PUBLIC HEALTH ASSESSMENT
Tucson International Airport Area Superfund Site
Tucson, Pima County, Arizona
CERCLIS

#AZ0980737530

Prepared by

Office of Environmental Health
Environmental Health Consultation Services
October 19, 2000

Under Cooperative Agreement with the Agency for Toxic Substances and Disease Registry

Public Comment Version -Tucson International Airport Area -CERCLIS # AZD980737530

Executive Summary
The purpose of this document is to summarize the body of
environmental health investigation work that has been developed for
the TIAA site. The report includes a summary of previous reports
and new data.
Contaminated groundwater was discovered in the area in 1981. The
pollution included trichloroethylene (TCE). Investigations revealed
the TCE was moving in a north to northwest direction.
TCE was also discovered in production wells used by Tucson Water
in 1981. These wells were shut down shortly after the
contamination was discovered. No groundwater data exist prior to
1981. Since historical exposure levels are unknown prior to 1981,
exposure to contaminated groundwater posed an unknown public
health hazard. Municipal groundwater posed no public health hazard
after the contaminated municipal wells were closed.
There is currently no exposure of public health concern. However,
no regulation prevents persons from installing private drinking
water wells in the contaminated groundwater. Because the
pollutants in the groundwater may be of public health concern if it
were used for drinking water, the site may pose a potential public
health hazard unless actions are taken to prevent such use.

1.0

Introduction

The Tucson International Airport Area Superfund Site (TIAA) is located on the southside of
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Tucson, Arizona. The site is approximately bounded by Valencia Road on the north, Hughes
Access Road to the east and south, and Highway 89 to the west (as shown in Figures 1 and 2). In
May 1981, contaminated groundwater was discovered beneath part of the site, beginning a
number of investigations evaluating the nature and extent of contamination in the area. From
these investigations, at least three separate areas of contamination, potentially from different
sources, have been identified. The Tucson International Airport Area (TIAA) Superfund Site was
officially added to the National Priorities List (NPL) in 1983.
Various environmental sampling reports and health evaluations have been conducted over the
years (for example - Hargis & Montgomery, 1982; PCDEQ, 1994; D.B. Stephens, 1995; Baseline
Risk Assessment ADHS, 1996; ATSDR, 2000a; ATSDR, 2000b; ATSDR, 2000c). In addition to
reports focusing on individual areas of contamination, the Agency for Toxic Substances and
Disease Registry (ATSDR) released a Public Health Assessment (PHA) for the TIAA in 1988
and a draft version of a subsequent Public Health Assessment Addendum for the TIAA in 1996.
This document is prepared by the Arizona Department of Health Services (ADHS) in cooperative
agreement with the ATSDR to incorporate past public comments and the most recent data
available in evaluating the public health risks posed by the TIAA site. Public comments
submitted to ATSDR regarding the 1996 Public Health Assessment Addendum (ATSDR, 1996a)
have been reviewed and incorporated into this document where pertinent.
Because this current document is able to make use of a substantial body of public health
evaluations previously unavailable, it is laid out differently than the 1996 ATSDR document.
This PHA is essentially a new document (rather than a revised version of a previous document),
and is being issued in draft form for public comment before being finalized.
1.1

Purpose

The purpose of this document is to summarize the body of environmental health investigation
work that has been developed regarding the TIAA site. The report includes data available since
previous documents were created, and develops and presents the overall public health findings
for the TIAA site based on the current body of available data.
1.2 Background
Site Description and History
The Tucson Airport and surrounding area has been the site of various aviation, aerospace, and
industrial facilities that have occupied portions of the site since 1942. The TIAA site includes
one main contaminated groundwater plume with smaller areas of groundwater contamination
located east of the main plume. Areas of contaminated soil have also been identified as part of
the site. Figures 1 and 2 show the location of the site and specific areas mentioned in this text.
Approximately 20 facilities have operated at various times in the TIAA vicinity. Known waste
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handling activities related to the TIAA site consisted of:
!

surface discharge of waste liquids, containing several organic compounds, into soils,
disposal ponds, and unlined landfills, and

!

burning of wastes for use in fire training exercises (flammable wastes ignited in unlined
fire pit areas, followed by application of water to extinguish the blaze).

