Final Draft ASSESSING MULTIMEDIA/MULTIPATHWAY EXPOSURES TO ARSENIC Using a ...

283 Pages·2006·7.64 MB·English

Final Draft
ASSESSING MULTIMEDIA/MULTIPATHWAY
EXPOSURES TO ARSENIC
Using a Mechanistic Source-to-Dose Modeling Framework
Case Studies Employing MENTOR/SHEDS-4M
Technical Report CERM.2005-01
by
P.G. Georgopoulos, S.W. Wang and Y.C. Yang
Computational Chemodynamics Laboratory - EOHSI∗
and
¨
J. Xue, V.G. Zartarian, T. McCurdy, and H. Ozkaynak
National Exposure Research Laboratory - USEPA
www.ccl.rutgers.edu
∗ EOHSI, Environmental and Occupational Health Sciences Institute (EOHSI)
UMDNJ – R.W. Johnson Medical School & Rutgers, The State University of NJ
170 Frelinghuysen Road, Piscataway, NJ 08854
Final Draft: February 2005
This page left intentionally blank.
Contents
Table of Contents i
List of Figures iv
List of Tables x
Executive Summary xi
Acknowledgment xiii
1 INTRODUCTION 1
1.1 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Rationale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 Problem definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.4 Towards a Comprehensive Arsenic Exposure Information System . . . . . . . . . 2
2 BACKGROUND AND SIGNIFICANCE 4
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Environmental Arsenic and Human Health . . . . . . . . . . . . . . . . . . . . 4
2.2.1 Arsenic Occurrence and Toxicity . . . . . . . . . . . . . . . . . . . . . . 4
2.2.2 A History of Regulating Arsenic in Drinking Water in the United States
(from [USEPA, 2002]) . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2.3 Information on Arsenic Exposures in the United States . . . . . . . . . . 7
2.3 A Survey of Recent Studies of Human Exposure to Arsenic . . . . . . . . . . . . 10
2.3.1 Arsenic - Dietary Exposure . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3.2 Arsenic in the NHEXAS -Region V Study: Diet and Drinking Water . . . 10
2.3.3 Arsenic in the NHEXAS-Maryland Study: Drinking Water and Diet . . . 11
2.4 Estimation of Multimedia Inorganic Arsenic Intake in the
US Population . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3 AN INTEGRATED MULTIMEDIA/MULTIPATHWAY EXPOSURE AND DOSE
MODELING FRAMEWORK 18
3.1 Individual Based Modeling (IBM) Framework . . . . . . . . . . . . . . . . . . . 18
3.2 Population Based Modeling (PBM) Framework . . . . . . . . . . . . . . . . . . 19
4 DATABASES FOR ARSENIC EXPOSURE ASSESSMENTS 26
4.1 Arsenic Databases - National US . . . . . . . . . . . . . . . . . . . . . . . . . 26
Multimedia Exposure/Biomarker Studies . . . . . . . . . . . . . . . . . . . . . 26
4.1.1 USEPA National Human Exposure Assessment Survey (NHEXAS) Database 26
Environmental Releases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4.1.2 USEPA National Toxics Inventory (NTI) . . . . . . . . . . . . . . . . . 28
4.1.3 USEPA Toxics Release Inventory (TRI) . . . . . . . . . . . . . . . . . . 29
i
4.1.4 ATSDR’s Hazardous Substance Release and
Health Effects Database (HazDat) . . . . . . . . . . . . . . . . . . . . 30
Outdoor Air Quality Measurements . . . . . . . . . . . . . . . . . . . . . . . . 30
4.1.5 USEPA Aerometric Information Retrieval System (AIRS) . . . . . . . . . 30
Surface and Ground Water, and Sediments . . . . . . . . . . . . . . . . . . . . 31
4.1.6 USGS Water Quality Network (WQN) . . . . . . . . . . . . . . . . . . 31
4.1.7 USGS National Water Quality Assessment (NAWQA) Data Warehouse . 31
4.1.8 USEPA Storage and Retrieval (STORET) . . . . . . . . . . . . . . . . . 32
4.1.9 USEPA Environmental Monitoring and Assessment Program (EMAP) . . 33
Soils and Sediments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4.1.10 USGS National Geochemical Atlas (NGA) . . . . . . . . . . . . . . . . . 33
