September 2007 SERA Bibliometric Analysis for the U.S. Environmental Protection Agency/Office of Research and Development's Air (Particulate Matter, Ozone, Air Toxics, and Indoor Air) Research Program This is a bibliometric analysis of the papers prepared by intramural and extramural researchers of the U.S. Environmental Protection Agency's (EPA) Air Research Program. For this analysis, 2,067 papers were reviewed, and they were published from 1998 to 2007. These publications were cited 34,632 times in the journals covered by Thomson Scientific's Web of 1 • 2 Science and Elsevier's Scopus". Of these 2,067 publications, 1,828 (88.4%) 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 Air Research Program 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 air 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 air 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 2,067 air research papers analyzed by ESI field (e.g., Clinical Medicine, Environment/Ecology, and Geosciences), an analysis of the journals in which the air papers were published, a table of the highly cited researchers in the Ar Research Program, a list of patents that have resulted from the program, and other parameters reported by ESI. 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. 1 ------- Bibliometric Analysis of Air Research Program Journal Articles Summary of Results 1. One-third of the air publications are highly cited papers. 682 (33.0%) of the air papers qualify as highly cited when using the ESI criteria for the top 10% of highly cited publications. This is 3.3 times the 10% of papers expected to be highly cited. 107 (5.2%) of the air papers qualify as highly cited when using the ESI criteria for the top 1 %, which is 5.2 times the number expected. 14 (0.7%) of these papers qualify as very highly cited when using the criteria for the top 0.1%, which is 7 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 air papers are more highly cited than the average paper. Using the ESI average citation rates for papers published by field as the benchmark, in 15 of the 19 fields in which the 2,067 EPA air papers were published, the ratio of actual to expected cites is greater than 1, indicating that the air papers are more highly cited than the average papers in those fields. For all 19 fields combined, the ratio of total number of cites to the total number of expected cites (34,632 to 15,325.30) is 2.2, indicating that the air papers are more highly cited than the average paper. 3. More than one-third of the air papers are published in high impact journals. 697 of the 2,067 papers were published in the top 10% of journals ranked by JCR Impact Factor, representing 33.7% of EPA's air papers. This number is 3.4 times higher than the expected 207 papers. 962 of the 2,067 papers appear in the top 10% of journals ranked by JCR Immediacy Index, representing 46.5% of EPA's air papers. This number is 4.6 times higher than the expected 207 papers. 4. Fifty-two of the air papers qualify as hot papers. Using the hot paper thresholds established by ESI as a benchmark, 52 hot papers, representing 2.5% of the air papers, were identified in the analysis. Hot papers are papers that were highly cited shortly after they were published. The number of air hot papers identified is 25 times higher than the expected 2 hot papers. 5. The authors of the air papers cite themselves much less than the average author. 1,607 of the 34,632 cites are author self-cites. This 4.6% author self-citation rate is well below the accepted range of 10-30% author self-citation rate. 6. Fifty-nine of the 3,452 authors of the air 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 Air Research Program. Two of these patents were cited by a total of 9 other patents. 8. EPA's Air Research Program includes 4 of the top 20 air pollution papers (published from January 2003 to April 2005) and 18 of the top 20 air pollution authors (from 1995 to 2005) authored papers for EPA's Air Research Program. ------- Bibliometric Analysis of Air Research Program Journal Articles Summary of Results (Continued) 10. The United States ranks first among the top 20 countries publishing on air pollution. 11. More than one-half of the EPA air papers are published in ESFs top 20 journals in air pollution. 12. Harvard University (one of EPA's grantees) ranks number one and EPA ranks number two on ESFs top 20 institutions publishing on air pollution. 13. The number of air pollution papers published in journals covered by ESI from 2001 to 2005 has declined compared to the number published from 2000 to 2004. The number of cites and cites/paper for papers published from 2001 to 2005 also have declined. The number of EPA Air Research Program publications, however, has increased slightly from 2001 to 2005 (1,257 publications) when compared to the number published from 2000 to 2004 (1,240 publications). Like the overall air pollution paper trends identified by ESI, the number of cites and the cites per paper have declined. Highly Cited Air 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 2,067 air research papers reviewed for this analysis were published in journals that were assigned to 19 of the 22 ESI fields. The distribution of the papers among these 19 fields and the number of citations by field are presented in Table 1. Ta )le 1. Air Papers by ESI Fields ESI Field No. of Citations No. of Air Papers Average Cites/Paper Biology & Biochemistry 546 41 13.3 Chemistry 2,375 150 15.8 Clinical Medicine 6,479 260 24.9 Computer Science 15 4 3.8 Economics & Business 25 3 8.3 Engineering 4,278 361 11.8 Environment/Ecology 7,910 436 18.1 Geosciences 8,477 490 17.3 ------- Bibliometric Analysis of Air Research Program Journal Articles ESI Field No. of Citations No. of Air Papers Average Cites/Paper Immunology 377 14 26.9 Materials Science 1 2 0.5 Mathematics 35 7 5.0 Microbiology 22 1 22.0 Molecular Biology & Genetics 62 8 7.8 Multidisciplinary 420 9 46.7 Neuroscience & Behavior 227 20 11.4 Pharmacology & Toxicology 3,002 221 13.6 Physics 194 15 12.9 Plant & Animal Science 124 11 11.3 Social Sciences, general 63 14 4.5 Total = 34,632 Total = 2,067 16.8 There are 682 (33.0% of the papers analyzed) highly cited EPA air papers in 14 of the 19 fields— Biology & Biochemistry, Chemistry, Clinical Medicine, Economics & Business, Engineering, Environment/Ecology, Geosciences, Immunology, Mathematics, Multidisciplinary, Pharmacology & Toxicology, Physics, Plant & Animal Science, and Social Sciences—when using