Main Plume Area
In May 1981 contaminated groundwater was discovered at the site beneath Air Force Plant No.
44 (AFP44), which was operated for the Air Force at that time by Hughes Aircraft Corporation.
This area is currently operated by Raytheon Corporation. Further investigations of the site
revealed a sizable area of groundwater contamination, called the main plume, containing several
organic compounds, including trichloroethylene (TCE), and chromium. Investigations revealed
the contaminated groundwater plume was moving off-site in a north to northwest direction.
In 1987, the area of the plume was approximately 4 miles long and 3000 feet wide covering an
area located from the northwest corner of the AFP44 facility to near Irvington Road (see Figure
1). A cooperative agreement between the USEPA and the United States Air Force (USAF)
divided the plume into two major remedial areas with Los Reales Road as the dividing point. The
portions of the main plume south of Los Reales Road are treated with a reclamation well field
and full-scale air stripping facility that began operation in 1987 at the AFP44 site. North of Los
Reales Road, the main plume is contained by extraction wells which feed the Tucson Aquifer
Remediation Project (TARP) plant. Figure 2 displays a recent overview of the main plume
showing the effect of remedial work in the AFP44 area over the last several years.
Plume B Area
East of the main plume are smaller areas of contamination indicated by soil and water quality
analyses from sampling programs conducted in the TIAA area. Based on the analyses conducted
to date and a review of historical activities at the facilities in the area, the contamination
(primarily TCE and chromium) may have resulted from operations of any of the following: the
Tucson Airport, the Burr-Brown facility, the former West Cap property, and the Arizona Air
National Guard. In this report, these smaller areas of contaminated groundwater have been
collectively referred to as “Plume B.” The Plume B area is the subject of a separate Public Health
Assessment (ATSDR, 2000c).
Other Areas
In addition to the areas of groundwater contamination, areas of soil and sediment contamination
related to surface water runoff from the site were also identified during site investigations. A
primary area was associated with the “Three Hangars” area of the airport. The Three Hangars
area has been used for aircraft modification operations, general aircraft and vehicle maintenance,
synthetic rubber and plastics manufacturing, charter services, and other industrial activities. Soil
contaminated by runoff from this area has been discussed in a recent Public Health Assessment
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subtitled “El Vado Residential Properties”(ATSDR, 2000a).
1.3 Site Visits
In addition to numerous site visits, ADHS also obtained information about the area from the
ATSDR, the Pima County Department of Environmental Quality (PCDEQ), Arizona Department
of Environmental Quality (ADEQ), U.S. Environmental Protection Agency (EPA), and from
residents who attended numerous community meetings over the last several years.
Additional groundwater data were obtained from the TCE library located at the El Pueblo
Community Center in south Tucson. The TCE library collects data and information that are
provided by various governmental and community sources relating to the TIAA Superfund Site.
This information is available to the public at the TCE Library located at 101 W. Irvington,
Tucson, Arizona.
1.4 Demographics, Land Use, Natural Resources
Demographics and Land Use
The area around the TIAA is an area of mixed commercial and residential usage. Areas closest to
the airport tend to be more commercial than areas slightly further from the airport. The greatest
concentrations of residences are west and north of the airport. Approximately 55,000 people live
within one mile of the site (1990 census). Figure 3 presents a map displaying general population
characteristics in the vicinity of the TIAA site.
Natural Resources
Climate
The climate of Tucson, Arizona is semi-arid with an average of between 10 and 11 inches of
rainfall annually. Annual evaporation is about four times greater than the average annual
precipitation. Summertime high temperatures average about 100 degrees Fahrenheit. Winter
high temperatures average in the upper 60s.
Water Resources
Most of the residential community obtains their water supply from the Tucson municipal water
system. However, there are some residences in the area which still use private wells for drinking
or irrigation purposes. Surface water is not a significant source of water supply in the Tucson
area.
Natural surface waters in the site area are intermittent and occur primarily as runoff from storm
events. The Airport Wash is the dominant surface water feature at the Tucson Airport, and is
located in the northeastern part of the airport. The other major surface water feature consists of
the Diversion Channel, which flows from Aero Park Road to the Hughes Access Road on the
western side of the main runway. Under current land use conditions, artificial surface coverings
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including pavement and tarmacs essentially prevent soil or groundwater contaminants from
coming into contact with surface water. These coverings do allow the potential for surface water
runoff to contaminate soils in areas where surface waters pond during storm events.
Geology
The upper 200 feet of sedimentary materials within the area show a general coarsening trend
from east to west. Predominately fine-grained material is interbedded with layers and lenses of
sand and gravel in a complex manner exist east of the Nogales Highway (PCDEQ, 1998).
General Hydrogeology
The regional aquifer system at the TIAA site is hydogeologically complex due to lateral and
vertical lithologic changes. Three units of the regional aquifer system (the upper zone, lower
zone, and undivided regional aquifer) are present within the boundaries of the TIAA Site. The
middle aquitard divides the regional aquifer into upper and lower zones under most of the TIAA
Site.
Transport and fate of groundwater contamination has been associated mainly with the upper zone
regional aquifer. The vertical extent of contamination has been limited by the presence of the
middle aquitard. In this area, the upper zone regional aquifer is about 70 - 100 feet thick,
extending from the water table, which occurs at depths of about 85 - 100 feet below the ground
surface (bgs), to the top of the middle aquitard at a depth of about 175 feet bgs. As a consequence
of the heterogeneous geology and groundwater pumpage, the depth to groundwater, nature of the
aquifer system (unconfined versus confined), and direction of groundwater flow vary within the
area depending on location and depth (PCDEQ, 1998).
1.5 Health Outcome Data
Several health studies have been conducted over the past 15 years to determine the health effects
to residents in the TIAA area from exposures to trichloroethylene (TCE) in drinking water
Although these studies focus on exposures to TCE in drinking water primarily from the larger
Main Plume, they are also applicable to the Plume B area since it also is contaminated with TCE
and chromium similar to the Main Plume (ADHS, 1996; ATSDR, 1994). In many cases, the
studies included participants or databases which covered both areas. These studies are as follows:
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Mortality Rates on Tucson's Southside. Caldwell G. ADHS. 1986.