Ecological . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.1.11 NOAA Ocean Resources Conservation and Assessment (ORCA) . . . . . 34
Drinking Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.1.12 USEPA Arsenic Occurrence and Exposure Database (AOED) . . . . . . 34
4.1.13 USEPA Safe Drinking Water Information
System/Federal Version (SDWIS/FED) . . . . . . . . . . . . . . . . . . 35
4.1.14 US FDA Total Diet Study (TDS) . . . . . . . . . . . . . . . . . . . . . 36
Modeled Estimates of Ambient And Exposure As Concentrations . . . . . . . . 36
4.1.15 USEPA Cumulative Exposure Project (CEP) . . . . . . . . . . . . . . . 36
4.1.16 USEPA National Air Toxics Assessment (NATA) . . . . . . . . . . . . . 37
4.2 Regional US Arsenic Databases: New Jersey Examples . . . . . . . . . . . . . . 37
4.2.1 NJDEP NJ Bureau of Safe Drinking Water (NJBSDW) . . . . . . . . . 37
4.2.2 Rutgers New Jersey Atmospheric Deposition Network (NJADN) . . . . . 38
4.2.3 USGS National Water Information System (NWIS) . . . . . . . . . . . . 38
4.3 Regional/International Arsenic Databases
(that include US Territories) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.3.1 Arctic Monitoring and Assessment Program (AMAP) . . . . . . . . . . . 39
4.4 Supporting Databases for Arsenic Exposure Assessment . . . . . . . . . . . . . 39
4.4.1 CDCSecondandThirdNationalHealthandNutritionExaminationSurvey
(NHANES II & III) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.4.2 US Bureau of Census American Housing Survey (AHS) . . . . . . . . . . 40
4.4.3 USDA Continuing Survey of Food Intakes by Individuals (CSFII) . . . . . 40
4.4.4 USEPA Consolidated Human Activity Database (CHAD) . . . . . . . . . 41
5 INTAKE ROUTES AND PATHWAYS FOR ARSENIC EXPOSURES 63
5.1 Inhalation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.2 Oral Intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.2.1 Drinking water intake . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.2.2 Dietary (food) intake . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.2.3 Non-dietary (soil) ingestion . . . . . . . . . . . . . . . . . . . . . . . . 68
5.3 Dermal Intake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
ii
6 PHYSIOLOGICALLYBASEDPHARMACOKINETIC(PBPK)MODELINGFOR
ARSENIC 79
6.1 Basic PBPK Model Structure for Arsenic . . . . . . . . . . . . . . . . . . . . . 79
6.2 Flow-Limited PBPK Model Equations (Yu’s Formulation) . . . . . . . . . . . . 81
6.3 Diffusion-Limited PBPK Model Equations (Mann’s Formulation) . . . . . . . . . 82
6.4 Physiological Variability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
6.5 Variability and Uncertainty in Arsenic Metabolism . . . . . . . . . . . . . . . . 85
7 SYSTEMATIC REDUCTION OF THE ARSENIC PBPK MODEL THROUGH
THE HDMR METHOD 97
7.1 The High Dimensional Model Representations (HDMR) Method . . . . . . . . . 97
7.2 Reduction of the Arsenic PBPK Model . . . . . . . . . . . . . . . . . . . . . . 99
8 CASE STUDIES AND RESULTS 106
8.1 Individual Based Modeling: Case Study . . . . . . . . . . . . . . . . . . . . . . 106
8.2 Population Based Modeling: Case Studies . . . . . . . . . . . . . . . . . . . . . 106
8.2.1 Case Study I: Pima County, Arizona . . . . . . . . . . . . . . . . . . . . 107
8.2.2 Case Study II: Hunterdon County, New Jersey . . . . . . . . . . . . . . 107
8.2.3 Case Study III: Franklin County, Ohio . . . . . . . . . . . . . . . . . . . 107
8.2.4 ComparisonsofTotalInorganicArsenicIntakesEstimatedinMENTOR/SHEDS-
4M with the Nationwide Estimates . . . . . . . . . . . . . . . . . . . . 108
8.2.5 Comparisons of Arsenic Exposure Concentrations Estimated in
MENTOR/SHEDS-4M and NATA Studies . . . . . . . . . . . . . . . . 109
8.2.6 Comparisons of Total Arsenic Amount in Urine Estimated in
MENTOR/SHEDS-4M with NHEXAS-Region V Measurements . . . . . 110
