Document QXxg4aVmZaO1pNGVq8gj1Ybpk
VT4JblSMC&M02 E. I. d u Po n t d e Ne mo u r s & Co mp a n y
INCORKHA1ID Wil min g t o n , De l a w a r e 19898
ENGINEERING DEPARTMENT
CC: W.H. Walsh-ESD IC 13/AH&HE
May 16, 1985
D. R. DIGGS-CHEMICALS & PIGMENTS DEPT-BRANDYWINE 16204 W. E. SMITH, IV-CHEMICALS 5c PIGMENTS DEPT-PET LAB-CHAMBERS WORKS C. G. PFEIFER-ESD-LOUVIERS 5185
CASAC LEAD MEETING
Attached are copies of
1. The CASAC Lead Subcommittee membership list. Member attendance at the May 13-15 meetinq on the Criteria Document and Staff Paper is shown by my handwritten notes.
2. The Agenda of the May 13-15 meeting. The only significant departure from the Agenda was that Mort Lippmann summarized the Criteria Document review after completion of the discussion early Tuesday afternoon. In essence, CASAC provisionally closed on the Criteria Document contingent on some corrections and revisions. Of key interest to us is that EPA committed to issuance of an Addendum revising the treatment of the BPb-BP relationship and risk assessment issues introduced in the Corrigenda. Du Pont's input at the CASAC meeting was decisive in forestalling CASAC acceptance of the Corriqenda. In accordance with the Notice and Comment rulemakinq procedure, EPA will offer the Addendum for public comment before the fall CASAC meetinq, which will be held sometime after October 1, 1985.
3. The charts/handout used by Ooel Schwartz for hiss presentation on "Evidence for a Blood Lead - Blood Pressure Relationship."
ENGINEERING SERVICE DIVISION Air, Hazards and Health Engineering
J/ M. Pierrard "Senior Consultant
JMP:dll 0MP1:30
Atchs
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May 1985
U.S. ENVIRONMENTAL PROTECTION AGENCY CLEAN AIR SCIENTIFIC ADVISORY COMMITTEE
SCIENCE ADVISORY BOARD
Subcommittee on Lead
Chairman
* Dr. Morton Lippmann
<toC*
Institute of Environmental Medicine
Lanza Laboratory
Long Meadow Road
New York University
Tuxedo, New York 10987
Executive Secretary
Mr. Robert Flaak Science Advisory Board (A-101F) U.S. Environmental Protection
Agency 401 M Street, S.W. Washington, D.C. 20460
Members/Consultants
Dr. Carol R. Angle Tv
Department of Pediatrics University of Nebraska Medical
Center 42nd and Dewey Avenue Omaha, Nebraska 68105
* Dr. Robert Frank
Department of Environmental and Health Sciences
Johns Hopkins School of Hygiene and Public Health
615 North Wolfe Street Baltimore, Maryland 21205
Dr. Julian Chisolm, Jr.
4*^"^
Senior Staff Pediatrician
Francis Scott Key Medical Center
Building G, Room 224
4940 Easter Avenue
Baltimore, Maryland 21224
Dr. Robert Goyer
Deputy Director NIEHS P.0. 12233 Research Triangle Park, NC
27709
Dr. Anita S. Curran "TV" AfA'P* Commissioner Department of Public Health Westchester County County Building No. 2 112 East Post Road White Plains, New York 10601
Dr. Paul B. Hammond Professor of Environmental Health Department of Environmental Health University of Cincinnati Cincinnati, Ohio 45267
Dr. Ben B. Ewing
vF
^
Professor of Environmental Engineering Institute for Environmental Studies
University of Illinois 408 S. Goodwin Urbana, Illinois 61801
Dr. Lloyd Humphreys Department of Psychology and
Educational Psychology University of Illinois Champaign, Illinois 61820
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U.S. Environmental Protection Agency Science Advisory Board
Clean Air Scientific Advisory Committee (CASAC)
Subcommittee on Lead
Rosslyn Westpark Hotel 1900 North Fort Myer Drive
Rossyln, Virginia Open Meeting - May 13-15, 1985
Monday - May 13
AGENDA
9:00 a.m. Welcome and Opening Remarks
Dr. Lippmann
9:15
Introduction and Overview of the Air Quality Criteria Document for Lead
Dr. Grant Dr. Weil
9:30
CASAC Review of Volume II of the Criteria Document (Chapters 2-8)
Chapter 2 - Introduction
