Bibliometric Analysis for the U.S. Environmental Protection Agency/Office of Research and Development’s Human Health Risk Assessment Research Program

August 2007

Bibliometric Analysis
for the U.S. Environmental Protection Agency/Office of Research and
Development's Human Health Risk Assessment Research Program

This is a bibliometric analysis of the papers prepared by researchers of the U.S. Environmental
Protection Agency (EPA) for the Human Health Risk Assessment (HHRA) Research Program. For this
analysis, a total of 420 publications published from 2001 to 2007 were reviewed. The 420 publications
included 292 journal articles and 128 non-journal publications (e.g., technical reports, handbooks,
books/book chapters). These publications were cited 2,152 times in the journals covered by Thomson's
Web of Science1 and Scopus2. The 292 journal publications were cited 1,897 times in the journals and
the 128 non-journal publications were cited 255 times in the journals. Of the 292 journal publications,
226 (77%) have been cited at least once in a journal. Of the 128 non-journal publications, 39 (30.5%)
were cited at least once in a journal.

Searches of Thomson Scientific's Web of Science and Scopus were conducted to obtain times cited data
for the HHRA journal publications. Searches of Web of Science were used to obtain times cited data for
the HHRA non-journal publications. The process for searching non-journal publications differed from
that used for the journal publications in that the Cited Reference Search feature was used to identify the
number of times the non-journal publications were cited in the journals covered by Web of Science. Such
searching involves an iterative process to identify the citing references; for example, searches for EPA,
Environmental Protection Agency, USEPA, the document number, the publisher, and so on, are
conducted. The results of these different searches then are combined to eliminate duplicate citations and
determine total times cited data. The times cited data for the non-journal publications in this report do
not include the citations of these documents in other non-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 HHRA publications. 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 HHRA papers were 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.
Thomson Scientific's Web of Science provides access to current and retrospective multidisciplinary information from
approximately 8,830 of the most prestigious, high impact research journals in the world. Web of Science also provides
cited reference searching.

Scopus is a large abstract and citation database of research literature and quality Web sources designed to support the
literature research process. Scopus offers access to 15,000 titles from 4,000 different publishers, more than 12,850
academic journals (including coverage of 535 Open Access journals, 750 conference proceedings, and 600 trade
publications), 27 million abstracts, 245 million references, 200 million scientific Web pages, and 13 million patent
records.

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Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
The report includes a summary of the results of the bibliometric analysis, an assessment of the 292
HHRA journal articles analyzed by ESI field (e.g., Clinical Medicine, Environment/Ecology), an
analysis of the journals in which the HHRA papers were published, an assessment of the non-journal
publications, a table of the highly cited researchers in the HHRA Research Program, and information on
the patents/patent applications (if any) that have resulted from the program.
SUMMARY OF RESULTS

1. About one-sixth of the 292 HHRA journal publications are highly cited papers. 48 (16.4%) of the 292 HHRA journal
publications qualify as highly cited when using the ESI criteria for the top 10% of highly cited publications. This is 1.6 times
the number expected. 3 (1.0%) of the HHRA journal papers qualify as highly cited when using the ES/ criteria for the top
1 %, which is about the number expected. No journal publications qualified as very highly cited when using the criteria for
the top 0.1% or top 0.01% thresholds for the most highly cited papers.

2. The HHRA journal publications are more highly cited than the average paper. Using the ES/ average citation rates for
papers published by field as the benchmark, in 9 of the 14 fields in which the 292 HHRA journal papers were published, the
ratio of actual to expected cites is greater than 1, indicating that the HHRA journal publications are more highly cited than
the average papers in those fields. For all 14 fields combined, the ratio of total number of cites to the total number of
expected cites (1,897 to 1,592) is 1.2, indicating that the HHRA journal papers are more highly cited than the average
paper.

3. Nearly one-half of the HHRA journal papers are published in high impact journals. 120 of the 292 journal papers
were published in the top 10% of journals ranked by JCR Impact Factor, representing 41.1% of the HHRA journal
publications. This number is 4.1 times higher than expected. 131 of the 292 papers appear in the top 10% of journals
ranked by JCR Immediacy Index, representing 44.9% of EPA's HHRA journal publications. This number is 4.5 times higher
than expected.

4. There were no hot papers. Using the hot paper thresholds established by ESI as a benchmark, no hot papers were
identified in the analysis. Hot papers are papers that are highly cited shortly after they are published.