the ESI criteria for the top 10% of papers. Table 2 shows the number of EPA air papers in those 14 fields that meet the top 10% threshold in ESI. One hundred-seven (5.2%) of the papers analyzed qualify as highly cited when using the ESI criteria for the top 1% of papers. These papers cover 9 fields— Biology & Biochemistry, Chemistry, Clinical Medicine, Economics & Business, Engineering, Environment/ Ecology, Geosciences, Multidisciplinary, and Pharmacology & Toxicology. Table 3 shows the 107 (5.2% of the papers analyzed) papers by field that meet the top 1% threshold in ESI. The citations for these 107 papers are provided in Tables 4 through 12. Table 13 shows the 14 (0.7%) papers by field that meet the top 0.1% threshold in ESI. These 14 very highly cited air papers in the fields of Chemistry, Clinical Medicine, Economics & Business, Engineering, Environment/Ecology, and Geosciences are listed in Table 14. None of the air 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. Table 2. Number of Highly Cited Air Pa ESI Field No. of Citations No. of Papers Average Cites/Paper % of Papers in Field Biology & Biochemistry 216 6 36.0 14.6% Chemistry 1,156 34 34.0 22.7% Clinical Medicine 4,970 91 54.6 35.0% Economics & Business 7 1 7.0 33.3% )ers by Field (top 10%) ------- Bibliometric Analysis of Air Research Program Journal Articles ESI Field No. of Citations No. of Papers Average Cites/Paper % of Papers in Field Engineering 3,544 145 24.4 40.2% Environment/Ecology 5,655 170 33.3 39.0% Geosciences 5,737 164 35.0 33.5% Immunology 303 5 60.6 35.7% Mathematics 25 2 12.5 28.6% Multidisciplinary 398 6 66.3 66.7% Pharmacology & Toxicology 1,743 48 36.3 21.7% Physics 117 3 39.0 20.0% Plant & Animal Science 64 2 32.0 18.2% Social Sciences, general 21 5 4.2 35.7% Total = 23,956 Total = 682 35.1 33.0% Table 3. Number of Highly Cited Air Pa ESI Field No. of Citations No. of Papers Average Cites/Paper % of Air Papers in Field Biology & Biochemistry 37 1 37.0 2.4% Chemistry 62 2 31.0 0.5% Clinical Medicine 1,513 8 189.1 3.1% Economics & Business 7 1 7.0 33.3% Engineering 1,768 32 55.2 8.9% Environment/Ecology 1,549 31 50.0 7.1% Geosciences 2,255 28 80.5 5.7% Multidisciplinary 272 2 136.0 22.2% Pharmacology & Toxicology 259 2 129.5 0.9% Total = 7,722 Total MP 72.2 5.2% )ers by Field (top 1%) ------- Bibliometric Analysis of Air Research Program Journal Articles Table 4. Highly Cited Air Papers in the Field of Biology & Biochemistry (top 1%) No. of Cites First Author Paper 37 Kadiiska MB Biomarkers of Oxidative Stress Study II: are oxidation products of lipids, proteins, and DNA markers of CC14 poisoning? Free Radical Biology & Medicine 2005;38(6):698-710. Table 5. Highly ( ]!ited Air Papers in the Field of Chemistry (top 1%) No. of Cites First Author Paper 59 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 Rudich Y Aging of organic aerosol: bridging the gap between laboratory and field studies. Annual Review of Physical Chemistry 2007;5 8:321- 352. Table 6. Highly Cited Air Papers in the Field of Clinical Medicine (top 1%) No. of Cites First Author Paper 187 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 Gold DR Ambient pollution and heart rate variability. Circulation 2000; 101(11): 1267-1273. 249 Peters A Increased particulate air pollution and the triggering of myocardial infarction. Circulation 2001;103(23):2810-2815. 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. 89 Peters A Exposure to traffic and the onset of myocardial infarction. New England Journal of Medicine 2004;351(17): 1721-1730. 131 Pope CA Cardiovascular mortality and long-term exposure to particulate air pollution: epidemiological evidence of general pathophysiological pathways of disease. Circulation 2004;109(l):71-77. 2 Baccarelli A Effects of exposure to air pollution on blood coagulation. Journal of Thrombosis andHaemostasis 2007;5(2):252-260. ------- Bibliometric Analysis of Air Research Program Journal Articles No. of Cites First Author Paper 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. Table 7. Highly Cited Air Papers in the Field of Economics & Business (top 1%) No. of Cites First Author Paper 7 Peng RD Model choice in time series studies of air pollution and mortality. Journal of the Royal Statistical Society: Series A (Statistics in Societyj 2006;169(2): 179-203. "able 8. High y Cited Air Papers in the Field of Engineering (top 1%) No. of Cites First Author Paper 54 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 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 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 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 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 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 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. 38 Vette AF Characterization of indoor-outdoor aerosol concentration relationships during the Fresno PM exposure studies. Aerosol Science and Technology> 2001;34(1): 118-126. ------- Bibliometric Analysis of Air Research Program Journal Articles No. of Cites First Author Paper 42 Lewtas J Comparison of sampling methods for semi-volatile organic carbon associated with PM2.5. Aerosol Science and Technology 2001;34(l):9-22. 57 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 Woo KS Measurement of Atlanta aerosol size distributions: Observations of ultrafine particle events. Aerosol Science and Technology 2001;34(1):75- 87. 105 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 Cabada JC Sources of atmospheric carbonaceous particulate matter in Pittsburgh, Pennsylvania. Journal of the Air & Waste Management Association 2002;52(6):732-741. 34 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 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 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 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 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 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. 22 Lemieux PM Emissions of organic air toxics from open burning: a comprehensive review. Progress in Energy and Combustion Science 2004;30(1): 1-32. 23 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 ZhuY Seasonal trends of concentration and size distribution of ultrafine particles near maior hiehwavs in Los Aneclcs. Aerosol Science and Technology 2004;38(S1):5-13. 