Journal of Medicine 2007;356(5):447-458. |
Economics & Business |
7 |
7 |
Peng RD |
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. |
Engineering |
116 |
207 |
Jayne JT |
Development of an aerosol mass spectrometer for size and composition analysis of submicron particles. Aerosol Science and Technology 2000;33(1-2):49-70. |
|
116 |
209 |
Richter H |
Formation of polycyclic 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. |
|
76 |
130 |
Zhu YF |
Concentration and size distribution of ultrafine particles near a major highway. Journal of the Air & Waste Management Association 2002;52(9):1032-1042. |
|
39 |
39 |
Subramanian R |
Positive and negative artifacts in particulate organic carbon measurements with denuded and undenuded sampler configurations. Aerosol Science and Technology 2004;38(S1):27-48. |
Engineering |
39 |
55 |
Canagaratna M |
Chase studies of particulate emissions from in-use New York City vehicles. Aerosol Science and Technology 2004;38(6):555-573. |
|
9 |
14 |
Byun D |
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. |
|
9 |
17 |
Bond TC |
Light absorption by carbonaceous particles: an investigative review. Aerosol Science and Technology 2006;40(1):27-67. |
Environment/ Ecology |
116 |
144 |
Li N |
Ultrafine particulate pollutants induce oxidative stress and mitochondrial damage. Environmental Health Perspectives 2003;111(4):455-460. |
|
43 |
133 |
Oberdorster G |
Nanotoxicology: an emerging discipline evolving from studies of ultrafine particles. Environmental Health Perspectives 2005;113(7):823-839. |
Geosciences |
176 |
178 |
Huser RB |
Asian dust events of April 1998. Journal of Geophysical Research–Atmospheres 2001;106(D16):18317-18330. |
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 |
Total Cites |
Expected Cite Rate |
Ratio |
Biology & Biochemistry |
486 |
497.14 |
1.0 |
Chemistry |
1,056 |
642.11 |
1.6 |
Clinical Medicine |
6,346 |
2,274.10 |
2.8 |
Computer Science |
6 |
5.14 |
1.2 |
Economics & Business |
25 |
7.29 |
3.4 |
Engineering |
3,628 |
815.40 |
4.4 |
Environment/Ecology |
6,507 |
2,250.50 |
2.9 |
Geosciences |
5,527 |
2,091.43 |
2.6 |
Immunology |
372 |
213.76 |
1.7 |
Materials Science |
1 |
3.20 |
0.3 |
Mathematics |
31 |
11.07 |
2.8 |
Molecular Biology & Genetics |
25 |
82.44 |
0.3 |
Multidisciplinary |
389 |
39.00 |
10.0 |
Neuroscience & Behavior |
185 |
220.51 |
0.8 |
Pharmacology & Toxicology |
2,642 |
1,542.98 |
1.7 |
Physics |
164 |
100.75 |
1.6 |
Plant & Animal Science |
32 |
38.05 |
0.8 |
Social Sciences, general |
27 |
21.47 |
1.2 |
TOTAL |
27,449 |
10,856.34 |
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.