!

An Association of Human Congenital Cardiac Malformations and Drinking Water
Contamination. Goldberg SJ, Lebowitz MD, Graver EJ, Hicks S. Journal of the
American College of Cardiology. 1990; 16;1:155-164.

!

Maricopa and Pima County Birth Defects Study. ADHS. 1987.

!

A Comparison of Homebound Program Admission Rates in the Tucson Unified and
Sunnyside School Districts. K. Komatsu, ADHS. 1986.
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!

Historical Prospective Mortality Study of Hughes Aircraft Employees at Air Force
Plant #44. ENSR. 1990.

!

The Incidence of Childhood Leukemia and Testicular Cancer in Pima County,
1970-1986. ADHS. 1990.

!

Effects on Neurobehavioral Performance of Chronic Exposure to Chemically
Contaminated Well Water. Kilburn KH, Warshaw RH, University of Southern
California, Los Angeles, CA. 1994.

!

Prevalence of Symptoms of Systemic Lupus Erythematosus (SLE) and of Fluorescent
Antinuclear Antibodies Associated with Chronic Exposure to Trichloroethylene and
other Chemicals in Well Water: Kilburn KH, Warshaw RH. Environmental Research.
1992; 57:1-9.

These studies have been summarized and discussed in previous documents (ATSDR, 1996a;
ATSDR, 2000c) and the reader is referred to those documents for further interest. A brief
summary of the findings from these is found in Section 4.3, “Health Outcome Data Evaluation.”
Other available Health Outcome Data include a Disease and Symptom Prevalence Survey for part
of the TIAA site area conducted by ATSDR (ATSDR, 1996b), and information emerging from
the ongoing National Exposure Registry - Trichloroethylene (TCE) Subregistry developed by
ATSDR (see ATSDR, 1999 for a recent summary report of the Registry program). Information
from these projects is discussed in Section 4.3, “Health Outcome Data Evaluation.”
2.0 Community Health Concerns
This section describes general concerns voiced by community residents who live near the TIAA
site. Detailed descriptions of these concerns have been documented in previous reports (ATSDR,
1988; ATSDR, 1996a; ATSDR, 2000c). These concerns have already been discussed in detail in
the 1996 PHA Addendum (ATSDR, 1996a).
Groundwater contamination in southwest Tucson has been a concern of residents living near the
TIAA site for many years. The community includes many residents who understand the history of
the site, the exposure scenarios, and what is happening with the remediation activities. Some
believe that public drinking water is still contaminated. While many residents have switched over
to City water, a few believe that drinking water out of a contaminated private well is safer than
drinking the “contaminated Tucson Water” and have chosen not to hook up to city water
(ATSDR, 2000c; PCDEQ, 1998). ADHS has made recommendations in previous documents
(ATSDR, 2000c) to address potential exposure due to use of private wells.
In the past, residents in southwest Tucson have expressed concerns about the prevalence of
congenital heart disease, lupus, and, cancer in their community that they associate with exposure
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to the contaminated groundwater (ATSDR, 1988, 1996a). Several studies have been conducted
to address these concerns, as described in Section 1.5, “Health Outcome Data,” and Section 4.3,
“Discussion: Health Outcome Data Evaluation.”
In addition, former workers from the AFP44 facility have expressed concerns about potential
workplace exposures. ADHS was unable to locate environmental data to evaluate past conditions
inside the facility. Investigations of workplace health concerns are the authority of the
Occupational Safety and Health Administration (OSHA) and the Arizona Industrial Commission
-Occupational Safety and Health Division, and are beyond the scope of this report.
3.0