8.3 Additional “Corroboration” of Arsenic Population Dose Findings . . . . . . . . . 111
9 DISCUSSION AND CONCLUSIONS 155
9.1 On-Going and Planned Work . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
10 BIBLIOGRAPHY 157
A ARSENIC DATABASES - USA A-1
B REGIONAL US ARSENIC DATABASES: NEW JERSEY EXAMPLES B-1
C REGIONAL/INTERNATIONAL ARSENIC DATABASES C-1
D SUPPORTING DATABASES FOR EXPOSURE ASSESSMENT D-1
E ACRONYMS E-1
iii
List of Figures
1 Flowchart of a comprehensive exposure information analysis and modeling system
for arsenic, utilizing the framework of MENTOR/SHEDS-4M for source-to-dose
exposure studies; discussions of the databases listed in this chart can be found in
Section 4 and Appendices A through D; discussion of models listed here will be
included in a final version of this report. . . . . . . . . . . . . . . . . . . . . . . 3
2 Aunifiedmultimedia/multiscaleframeworktosupporthuman/ecologicalexposure
assessments for arsenic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3 Chemical structures of various arsenic species . . . . . . . . . . . . . . . . . . . 14
4 Summary of Ecological (Terrestrial) Biotransformations of Arsenic [Salamons and
Forstner, 1984] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5 Summary of Marine Biotransformations of Arsenic [Baker et al., 2001] . . . . . . 16
6 Summary of Human Biotransformation of Arsenic [NRC, 2001] . . . . . . . . . 17
7 Structure of source-to-dose Individual Based Modeling (IBM) of exposure to
Arsenic (coupled environmental/microenvironmental/dosimetry modeling) in the
MENTOR/SHEDS-4M framework . . . . . . . . . . . . . . . . . . . . . . . . . 21
8 Structure (components and information flows) of the EPANET drinking water
distribution model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9 Example EPANET application: estimation of arsenic distribution in a municipal
water network (two suppliers) . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
10 Frequency histogram of concentrations at network nodes calculated for the exam-
ple of Figure 9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
11 Structure of source-to-dose Population Based Modeling (PBM) of exposure to
Arsenic (coupled environmental/microenvironmental/dosimetry modeling) in the
MENTOR/SHEDS-4M framework . . . . . . . . . . . . . . . . . . . . . . . . . 25
12 Locations of counties that participated in NHEXAS Phase I study of Region V
(See text for additional information and references) . . . . . . . . . . . . . . . . 43
13 County-widetotalarsenic(arsenicandarseniccompounds)emissionsdensity(tons/yr/sq.
mi.) from the NTI inventory, for 1996 (See text for additional information and
references) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
14 Annual county-average total arsenic concentrations in air, estimated using the
ASPEN model and NTI inventory, for 1996 (See text for additional information
and references) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
15 Releases of Arsenic compounds from point sources reported in TRI 1998, cat-
egorized by media: (a) Air emissions; (b) Surface discharges; (c) On-site land
releases. On-site land releases are the biggest sources. Releases through air and
surface water are about 10,000 times less than on-site land releases. (See text for
additional information and references) . . . . . . . . . . . . . . . . . . . . . . . 46
iv
16 Releases of Arsenic (metal) from point sources reported in TRI 1998, categorized
by media: (a) air emissions; (b) surface water discharges; and (c) on-site land
releases. Releases through ground water are omitted because their contribution
is negligible. Since only arsenic that was released at a specific facility/location is
of interest, wastes transferred for off-site treatment or recycling are not included.