Chapter 3 - Chemical and Physical Properties
Chapter 4 - Sampling and Analytical Methods for Environmental Lead
Chapter 5 - Sources and Emissions
Chapter 6 - Transport and Transformation
Chapter 7 - Environmental Concentrations and Potential Pathways to Human Exposure
Chapter 8 - Effects of Lead on Ecosystems
10:45
Break s
11:00
CASAC Review of Volume III of the Criteria Document (Chapters 9-11)
Chapter 9 - Quantitative Evaluation of Lead and Biochemical Indices of Lead Exposure in Physiological Media
Chapter 10 - Metabolism of Lead
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12:15 p.m. 1:15
1:40
Chapter 11 - Assessment of Lead Exposures and Absorption in Human Population
Lunch
Evidence for a Blood Lead - Blood Pressure Relationship
Blood Lead and Stature
Dr. Schwartz Dr* Landis
Dr. Schwartz
2:00
2:45 3:00 5:30
Statements from the Public
('wu>' Dr. John Pierrard - du Pont Corporation Dr. Jerome Cole - International Lead Zinc Research Organization (ILZRO)
i Dr. Robert Putnam - ILZRO
Q i Dr. Peter Gartside - University of Cincinnati Medical Center
--Dr-r-Edward McCabe - University of Wisconsin _Med4e-al--School
Break
CASAC Review of Volume IV of the Criteria Document
Chapter 12 - Biological Effects of Lead Exposure
Recess
Tuesday - May 14
8:30 a.m. CASAC Review of Volume IV of the Criteria Document
Chapter 13 - Evaluation of Human Health Risk Associated with Exposure to Lead
and i,ts Compounds
10:00
Break
10:15
CASAC Review of Volume IV of the Criteria Document (Chapter 13) - Continued
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11:15
CASAC Review of Volume I of the Criteria Document
Chapter 1 - Executive Summary and Conclusions
12:00 p.m. 1:00 1:45
Lunch Wrap-up of the Criteria Document Lead in the Drinking Water Program
2:00 2:45 3:00 3:15
Introduction and Overview of the Staff Paper for Lead
Break
Modeling the Tail of the Blood Lead Distribution
CASAC Review of the Staff Paper for Lead
5:15
Recess
7:00
CASAC Dinner - Location to be Announced
Dr. Cotruvo
Mr. Jordan Mr. Cohen Mr. Haines
Dr. Schwartz
Wednesday - May 16
8:30 a.ra. CASAC Review of the Staff Paper - Continued
9:30
Wrap-up of the Staff Paper
10:00
Break
10:15
Results of Expert Elicitation Project on the Effects of Lead Exposure on Hemoglobin Levels
Dr. Whitfield Dr. Wallsten
11:15
Chairman's Summary of the CASAC Review of the Air Quality Criteria Document for Lead and the Staff Paper for Lead
Dr. Lippmann
12:00 p.m. Adjourn
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EVIDENCE FOR A BLOOD LEAD BLOOD PRESSURE RELATIONSHIP
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I
VICTERY ET AL. IANNACONE ET'AL.
CARMIGNANI ET AL.
PERRY AND ERLANGER KOPP REVIS ET AL.
WEBB ET AL.
PICCININI ET AL. FAVALLI ET AL.
FILO ET AL. POUNDS ROSEN GOLDSTEIN
EXPERIMENTAL EVIDENCE
IN VIVO
LEAD CAUSES BLOOD PRESSURE INCREASES IN RATS
LEAD CAUSES BLOOD PRESSURE INCREASES IN RATS, INCREASED REACTIVITY TO ALPHA ADRENERGIC STIMULATION
LEAD CAUSES BLOOD PRESSURE INCREASES IN RATS, INCREASED REACTIVITY TO ALPAH ADRENERGIC STIMULATION
LEAD CAUSES BLOOD PRESSURE INCREASES IN RATS
LEAD CAUSES BLOOD PRESSURE INCREASES IN RATS
LEAD CAUSES BLOOD PRESSURE INCREASES IN PIGEONS
IN VITRO
HELICAL STRIPS OF LEAD EXPOSED TAIL ARTERIES HAVE INCREASED REACTIVITY TO ALPHA ADRENERGIC STIMULATION IN VITRO
LEAD ADDED TO MEDIA CAUSES CONSTRICTION OF WHOLE ARTERIES FROM UNEXPOSED RATS INCREASED INTRACELLULAR CALCIUM STORES AND INCREASED SENSITIVITY TO EXTRACELLULAR CALCIUM
SMOOTH MUSCLE TONE IS A FUNCTION OF INTRACELLULAR CALCIUM
LEAD ALSO INCREASES INTRACELLULAR CALCIUM IN HEPATOCYTES. OSTEOCLASTS AND NEURONS
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EPIDEMIOLOGICAL EVIDENCE
BEEVERS ET AL. MOREAU ET.AL.
KROMHOUT ET AL BATUMAN ET AL. KHERA ET AL. POCOCK ET AL. HARLAN ET AL. PIRKLE ET AL.