Environmental Contamination and Other Hazards

In this section, contamination in the site area will be discussed based on the medium (air, soil,
water) and where the chemicals are, or have been, found. For issues which have been addressed
by previous documents, the reader will be referred to those documents for detailed discussion.
3.1 Data
Air
No air sampling data were located for public exposures in the site area. No significant air
exposure pathway appears likely based on site contaminants and conditions and past public
health evaluations did not find a need for any air sampling (ATSDR, 1988, 1996a). On-site soil
gas samples have been collected and evaluated for part of the site (ATSDR, 2000b). The
available data are discussed in section 4.1 “Environmental Data Evaluation.”
Soil
Evidence of past off-site soil contamination related to drainage system runoff from the TIAA site
has been detected. This contamination was evaluated in the PHA document subtitled “El Vado
Residential Properties” (ATSDR, 2000a). Other areas of contaminated soil were found onsite and
are discussed in section 4.1, “Environmental Data Evaluation.”
Water
As noted previously, no significant perennial surface waterways exist in the TIAA site area, and
surface water is not considered to be a pathway of public health significance. However, the site
has multiple areas of significant groundwater contamination associated with it, and groundwater
is the main source of drinking water supply for the TIAA site area. For ease of discussion,
groundwater contamination will be discussed in separate detail for the past and present
timeframes.
Past Groundwater Data
Past groundwater conditions have been evaluated for the time period 1981 to 1999 in previous
documents (ATSDR, 1988, 1996a, 2000c). No sampling data were located which indicate
groundwater chemical conditions prior to 1981. ATSDR (1996a) did evaluate scenarios to
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estimate potential levels of groundwater contaminants prior to 1981 in the draft PHA. However,
comments on that draft text indicated that the model oversimplified the complex hydrogeology of
the site. ATSDR’s text accompanying the modeling effort also indicated that the estimates were
only for purposes of estimating approximate dates of contamination in wells and that the
numbers should not be used to evaluate public health exposures. In addition, ADHS notes that
the definition of multiple distinct areas of contamination (e.g., Main Plume and Plume B) is more
complex than the model effort incorporated. Based on these comments, ADHS finds the existing
database inadequate to evaluate groundwater exposures prior to 1981. The ADHS could not
locate any actual data or detailed estimates suitable for use in public health evaluation of
groundwater contaminant concentrations prior to 1981.
Present Groundwater Data
Groundwater sampling of the two plumes associated with the site continues at present. ADHS’
most recent evaluation of this data was published in 2000 (ATSDR, 2000c). Additional data on
groundwater conditions are routinely reported by USEPA and AFP44. These data are publicly
available from USEPA or at the TCE Library at 101 W. Irvington, Tucson. USEPA drinking
water regulations also require the Tucson Municipal Water authority to notify customers if any of
the municipal drinking water is not meeting EPA standards for maximum contaminant levels.
Current data indicate local drinking water contains less than 5 ug/l of TCE.
4.0 Discussion
ADHS evaluates a site by considering the level of exposure in potential or completed exposure
pathways. An exposure pathway is the way chemicals may travel through the environment and
enter a person’s body to cause a health effect. It includes all of the steps between the release of
the chemical and the population exposed: (1) a chemical release source, (2) chemical movement,
(3) a place where people can come into contact with the chemical, (4) a route of human exposure,
such an inhalation or ingestion, and (5) a population that is exposed. ADHS considers which
chemicals, if any, from a site are present at levels of public health concern (i.e., above an
appropriate comparison value) through all five elements of a completed pathway when
determining the public health implications of a site.
4.1 Environmental Data Evaluation
This section presents ADHS’ evaluation of the available data based either on data listed in the
section titled “Environmental Contamination” or on previously published reports as identified in
the text.
Air
No data were found indicating large-scale chemical releases to the air which would affect the
ambient air around the Tucson International Airport Area site. Limited data from a portion of the
site were evaluated (ATSDR, 2000b) and are summarized in Table 1. Based on the limited
available data, activities conducted at the TIAA site, and the nature of the soil and groundwater
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contamination, ADHS does not find any public health issues from ambient air exposures to siterelated chemicals for either the past, present, or future timeframes.
Table 1: Maximum Contaminant Concentrations of On-Site Soil Gas Samples, Modeled Indoor
Air Concentrations and ATSDR’s Air Comparison Values.
Contaminant

Concentration
Range in Soil
Vapor (µg/L)†

Maximum
Concentration in
Samples (µg/L)

Modeled Air
Concentration
(µg/L)

ATSDR Air
CV ‡
(µg/L)

Exceed
ATSDR
CV?