24 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. ------- Bibliometric Analysis of Air Research Program Journal Articles No. of Cites First Author Paper 25 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 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 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(Sl):253-264. 34 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 Subramanian R Positive and negative artifacts in particulate organic carbon measurements with denuded and undenuded sampler configurations. Aerosol Science and Technology 2004;38(Sl):27-48. 55 Canagaratna M Chase studies of particulate emissions from in-use New York City vehicles. Aerosol Science and Technology 2004;38(6):555-573. 13 KimE 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 ;5 5 (8): 1190-1199. 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. 17 Bond TC Light absorption by carbonaceous particles: an investigative review. Aerosol Science and Technology 2006;40(l):27-67. Table 9. Highly Cit ed Air Papers in the Field of Environment/Ecology (top 1%) No. of Cites First Author Paper 175 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 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 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. ------- Bibliometric Analysis of Air Research Program Journal Articles No. of Cites First Author Paper 83 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 Dockery DW Epidemiologic evidence of cardiovascular effects of particulate air pollution. Environmental Health Perspectives 2001;109(S4):483-486. 67 Park K Relationship between particle mass and mobility for diesel exhaust particles. Environmental Science & Technology 2003;37(3):577-583. 144 LiN Ultrafine particulate pollutants induce oxidative stress and mitochondrial damage. Environmental Health Perspectives 2003; 111(4):455-460. 34 Landrigan PJ Health and environmental consequences of the World Trade Center disaster. Environmental Health Perspectives 2004; 112(6): 731-739. 40 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 XiaT 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 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 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 Gao S Particle phase acidity and oligomer formation in secondary organic aerosol. Environmental Science & Technology 2004;38(24):6582-6589. 17 Reisen F Atmospheric reactions influence seasonal PAH and nitro-PAH concentrations in the Los Angeles Basin. Environmental Science & Technology 2005;39(l):64-73. 18 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 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 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 Lim H Isoprene forms secondary organic aerosol through cloud processing: model simulations. Environmental Science & Technology 2005;39(12):4441-4446. ------- Bibliometric Analysis of Air Research Program Journal Articles No. of Cites First Author Paper 25 Park SK Effects of Air Pollution on Heart Rate Variability: The VA Normative Aging Study. Environmental Health Perspectives 2005; 113(3):304-309. 26 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 Lough GC Emissions of metals associated with motor vehicle roadways. Environmental Science & Technology 2005;39(3):826-836. 40 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 Oberdorster G Nanotoxicology: an emerging discipline evolving from studies of ultrafine particles. Environmental Health Perspectives 2005;113(7): 823-839. 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 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 Elder A Translocation of inhaled ultrafine manganese oxide particles to the central nervous system. Environmental Health Perspectives 2006; 114(8): 1172- 1178. 7 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 Shrivastava MK Modeling semivolatile organic aerosol mass emissions from combustion systems. Environmental Science & Technology> 2006;40(8):2671-2677. 8 Donahue NM Coupled partitioning, dilution, and chemical aging of semivolatile organics. Environmental Science & Technology 2006;40(8):2635-2643. 9 Presto AA Investigation of a-pinene + ozone secondary organic aerosol formation at low total aerosol mass. Environmental Science & Technology 2006;40(11):3536-3543. 13 McConnell R Traffic, susceptibility, and childhood asthma. Environmental Health Perspectives 2006; 114(5):766-772. 1 able 10. High y Cited Air Papers in the Field of Geosciences (top 1%) No. of Cites First Author Paper ------- Bibliometric Analysis of Air Research Program Journal Articles No. of Cites First Author Paper 116 Wang YH Global simulation of tropospheric 03-NOx-hydrocarbon chemistry, 2. Model evaluation. Journal of Geophysical Research-Atmospheres 1998;103(D9): 10727-10756." 148 Wang YH Global simulation of tropospheric 03-NOx-hydrocarbon chemistry, 1. Model formulation. Journal of Geophysical Research-Atmospheres 1998;103(D9): 10713-10726. ' 149 Nenes A ISORROPIA: a new thermodynamic equilibrium model for multiphase multicomponent inorganic aerosols. Aquatic Geochemistry 1998;4:123- 152. 121 Simpson D Inventorying emissions from nature in Europe. Journal of Geophysical Research-Atmospheres 1999;104(D7):8113-8152. 166 Griffin RJ Organic aerosol formation from the oxidation of biogenic hydrocarbons. Journal of Geophysical Research-Atmospheres 1999;104(D3):3555-3567. 170 YuJ Gas-Phase ozone oxidation of monoterpenes: gaseous and particulate products. Journal of Atmospheric Chemistry 1999;34(2):207-258. 188 Simoneit BRT Levoglucosan, a tracer for cellulose in biomass burning and atmospheric particles. Atmospheric Environment 1999;33(2): 173-182. 112 Russell A NARSTO critical review of photochemical models and modeling. Atmospheric Environment 2000;34(12-14):2283-2324. 130 Fuentes JD Biogenic hydrocarbons in the atmospheric boundary layer: a review. Bulletin of the American Meteorological Society 2000;81(7): 1537-1575. 174 Guenther A Natural emissions of non-methane volatile organic compounds, carbon monoxide, and oxides of nitrogen from North America. Atmospheric Environment 2000;34(12-14):2205-2230. 92 Sokolik IN Introduction to special section: outstanding problems in quantifying the radiative impact of mineral dust. Journal of Geophysical Research- Atmospheres 2001;106(D 16): 18015-18027. 178 Huser RB Asian dust events of April 1998. Journal of Geophysical Research Atmospheres 2001;106(D 16): 18317-18330. 121 ZhuY Study of ultrafine particles near a major highway with heavy-duty diesel traffic. Atmospheric Environment 2002;36(27):4323-4335. 