TRI 1998 arsenic metal releases data show that on-site land releases are the
biggest source of anthropogenic arsenic to the environment, while surface water
discharges are several magnitudes lower. (See text for additional information and
references) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
17 Locations of AIRS monitoring stations that measured arsenic compounds in 2001
(See text for additional information and references) . . . . . . . . . . . . . . . . 48
18 Mean and maximum arsenic concentrations measured in PM2.5 at AIRS monitor-
ing stations during 2001 (See text for additional information and references) . . 49
19 Arsenic surface water concentrations for 1962-97 from USGS’s Water Quality
Network (WQN) (See text for additional information and references) . . . . . . 50
20 Arsenic concentrations in ground water for 1996 in μg/L from USGS’s NAWQA
arsenic database (See text for additional information and references) . . . . . . . 51
21 Arsenic concentrations in sediments for 1990-96 in μg/g from USGS’s NAWQA
arsenic database (See text for additional information and references) . . . . . . . 52
22 Arsenicconcentrations ingroundwaterfor1996-97 fromtheNAWQAdataset(See
text for additional information and references) . . . . . . . . . . . . . . . . . . 53
23 Counties in which at least 10% of wells exceed different As levels (10, 5, 3, and
0 μg/L; from USGS NAWQA database) (See text for additional information and
references) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
24 Arsenic water concentrations (in ppm) from the EMAP Coastal Assessment Pro-
gram, 1990 - 2000 (See text for additional information and references) . . . . . 55
25 Arsenic liver concentrations reported in the National Status and Trends program
(See text for additional information and references) . . . . . . . . . . . . . . . . 56
26 Arsenic concentrations in benthic sediments reported in the National Status and
Trends program (See text for additional information and references) . . . . . . . 57
27 Arsenic concentrations observed in mussels reported in the National Status and
Trends program (See text for additional information and references) . . . . . . . 58
28 The four US census regions, as defined in the USFDA Total Diet Study . . . . . 59
29 Total arsenic (mg/kg) measured in twelve major food groups generated from total
267 food items. Data source: Total Dietary Study 1991-1997, FDA. (See text for
additional information and references) . . . . . . . . . . . . . . . . . . . . . . . 60
30 Locations of New Jersey Atmospheric Deposition Network (NJADN) monitoring
stations. Of these, the Sandy Hook, Jersey City (Liberty Science Center), New
Brunswick, Camden, and Pinelands stations measure wet and dry deposition of
arsenic. (See text for additional information and references) . . . . . . . . . . . 61
31 The hierarchy structure of the CSFII database. . . . . . . . . . . . . . . . . . . 62
32 Flowchart that summarizes the procedure to calculate total lung burden . . . . . 76
v
33 Calculations of age and gender dependent dose of PM in μg for 2 different
2.5
intensity levels of activity, where PM2.5 particle sizes are assumed to be uniformly
distributed as 2.5 μm or lognormally distributed. The parameters of lognormal
size distribution are taken from the accumulation mode of the grand average
continental size distribution in [Whitby, 1978]. . . . . . . . . . . . . . . . . . . 77
34 Comparison of dietary (food) arsenic intakes measured in the NHEXAS Region V
study and calculated by the dietary model (with nation-wide prameters) . . . . . 78