TCE §

ND¶ - 111

111b

6.5E-06

5.5E+022

NO

PCE**

ND - 28.7

28.7b

2.1E-06

2.8E+021

NO

1,1-DCE††

ND - 140

140 c

7.5E-07

8.1E+012

NO

1,1,1-TCA‡‡

ND - 4.3

4.3 a

2.5E-07

3.9E+032

NO

† ug/L = micrograms per liter; ‡ CV = Comparison Values; ¶ ND = non-detect;
§ TCE = trichloroethylene; ** PCE = tetrachloroethane; †† 1,1-DCE = 1,1-dichloroethylene; ‡‡ 1,1,1-TCA = 1,1,1 trichloroethane.
a= 1996 sampling data; b= from sample WC-1, 1997 data; c= from sample WC-2, 1997 data.
1= ATSDR chronic EMEG; 2= ATSDR intermediate EMEG
Table from ATSDR (2000b).

Soil
Evidence of past soil contamination related to drainage system runoff from the TIAA site has
been detected. This contamination was evaluated in previous public health assessments (ATSDR,
1988, 1996a, 2000a). As presented in the document subtitled “El Vado Residential Properties,”
(ATSDR, 2000a) remediation of these areas has occurred to below Residential Arizona Soil
Remediation Levels (SRLs). SRLs are levels of contaminants in soils promulgated by
administrative rule that do not represent a health risk. A summary table of representative soil
data is presented as Table 2.
Other areas of contaminated soil related to AFP44 and the airport itself have either been
remediated or are being remediated as part of ongoing TIAA site work (EPA, 2000). The AFP44
and airport property soil sites are completely fenced to restrict site access and the fencing is
routinely monitored. Based on this restriction of access, ADHS finds no public health concern
from on-site soil contamination because there currently is no completed pathway of exposure.

Table 2: Sample Results From Remediated Areas in El Vado Residential Area (1997)
Remediation Area

Number of
Samples

Range of PCB
Concentrations
(mg/kg)
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Mean
(mg/kg)

SRL for
PCBs
(mg/kg)

Above
SRL

AREA A:
Drainage Area

12

0.643 - <0.033

0.32

2.5

NO

AREA B:
Vacant Lot

9

0.182 - <0.033

0.100

2.5

NO

AREA C:
Backyards of
Residences

5

0.122 - <0.033

0.076

2.5

NO

AREA D1:
Vacant Area North
of the Church

3

0.120 - 0.045

0.07

2.5

NO

AREA D2:
Vacant Area West
of the Church

2

0.039 - 0.035

0.037

2.5

NO

Results from Conestoga (1997) as reported in ATSDR (2000a).

Water
Past Groundwater Conditions
As noted previously, insufficient data exist to evaluate groundwater contamination prior to 1981.
Therefore, ADHS finds that pre-1981 groundwater exposure is an indeterminate public health
concern.
Groundwater conditions since 1981 have been evaluated in previous public health reports
(ATSDR, 1988, 1996a, 2000c). Summarizing these documents, ADHS finds that groundwater
offsite was contaminated with trichloroethylene (TCE) at levels above public health guidelines
prior to 1981. However, there have been no significant exposures since site monitoring and
remedial activities began in 1981. A summary of past municipal well monitoring data is
presented in Table 3.
Table 3. Maximum Contaminant Concentrations, Municipal Supply Wells Removed from
Service.
Well

Month/Yr
Removed from Use

TCE (ppb)

Sample Date
(month/yr)

SC-007A

5/81

122

11/81

C-062B

6/81

126

5/82

C-064B

10/81

10

9/81

C-066A

8/83

9

8/83

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C-072A

?/70

22

3/82

B-087A

11/81

43

5/82

B-101A

8/81

112

5/82

B-102A

10/78

239

5/82

MCL

5

data source: ATSDR,1996
MCL = current EPA drinking water standard (Maximum Contaminant Level)

Present Groundwater Conditions
Current groundwater data indicate that contaminated groundwater from the site is not being used
as a drinking water source (ATSDR, 2000c). A summary of recent private drinking water well
data is provided in Table 4. The site currently poses no apparent public health concern (ATSDR,
2000c) from exposure to groundwater.
Table 4: Maximum Contaminant Concentrations in 12 Private Drinking Wells and Comparison
to Corresponding MCLs*.
Well ID #

Present Status

TCE†
MCL=5 µg/L‡

Chromium
MCL=100 µg/L

Above MCL?