42 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 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 Jiminez JL Ambient aerosol sampling using the Aerodyne Aerosol Mass Spectrometer. Journal of Geophysical Research-Atmospheres 2003;108(D7):8425. ------- Bibliometric Analysis of Air Research Program Journal Articles No. of Cites First Author Paper 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 Wittig AE Pittsburgh Air Quality Study overview. Atmospheric Environment 2004;38(20):3107-3125. 31 KimE Improving source identification of Atlanta aerosol using temperature resolved carbon fractions in positive matrix factorization. Atmospheric Environment 2004;38(20):3349-3362. 18 McKeen S Assessment of an ensemble of seven real-time ozone forecasts over eastern North America during the summer of 2004. Journal of Geophysical Research-Atmospheres 2005;110(D21307). 27 Edney EO Formation of 2-methyl tetrols and 2-methylglyceric acid in secondary organic aerosol from laboratory irradiated isoprene/NOx/S02/air mixtures and their detection in ambient PM2 5 samples collected in the eastern United States. Atmospheric Environment 2005;39(29):5281-5289. 32 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 Hallock- Waters KA Carbon monoxide in the U. S. Mid-Atlantic troposphere: evidence for a decreasing trend. Geophysical Research Letters 2006;26(18):2861-2864. 8 Offenberg JH Thermal properties of secondary organic aerosols. Geophysical Research Letters 2006;33(3):L03816. 8 TakegawaN 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). 12 Guenther A Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature/ Journal of Geophysical Research-Atmospheres 2006;6:3181-3210. 3 Kondo Y Oxygenated and water-soluble organic aerosols in Tokyo. Journal of Geophysical Research-Atmospheres 2007;112(D1):D01203. 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. ------- Bibliometric Analysis of Air Research Program Journal Articles Tab ell. Highly Cited Air Papers in the Field of Multidisciplinary (top 1%) No. of Cites First Author Paper 117 Gard EE Direct Observation of Heterogeneous Chemistry in the Atmosphere. Science 1998;279(5354): 1184-1187. 155 Jang M Heterogeneous Atmospheric Aerosol Production by Acid-Catalyzed Particle-Phase Reactions. Science 2002;298(5594):814-817. Table 12. Highly Cited Air Papers in the Field of Pharmacology & Toxicology (top 1%) No. of Cites First Author Paper 157 Oberdorster G Pulmonary effects of inhaled ultrafine particles. International Archives of Occupational and Environmental Health 2001;74(1): 1-8. 102 Oberdorster G Translocation of inhaled ultrafine particles to the brain. Inhalation Toxicology 2004;16(6-7):437-445. Table 13. Number of Very Highly Cited Papers by Field (Top 0.1%) ESI Field No. of Citations No. of Papers Average Cites/Paper % of Air Papers in Field Chemistry 3 1 3.0 0.7% Clinical Medicine 639 2 319.5 0.8% Economics & Business 7 1 7.0 33.3% Engineering 671 7 95.8 1.9% Environment/Ecology 277 2 138.5 0.5% Geosciences 178 1 178.0 0.2% Total = 1,775 Total 14 126.8 0.7% Table 14. Very Highly Cited Air Papers (top 0.1%) ESI Field No. of Cites First Author Paper Chemistry 3 Rudich Y Aging of organic aerosol: bridging the gap between laboratory and field studies. Annual Review of Physical Chemistry 2007;58:321-352. ------- Bibliometric Analysis of Air Research Program Journal Articles ESI Field No. of Cites First Author Paper Clinical Medicine 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. 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 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 207 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 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. 130 ZhuYF Concentration and size distribution of ultrafine particles near a major highway. Journal of the Air & Waste Management Association 2002;52(9): 1032-1042. 39 Subramanian R Positive and negative artifacts in particulate organic carbon measurements with denuded and undenuded sampler configurations. Aerosol Science and Technology 2004;38(Sl):27-48. 55 Canagaratna M Chase studies of particulate emissions from in-use New York City vehicles. Aerosol Science and Technology> 2004;38(6):555- 573. 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. 17 Bond TC Light absorption by carbonaceous particles: an investigative review. Aerosol Science and Technology> 2006;40(l):27-67. Environment/ Ecology 144 LiN Ultrafine particulate pollutants induce oxidative stress and mitochondrial damage. Environmental Health Perspectives 2003; 111(4):455-460. 133 Oberdorster G Nanotoxicology: an emerging discipline evolving from studies of ultrafine particles. Environmental Health Perspectives 2005;113(7):823-839. ------- Bibliometric Analysis of Air Research Program Journal Articles ESI Field No. of Cites First Author Paper Geosciences 178 Huser RB Asian dust events of April 1998. Journal of Geophysical Research-Atmospheres 2001 ;106(D 16): 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 15 of the 19 fields in which the EPA air papers were published, the ratio of actual to expected cites is greater than 1, indicating that the air papers are more highly cited than the average papers in those fields (see Table 15). 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 19 fields combined, the ratio of total number of cites to the total number of expected cites (34,632 to 15,325.30) is 2.2, indicating that the air papers are more highly cited than the average paper. Table 15. Ratio of Actual Cites to Expected Cites for Air Papers by Field ESI Field Total Cites Expected Cite Rate Ratio Biology & Biochemistry 546 570.96 1.0 Chemistry 2,375 1,476.02 1.6 Clinical Medicine 6,479 2,404.04 2.7 Computer Science 15 14.06 1.1 Economics & Business 25 7.29 3.4 Engineering 4,278 1,183.42 3.6 Environment/Ecology 7,910 3,300.02 2.4 Geosciences 8,477 3,378.05 2.5 Immunology 377 225.52 1.7 Materials Science 1 9.72 0.1 Mathematics 35 15.00 2.3 Microbiology 22 20.07 1.1 Molecular Biology & Genetics 62 202.11 0.3 Multidisciplinary 420 42.06 10.0 Neuroscience & Behavior 227 330.78 0.7 Pharmacology & Toxicology 3,002 1,883.33 1.6 ------- Bibliometric Analysis of Air Research Program Journal Articles ESI Field Total Cites Expected Cite Rate Ratio Physics 194 138.43 1.4 Plant & Animal Science 124 88.47 1.4 Social Sciences, general 63 35.95 1.8 TOTAL 34,632 15,325.30 2.2 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 16 indicates the number of air papers published in the top 10% of journals, based on the JCR Impact Factor. Six hundred ninety-seven (697) of 