NON--OCCUPATIONAL STUDIES
ALL REPORT A STATISTICALLY SIGNIFICANT ASSOCIATION
OCCUPATIONAL STUDIES
SFLIT ABOUT EVENLY, BUT ARE CONFOUNDED BY METHODOLOGICAL PROBLEMS
- IGNORE HEALTHY WORKER EFFECT (E.G. COOPER)
- INADAQUATE EXPOSURE MEASURE (E.G. CRAMER AND DAHLBERG)
- INADAQUATE STATISTICS (E.G. RAMIRE2-CERVANTES)
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ANALYSIS OF NHAN' WE FIRST LOOKED AT ALL WALES
(HARLAN ET AL.) THEN EXAMINED THE AGE GROUF THAT MINIMIZED COLLINEARITY WITH AGE
WE WILL FIRST PRESENT MODELS FOR ALL ADULT MEN, THEN DISCUSS SUEGHOUF5 METHODOLOGY WAS TO CONSIDER MANY POSSIBLE CONFOUNDING VARIABLES FIND THE MODEL WHICH MAXIMIZES E-SQUARE FOR ANY MODEL SIZE PICK LARGEST SIGNIFICANT MODEL ALMOST EQUIVALENT TO ALL POSSIBLE REGRESSIONS
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Table I VARIABLES INCLUDED IN THE STEPWISE REGRESSION ANALYSIS I. DIETARY VAP.IAELES
Dietary Sodium * Dietary sodium*salt shaker sodium dietary sodium-potassium ratio dietary phosphorus* dietary fat* dietary cholesterol* dietary oleic acid* dietary iron* dietary vitamin C* dietary riboflavin* dietary niacin* total dietary calories*
Salt shaker sodium dietary potassium* dietary calcium* dietary protein* dietary carbohydrates* saturated fatty acids* dietary lincleic acid* dietary vitamin A* dietary thiamine dietary riboflavin* total dietary grams*
II. SEF'JM BIOCHEMISTRIES
serum vitamin c* serum transferrin saturation serum copper* hemoglobin* serum creatinine*
serum iron* serum zinc* serum albumin* red cell count
III. PERSONAL HISTORY VARIABLES
ethanol consumption/week* cigar or pipe smoking subscapular skinfold
cigarettes smoked/day tricep skinfold recreational exercise
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wcrK-related exercise family history of hypertension body mass index age squared
recent weight loss Kidney disease age
IV, DEMOGRAPHIC VAF.IAELES family income region of the country degree of urbanization
educational level
poverty index
season of the year
residence inside central city
* log and square transform also included
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EFFECT
AGEYRS AGESQUAF.ED BODY MASS INDEX LOGSINC ALEUMIN SQUARED CALCIUM FAMILY HISTORY LOG t FAT) LOG(ELOOD LEAD)
TABLE II
SYSTOLIC BLOOD PRESSURE ALL MEN OVER 20
F VALUE
12.58 32.77 275.77 7.42 45.55 .76 3 0.73 4.73 10.16
P VALUE
0.0012 0.0000 0.0000 0. 0104 0.0000 0.0140 c.occc 0.C3l 0.0032
AGE
AGE SQUARED BODY MASS INDEX LOG(ZINC)
LOG(VITAMIN C) ALBUMIN SQUARED CIGARETTES CALCIUM
DIET VITAMIN C ZINC HEMOGLOEIN SUBSCAPULAR SKINFOLD FAMILY HISTORY RACE LOG(BLOOD LEAD)
DIASTOLIC ELOOD PRESSURE
ALL MEN OVER 20
S4.76 3.67 68.94 17.50 15.48 44.21 6.89 4.76 10.49 12.78 19. 17 7.65 12.28 12.28 7.92
c.COCO 0.0000 0.0000 0.0002 0.0004 0.0000 0.0132 0.0365 0.0028 0.0011 0.0001 0.0034 0.0014 0.0014 0.0083
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ADJUSTED BLOOD LEAD LEVELS (MICROGRAMS/DECILITER)
ADJUSTED SYSTOLIC BLOOD PRESSURE (mm Hg)
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degression Results:
EFFECT
AGE AGE SQUARED BODY MASS INDEX LOG(ZINC) ALBUMIN SQUARED CALCIUM f a mil y HISTORY COFFEE HEIGHT LOG(BLOOD LEAD)
TABLE III
Including Height and Coffee as Variables
SYSTOLIC BLOOD PRESSURE ALL MEN OVER 20
F VALUE
P VALUE
8.11 26.51 273.09 9.55 42.38 cr cr --
37.47 11.53 9. 51 11.12
0.0076 0. 0000 0.0000 0.0041 0.0000 0.0251 0.0000 0.0018 0.0042 0.CC21
DIASTOLIC BL OOD PRESSURE ALL MEN OVER 20
AGE AGE SQUARED BODY MASS INDEX LOG(ZINC) LOG( SERUM VIT C) ALBUMIN SQUARED LOG(SERUM CHOLESTEROL) CIGARETTES CALCIUM DIET VITAMIN C ZINC HEMOGLOBIM TRICEP SKINFOLD FAMILY HISTORY COFFEE HEIGHT RACE LOG(BLOOD LEAD)
58.68 42.15 76.42 15. 8S 8.51 34.70 5.12 5.52 5.58 6.61 11.61 19.32 4.80 36.71
5.32 22.26 11.60 7.96
0.0000 0.oocc 0.0000 0.0004 0.0064 0.0000 0.0305 0.02 52 0.0244 0.0150 0.0018 0.0001
0.0359 0.0000 0.0277 0.0000 0.0018 0.0081
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TABLE IV
Regression results: Including Height. Coffee, and Hypertensive Medication as Variables.