25

Cemetery

N.D.§

N.D.

NO

28

Private residence

N.D.

N.D.

NO

29

Private residence

N.D.

N.D.

NO

3

Private residence

N.D.

2.2

NO

12

Mobile Home Park

N.D.

6.3 **

NO

9

Private residence

N.D.

3.0 **

NO

18

Private residence

N.D.

5.6 **

NO

21

Private residence

N.D.

5.8 **

NO

17

Private residence

N.D.

1.2 **

NO

7

Private residence

4 **

N.D.

NO

13

Mobile Home Park

3.6

5

NO

15

Private residence

3 **

6.3 **

NO

* MCLs = maximum contaminant levels; † TCE = trichloroethylene; ‡ µg/L = micrograms per liter; § N.D. = non-detect;
** Indicates an increase in contaminant level from 1994 samples to 1998 samples.
Table from: ATSDR, 2000c

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Future Groundwater Conditions
No current private drinking water wells contain TCE at levels of concern at the site. However,
contamination of a number of private irrigation water wells has been documented (ATSDR,
2000c). The presence of private irrigation wells contaminated with TCE and the possibility that
these wells could be converted for drinking water use presents a potential public health concern.
ADHS has recommended that safeguards be enacted to preclude private use of any contaminated
irrigation well for drinking water purposes until site remediation has been completed (ATSDR,
2000c). ADHS affirms that recommendation in this current document.
4.2 Previous Public Health Reports and Findings
As noted previously, a number of public health evaluations have been conducted over the last
several years regarding the Tucson International Airport Area superfund site. Some of the key
reports are listed below along with a brief summary of their public health findings:
!

Public Health Assessment for Tucson International Airport Site (ATSDR, 1988) - This
report evaluated the (limited) available data and concluded that public drinking water
supplies posed no public health concern. The report also found a lack of adequate
information on previous conditions which left past conditions as an indeterminate public
health concern.

!

Baseline Human Health Risk Assessment (ADHS, 1996) - This document used formal risk
assessment methods following EPA’s “Risk Assessment Guidance for Superfund” and
found that offsite soils posed a potential public health risk due to PCB contamination.
These soils have since been remediated. No completed pathway of groundwater exposure
was identified, and no risk was found from groundwater.

!

Petitioned Public Health Assessment Addendum for Tucson International Airport Area
(ATSDR, 1996a) - This document evaluated a large body of environmental data and found
that groundwater and municipal drinking water posed no apparent public health hazard.
Soils in wash areas were of public health concern based on the presence of polychlorinated
biphenyls (PCBs). Note that the wash areas have since been remediated and were discussed
in the document regarding the “El Vado Residential Properties” (ATSDR, 2000a).

!

Public Health Assessment for Tucson International Airport Area (a/k/a El Vado Residential
Properties) (ATSDR, 2000a) - This public health assessment evaluated off-site soil
contamination west of the Tucson Airport property. The contamination was apparently the
result of surface water runoff from the western portion of the airport near the three hangars
area. ATSDR found that soils had been remediated to an acceptable level and the site posed
no public health hazard.

!

Public Health Consultation for Tucson International Airport (a/k/a West Cap Facility)
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(ATSDR, 2000b) - This consultation evaluated specific concerns regarding soil
contamination and soil gas vapors inside buildings on the former West-Cap property. Indoor
air concentrations modeled from soil gas data were found to present no public health
hazard.
!

Public Health Assessment for Tucson International Airport Area (Plume B Area) (ATSDR,
2000c) - This PHA evaluated private wells in the Plume B area north of the airport. Twelve
private drinking water wells were evaluated and were found to pose no public health
hazard. In addition to private drinking water wells, a number of private wells used for
irrigation purposes were also evaluated and three were found to contain TCE at levels above
drinking water standards. Because it is possible to convert an existing irrigation well to a
drinking water source or to install a new private well for drinking use in the area, this was
considered to be a potential public health concern for the future. Actions to prevent any
exposures of public health concern were recommended.