Table 15. PM Papers in Top 10% of Journals by JCR Impact Factor
EPA PM Papers in that Journal |
Journal |
Impact Factor |
JCR IF Rank |
2 |
New England Journal of Medicine |
51.296 |
2 |
6 |
Science |
30.028 |
9 |
3 |
Lancet |
25.800 |
18 |
4 |
JAMA—Journal of the American Medical Association |
23.175 |
23 |
1 |
Journal of Clinical Investigation |
15.754 |
42 |
1 |
Annual Review of Physical Chemistry |
11.250 |
83 |
10 |
Circulation |
10.940 |
88 |
1 |
Nano Letters |
9.960 |
110 |
2 |
Proceedings of the National Academy of Sciences of the United States of America |
9.643 |
116 |
27 |
American Journal of Respiratory and Critical Care Medicine |
9.091 |
131 |
6 |
Journal of Allergy and Clinical Immunology |
8.829 |
136 |
1 |
Advanced Drug Delivery Reviews |
7.977 |
156 |
2 |
Cancer Research |
7.656 |
172 |
1 |
Journal of Neuroscience |
7.453 |
177 |
1 |
FASEB Journal |
6.721 |
206 |
1 |
Critical Care Medicine |
6.599 |
211 |
5 |
Journal of Immunology |
6.293 |
223 |
5 |
Thorax |
6.064 |
237 |
1 |
American Journal of Pathology |
5.917 |
249 |
117 |
Environmental Health Perspectives |
5.861 |
255 |
4 |
Journal of Biological Chemistry |
5.808 |
260 |
12 |
Analytical Chemistry |
5.646 |
276 |
5 |
Free Radical Biology & Medicine |
5.440 |
289 |
1 |
Stroke |
5.391 |
293 |
12 |
American Journal of Epidemiology |
5.241 |
308 |
1 |
Journal of Thrombosis and Haemostasis |
5.138 |
325 |
4 |
European Respiratory Journal |
5.076 |
335 |
1 |
TrAC - Trends in Analytical Chemistry |
5.068 |
337 |
1 |
Cellular Signalling |
4.887 |
363 |
1 |
Faraday Discussions |
4.731 |
393 |
25 |
Toxicology and Applied Pharmacology |
4.722 |
397 |
16 |
American Journal of Respiratory Cell and Molecular Biology |
4.593 |
412 |
1 |
Journal of Leukocyte Biology |
4.572 |
415 |
1 |
Journal of Catalysis |
4.533 |
418 |
1 |
International Journal of Epidemiology |
4.517 |
424 |
1 |
Antioxidants & Redox Signaling |
4.491 |
431 |
2 |
Atmospheric Chemistry and Physics |
4.362 |
449 |
23 |
Epidemiology |
4.339 |
452 |
2 |
American Journal of Physiology - Cell Physiology |
4.334 |
455 |
1 |
Progress in Energy and Combustion Science |
4.333 |
456 |
34 |
American Journal of Physiology - Lung Cellular and Molecular Physiology |
4.250 |
472 |
2 |
Journal of Physical Chemistry B |
4.115 |
501 |
120 |
Environmental Science & Technology |
4.040 |
518 |
2 |
Applied Catalysis B: Environmental |
3.942 |
548 |
3 |
Chest |
3.924 |
552 |
1 |
Experimental Cell Research |
3.777 |
596 |
1 |
Human Reproduction |
3.769 |
599 |
1 |
Bulletin of the American Meteorological Society |
3.728 |
614 |
1 |
American Journal of Physiology - Heart and Circulatory Physiology |
3.724 |
616 |
1 |
American Journal of Public Health |
3.698 |
626 |
1 |
Journal of Cellular Physiology |
3.638 |
646 |
2 |
Clinical Immunology |
3.606 |
659 |
31 |
Toxicological Sciences |
3.598 |
662 |
1 |
Journal of Chromatography A |
3.554 |
678 |
3 |
Journal of Neuroscience Research |
3.476 |
704 |
11 |
Journal of Applied Physiology |
3.178 |
807 |
1 |
Journal of Chemical Physics |
3.166 |
814 |
3 |
Chemical Research in Toxicology |
3.162 |
818 |
1 |
Remote Sensing of Environment |
3.064 |
855 |
4 |
Journal of Physical Chemistry A |
3.047 |
863 |
1 |
American Journal of Cardiology |
3.015 |
876 |
Total = 537 |
|
|
|
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
EPA PM Papers in that Journal |
Journal |
Immediacy Index |
JCR II Rank |
2 |
New England Journal of Medicine |
12.743 |
2 |
4 |
JAMA - Journal of the American Medical Association |
7.781 |
4 |
3 |
Lancet |
7.419 |
6 |
6 |
Science |
5.555 |
16 |
1 |
Journal of Clinical Investigation |
3.911 |
29 |
1 |
Faraday Discussions |
2.766 |
59 |
10 |
Circulation |
2.674 |
63 |
1 |
International Journal of Epidemiology |
2.200 |
84 |
27 |
American Journal of Respiratory and Critical Care Medicine |