5. The authors of the HHRA journal publications cite themselves much less than the average author. 111 of the 1,897
cites are author self-cites. This 5.8% author self-citation rate is well below the accepted range of 10-30% author self-citation
rate.

6. About 5% of the non-journal publications are highly cited and the non-journal publications are cited less than the
average journal publication. 6 (4.7%) of the 128 non-journal publications qualify as highly cited when using the ESI
criteria for the top 10% of highly cited publications. This is about one-half the number expected. 2 (1.6%) of the HHRA
papers qualify as highly cited when using the ESI criteria for the top 1 %, which is 1.6 times the number expected. None of
the non-journal publications qualified as very highly cited when using the criteria for the top 0.1% or top 0.01% thresholds
for the most highly cited publications. The ratio of total number of cites to the total number of expected cites (255 to 664) is
0.4, indicating that the HHRA non-journal publications are cited less than the average journal article.

7. Sixteen of the 402 authors of the HHRA journal publications 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.

8. No patents were issued and no patent applications were filed by investigators from 2001 to 2007 for research that was
conducted under EPA's HHRA Research Program.

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Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
Highly Cited HHRA Journal 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 292 HHRA journal publications reviewed for this analysis were published in journals that were
assigned to 17 of the 22 ESI fields. The distribution of the papers among these 17 fields and the
number of citations by field are presented in Table 1.

Table 1. HHRA Journal Publications by £37 Fields
ESI Field
Clinical Medicine
Environment/Ecology
Neuroscience & Behavior
Pharmacology & Toxicology
Biology & Biochemistry
Social Science, General
Immunology
Agricultural Sciences
Geosciences
Molecular Biology & Genetics
Engineering
Chemistry
Mathematics
Microbiology
Computer Science
Multidisciplinary
Materials Science
Total = 17
No. of
Citations
592
472
281
237
62
59
56
40
40
29
13
9
6
1
0
0
0
Total = 1,897
No. of EPA
HHRA Papers
79
92
17
54
8
14
3
3
5
4
4
3
2
1
1
1
1
Total = 292
Average
Cites/Paper
7.5
5.1
16.5
4.4
7.8
4.2
18.7
13.3
8.0
7.2
3.2
3.0
3.0
1.0
0.0
0.0
0.0
6.5
There are 48 (16.4% of the 292 journal papers analyzed) highly cited HHRA journal publications in 9
of the 17 fields—Clinical Medicine, Environment/Ecology, Neuroscience & Behavior, Pharmacology

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Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
& Toxicology, Immunology, Social Sciences, Agricultural Sciences, Geosciences, and Engineering—
when using the ESI criteria for the top 10% of papers. Table 2 shows the number of HHRA journal
publications in those 9 fields that meet the top 10% threshold in ESI.

Table 2. Number of Highly Cited HHRA Journal Publications by Field (top 10%)
ESI Field
Clinical Medicine
Environment/Ecology
Neuroscience & Behavior
Pharmacology & Toxicology
Immunology
Social Sciences, General
Agricultural Sciences
Geosciences
Engineering
Total =9
No. of
Citations
217
175
141
83
47
47
40
22
11
Total =
783
No. of
Papers
10
18
3
8
1
4
2
1
1
Total =
48
Average
Cites/Paper
21.7
9.7
47.0
10.4
47.0
11.8
20.0
22.0
11.0
16.3
% of HHRA
Papers in
Field
12.7%
19.6%
17.6%
14.8%
33.3%
28.6%
66.7%
20.0%
25.0%
16.4%
Three (1.0%) of the journal publications analyzed qualify as highly cited when using the ESI criteria
for the top 1% of papers. These publications cover two fields—Environment/Ecology and Clinical
Medicine. Table 3 shows the 3 papers by field that meet the top 1% threshold in ESI. The citations
for these 3 papers are provided in Tables 4 and 5. None of the HHRA journal publications meet the
top 0.1% or top 0.01% ESI thresholds for highly cited papers.
Table 3. Number of Highly Cited HHRA Journal Publications by Field (top 1%)
ESI Field
Environment/Ecology
Clinical Medicine
Total = 2
No. of
Citations
26
33
Total =
59
No. of
Papers
2
1
Total =
3
Average
Cites/Paper
13.0
33.0
19.7
% of HHRA
Papers in
Field
2.2%
1.3%
1.0%