35 Structure of Flow Limited Human PBPK model for Arsenic (based on Yu’s for-
mulation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
36 Structure of Perfusion Limited Human PBPK model for Arsenic (based on Mann’s
formulation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
37 Amount of four arsenic species in urine for a single 1.0 μmol oral dose of AsV, pre-
dictedbytheflow-limitedmodel(Yu’sformulation)(ascodedinMENTOR/SHEDS-
4M) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
38 Amount of four arsenic species in urine for a single 1.0 μmol oral dose of AsV, pre-
dictedbythediffusion-limitedmodel(Mann’sformulation)(ascodedinMENTOR/SHEDS-
4M) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
39 Output comparisons between the Mann and Yu formulations of the PBPKM for
Arsenic (as coded in MENTOR/SHEDS-4M) . . . . . . . . . . . . . . . . . . . 95
40 Population variations in the percentages of various arsenic metabolites in urine.
(a) Percentage of DMA; (b) percentage of MMA; and (c) percentage of inorganic
arsenic [Vahter, 2000]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
41 Comparison of the diurnal profiles of AsIII dose for a 50 year-old female calculated
by the “full” As-PBPK model and HDMR reduced model . . . . . . . . . . . . 102
42 ComparisonofthediurnalprofilesofDMAdosefora50year-oldfemalecalculated
by the “full” As-PBPK model and HDMR reduced model . . . . . . . . . . . . 103
43 Comparison of AsIII dose distributions calculated by the “full” As-PBPK model
and HDMR reduced model for the population of 1000 people . . . . . . . . . . 104
44 Comparison of DMA dose distributions calculated by the “full” As-PBPK model
and HDMR reduced model for the population of 1000 people . . . . . . . . . . 105
45 Temporal profiles of arsenic air concentrations in different rooms of the house
under study calculated by the MENTOR Individual Based Model . . . . . . . . . 115
46 Temporal profile of the inhaled dose for the exposed person during the one day
simulation calculated by the MENTOR/SHEDS-4M Individual Based Model . . . 116
47 Temporal profile of the inhalation and oral exposure and dose to arsenic (source:
tap water use, 50 ppb As) for the exposed person during the one day simulation
calculated by the MENTOR/SHEDS-4M Individual Based Model . . . . . . . . 117
48 The geographic locations of the three counties considered in the case studies . . 118
49 USEPA NTI (1996) estimates of annual arsenic emissions from area sources (as
PM fine; census tract allocation via EMS-HAP) . . . . . . . . . . . . . . . . . 119
50 1996 NATA estimates of ambient annual averages total arsenic concentrations
(based on USEPA EMS-HAP/ASPEN/HAPEM simulations) . . . . . . . . . . . 120
vi
51 1996 NATA estimates of annual time-weighted average total arsenic exposure
concentrations (based on USEPA EMS-HAP/ASPEN/HAPEM simulations) . . . 121
52 CumulativearsenicdosedistributionsfrominhalationandingestionroutesforPima
County, Arizona(calculatedbytheMENTOR/SHEDS-4MPopulationBasedModel)122
53 Arsenic in New Jersey aquifers . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
54 CumulativearsenicdosedistributionsfrominhalationandingestionroutesforHun-
terdon County, New Jersey (calculated by the MENTOR/SHEDS-4M Population
Based Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
55 Cumulative arsenic (total and inorganic) exposure distributions from inhalation,
food intake, drinking water consumption, and non-dietary routes for Franklin
County, Ohio (calculated by the MENTOR/SHEDS-4M Population Based Model) 125
56 Cumulative arsenic (inorganic (AsIII, AsV) and organic (MMA, DMA) species)
internaldosedistributionsofkidneyandliverforthepopulationofFranklinCounty,
Ohio (calculated by the MENTOR/SHEDS-4M Population Based Model) . . . . 126
57 Cumulative arsenic (inorganic (AsIII) and organic (DMA) species) internal dose
distributions of kidney and liver for the population of Franklin County, Ohio (cal-
culated by the MENTOR/SHEDS-4M Population Based Model) . . . . . . . . . 127
58 Cumulative arsenic exposure distributions from inhalation, food intake, and drink-
ing water consumption routes for the 1st age group (0-4 years old) of Franklin
County, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
59 Cumulative arsenic exposure distributions from inhalation, food intake, and drink-
ing water consumption routes for the 2nd age group (5-19 years old) of Franklin
County, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
60 Cumulative arsenic exposure distributions from inhalation, food intake, and drink-