2.006 |
98 |
6 |
Journal of Allergy and Clinical Immunology |
1.790 |
118 |
1 |
Annual Review of Physical Chemistry |
1.762 |
124 |
2 |
Proceedings of the National Academy of Sciences of the United States of America |
1.758 |
126 |
1 |
Critical Care Medicine |
1.641 |
146 |
4 |
Philosophical Transactions of the Royal Society of London Series A: Mathematical and Physical Sciences |
1.534 |
166 |
1 |
Nano Letters |
1.485 |
177 |
5 |
Thorax |
1.460 |
184 |
23 |
Epidemiology |
1.437 |
187 |
1 |
Journal of Thrombosis and Haemostasis |
1.397 |
194 |
1 |
Journal of Neuroscience |
1.319 |
216 |
1 |
Stroke |
1.242 |
237 |
1 |
FASEB Journal |
1.241 |
238 |
2 |
Cancer Research |
1.220 |
246 |
1 |
Cellular Signalling |
1.213 |
249 |
1 |
Antioxidants & Redox Signaling |
1.131 |
281 |
4 |
Journal of Biological Chemistry |
1.110 |
291 |
3 |
Chest |
1.110 |
291 |
4 |
European Respiratory Journal |
1.108 |
294 |
12 |
American Journal of Epidemiology |
1.091 |
306 |
11 |
Journal of Applied Physiology |
1.026 |
343 |
2 |
Atmospheric Chemistry and Physics |
1.015 |
350 |
117 |
Environmental Health Perspectives |
0.994 |
373 |
1 |
Environmental Science and Pollution Research |
0.982 |
376 |
16 |
American Journal of Respiratory Cell and Molecular Biology |
0.925 |
404 |
2 |
American Journal of Physiology - Cell Physiology |
0.906 |
417 |
5 |
Journal of Immunology |
0.886 |
435 |
1 |
Journal of Cellular Physiology |
0.867 |
453 |
1 |
Physical Chemistry Chemical Physics |
0.866 |
454 |
1 |
American Journal of Pathology |
0.833 |
487 |
34 |
American Journal of Physiology - Lung Cellular and Molecular Physiology |
0.832 |
493 |
12 |
Analytical Chemistry |
0.795 |
524 |
1 |
American Journal of Physiology - Heart and Circulatory Physiology |
0.777 |
547 |
1 |
TrAC - Trends in Analytical Chemistry |
0.752 |
578 |
5 |
Free Radical Biology & Medicine |
0.751 |
580 |
1 |
Journal of Catalysis |
0.751 |
580 |
1 |
American Journal of Public Health |
0.740 |
588 |
1 |
Human Reproduction |
0.734 |
597 |
31 |
Toxicological Sciences |
0.734 |
597 |
4 |
Journal of Physical Chemistry A |
0.730 |
602 |
1 |
Journal of Chemical Physics |
0.721 |
616 |
103 |
Journal of Geophysical Research |
0.684 |
673 |
1 |
Agricultural and Forest Meteorology |
0.669 |
690 |
1 |
Journal of Leukocyte Biology |
0.668 |
691 |
3 |
Chemical Research in Toxicology |
0.663 |
703 |
120 |
Environmental Science & Technology |
0.646 |
729 |
1 |
Bulletin of the American Meteorological Society |
0.646 |
729 |
1 |
Journal of Environmental Pathology, Toxicology and Oncology |
0.639 |
742 |
2 |
Journal of Physical Chemistry B |
0.637 |
746 |
4 |
Boundary-Layer Meteorology |
0.629 |
758 |
1 |
American Journal of Cardiology |
0.615 |
781 |
1 |
Equine Veterinary Journal |
0.611 |
790 |
2 |
Clinical Immunology |
0.604 |
804 |
6 |
Journal of Exposure Science and Environmental Epidemiology |
0.596 |
821 |
6 |
Environmental Research |
0.583 |
844 |
132 |
Aerosol Science and Technology |
0.571 |
872 |
Total = 762 |
|
|
|
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 |
ESI Hot Papers Threshold |
No. of Cites in 2-Month Period |
Paper |
Clinical Medicine |
7 |
7 cites in March-April 2002 |
Peters A, et al. Increased particulate air pollution and the triggering of myocardial infarction. Circulation 2001;103(23):2810-2815. |
|
12 |
21 cites in August-September 2003 |
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. |
|
10 |
11 cites in November-December 2005 |
Peters A, et al. Exposure to traffic and the onset of myocardial infarction. New England Journal of Medicine 2004;351(17):1721-1730. |
|
13 |
19 cites in November- December 2005 |
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(1):71-77. |
Engineering |
4 |
4 cites in October-November 2001 |