SYSTOLIC BLOOD PRESSURE ALL MEN OVER 20
EFFECT
F VALUE
P VALUE
AGE AGE SQUARED BODY MASS INDEX
LOG(ZINC) ALBUMIN SQUARED CALCIUM
FAMILY HISTORY COFFEE HEIGHT HYPERTENSIVE MEDICATION LOG(BLOOD LEAD)
8.11 26.55 303.14 10.39 39.13 5.22 26.25 15.05 6.45 42.29 13.86
0.0076 0.0000 0.0000 0.0029 0.0000 0.0291 0.OOCC 0.0005 0.0065 0.0000 0.0006
DIASTOLIC ELOOD PRES SURE ALL MEN OVER 20
AGE AGE SQUARED
BODY MASS INDEX LOGtZINC)
ALBUMIN DIET VITAMIN C CIGARETTES CALCIUM
ZINC HEMOGLOBIN TRICEP SKINFOLD FAMILY HISTORY COFFEE
HEIGHT HYPERTENSIVE MEDICATION
RACE LOG(SERUM VIT C) LOG(BLOOD LEAD)
82.28 59.53 74.84 17.49 40.38 9.83 4.96 4.91 12.28 19.72 4.99 29.28 6.57 16. 92 41,45 9.45 13.65 9.69
0.0000 0.0000
0.0000 0.0002 0.0000 0.0037 0.0331 0.0339 0.0014
0.0001 0.0326 0.0000 0.0153 0.0003 0.0000 0.0043 0.0008 0.0039
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TAELE V Regression Results Excluding Men on Hypertensive Medication
SYSTOLIC BLOOD PRESSURE ALL MEN OVER 20
EFFECT
AGE AGE SQUARED BODY MASS INDEX LOGfZINC) ALBUMIN s q u a r e d CALCIUM FAMILY HISTORY COFFEE HEIGHT LOG!BLOOD LEAD)
F VALUE
6.56 23.92 255.30 13.16 43.9B 5.79 29.20 15.01 8.43 12.05
P VALUE
0.0153 0.0000 0.0000 0.0010 0.0000 0.0221 0.oooo 0.0005 0.0066 0.0015
DIASTOLIC BLOOD PRESSURE ALL MEN OVER 20
AGE
AGE SQUARED BODY MASS INDEX LOG(21NC) LOG(SERUM VIT 0) ALBUMIN SQUARED LOG(SERUM CHOLESTEROL) CIGARETTES DIET VITAMIN C ZINC HEMOGLOBIN FAMILY HISTORY COFFEE
HEIGHT LOG(BLOOD LEAD)
47.17 32.27
266.06 9.91 9.30 28.36 7.2 8 5.56 6.41 6.48 15.15 24.64 7.14 22.34 11.53
0.0000 0.0000 0.0000 0.0036 0.0046 0.0000 0.0110 0.0247 0.0165 0.0160 0.0005 0.0000 0.0118 0.0000 0.001B
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BECAUSE LEAD LEVELS FELL OVER THE FOUR YEARS WE TOOK STEFS TO ASSURE LEAD WAS NOT PICKING UP THE EFFECT OF ANOTHER VARIABLE BY
1 . INCLUDING A LARGE SET OF VARIABLES INCLUDING ALL MAJOR PREDICTORS OF BLOOD PRESSURE SO THE CHANGE CAN BE PROPERLY ATTRIBUTED.
2. RUNNING THE STEPWISE REGRESSIONS WITH EVERY VARIABLE EXCEPT LEAD, FINDING THE BEST MODEL, AND REINSERTING LEAD. LEAD WAS STILL SIGNIFICANT CP < 0.01).
3. TESTING AN INTERACTION TERM BETWEEN LEAD AND THE FIRST TWO YEARS OF THE SURVEY. SINCE LEAD LEVELS FELL MUCH FASTER IN THE SECOND TWO YEARS BECAUSE OF THE CHANGE IN EPA'S GASOLINE LEAD RULE. IF LEAD WAS ONLY PICKING UP THE EFFECT OF ANOTHER VARIABLE THEIR CORRELATION SHOULD HAVE BEEN DIFFERENT IN THE TWO INTERVALS. THE INTERACTION TERMS WERE INSIGNIFICANT F = .75 SYSTOLIC P = .79 DIASTOLIC
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AGE SUBGROUPS
BECAUSE BOTH LEAD AND BLOOD PRESSURE ARE NOISY MEASURES. STATISTICAL POWER IS AN IMPORTANT CONCERN.
PIRKLE ET AL. LOOKED AT THE AGE 3UEGR0UP THAT MINIMIZED THE COLLINEARITY BETWEEN AGE AND LEAD. 1EAD WAS HIGHLY SIGNIFICANT IN THE 40-59 YEAR AGEGEOUP. WE USED INTERACTION TERMS EETWEEN LEAD AND AGE TO TEST WHETHER THE RELATIONSHIP WAS DIFFERENT FOR 20-45 YEAR OLD MEN THAN FOR 4c74 YEAR OLD MEN AND THEY WERE INSIGNIFICANT. WE ALSO RERAN OUR STEPWISE REGRESS! IN' FOR BOTH AGE GROUPS. AND LEAD WAS STATISTICALLY SIGNIFICANT IN BOTH OF THEM.