2,067 papers were published in the top 10% of journals, representing 33.7% of EPA's air papers. This indicates that more than one-third of the air 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 16. Air Papers in Top 10% of Journals by JCR Impact Factor EPA Air Papers in that Journal Journal Impact Factor (IF) JCR IF Rank 2 New England Journal of Medicine 51.296 2 7 Science 30.028 9 3 Lancet 25.800 18 5 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 7 Journal of Allergy and Clinical Immunology 8.829 136 ------- Bibliometric Analysis of Air Research Program Journal Articles EPA Air Papers in that Journal Journal Impact Factor (IF) JCR IF Rank 1 Neuroscience & Biobehavioral Reviews 8.293 149 1 Advanced Drug Delivery Reviews 7.977 156 1 Journal of the American Chemical Society 7.696 168 2 Cancer Research 7.656 172 1 Mutation Research-Reviews in Mutation Research 7.579 175 1 Journal of Neuroscience 7.453 111 1 FASEB Journal 6.721 206 1 Critical Care Medicine 6.599 211 5 Journal of Immunology 6.293 223 1 Plant Physiology 6.125 232 5 Thorax 6.064 231 1 American Journal of Pathology 5.917 249 130 Environmental Health Perspectives 5.861 255 4 Journal of Biological Chemistry 5.808 260 14 Analytical Chemistry 5.646 276 6 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 2 TrAC - Trends in Analytical Chemistry 5.068 337 1 Cellular Signalling 4.887 363 1 Faraday Discussions 4.731 393 28 Toxicology and Applied Pharmacology 4.722 397 1 Environmental Microbiology 4.630 406 18 American Journal of Respiratory Cell and Molecular Biology 4.593 412 1 Journal of Leukocyte Biology 4.572 415 5 Journal of Catalysis 4.533 418 1 International Journal of Epidemiology 4.517 424 ------- Bibliometric Analysis of Air Research Program Journal Articles EPA Air Papers in that Journal Journal Impact Factor (IF) JCR IF Rank 1 Antioxidants & Redox Signaling 4.491 431 2 Atmospheric Chemistry and Physics 4.362 449 24 Epidemiology 4.339 452 2 American Journal of Physiology - Cell Physiology 4.334 455 3 Progress in Energy and Combustion Science 4.333 456 1 Cancer Epidemiology Biomarkers & Prevention 4.289 463 36 American Journal of Physiology - Lung Cellular and Molecular Physiology 4.250 472 4 Journal of Physical Chemistry B 4.115 501 2 Mutation Research-Fundamental and Molecular Mechanisms of Mutagenesis 4.111 505 167 Environmental Science & Technology 4.040 518 1 Journal of Pharmacology and Experimental Therapeutics 3.956 545 2 Applied Catalysis B: Environmental 3.942 548 3 Chest 3.924 552 1 Carbon 3.884 562 1 Experimental Cell Research 3.777 596 1 Human Reproduction 3.769 599 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 Clinical Immunology 3.606 659 1 Optics Letters 3.598 662 41 Toxicological Sciences 3.598 662 1 Biochemical Pharmacology 3.581 667 1 Genomics 3.558 676 4 Journal of Chromatography A 3.554 678 3 Journal of Neuroscience Research 3.476 704 ------- Bibliometric Analysis of Air Research Program Journal Articles EPA Air Papers in that Journal Journal Impact Factor (IF) JCR IF Rank 1 Ecological Applications 3.470 708 1 Cancer Letters 3.277 111 15 Journal of Applied Physiology 3.178 807 2 Journal of Chemical Physics 3.166 814 8 Chemical Research in Toxicology 3.162 818 1 Remote Sensing of Environment 3.064 855 38 Journal of Physical Chemistry A 3.047 863 1 American Journal of Cardiology 3.015 876 Total = 697 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 17 indicates the number of air papers published in the top 10% of journals, based on the JCR Immediacy Index. Nine hundred sixty-two (962) of the 2,067 papers appear in the top 10% of journals, representing 46.5% of the air papers. This indicates that nearly one-half of the air papers are published in the highest quality journals as determined by the JCR Immediacy Index, which is 4.6 times higher than the expected percentage. Table 17. Air Papers in Top 10% of Journals by JCR Immediacy Index EPA Air Papers in that Journal Journal Immediacy Index (II) JCR II Rank 2 New England Journal of Medicine 12.743 2 5 JAMA - Journal of the American Medical Association 7.781 4 3 Lancet 7.419 6 7 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 ------- Bibliometric Analysis of Air Research Program Journal Articles EPA Air Papers in that Journal Journal Immediacy Index (II) JCRII Rank 27 American Journal of Respiratory and Critical Care Medicine 2.006 98 7 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 Journal of the American Chemical Society 1.510 168 1 Nano Letters 1.485 111 5 Thorax 1.460 184 24 Epidemiology 1.437 187 1 Journal of Thrombosis and Haemostasis 1.397 194 1 Journal of Neuroscience 1.319 216 1 Stroke 1.242 231 1 FASEB Journal 1.241 238 1 Neuroscience & Biobehavioral Reviews 1.222 243 2 Cancer Research 1.220 246 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 1 Mutation Research-Reviews in Mutation Research 1.050 331 15 Journal of Applied Physiology 1.026 343 2 Atmospheric Chemistry and Physics 1.015 350 130 Environmental Health Perspectives 0.994 373 1 Environmental Science and Pollution Research 0.982 376 18 American Journal of Respiratory Cell and Molecular Biology 0.925 404 ------- Bibliometric Analysis of Air Research Program Journal Articles EPA Air Papers in that Journal Journal Immediacy Index (II) JCRII Rank 2 American Journal of Physiology - Cell Physiology 0.906 417 1 Plant Physiology 0.900 423 5 Journal of Immunology 0.886 435 1 Journal of Cellular Physiology 0.867 453 1 Physical Chemistry Chemical Physics 0.866 454 1 Environmental Microbiology 0.850 469 1 Computer Physics Communications 0.845 478 1 American Journal of Pathology 0.833 487 36 American Journal of Physiology - Lung Cellular and Molecular Physiology 0.832 493 2 Annals of Occupational Hygiene 0.808 513 11 Analytical Chemistry 0.795 524 2 Journal of Pharmacology and Experimental Therapeutics 0.791 531 1 Optics Letters 0.778 543 1 American Journal of Physiology - Heart and Circulatory Physiology 0.777 547 2 TrAC - Trends in Analytical Chemistry 0.752 578 6 Free Radical Biology & Medicine 0.751 580 5 Journal of Catalysis 0.751 580 1 American Journal of Public Health 0.740 588 1 Human Reproduction 0.734 597 41 Toxicological Sciences 0.734 597 38 Journal of Physical Chemistry A 0.730 602 2 Journal of Chemical Physics 0.721 616 4 Journal of the Atmospheric Sciences 0.712 631 1 Biochemical Pharmacology 0.705 641 1 Carbon 0.690 664 145 Journal of Geophysical Research 0.684 673 1 Agricultural and Forest Meteorology 0.669 690 1 Journal of Leukocyte Biology 0.668 691 ------- Bibliometric Analysis of Air Research Program Journal Articles EPA Air Papers in that Journal Journal Immediacy Index (II) JCRII Rank 8 Chemical Research in Toxicology 0.663 703 1 Genomics 0.659 706 1 Cancer Letters 0.658 707 1 Monthly Weather Review 0.654 716 167 Environmental Science & Technology 0.646 729 5 Bulletin of the American Meteorological Society 0.646 729 1 Journal of Environmental Pathology, Toxicology and Oncology 0.639 742 4 Journal of Physical Chemistry B 0.637 746 5 Boundary-Layer Meteorology 0.629 758 1 American Journal of Cardiology 0.615 781 1 Equine Veterinary Journal 0.611 790 3 Clinical Immunology 0.604 804 6 Journal of Exposure Science and Environmental Epidemiology 0.596 821 7 Environmental Research 0.583 844 135 Aerosol Science and Technology 0.571 872 Total = 962 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, 52 hot papers, representing 2.5% of the air papers, were identified in six fields—Clinical Medicine, Engineering, Environment/Ecology, Multidisciplinary, and Pharmacology & Toxicology. The number of air hot papers is 25 times higher than expected. The hot papers are listed in Table 18. ------- Bibliometric Analysis of Air Research Program Journal Articles Table 8. 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. Clinical Medicine 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. 3 3 cites in July 2005 Ito K, et al. Associations between ozone and daily mortality: analysis and meta-analysis. Epidemiology 2005; 16(4): 446-45 7. 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 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. 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. 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. ------- Bibliometric Analysis of Air Research Program Journal Articles Field ESI Hot Papers Threshold No. of Cites in 2-Month Period Paper Engineering 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 4 cites in July 2003 Fujita, et al. Diurnal and weekday variations in source contributions of ozone precursors in California's South Coast Air Basin. Journal of the Air & Waste Management Association 2003;53(7):844-863. 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;ll(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. ------- Bibliometric Analysis of Air Research Program Journal Articles Field ESI Hot Papers Threshold No. of Cites in 2-Month Period Paper Environment/ Ecology 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. 5 5 cites in August 2001 Seila RL, et al. Atmospheric volatile organic compound measurements during the 1996 Paso Del Norte Ozone Study. Science of the Total Environment 2001;276( 1-3): 153-169. 5 6 cites in August 2001 Fujita EM. Hydrocarbon source apportionment for the 1996 Paso del Norte Ozone Study. Science of the Total Environment 2001;276(l-3): 171-184. 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) : 45 5-460. 3 3 cites in April-May 2004 Sexton K, et al. Comparison of personal, indoor, and outdoor exposures to hazardous air pollutants in three urban communities. Environmental Science & Technology 2004;38(2):423-430. 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): 499-5 03. ------- Bibliometric Analysis of Air Research Program Journal Articles Field ESI Hot Papers Threshold No. of Cites in 2-Month Period Paper Environment/ Ecology 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. 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(D 16): 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. ------- Bibliometric Analysis of Air Research Program Journal Articles Field ESI Hot Papers Threshold No. of Cites in 2-Month Period Paper Geosciences 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. 6 6 cites in November- December 2006 McKeen S, et al. Assessment of an ensemble of seven real- time ozone forecasts over eastern North America during the summer of 2004. Journal of Geophysical Research- Atmospheres 2005;110(D21):Art. No. D21307. 5 5 cites in February- March 2007 Guenther A. Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature). Atmospheric Chemistry and Physics 2006;6:3181-3210. 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 Toxicolog}' 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(l):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 air papers. Of the 34,632 total cites, 1,607 are author self-cites—a 4.6% author self-citation rate. Garfield and Sher found that authors working in research-based disciplines tend to 3 Garfield E, Sher IH. New factors in the evaluation of scientific literature through citation indexing. American Documentation 1963; 18(July): 195-210. ------- Bibliometric Analysis of Air Research Program Journal Articles 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 4.6% self-cite rate for the air papers is well below the range for author self-citation. Highly Cited Researchers A search of Thomson's ISIHighlyCited.com revealed that 59 (1.7%) of the 3,452 authors of the air 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 air publications are presented in Table 19. Table 19. Highly Cited Researchers Authoring Air Publications Highly Cited Researcher Affiliation ESI Field Ames, Bruce N. Children's Hospital Oakland Research Institute Biology & Biochemistry Molecular Biology & Genetics Andersen, Melvin E. CIIT Centers for Health Research Pharmacology Anderson, James G. Harvard University Geosciences Arey, Janet University of California-Riverside Environment/Ecology Atkinson, Roger University of California-Riverside Environment/Ecology Calvert, Jack G. National Center for Atmospheric Research Geosciences Carter, William P.L. 