Christoforou CS, et al. Trends in fine particle concentration and chemical composition in southern California. Journal of the Air & Waste Management Association 2000;50(1):43-53. |
|
4 |
4 cites in July 2001 |
Richter H, Howard JB. Formation of polycyclic 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. |
|
3 |
3 cites in May 2001 |
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. |
Engineering |
3 |
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 |
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 |
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. |
|
2 |
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 |
3 cites in November- December 2003 |
Lewis CW, et al. Source apportionment of Phoenix PM2.5 aerosol with the Unmix receptor model. Journal of the Air & Waste Management Association 2003;53(3):325-338. |
|
3 |
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 |
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 |
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 |
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 |
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. |
|
3 |
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. |
Environment/ Ecology |
3 |
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 |
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 |
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 |
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 2001;35(24):4758-4766. |
|
5 |
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. |
|
5 |
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 |
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. |
|
5 |
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. |
|
3 |
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 |
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;113(4):499-503. |
|
3 |
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. |
Environment/ Ecology |
6 |
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. |
|
6 |
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;113(8):978-982. |
|
6 |
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;113(3):304-309. |
|
4 |
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 |
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. |
|
6 |
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 & Technology 2005;39(13):4938-4952. |
|
10 |
24 cites in March-April 2007 |
Oberdorster G, et al. Nanotoxicology: an emerging discipline evolving from studies of ultrafine particles. Environmental Health Perspectives 2005;113(7):823-839. |
|
4 |
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 |
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 |
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. |
Multidisciplinary |
6 |
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 |
5 |
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. |
|
5 |
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 |
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(1):237-246. |
|
2 |
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 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 |
Affiliation |
ESI Field |
Arey, Janet |
University of California–Riverside |
Environment/Ecology |
Atkinson, Roger |
University of California–Riverside |
Environment/Ecology |
Cass, Glen R. |
Georgia Institute of Technology |
Environment/Ecology |
Corey, Lawrence |
University of Washington |
Clinical Medicine |
Dickey, David A. |
North Carolina State University |
Mathematics |
Dockery, Douglas W. |
Harvard University |
Environment/Ecology |
Fehsenfeld, Fred C. |
National Oceanic and Atmospheric Administration |
Geosciences |
Folsom, Aaron R. |
University of Minnesota |
Clinical Medicine |
Fuster, Valentin |
Mount Sinai Medical Center |
Clinical Medicine |
Garcia, Rolando R. |
National Center for Atmospheric Research |
Geosciences |
Giorgi, Filippo |