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TABLE 6 Regression Results: by age group
DIASTOLIC BLOOD PRESSURE MEN 20-45
EFFECT
F VALUE
P VALUE
AGE AGE SQUARED BODY MASS INDEX CALCIUM SQUARED
2.16 0.90 137.32 5.74
SERUM CHOLESTEROL SQUARED6.90
a l b u min s q u a r e d
LOG(ZINC)
FAMILY HISTORY LOG(SEFUM VIT C) DIET VIT C CIGARETTES
15.42 5.42 12.59
13.78 9.30 V. 15
HEMOGLOBIN TRANSFER?IN SATURATION HEIGHT
LOG(ELOCD LEAD)
5.61 4.5?
18.33 11.32
0.1517 0.3510 0.0000 0.0226 0.0131
0.0004 0.0264 0.0012 0.00C8 C.0046 0.0117 0.0240 0.03SS C.0002 0.0020
AGE AGE SQUARED EODY MASS INDEX CIGARETTES
ALB'JMIN HEMOGLOBIN TRICEP SKINFOLD FAMILY HISTORY COFFEE LOGCBLOOD LEAD)
3.92 4.60 31.54 4.77
5.95 5.46 6.04 9.52 8.29 5.72
0.0564 0.0396 0.0000 0.0364
0.0205 0.0259 0.0196 0.0042 0.0070 0.0228
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DR GARTSIDE'S COMMENTS FOR THE ETHYL CORPORATION
DID NOT USE BLOOD PRESSURE AS THE DEPENDENT VARIABLE
DID NOT DROP VARIABLES ONE AT A TIVZ IN BACKWARDS ELIMINATION
USED DATE OF EXAMINATION AS A VARIABLE
SINCE WE INCLUDED VARIABLES FOR ALL OF THE KNOWN CORRELATES OF BLOOD PRESSURE IN OUR MODEL DATE OF EXAMINATION IS NOT NEEDED TO PICK UP THE EFFECT OF AN CMMITTED VARIABLE, BUT IS HIGHLY CORRELATED WITH BLOCS LEAD,
ARTIFICIALLY REDUCING ITS SIGNIFICANCE.
k aC
X>'
BUT WHEN GARTSIDE'3 MODEL IS RE-ESTIMATED USING BLOOD PRESSURE AS THE DEPENDENT VARIABLE,
LEAD IS SIGNIFICANT DATE IS INSIGNIFICANT
LEAD ALSO MAINTAINS ITS SIGNIFICANCE WHEN DATE IS ADDED TO OUR MODELS
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TABLE VII
regression with Gartside variables
DIASTOLIC. BLOOD PRESSURE WITH ALL GARTSIDE VARIABLES
EFFECT AGE
RACE POVERTY INDEX
DEGREE OF URBAN,, REGION OF COUNTRY DATE RECREATIONAL EXERCISE SODIUM HEIGHT BODY MASS INDEX LOG;BLOOD LEAD)
F VALUE 10.43 2.54 0.02 0.19 0.32 2.66 4.98 0.20 6.54 201.74 7.50
P VALUE 0.0029 0.1211 0.8977
0.6642 0.5780 0.1129 0.0328 0.6594 0.0155 0.0000 0.0100
AFTER STEPWISE BACKWARDS ELIMIN
AGE
RECREATIONAL EXEP.CI SE HEIGHT BODY MASS INDEX LOG(BLOOD LEAD)
8.52 6.C2 7.73 187.11
11.85
0,0064 0.0197 0.0090 0.0000 0.0016
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TABLE VIII REGRESSION RESULTS WITH DATE INCLUDED
EFFECT AGE
AGE SQUARED BODY MASS INDEX LOG(ZINC) ALBUMIN SQUARED LOG(FAT) CALCIUM
FAMILY HISTORY DATE LOG(BLOOD LEAD)
SYSTOLIC BLOOD PRESSURE ALL MEN OVER 20
F VALUE 12.20 32.29 280.83 8.80
51.39 4.32 6.75 33.33 5.4e 6.88
F VALUE 0.0014 0.0000 0.0000 0.0056 0.0000 0.0458 0.0140 0.0000 0.0257 0.0133
AGE
AGE SQUARED BODY MASS INDEX LOG(ZINC) LOG(SERUM VIT C) ALBUMIN SQUARED CIGARETTES CALCIUM
DIET VIT C ZINC
HEMOGLOBIN SUBSCAFULAR SKINFOLD FAMILY HISTORY RACE DATE LOG(BLOOD LEAD)
DIASTOLIC BLOOD PRESSURE
99.29 65.39 74.81 17.15 13.93 48. 14 6.31
4.88 10.24
12.01 16. 95
11.11 39.44
11.20 6.04
4.35
0.0000
0.0000 0.0000 0.0002 0.0007
0.0000