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 Economics & Business Dockery, Douglas W. Harvard University Environment/Ecology Driscoll, Charles T. Syracuse 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 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. ------- Bibliometric Analysis of Air Research Program Journal Articles Highly Cited Researcher Affiliation ESI Field Garcia, Rolando R. National Center for Atmospheric Research Geosciences Giorgi, Filippo Abdus Salam International Centre for Theoretical Physics (Trieste, Italy) Geosciences Hites, Ronald A. Indiana University School of Public and Environmental Affairs Environment/Ecology Holben, Brent N. National Air and Space Administration Goddard Space Flight Center Geosciences Houk, Kendall N. University of California-Los Angeles Chemistry Hubler, Gerhard F. National Oceanic and Atmospheric Administration 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 Khalil, Mohammed A.K. Portland State University Environment/Ecology Kloner, Robert A. Good Samaritan Hospital Clinical Medicine Koutrakis, Petros Harvard School of Public Health Environment/Ecology Lay, Thorne University of California-Santa Cruz Geosciences Likens, Gene E. Institute of Ecosystem Studies Environment/Ecology Lindberg, Steven E. Oak Ridge National Laboratory 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 Logan, Jennifer A. Harvard University Geosciences Madronich, Sasha National Center for Atmospheric Research Geosciences Mannucci, Pier M. Universita degli Studi di Milano Clinical Medicine Mazurek, Monica A. Rutgers University Environment/Ecology Pankow, James F. Oregon Health and Science University Environment/Ecology ------- Bibliometric Analysis of Air Research Program Journal Articles Highly Cited Researcher Affiliation ESI Field Parker, John (Jack) C. University of Tennessee Environment/Ecology Engineering Rasmussen, Reinhold A. Oregon Health and Science University Environment/Ecology Geosciences Richards, James H. University of California-Davis Environment/Ecology Rogge, Wolfgang F. Florida International University Environment/Ecology Salawitch, Ross J. California Institute of Technology Geosciences Schwartz, Joel D. Harvard School of Public Health Environment/Ecology Pharmacology Schwartz, Stephen E. Brookhaven National Laboratory Geosciences Seinfeld, John H. California Institute of Technology Geosciences Environment/Ecology Engineering Simoneit, Bernd R.T. Oregon State University Environment/Ecology Engineering Speizer, Frank E. Harvard Medical School Clinical Medicine Spengler, John D. Harvard University Environment/Ecology Trainer, Michael National Oceanic and Atmospheric Administration Geosciences Turco, Richard P. University of California-Los Angeles Geosciences Van Thiel, David H. Loyola University Medical Center Clinical Medicine Wang, J. National Centers for Environmental Prediction Geosciences Watson, John G. Desert Research Institute Environment/Ecology Winer, Arthur M. University of California-Los Angeles Environment/Ecology Wofsy, Steven C. Harvard University Geosciences Wolff, George T. General Motors Corporation Environment/Ecology Zeger, Scott L. Johns Hopkins University Mathematics Total = 59 Patents There were 6 patents issued by investigators from 1998 to 2007 for research that was conducted under EPA's air research program. The patents are listed in Table 20. Two of the 6 patents (33.3%) were referenced by a total of 9 other patents. ------- Bibliometric Analysis of Air Research Program Journal Articles Table 20. Patents from the Air Research Program (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 Li J 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: (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 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: (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 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 ------- Bibliometric Analysis of Air Research Program Journal Articles Patent or Patent Application No. Inventor(s) Title Patent/Patent Application Date Patents that Referenced This Patent U.S. Patent No. 7,168,292 Gundel LA Apte MG Hansen AD Black DR Apparatus for particulate matter analysis January 2007 None Additional ESI Parameters for Air Pollution Publications Since the last bibliometric analysis for the Particulate Matter/Ozone Research Program, which was conducted in 2005, ESI has begun analyzing special topics and reporting information such as the top 20 papers, top 20 authors, top 20 institutions, and top 20 countries for these special topics. One of the of ESI special topics is Air Pollution. The parameters reported by ESI for the special topic of Air Pollution are compared with the results of the analysis of the EPA Air Research Program publications below. Top 20 Papers in Air Pollution—A review of ESF s top 20 papers on the topic of air pollution (published from January 1, 2003 to April 30, 2005), indicates that 4 (20.0% of the top 20 papers) are papers from EPA's Air Research Program. These papers are listed in Table 21. Top 20 Authors in Air Pollution—Eighteen of ESF s top 20 authors (90.0% of the top 20 authors) in air pollution (ranked by total cites from 1995-2005) authored papers for EPA's Air Research Program. These authors are listed in Table 22. Table 21. EPA Air Papers in ESF s Top 20 Air Pollution Papers Overall (Published from January 1, 2003 to April 30, 2005) ESI Rank EPA Air Program Publication 3 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. 4 Binkowski FS, Roselle SJ. Models-3 Community Multiscale Air Quality (CMAQ) model aerosol component. 1. Model description. Journal of Geophysical Research-Atmospheres 2003; 108(D6):4183. 9 Becker S, et al. Response of human alveolar macrophages to ultrafine, fine, and coarse urban air pollution particles. Experimental Fang Research 2003;29(1):29- 44. 13 McConnell R, et al. Prospective Study of Air Pollution and Bronchitic Symptoms in Children with Asthma. American Journal of Respiratory and Critical Care Medicine 2003; 168(7): 790-797. ------- Bibliometric Analysis of Air Research Program Journal Articles Table 22. ESPs Top 20 Overall Authors in Air Pollution (Ranked by Total Cites, 1995-2005) ESI Rank Author Total Cites Number of Papers Cites Per Paper EPA Air Research Paper Author 1 Schwartz, J. 2,537 93 27.28 Yes 2 Dockery, DW 2,473 35 70.66 Yes 3 Pope, CA 1,973 29 68.03 Yes 4 Samet, JM 1,255 28 44.82 Yes 5 Speizer, FE 1,193 11 108.45 Yes 6 Brunkekreef, B 967 55 17.58 Yes 7 Thun, MJ 952 4 238.00 Yes 8 Anderson, HR 906 31 29.23 No 9 Cass, GR 869 27 32.19 Yes 10 Peters, A 770 39 19.74 Yes 11 Burnett, RT 668 39 17.13 Yes 12 Zeger, SL 653 15 43.53 Yes 13 Katsouyanni, K 640 35 18.29 Yes 14 Wichmann HE 606 27 22.44 Yes 15 Donaldson, K 598 7 85.43 Yes 16 Macnee, W 598 7 85.43 Yes 17 Ghio, A J 577 12 48.08 Yes 18 Dominici, F 556 16 34.75 Yes 19 Spix, C 546 13 42.00 No 20 Touloumi, G 539 18 29.94 Yes Top 20 Countries Publishing in Air Pollution—The United States ranks number one among the top 20 countries publishing on air pollution. From 1995-2005, the United States published 1,608 papers that were cited 16,899 times. The second ranking country, England, published 421 papers that were cited 3,295 times. Top 20 Journals in Air Pollution—1,038 (50.2%) of the EPA Air Research Program papers were published in ESFs top 20 journals in air pollution (ranked