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Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
Table 4. Highly Cited HHRA Journal Publications in the Field of
Environment/Ecology (top 1%)
No. of
Cites
20
6
First Author
Meng QY
Selgrade MK
Paper
Influence of ambient (outdoor) sources on residential indoor and
personal PM2 5 concentrations: analyses of RIOPA data. Journal of
Exposure Analysis and Environmental Epidemiology 2005; 15(1): 17-
28.
Induction of asthma and the environment: what we know and need to
know. Environmental Health Perspectives 2006;114(4):615-619
Fable 5. Highly Cited HHRA Journal Publications in the Field of Clinical Medicine (top 1%
No. of
Cites
33
First Author
KelloffG
Paper
Progress and promise of FDG-PET imaging for cancer patient
management and oncologic drug development. Clinical Cancer
Research 2005;11(8):2785-2808.
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 9 of the 17 fields in which the EPA HHRA journal papers were published, the ratio
of actual to expected cites is greater than 1, indicating that the HHRA journal publications are more
highly cited than the average papers in those fields (see Table 6). For all 17 fields combined, the ratio
of total number of cites to the total number of expected cites (1,897 to 1,594) is 1.2, indicating that the
HHRA journal publications are more highly cited than the average paper.
Table 6. Ratio of Actual Cites to Expected Cites for HHRA Journal Publications by Field
ESI Field
Agricultural Sciences
Biology & Biochemistry
Chemistry
Clinical Medicine
Computer Science
Total
Cites
40
62
9
592
0
Expected Cite
Rate
8.1
99.7
16.2
446.9
0.2
Ratio
4.9
0.6
0.6
1.3
0.0

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Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
ESI Field
Engineering
Environment/Ecology
Geosciences
Immunology
Materials Science
Mathematics
Microbiology
Molecular Biology & Genetics
Multidisciplinary
Neuroscience & Behavior
Pharmacology & Toxicology
Social Sciences, General
TOTAL
Total
Cites
13
472
40
56
0
6
1
29
0
281
237
59
1,897
Expected Cite
Rate
5.4
406.5
15.8
43.6
0.0
3.7
11.4
42.1
1.8
191.9
274.8
26.0
1,594.1
Ratio
2.4
1.2
2.5
1.3
*1.0
1.6
0.1
0.7
0.0
1.5
0.9
2.3
1.2
* The actual number of cites is equal to the expected number of cites, making the ratio 1.0.

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 7 indicates the number of HHRA journal publications published in the top 10% of journals,
based on the JCR Impact Factor. One hundred twenty (120) of 292 journal papers were published in
the top 10% of journals, representing 41.1% of EPA's FIFIRA journal publications. This indicates that
nearly one-half of the FIFIRA journal publications are published in the highest quality journals as
determined by the JCR Impact Factor, which is 4.1 times higher than the expected percentage.
Table 7. HHRA Journal Publications in Top 10% of Journals by JCR Impact Factor
EPA HHRA
Papers in
that Journal
1

Journal

New England Journal of Medicine
Impact
Factor
(IF)
51.296
JCR IF
Rank

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Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
EPA HHRA
Papers in
that Journal
2
1
2
1
2
2
1
1
4
31
1
2
5
1
1
2
8
1
1
1
7
1
2
1
1
7
1
2
Journal
Journal of the National Cancer Institute
Journal of Allergy and Clinical Immunology
Annals of Neurology
Development
Arthritis and Rheumatism
Cancer Research
Mutation Research - Reviews in Mutation Research
FASEB Journal
Clinical Cancer Research
Environmental Health Perspectives
Journal of Biological Chemistry
Neurology
American Journal of Epidemiology
Molecular Cancer Therapeutics
Emerging Infectious Diseases
Pediatrics
Toxicology and Applied Pharmacology
Breast Cancer Research and Treatment
Cancer
International Journal of Epidemiology
Epidemiology
Global Change Biology
Cancer Epidemiology Biomarkers & Prevention
Mutation Research - Fundamental and Molecular Mechanisms
of Mutagenesis
Rheumatology
Environmental Science & Technology
Autoimmunity Reviews
Critical Reviews in Toxicology
Impact
Factor
(IF)
15.27
8.829
8.051
7.764
7.751
7.656
7.579
6.721
6.177
5.861
5.808
5.690
5.241
5.137
5.094
5.012
4.722
4.671
4.582
4.517
4.339
4.339
4.289
4.111
4.052
4.040
3.760
3.707
JCR IF
Rank
44
136
154
165
166
172
175
206
228
255
260
270
308
326
332
345
397
401
413
424
452
452
463
505
516
518
603
623