4.3 Health Outcome Data Evaluation
ATSDR and ADHS have reviewed the eight studies listed in Section 1.4. A brief summary of the
findings of these studies is presented here. Readers are referred to the Public Health Assessment “Plume B Area” (ATSDR, 2000c), the 1996 PHA Addendum (ATSDR, 1996a), or the specific
study documents for more details about the findings and limitations of each study.
No statistically significant results were found for the following outcomes studied: a) homebound
program admission rates in the Tucson Unified and Sunnyside school districts, b) mortality rates
of Hughes aircraft employees, and, c) childhood leukemia and testicular cancer incidence in Pima
County.
In the reviewed studies, the reported results were suggestive, but not conclusive, for the
following outcomes: a) congenital heart disease, b) musculoskeletal birth defects (county-year
interactions), c) mortality due to asthma, d) neuro-behavioral performance, and, e) prevalence of
systemic lupus erythematosus.
In addition to these studies, ATSDR has conducted two additional activities pertinent to the
trichloroethylene in groundwater at the TIAA site. First, ATSDR conducted a “Disease and
Symptom Prevalence Survey” (ATSDR, 1996b) in an area around the site. In addition to the
survey, ATSDR has developed a National Exposure Subregistry of persons significantly exposed
to TCE at various locations in the US. The TCE Subregistry began in 1989 and is ongoing. The
most recent report (ATSDR, 1999) covers data collected through 1997 and incorporates
information collected from nearly 5000 persons.
The Disease and Symptom Prevalence Survey (ATSDR, 1996a) found “a statistically
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significantly greater proportion of residents from the target area than the comparison area
reported having had most of the general and neurological-specific disease and symptoms with
onset since moving into the home occupied at the time of the survey.” The conclusions then note
that “the association between the reported health outcomes and TCE exposure could not be
determined without......more detailed exposure information.”
ATSDR compares data from the TCE Subregistry to the National Health Interview Survey
conducted throughout the US (ATSDR, 1999). In the information reported to date, TCE
registrants reported some conditions at a higher rate than the general population. The health
conditions reported in excess at one or more interview time periods were: anemia, diabetes,
hearing impairment, hypertension, kidney disease, liver problems, skin rashes, speech
impairment, stroke, and urinary tract disorders (ATSDR, 1999). ATSDR notes that these results
do not identify a causal relationship between TCE exposure and adverse health effect because the
excess reporting of some health conditions might be explained by methodological differences in
data collection. ATSDR states it intends to continue the registry and follow-up evaluation
(ATSDR, 1999).
4.4 Child Health Initiative
ATSDR’s Child Health Initiative recognizes that the unique vulnerabilities of infants and
children demand special emphasis in communities faced with contamination of their water, soil,
air, or food. Children are at greater risk than adults from certain kinds of exposures to hazardous
substances emitted from waste sites and emergency events. They are more likely to be exposed
because they play outdoors, they often bring food into contaminated areas, and the developing
body systems of children can sustain permanent damage if toxic exposures occur during critical
growth stages. ADHS has considered the special needs of children in the evaluation of the TIAA
site.
5.0 Conclusions
Based upon the available data and previously published reports, ADHS has reached the following
conclusions regarding the potential public health hazards posed by the Tucson International
Airport Area (TIAA) superfund site.
Past Conditions
Since no groundwater sampling data exist for site related contaminants prior to 1981, the TIAA
site posed an indeterminate public health hazard prior to 1981. Groundwater represented no
apparent public health hazard after the contaminated municipal wells were closed.
Soils in wash areas were a potential public health concern due to the presence of polychlorinated
biphenyls (PCBs) prior to the soil remediaton activities conducted in 1996. However, after the
clean up effort, the soils represented no apparent public health hazard.
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Current Conditions
ADHS finds no current completed exposure pathways at levels of public health concern. The
TIAA site currently poses no apparent public health hazard.
Future Conditions
ADHS notes that ongoing remedial activities should improve local environmental conditions.
The potential currently exists for people to install private drinking water wells in currently
contaminated groundwater. Because of this potential pathway, ADHS finds the TIAA site may
pose a potential public health hazard unless further actions are taken. ADHS will share these
findings with EPA site managers and parties responsible for the ongoing remedial activities in an
effort to prevent any future public health hazard from occurring.
6.0 Recommendations
ADHS recommends the following for the TIAA superfund site:
!

ongoing remedial efforts should continue at the TIAA site to reduce on-site contaminant
levels; and

!

actions should be taken to prevent potential future use of contaminated groundwater by
private well users.

In the event additional data become available regarding the TIAA site, ADHS will consider
modifying, or issuing an addendum to, this Public Health Assessment as appropriate.
7.0 Public Health Action Plan
ADHS has actively participated in regular site-related meetings with the local community
(Unified Community Advisory Board - UCAB), regulatory agencies (EPA and ADEQ), and
parties responsible for site remediation activities (AFP44, Tucson Airport Authority, contractors)
to provide public health evaluations throughout the site investigation and remediation process.
ADHS will continue to participate as needed in site related remedial activities to address public
health concerns related to the TIAA site.
ADHS will also work to educate the local community about the use of private wells and health
concerns that may be related to that use.