0.0172 0.0345 0.0031 0.0015 0.0003 0.0022 0.0000 0.0021 0.0196 0.0451
DUP050298754
DR. GARTSIDE'S LETTER TO THE AMERICAN JOURNAL OF EPIDEMIOLOGY
- NEW MODEL - RESTRICTED TO 21-65 YEAR AGE GROUP - RESTRICTED TO WHITES
CLAIMED THAT LEAD WAS NOT SIGNIFICANT
BUT OVER THE FULL 21-65 YEAR AGEGROUP USING GARTSIDE'S MODEL
- LEAD IS SIGNIFICANT FOR BOTH SYSTOLIC AND DIASTOLIC BLOOD PRESSURE WITHOUT DATE IN THE MODEL
- LEAD IS SIGNIFICANT FOE BOTH SYSTOLIC AND DIASTOLIC BLOOD PRESURE EVEN WHEN DATE IS IN THE MODEL
DR GARTSIDE CAN ONLY MAKE LEAD INSIGNIFICANT BY SUBDIVIDING HIS AGE GROUP AND INCLUDING DATE WE TESTED WHETHER LEAD HAD A DIFFERENT RELATIONSHIP TO BLOOD PRESSURE IN HIS TWO AGE GROUPS BY USING AN INTERACTION TERM. IT WAS HIGHLY INSIGNIFICANT
P = .85 SYSTOLIC P = .58 DIASTOLIC INDICATING THE SIGNIFICANT RELATIONSHIP IN HIS MODEL DID NOT DIFFER BY AGE GROUP
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TAELE IX
REGRESSIOK ON AGES 21-E5 KITH GARTSIDE VARIABLES
DIASTOLIC BLOOD PRESSURE
EFFECT AGE BODY MASS INDEX HYPERTENSIVE MED. HEIGHT COFFEE LOG(BLOOD LEAD)
P VALUE 0.0001 0.0001 0.0001 0.0031 0.1515 0.0004
AGE BODY MASS INDEX
HYFEF.TENS. MED. HEIGHT COFFEE LOG(BLOOD LEAD)
SYSTOLIC BLOOD PRESSURE
0.0001 0.0001 0.0001 0.0076 0.0001 0.0123
TAELE X
REGRESSION KITH GARTSIDE VAF.IAELES INCLUDING DATE 21-65
AGE BODY MASS INDEX
HYPERTEN. MED. HEIGHT COFFEE DATE LOG(BLOOD LEAD)
DIASTOLIC BLOOD PRESSURE
0.0000 0.0000 0.0000 0.0046 0.1504 0.0204 0.0025
AGE BODY MASS INDEX
HYPERTEN. MED. HEIGHT COFFEE BATE LOG(BLOOD LEAD)
SYSTOLIC BLOOD PRESSURE
0.0000 0.0000 0.0000 0.0095 0.0001 0.0836 0.0307
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DR GARTSIDE'S LATEST ANALYSIS
- USES 20 YEAR AGE GROUPS, LIMITING SAMPLE SIZE
- STILL USES DATE OF EXAMINATION
- CREATES 25 AGE SUBGROUPS, 21-40, 22-41, ETC. SPANNING 21-65
- USES A FEW NEW VARIABLES
-FINDS LEAD IS NOT SIGNIFICANT
TO DEMONSTRATE THAT THIS IS MERELY AN ARTIFACT OF HIS SIMULTANEOUSLY REDUCING SAMPLE SIZE BY LOOKING AT SMALL AGE SUBGROUPS AND INCLUDING A HIGHLY COLLINEAR VARIABLE, WE HAVE DONE THREE ANALYSES
WE RERAN HIS MODEL FOR THE FULL AGE RANGE 2165 AND LEAD WAS SIGNIFICANT
WE RERAN HIS MODEL USING HIS ENTIRE 21-65 AGE GROUP AND INCLUDED INTERACTION TERMS FOR EACH OF HIS 25 AGE SUBGROUPS TO SEE IF LEAD HAD A DIFFERENT RELATIONSHIP TO BLOOD PRESSURE IN ANY ONE, NOT ONE INTERACTION TERM WAS SIGNIFICANT EITHER WITH OR WITHOUT DATE IN THE MODEL.
WE REPEATED HIS ANALYSIS USING 25 AGE SUBGROUPS OF 30 YEARS EACH. THIS STILL TESTES WHETHER LEAD IS SIGNIFICANT IN YOUNGER OP. OLDER SUBGROUPS, BUT ALLOWS A LARGE ENOUGH SAMPLE SIZE TO HAVE STATISTICAL POWER.
WHEN DATE WAS NOT IN THE MODEL LEAD WAS SIGNIFICANT IN EVERY AGE GROUP
WHEN DATE WAS IN THE MODEL, DATE WAS INSIGNIFICANT IN EVERY SUBGROUP, AND LEAD WAS SIGNIFICANT IN 22 OUT OF THE 25 SUBGROUPS. ELIMINATING THE INSIGNIFICANT DATE VARIABLE RETURNS LEAD TO SIGNIFICANCE IN EVERY AGE GROUP.