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           Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
EPA HHRA
Papers in
that Journal
2
1
17
2
1
3
1
Total = 120
Journal
Journal of Neurophysiology
BMC Bioinformatics
Toxicological Sciences
Biology of Reproduction
Neuroscience
Cancer Letters
Journal of Endocrinology

Impact
Factor
(IF)
3.652
3.617
3.598
3.498
3.427
3.277
3.072

JCR IF
Rank
645
656
662
694
721
111
853

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 8 indicates the number of HHRA journal publications published in the top 10% of journals,
based on the JCR Immediacy Index.  One hundred thirty-one (131) of the 292 papers appear in the top
10% of journals, representing 44.9% of the HHRA journal papers. This indicates that nearly half of the
HHRA journal papers are published in the highest quality journals as determined by the JCR
Immediacy Index, which is 4.5  times higher than the expected percentage.
     Table 8. HHRA Journal Publications in Top 10% of Journals by JCR Immediacy Index
EPA HHRA
Papers in that
Journal
1
2
2
1
1
1
7
1
Journal
New England Journal of Medicine
Journal of the National Cancer Institute
Annals of Neurology
International Journal of Epidemiology
Journal of Allergy and Clinical Immunology
Development
Epidemiology
FASEB Journal
Immediacy
Index
(II)
12.743
2.776
2.716
2.200
1.790
1.579
1.437
1.241
JCR 11
Rank
2
58
61
84
118
157
187
238

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Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
EPA HHRA
Papers in that
Journal
2
2
2
1
2
5
1
4
30
2
2
2
2
17
1
1
1
1
3
7
3
1
1
1
1
13
1
1
Journal
Emerging Infectious Diseases
Cancer Research
Arthritis and Rheumatism
Journal of Biological Chemistry
Neurology
American Journal of Epidemiology
Mutation Research - Reviews in Mutation Research
Clinical Cancer Research
Environmental Health Perspectives
Critical Reviews in Toxicology
Journal of Neurophysiology
Pediatrics
Biology of Reproduction
Toxicological Sciences
Cancer
Rheumatology
Omics - A Journal of Integrative Biology
Global Change Biology
Cancer Letters
Environmental Science & Technology
Journal of Rheumatology
Cancer Chemotherapy and Pharmacology
Bioorganic & Medicinal Chemistry Letters
Neuroscience
Thrombosis Research
Journal of Exposure Science and Environmental
Epidemiology
Environmental Research
Molecular Carcinogenesis
Immediacy
Index
(II)
1.222
1.220
1.204
1.110
1.110
1.091
1.050
1.010
0.994
0.880
0.821
0.784
0.736
0.734
0.713
0.698
0.694
0.660
0.658
0.646
0.637
0.631
0.624
0.611
0.605
0.596
0.583
0.580
JCRll
Rank
243
246
251
291
291
306
331
354
373
442
500
537
593
597
629
649
657
705
707
729
746
755
769
790
801
821
844
852

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Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
EPA HHRA
Papers in that
Journal
1
2
1
1
Total = 131
Journal
Molecular Cancer Therapeutics
Cancer Epidemiology Biomarkers & Prevention
Clinical Journal of the American Society of Nephrology
BMC Bioinformatics

Immediacy
Index
(II)
0.568
0.560
0.558
0.557

JCRll
Rank
877
889
897
899

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.

Using the hot paper thresholds established by ESI as a benchmark, there were no hot papers identified
among the 292 journal publications included in this analysis.

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 HHRA papers. Of the 1,897 total cites of the 292 journal publications, 111 are
author self-cites—a 5.8% 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 10-30% of all the citations listed fall into the category of author
self-citation. Kovacic and Misak5 reported a 20% author self-citation rate for medical literature.
Therefore, the 5.8% self-cite rate for the HHRA papers is well below the range for author self-citation.

Non-Journal Publications

This analysis included 128 non-journal publications (e.g., technical reports, books/book chapters,
handbooks). For the non-journal publications, the Cited Reference Search feature of Web of Science
was used to determine the number of times the non-journal publications were cited in the journals
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 Kovacic N, Misak A. Author self-citation in medical literature. Canadian Medical Association Journal
2004;170(13):1929-1930.
10

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Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
covered by Web of Science. Through an iterative search process, citing references were identified,
duplicates were eliminated, and times cited counts were generated. The times cited data for the non-
journal publications in this report do not include the citations of these documents in other non-journal
publications.