ing water consumption routes for the 3rd age group (20-34 years old) of Franklin
County, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
61 Cumulative arsenic exposure distributions from inhalation, food intake, and drink-
ing water consumption routes for the 4th age group (35-54 years old) of Franklin
County, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
62 Cumulative arsenic exposure distributions from inhalation, food intake, and drink-
ing water consumption routes for the 5th age group (55-64 years old) of Franklin
County, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
63 Cumulative arsenic exposure distributions from inhalation, food intake, and drink-
ing water consumption routes for the 6th age group (65 years old and above) of
Franklin County, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
64 Cumulative arsenic exposure distributions of total inorganic arsenic intake for 6
age groups of Franklin County, Ohio . . . . . . . . . . . . . . . . . . . . . . . . 134
65 Comparison of the cumulative distributions of total inorganic arsenic intakes be-
tween the MENTOR/SHEDS-4M study (Franklin County, Ohio) and the study of
Meacher et al. for adult males . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
vii
66 Comparison of the cumulative distributions of total inorganic arsenic intakes be-
tween the MENTOR/SHEDS-4M study (Franklin County, Ohio) and the study of
Meacher et al. for adult females . . . . . . . . . . . . . . . . . . . . . . . . . . 136
67 Comparison of percentile distributions of time-weighted average arsenic exposure
concentrations in air calculated by MENTOR/SHEDS-4M and NATA studies for
Pima County, Arizona . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
68 Comparison of percentile distributions of time-weighted average arsenic exposure
concentrations in air calculated by MENTOR/SHEDS-4M and NATA studies for
Hunterdon County, New Jersey . . . . . . . . . . . . . . . . . . . . . . . . . . 138
69 Comparison of percentile distributions of time-weighted average arsenic exposure
concentrations in air calculated by MENTOR/SHEDS-4M and NATA studies for
Franklin County, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
70 Profile of total body burden of arsenic dose (inorganic+organic) during a three-
week continuous exposure for a 32 year-old female . . . . . . . . . . . . . . . . 140
71 Comparison of percentile distributions of total arsenic amount in urine calculated
by MENTOR/SHEDS-4M and NHEXAS-Region V measurements for Franklin
County, Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
72 Quantile-quantileplotoftotalarsenicamountinurinebetweenMENTOR/SHEDS-
4McalculationsandNHEXASmeasurementsforthepopulationofFranklinCounty,
Ohio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
73 Comparison of cumulative distributions of total arsenic amount in urine from
MENTOR/SHEDS-4M calculations and NHEXAS measurements for the 1st age
group (0-4 years old) of Franklin County, Ohio . . . . . . . . . . . . . . . . . . 143
74 Comparison of cumulative distributions of total arsenic amount in urine from
MENTOR/SHEDS-4M calculations and NHEXAS measurements for the 2nd age
group (5-19 years old) of Franklin County, Ohio . . . . . . . . . . . . . . . . . 144
75 Comparison of cumulative distributions of total arsenic amount in urine from
MENTOR/SHEDS-4M calculations and NHEXAS measurements for the 3rd age
group (20-34 years old) of Franklin County, Ohio . . . . . . . . . . . . . . . . . 145
76 Comparison of cumulative distributions of total arsenic amount in urine from
MENTOR/SHEDS-4M calculations and NHEXAS measurements for the 4th age
group (35-54 years old) of Franklin County, Ohio . . . . . . . . . . . . . . . . . 146
77 Comparison of cumulative distributions of total arsenic amount in urine from
MENTOR/SHEDS-4M calculations and NHEXAS measurements for the 5th age
group (55-64 years old) of Franklin County, Ohio . . . . . . . . . . . . . . . . . 147
78 Comparison of cumulative distributions of total arsenic amount in urine from
MENTOR/SHEDS-4M calculations and NHEXAS measurements for the 6th age
group (65 years and above) of Franklin County, Ohio . . . . . . . . . . . . . . . 148
79 Airborne Arsenic in the atmosphere, from NHEXAS Phase I study of Region V . 149
80 Arsenic in urine, from NHEXAS Phase I study of Region V . . . . . . . . . . . . 150
81 Arsenic in food and beverages from NHEXAS Phase I study of Region V . . . . 151
82 Arsenic in soil and dust from NHEXAS Phase I study of Region V . . . . . . . . 152
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