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AGE GROUP 21-40 22-41 23-42 24-43 25-44 26-45 27-46 2 8-47 2 9-48 30-49 31-50 32-51 33-52 34-53 35-54 3 6-55 3 7-56 38-57 39-58 40-59 41-60 42-61 43-62 44-63
LEAD INTERACTION TERMS FOR DR GART3IDE'S AGE SUBGROUPS
P VALUE WITHOUT DATE . 6374 . 6989 , 7925 . 8032 . 7010 . 8873 . 4899 . 3146 . 3187 . 4360 . 4853 . 8148 .9875 . 6829 . 1832 . 0888 . 0978 . 1933 . 4755 .4582 . 6837 . 9446 . 982 7 . 9805
P VALUE . 6015 . 6705 . 7857 . 8231 . 7351 . 8741 . 4775 .2828 .3044 . 4101 . 4053 . 7611 . 9549 . 6841 . 1845 .1011 . 1023 . 1841 . 4i. &0 . 4507 . 6683 . 9249 . 9572 . 9677
Ten
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DUP050298758
GARTSIDE MODEL WITH 30 YEAR AGE INTERVALS P VALUE FOR LEAD (WITHOUT DATE)
BEFORE BACKWARDS ELIMINATION
AFTER ELIMINATION
21-50
0.0134
0.0083
22-51
0.0284
0.0159
23-52
- 0.0353
0.0177
24-53
0.0277
0.0126
25-54
0.0236
0.C096
2c-55
0.0107
0.0050
2 7-56
0.00S4
0.0035
28-57
0.0063
0.0 G15
29-58
0.0C70
0.0013
30-53
0.0096
0.CC17
31-60
0.0206
0.0053
32-61
0.0438
0.0132
33-62
0.0334
0.0092
3 4-63
0.0235
0.0061
35-64
0.0124
0.0026
3 6-65
0.0107
0. 0024
37-66
0.0084
0.0012
38-67
0.0106
0.0032
39-68
0.0169
0.0032
40-69
0.0135
0.0032
41-70
0.0156
0,0148
42-71
0.0469
0.0151
43-72
0.0533
0.01S4
44-73
0.0653
0.0229
45-74
0.0533
0.0184
TEH 0350130
DU P050298759
AGE 21-50 22-51 23-52 24-53 25-54 26-55 27-56 28-57 29-58 30-59 31-60 32-61 33-62 34-63 3 5-64 36-65 37-66 38-67 39-68 40-69 41-70 42-71 43-72 44-73 45-74
GARTSIDE MODEL WITH 30 YEAR AGE INTERVALS P VALUE FOR LEAD AND DATE
LEAD
DATE
0.0459
0.0769
0.0826
0.0647
- 0.0779
0.0678
0.0643
0.0762
0.0467
0.0759
0.0185
0.0752
0.0116
0.0SO9
0.0037
0.0995
0.0020
0.2289
0,0049
0.1464
0.0131
0.1486
0.0300
0.1601
0.0247
0.2053
0.0158
0.1991
0.0095
0.1967
0.0064
0.2631
0.0090
0.1263
0.0045
0.1718
0.0118
0.1113
0.0134
0.1162
0.0113
0.1523
0.0394
0.1655
0.0474
0.1925
0.0413
0.2240
0.0306
0.2038
0350737
DUP05 02 98760
*?.J. B97/1 unn
MODEL 'NUMBER 1
O - 32 DENOMINATOR DEGREES DF FREEDOM
DEPENDENT EFFECT
VALUE
DEGREES OF FREEDOM
PROBABILITY
BF2DIA
TEST FOR OVERALL MODEL 0INDEPENDENT EFFECTS
46
0.OOOO
AGEYRS BMI HEIGHT HYPERMED COFFEE DATE LL16
O. 55 116.25
3. 07 54.47
6.28 1.30 8.51
1 O.4640 1 0.0000 1 0.0896 1 0.0000 1 0.0175 1 O.2631 1 0.0064
HYPOTHESIS TESTING RESULTS
OMODEL NUMBER 2
O 32 DENOMINATOR DEGREES OF FREEDOM
DEPENDENT EFFECT
VALUE
DEGREES OF FREEDOM
SAS PROBABILITY
BP2DIA
TEST FOR OVERALL MDDEL INDEPENDENT EFFECTS
35. 24
o.oooo
AGEYRS BMI HYFERMED COFFEE DATE LL17
O. 66 120.60
58. 79 5.80 2. 46 7. 73
O.4241
O.0000 o.0000 0.0220
0.1268 0.0)090
HYPOTHESIS TESTING RESULTS
OMODEL NUMBER 3
O 32 DENOMINATOR DEGREES OF FREEDOM
DEPENDENT EFFECT
VALUE
DEGREES OF FREEDOM
PROBABILITY
BP2DIA
TEST FOR OVERALL MODEL OINDEPENDENT EFFECTS
37.51
O.0000
AGEYRS BMI HEIGHT HYPERMED COFFEE DATE LL1B
O. 02 134.63
^ 62. 96
5. 86 1.95 9. 34
0.8765
o.0000 0., 1 202
0. OO'OO o 0213 0. 1718 C)., 0)045
HYPOTHESIS TESTING RESULTS
OMODEL NUMBER 4
O 32 DENOMINATOR DEGREES OF FREEDOM
ODEPENDENT EFFECT
VALUE
DEGREES OF FREEDOM
BP2DIA
SAS
PROBABILITY
TEH 0350132
TEST FOR OVERALL MODEL
37.76
o.oooo
DUP050298761
DUPONT ANALYSIS
DUPONT HAS SUBMITTED A NEW ANALYSIS IN WHICH THEY USE A DUMMY VARIABLE FOR ALL 64 SITES OF THE NHANES II SURVEY
THIS APPROACH TO KEEPING BLOOD LEAD FROM CORRELATING WITH ANYTHING WAS REJECTED EARLIER IN THE DEBATE OVER THE GASOLINE LEAD - BLOOD DEAD RELATIONSHIP
THE POSSIBILITY OF OTHER VARIABLES SUCH AS OBESITY. EXERCISE. DEMOGRAPHIC FACTORS ETC CHANGING AS SAMPLING SITES CHANGED HAS ALREADY BEEN CONSIDERED BY INCLUSION OF THOSE VARIABLES IN THE MODEL. AND IN PARTICULAR BY LETTING THE STEPWISE REGRESSION SELECT VARIABLES WITHOUT COMPETITION FROM LEAD. AND THEN TESTING LEAD IN THOSE MODELS.