Of the 128 non-journal publications, 39 (30.5%) had been cited at least once in a journal. Each non-
journal publication was assigned an ESI field so that the ESI thresholds could be used as a baseline for
identifying highly cited publications. The non-journal publications covered 9 of the 22 ESI fields.
There are 6 (4.7% of the papers analyzed) highly cited HHRA non-journal publications in 1 of the 9
ESI fields—Environment/Ecology—when using the ESI criteria for the top 10% of papers. Two
(1.6%) of the non-journal publications analyzed qualify as highly cited when using the ESI criteria for
the top 1% of publications. These publications are in the field of Environment/Ecology. Table 9
shows the 6 non-journal publications that meet the top 10% threshold in ESI as well as the two
publications that meet the top 1% threshold in ESI. None of the non-journal publications meet the
ESI criteria for the top 0.1% or top 0.01%.

The 128 non-journal publications were cited 255 times. The ratio of the total number of cites to the
total number of expected cites (calculated using the ESI average citation rates for publications by field
as the benchmark) is 0.4 (255 to 664), indicating that the HHRA journal publications are cited less than
the average journal article.

Table 9. Highly Cited HHRA Non-Journal Publications (top 10%)
ESI Field
Environment/Ecology
Environment/Ecology
Environment/Ecology
Environment/Ecology
Environment/Ecology
Environment/Ecology
No. of
Cites
25
*70
18
24
*25
10
Publication
Child-Specific Exposure Factors Handbook (Interim Report).
U.S. Environmental Protection Agency, EPA 600/P-00/002B,
2002.
Health Assessment Document for Diesel Engine Exhaust. U.S.
Environmental Protection Agency, EPA 600/8-90/057F, 2002.
An Examination of EPA Risk Assessment Principles and
Practices. U.S. Environmental Protection Agency, EPA 100/B-
04/001,2004.
Air Quality Criteria for Particulate Matter. Volume I and Volume
II. U.S. Environmental Protection Agency, EPA 600/P-
99/002aF,bF, 2004.
Guidelines for Carcinogen Risk Assessment. U.S. Environmental
Protection Agency, EPA 930/P-03/001F, 2005.
Supplemental Guidance for Assessing Susceptibility from Early-
Life Exposure to Carcinogens. U.S. Environmental Protection
Agency, EPA 630/R-03/003F, 2005.
* These are the two non-journal publications that qualify as highly cited when using the ESI criteria for the top
1% of publications.
11

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Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
Highly Cited Researchers

A search of Thomson's ISIHighlyCited. com revealed that 16 (4.0%) of the 402 authors of the HHRA
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 HHRA publications are
presented in Table 10.
Table 10. Highl
Highly Cited Researcher
Andersen, Melvin E.
Birnbaum, Linda S.
Brown, John S.
Giesy, John P.
Goldman, Lee
Guillette, Louis J.
Klaassen, Curtis Dean
Lioy, Paul J.
Liu, Jie
Lovley, Derek R.
Needham, Larry L.
Peterson, Richard E.
Richards, James H.
Schwartz, Joel David
Watson, John G.
Winer, Arthur M.
Total = 16
y Cited Researchers Authoring HHRA Journal Publications
Affiliation
Chemical Industry Institute of
Toxicology (CUT)
U.S. EPA, National Health &
Environmental Effects Research
Laboratory
Battelle Coastal Resources and
Environmental Management
Michigan State University
University of California, San
Francisco
University of Florida
University of Kansas Medical Center
University of Medicine & Dentistry of
New Jersey
National Cancer Institute
University of Massachusetts Amherst
Centers for Disease Control and
Prevention, National Center for
Environment Health
University of Wisconsin, Madison
University of California, Davis
Harvard School of Public Health
Desert Research Institute
University of California, Los Angeles

ESI Field
Pharmacology
Pharmacology
Environment/Ecology
Environment/Ecology
Clinical Medicine
Environment/Ecology
Pharmacology
Environment/Ecology
Pharmacology
Microbiology
Environment/Ecology
Pharmacology
Environment/Ecology
Environment/Ecology
Environment/Ecology
Environment/Ecology

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           Bibliometric Analysis of Human Health Risk Assessment Research Program Publications
Patents
No patents have been issued or patent applications filed by investigators from 2001 to 2007 for
research that was conducted under EPA's HHRA Research Program.
                             This bibliometric analysis was prepared by
                       Beverly Campbell of The Scientific Consulting Group, Inc.
                                    in Gaithersburg, Maryland
                                under EPA Contract No. EP-C-05-015
                                               13

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