Abdus Salam International Centre for Theoretical Physics (Trieste, Italy) |
Geosciences |
Holben, Brent N. |
National Air and Space Administration Goddard Space Flight Center |
Geosciences |
Jacob, Daniel J. |
Harvard University |
Geosciences |
Karl, Thomas R. |
National Oceanic and Atmospheric Administration |
Geosciences |
Kaufman, Yoram J. |
National Air and Space Administration Goddard Space Flight Center |
Geosciences |
Kawachi, Ichiro |
Harvard School of Public Health |
Social Sciences, general |
Kloner, Robert A. |
Good Samaritan Hospital |
Clinical Medicine |
Koutrakis, Petros |
Harvard School of Public Health |
Environment/Ecology |
Likens, Gene E. |
Institute of Ecosystem Studies |
Environment/Ecology |
Liotta, Lance A. |
National Cancer Institute |
Clinical Medicine |
Lioy, Paul J. |
University of Medicine & Dentistry of New Jersey |
Environment/Ecology |
Lippmann, Morton |
New York University School of Medicine |
Environment/Ecology |
Madronich, Sasha |
National Center for Atmospheric Research |
Geosciences |
Mannucci, Pier M. |
Università degli Studi di Milano |
Clinical Medicine |
Mazurek, Monica A. |
Rutgers University |
Environment/Ecology |
Pankow, James F. |
Oregon Health and Science University |
Environment/Ecology |
Richards, James H. |
University of California–Davis |
Environment/Ecology |
Rogge, Wolfgang F. |
Florida International University |
Environment/Ecology |
Schwartz, Joel D. |
Harvard School of Public Health |
Environment/Ecology |
Schwartz, Stephen E. |
Brookhaven National Laboratory |
Geosciences |
Seinfeld, John H. |
California Institute of Technology |
Geosciences |
Simoneit, Bernd R.T. |
Oregon State University |
Environment/Ecology |
Speizer, Frank E. |
Harvard Medical School |
Clinical Medicine |
Spengler, John D. |
Harvard University |
Environment/Ecology |
Turco, Richard P. |
University of California–Los Angeles |
Geosciences |
Wang, Jun |
National Centers for Environmental Prediction, National Oceanic and Atmospheric Administration |
Geosciences |
Watson, John G. |
Desert Research Institute |
Environment/Ecology |
Winer, Arthur M. |
University of California–Los Angeles |
Environment/Ecology |
Wolff, George T. |
General Motors Corporation |
Environment/Ecology |
Zeger, Scott L. |
Johns Hopkins University |
Mathematics |
Total = 40 |
|
|
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.
Table 19. Patents Resulting From PM Research (1998-2007)
Patent or Patent Application No. |
Inventor(s) |
Title |
Patent/Patent Application Date |
Patents that Referenced This Patent |
U.S. Patent No. 6,890,372 |
Dasgupta PK Morris KJ |
Denuder assembly for collection and removal of soluble atmospheric gases |
May 2005 |
None |
U.S. Patent No. 5,763,360 |
Gundel L Daisey JM Stevens RK |
Quantitative organic vapor-particle sampler |
June 1998 |
Referenced by 6 patents: |
U.S. Patent No. 6,226,852 |
Gundel L Daisey JM Stevens RK |
Method for fabricating a quantitative integrated diffusion vapor-particle sampler for sampling, detection and quantitation of semi-volatile organic gases, vapors and particulate components |
May 2001 |
Referenced by 3 patents: |
U.S. Patent No. 6,780,818 |
Gundel L Daisey JM Stevens RK |
Quantitative organic vapor-particle sampler |
August 2004 |
None |
U.S. Patent No. 7,168,292 |
Gundel LA Apte MG Hansen AD Black DR |
Apparatus for particulate matter analysis |
January 2007 |
None |
U.S. Patent No. 7,168,292 |
Gundel LA Apte MG Hansen AD Black DR |
Apparatus for particulate matter analysis |
January 2007 |
None |
1 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.
2 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.
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.
This bibliometric analysis was prepared by
Beverly Campbell, The Scientific Consulting Group, Inc.
under EPA Contract No. EP-C-05-015