SINCE THESE OTHER FACTORS ARE WELL CONTROLLED FOR, AND DID NOT IN $ FACT VARY MUCH FROM SITE TO SITE. THE SITE VARIABLES ARE \w ' / ESSENTIALLY DUMMY VARIABLES FOR LEAD EXPOSURE.
WITH 65 LEAD EXPOSURE VARIABLES IN A MODEL IT IS DIFFICULT ALL OF THEM TO MAINTAIN SIGNIFICANCE.
Y'*j" FOR J
1
TO DEMONSTRATE THAT INSIGNIFICANT DEMOGRAPHIC FACTORS ARE NOT RESPONSIBLE FOR LEAD'S SIGNIFICANT RELATIONSHIP, WE PUT THEM BACK INTO OUR MODEL. LEAD IS SIGNIFICANT AFTER INCLUDING DEGREE OF URBANIZATION, REGIONS OF THE COUNTRY, EXERCISE. AND RESIDENCE IN OR OUT OF A CENTRAL CITY.
,w ^' ^ P'//
WHEN THE MEAN VALUES OF LEAD. BODY MASS INDEX. AND HEIGHT ARE COMPUTED FOR THE 64 SITES, WE SEE:
MEAN BLOOD LEAD LEVELS VARY FROM 11.7 TO 22,3 MEAN BMI ONLY VARIES FROM 23.4 TO 26.9 MEAN HEIGHT ONLY VARIES FROM 1.71M TO 1.79M
THEREFORE THE SITE DUMMIES ARE INDEED MAINLY REFLECTIONS OF BLOOD LEAD DIFFERENCES
\vJ V-
TEH 0350733
DUP050298762
-'DEPENDENT EFFECT
F VALUE
i BP2&IA
s TEST FOR OVERALL MODEL INDEPENDENT EFFECTS
50.85
AGEYRS AGESQ BMI LOGZINC ALBUMIN DIETVITC SMOK.NUM CALCIUM ZINC HEMOGLOB TRTCEPR FAMHYPER COFFEE HEIGHT HYPERMED RACE LOGVITC LL SIZE R1 R2 * R3 INCC RECEX.
85.79 60. 99 91.59
17.82 49. 19
8.97 4.34 5.30 13. 06 IB.38 4.8B 28. 13 7.25 16.16 41.98 9.72 12. 97 13. 26 0.26 0. 31 0. 09 0. 02 1.27 1.29
DEGREES OF FREEDOM PROBABILITY
24
1 1 ' 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
0.0000
0.0000 0.0000 0.0000 O.0002 0.0000 O.0053 0.0454 O.0279 0.0010 0.0002 0.0344 0.0000 O.0112 0.0003 O.0000 0.0033 0.0011 0.0009 0.6122 0.5791 0.7706 0.8767 0.2685 0.263B
-2-THESIS TESTING RESULTS
ZEl . NUMBER 2
32 DENOMINATOR DEGREES OF FREEDOM
ODEPENDENT EFFECT
F VALUE
DEGREES OF FREEDOM
PF: OBABILITY
BF2SYS
TEST FOR OVERALL MODEL INDEPENDENT EFFECTS
79.38
17 0.0000
AGEYRS AGESQ BMI LOGZINC ALBSQ CALCIUM
6.40 22.99 312.57 13. 17 57.05
5. 04
FAMHYPER
27. 61
COFFEE HEIGHT HYPERMED
20. 24 7.78
43. 39
LL 19. 05
SIZE
1.33
R1 R2 R3 INCC
0.70 3. 37
0.02 0. 45
RECEX
NOTE-- THE FROCEDURE CALCULATED THAT ? ***
JOB 566B XF'OSASPR ENDED AT NIHCU
? ***
63K
WAS
1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 l 1 NEEDED
FOR
ARRAY
0.0163 0.0000
0.0000 0.0010 0.0000 0.0318
0.0000
0.0001 0.0088 0.0000 O.0001 0.2568 0.4096 O.075S 0.8925 0.5066 0.1461 STORAGE
TEH 0350134
DUPO50298763