by total cites from 1995-2005). The top 20 journals and the number of EPA air papers published in these journals are provided in Table 23. ------- Bibliometric Analysis of Air Research Program Journal Articles Table 23. ESPs Top 20 Journals in Air Pollution (Ranked by Total Cites, 1995-2005) ESI Rank Journal Total Cites Number of Papers Cites Per Paper Number of EPA Air Papers in Journal 1 Atmospheric Environment 2,869 344 8.34 266 2 Environmental Health Perspectives 2,735 148 18.48 130 3 American Journal of Respiratory and Critical Care Medicine 2,486 66 37.67 27 4 Epidemiology 1,715 544 3.15 24 5 Environmental Science & Technology 1,122 93 12.06 167 6 Lancet 995 28 35.54 3 7 American Journal of Epidemiology 986 55 17.93 12 8 Inhalation Toxicology 907 56 16.20 103 9 European Respiratory Journal 809 52 15.56 4 10 Journal of the Air & Waste Management Association 800 110 7.27 120 11 Thorax 702 25 28.08 5 12 Science 697 27 25.81 7 13 Occupational and Environmental Medicine 632 54 11.70 7 14 Journal of Geophysical Research- Atmospheres 612 74 8.27 143 15 Journal of Epidemiology and Community Health 576 38 15.16 1 16 Archives of Environmental Health 538 48 11.21 4 17 Environmental Pollution 492 71 6.93 6 18 Water, Air, and Soil Pollution 412 75 5.49 2 19 Indoor Air 356 48 7.42 2 20 JAMA-Journal of the American Medical Association 342 11 31.09 5 Total 1,038 Top 20 Institutions Publishing on Air Pollution—Harvard University ranks number one on ESFs top 20 overall institutions publishing on air pollution with 192 papers (published from 1995-2005) that were cited 4,771 times. Harvard University is one of the recipients of EPA grants that publishes under the Air Research Program. The U.S. Environmental Protection Agency ranks number two with 175 publications that were cited 2,543 times. The top 20 institutions are listed in Table 24. ------- Bibliometric Analysis of Air Research Program Journal Articles Table 24. ESPs Top 20 Institutions Publishing on Air Pollution (Ranked by Total Cites, 1995-2005) ESI Rank Institution Total Cites Number of Papers Cites Per Paper 1 Harvard University 4,771 192 24.85 2 U.S. EPA 2,543 175 14.53 3 University of North Carolina 1,316 72 14.53 4 Brigham Young University 1,311 2 46.82 5 GSF Forschungszentrum Umwelt & Gesundheit 1,268 62 20.45 6 Johns Hopkins University 1,227 45 27.27 7 Health Canada 1,067 57 18.72 8 American Cancer Society 952 4 238.00 9 Wageningen University 830 38 21.84 10 Caltech 821 36 22.81 11 University of Athens 111 58 13.40 12 University of Groningen 633 19 33.32 13 St. George's Hospital 621 24 25.88 14 University of California-Berkeley 615 72 8.54 15 University of British Columbia 604 51 11.84 16 University of California-Irvine 603 24 25.13 17 University of Rochester 599 13 46.08 18 Napier University 591 8 73.88 19 Municipal Institute of Medical Research (IMIM- Barcelona) 584 18 32.44 20 University of Maryland 564 19 29.68 Air Pollution Publication Trends—According to ESI, the number of air pollution papers rose slightly each year from 2000 to 2004; however, the number of cites and the number of cites/paper have been declining since 1999. The number of air pollution papers published from 2001 to 2005 has declined from the number published from 2000 to 2004, and the number of cites and cites/paper from 2001 to 2005 have declined as well. These trends are depicted in Figure 1. The number of EPA Air Research Program publications, however, has increased slightly from 2001 to 2005 (1,257 publications) when compared to the number published from 2000 to 2004 (1,240 publications). Like the overall air pollution paper trends identified by ESI, the number of cites and the cites per paper have declined. ------- Bibliometric Analysis of Air Research Program Journal Articles Figure 1. Comparison of ESI Air Pollution Publication Trends with EPA Air Research Program Publication Trends ~ ESI Papers ¦ EPA Papers 3000 2500 2000 1500 1000 500 0 ~ ESI Cites ¦ EPA Cites 30000 25000 20000 15000 10000 5000 0 ~ ESI Cites/Paper ¦ EPA Cites/Paper n n n f ,r ,r x C? ^ ^ ' & <£' & C >* ------- Bibliometric Analysis of Air Research Program Journal Articles ESI Field Distribution of Air Pollution Papers—The majority of air pollution papers from 1995 to 2005 were published in journals that fall within the ESI field of Clinical Medicine, followed by the fields of Environment/Ecology, Geosciences, Engineering, and Chemistry. For the EPA air papers included in this analysis, the majority of the papers were published in the ESI field of Geosciences, followed by Environment/Ecology, Engineering, Clinical Medicine, and Pharmacology & Toxicology. The distribution of air pollution papers among the 22 ESI fields and the distribution of the EPA air papers for comparison are presented in Table 26. Table 26. Comparison of Field Distribution of Air Pollution Papers (Ranked by Number of Papers, 1995-2005) to Field Distribution of EPA Air Research Program Papers (Published from 1998-2007) ESI Rank ESI Field Air Pollution Papers Overall EPA Air Papers Total Cites Number of Papers Cites Per Paper % of Papers Total Cites Number of Papers Cites Per Paper % of Papers 1 Clinical Medicine 12,689 1,376 9.22 27.6% 6,479 260 24.9 12.6% 2 Environment/ Ecology 7,534 1,196 6.30 24.0% 7,910 436 18.1 21.1% 3 Geosciences 4,144 594 6.98 11.9% 8,478 490 17.3 23.7% 4 Engineering 1,921 566 3.39 11.3% 4,277 361 11.8 17.5% 5 Chemistry 450 301 1.50 6.0% 2,375 150 15.8 7.3% 6 Social Sciences 598 224 2.67 4.5% 63 14 4.5 0.7% 7 Pharmacology & Toxicology 1,572 139 11.31 2.8% 3,002 221 13.6 10.7% 8 Plant & Animal Science 433 116 3.73 2.3% 124 11 11.3 0.5% 9 Economics & Business 440 80 5.50 1.6% 25 3 8.3 0.1% 10 Immunology 357 75 4.76 1.5% 377 14 26.9 0.7% 11 Computer Science 91 66 1.38 1.3% 15 4 3.8 0.2% 12 Multidisciplinary 829 60 13.82 1.2% 420 9 46.7 0.4% 13 Materials Science 48 44 1.09 0.9% 1 2 0.5 0.1% 14 Biology & Biochemistry 74 41 1.8 0.8% 546 41 13.3 2.0% 15 Physics 126 34 3.71 0.7% 194 15 12.9 0.7% 16 Molecular Biology & Genetics 279 27 10.33 0.5% 62 8 7.8 0.4% 17 Agricultural Sciences 72 24 3 0.5% — — — — 18 Mathematics 60 15 4 0.3% 35 7 5.0 0.3% 19 Microbiology 23 4 5.75 0.1% 22 1 22.0 0.05% 20 Neuroscience & Behavior 8 4 2.00 0.1% 227 20 11.4 1.0% 21 Psychiatry/Psychology 3 4 0.75 0.1% — — — — 22 Space Science 1 4 0.25 0.1% — — — — Total 32,422 4,994 6.49 34,632 2,067 16.8 This bibliometric analysis was prepared by Beverly Campbell, The Scientific Consulting Group, Inc. under EPA Contract No. EP-C-05-015 ------- |