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-16-

References
Agency for Toxic Substances and Disease Registry, 1988. U.S. Department of Health & Human
Services, Public Health Service, Agency for Toxic Substances and Disease Registry; Public
Health Assessment, Tucson International Airport Site, Tucson, Pima County, Arizona. March 8,
1988.
Agency for Toxic Substances and Disease Registry, 1994. U.S. Department of Health & Human
Services, Public Health Service, Agency for Toxic Substances and Disease Registry; Division of
Health Assessment and Consultation. Review of Health Studies Related to TCE Contamination at
Tucson Superfund Site, Tucson Arizona. 1994.
Agency for Toxic Substances and Disease Registry, 1996a. U.S. Department of Health & Human
Services, Public Health Service, Agency for Toxic Substances and Disease Registry; Division of
Health Assessment and Consultation, Petitioned Public Health Assessment Addendum, Tucson
International Airport Area, Tucson, Pima County, Arizona. September 6, 1996.
Agency for Toxic Substances and Disease Registry, 1996b. U.S. Department of Health & Human
Services, Public Health Service, Agency for Toxic Substances and Disease Registry; Division of
Health Assessment and Consultation Final Report - Disease and Symptom PrevalenceSurvey,
Tucson International Airport Site, Tucson, Pima County, Arizona. September 1996.
Agency for Toxic Substances and Disease Registry, 1999. U.S. Department of Health & Human
Services, Public Health Service, Agency for Toxic Substances and Disease Registry. National
Exposure Registry - Trichloroethylene (TCE) Subregistry, Baseline through Followup 3
Technical Report. October 1999.
Agency for Toxic Substances and Disease Registry, 2000a. U.S. Department of Health & Human
Services, Public Health Service, Agency for Toxic Substances and Disease Registry. Public
Health Assessment, Tucson International Airport Area (a/k/a El Vado Residential Properties),
Tucson, Pima County, Arizona. March 15, 2000.
Agency for Toxic Substances and Disease Registry, 2000b. U.S. Department of Health & Human
Services, Public Health Service, Agency for Toxic Substances and Disease Registry; Division of
Health Assessment and Consultation. Health Consultation, Tucson International Airport (a/k/a
West-Cap Facility), Tucson, Pima County, Arizona. July 11, 2000.
Agency for Toxic Substances and Disease Registry, 2000c. U.S. Department of Health & Human
Services, Public Health Service, Agency for Toxic Substances and Disease Registry. Public
Health Assessment, Tucson International Airport Area (Plume B area), Tucson, Pima County,
Arizona. October 10, 2000.
Arizona Department of Health Services. Baseline Human Health Risk Assessment; Tucson
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International Superfund Site. December 1, 1996.
Daniel B. Stephens & Associates, 1995. Field Reconnaissance Investigation Results, Tucson
International Airport RI/FS, Volume 1. Albuquerque, NM. January 27, 1995.
Hargis & Montgomery, 1982. Phase I Investigation of Subsurface Conditions in the Vicinity of
Abandoned Waste Disposal Sites, Hughes Aircraft Company Manufacturing Facility, Tucson,
AZ.
Pima County Department of Environmental Quality. Southside TCE Private Well Investigation
for the Tucson International Airport Area Superfund Site (TIAASS), Tucson, Arizona. November,
1994.
Pima County Department of Environmental Quality. Southside TCE Private Well Investigation
for the Tucson International Airport Area Superfund Site (TIAASS), Tucson, Arizona. December
1998.
U.S. Environmental Protection Agency, 2000. Tucson International Airport Area (TIAA)
Superfund Site (newsletter), February 2000.

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Preparers of Report
Arizona Department of Health Services, Office of Environmental Health
Douglas Gouzie, Ph.D., Environmental Program Specialist
Will Humble, M.P.H., Chief, Office of Environmental Health, Principal Investigator
ATSDR Technical Project Officer
Tammie McRae, M.S.
Environmental Health Scientist
Division of Health Assessment and Consultation
Superfund Site Assessment Branch
State Program Section
ATSDR Regional Representative
William Nelson
Regional Services, Region IX
Office of the Assistant Administrator

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Figure 1. General Map of Tucson International Airport Area Site and extent of contamination.

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Figure 2. March 1999 Plume Outlines and TIAA Site Area.
Map from: Arizona Department of Environmental Quality, Southern Region Office

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Figure 3. Demographics of Site Area, Tucson International Airport Area site.

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