Att7_Example of Prior Exposure Investigation Final Report_Oct23_2014

Health Consultation

Exposure Investigation
Biological Monitoring for Exposure to Lead and Arsenic

Superior, Mineral County, Montana

Cost Recovery Number: 80ER

MARCH 31, 2011

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

Public Health Service

Agency for Toxic Substances and Disease Registry

Division of Health Assessment and Consultation

Atlanta, Georgia 30333

Health Consultation: A Note of Explanation

An ATSDR health consultation is a verbal or written response from ATSDR to a specific
request for information about health risks related to a specific site, a chemical release, or
the presence of hazardous material. In order to prevent or mitigate exposures, a
consultation may lead to specific actions, such as restricting use of or replacing water
supplies; intensifying environmental sampling; restricting site access; or removing the
contaminated material.
In addition, consultations may recommend additional public health actions, such as
conducting health surveillance activities to evaluate exposure or trends in adverse health
outcomes; conducting biological indicators of exposure studies to assess exposure; and
providing health education for health care providers and community members. This
concludes the health consultation process for this site, unless additional information is
obtained by ATSDR which, in the Agency’s opinion, indicates a need to revise or append
the conclusions previously issued.

You May Contact ATSDR TOLL FREE at

1-888-42ATSDR

or

Visit our Home Page at: http://www.atsdr.cdc.gov

HEALTH CONSULTATION

Exposure Investigation

Biological Monitoring for Exposure to Lead and Arsenic

Superior, Mineral County, Montana

Cost Recovery Number: 80ER

Prepared by:

Bruce C. Tierney, MD

Lourdes Rosales-Guevara, MD

ATSDR/DHAC/EISAB

Table of Contents
A.
B.
C.
D.
E.
F.

G.

H.

I.
J.
K.
L.
M.

Abbreviations and Acronyms
Executive Summary
Introduction
Purpose
Investigators and Collaborators
Methods
1. Criteria for Participation
2. Recruiting Participants
3. Field Activities
a. Community Health Education
b. Questionnaire
c. Biological Testing
i. Blood Lead Collection
ii. Urinary Arsenic Collection
d. EI Activities and Sample Collection Schedule
e. Environmental Testing - Home Tap Water Collection
f. Sample Handling and Shipping
i. Blood Lead
ii. Urinary Arsenic
iii. Water Sample for Lead
4. Lab Processing and Analysis
a. Blood Lead
b. Urinary Arsenic
c. Water Sample for Lead
Results
1. Participants in the Exposure Investigation
2. Environmental Testing – Home Tap Water
3. Blood Lead Testing
4. Urinary Arsenic Testing
Discussion
1. Environmental Testing – Home Tap Water
2. Biological Testing - Blood Lead
3. Biological Testing – Urinary Arsenic
4. Notifying the Community of Test Results
5. Child Health Considerations
Conclusions
Recommendations
Acknowledgements
Authors
References

Appendix A: Letter from Montana Department of Environmental Quality
Appendix B: Exposure Investigation Protocol
Appendix C: Homeowner Tap Water Sample Collection Directions

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A. Abbreviations and Acronyms
ATSDR

Agency for Toxic Substances and Disease Registry

BLL

Blood Lead Level

DHAC

Division of Health Assessment and Consultation

DMA

Dimethylarsonic Acid

DRO

Division of Regional Operations

EI

Exposure Investigation

EISAB

Exposure Investigations and Site Assessment Branch

EPA

Environmental Protection Agency

ETAAS

Electrothermal Atomic Absorption Spectometry

HPCIB

Health Promotion and Community Involvement Branch

IMM

Flat Creek Iron Mountain Mine and Mill

LOD

Limit of Detection

MCEHP

Mineral County Environmental Health and Planning

MCHD

Mineral County Health Department

MCL

Maximum Contaminant Level

MDEQ

Montana Department of Environmental Quality

MDL

Method Detection Limit

MDPHHSL

Montana Department of Public Health and Human Services Laboratory

MMA

Monomethylarsonic Acid

NCEH

National Center for Environmental Health

NHANES

National Health and Nutrition Examination Survey

NPL

National Priorities List

ppb

parts per billion

ppm

parts per million

PWS

Public Water Supply

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B. Executive Summary
The community of Superior, Montana is located in close proximity to the Flat Creek Iron
Mountain Mine and Mill (IMM) site. In the past, waste tailings from the IMM site were used as
fill material in Superior, resulting in high levels of metals in town soils. The Agency for Toxic
Substances and Disease Registry (ATSDR) conducted this Exposure Investigation (EI) to assess
the exposure of residents of this community to lead and arsenic that were found in soil samples
of residences and public spaces following soil evaluation by the U. S. Environmental Protection
Agency (EPA).
With the help of the Mineral County Health Department (MCHD) and community members, we
recruited 63 residents who lived in the community of Superior, MT. Although all residents of
Superior, MT were eligible to participate, our recruitment efforts focused on residents who
resided on property found to have soil samples with a lead level of more than 400 parts per
million (ppm). The EI population consisted of 33 adults and 30 children under the age of 18
years of age.
ATSDR, working with the MCHD, arranged for use of the Superior High School multipurpose
room as a central location for EI participants to provide blood samples for lead and urine samples
for arsenic. Tap water samples were collected from five homes for evaluation for lead. We also
administered a questionnaire to identify other potential sources of exposure to lead and arsenic.
The 95th percentile of a national reference population (1,2) was used as the references range for
the blood lead and urinary arsenic samples. Therefore, it was expected that about 5 percent of
the samples could be above the reference range, even if no unusual exposures were occurring.
However, no participant had a lead or arsenic sample that was above the 95th percentile of a
national reference population. A national reference range for urinary arsenic was not available
for participants below the age of six. Fifteen participants below the age of six years of age did
not undergo urine testing for arsenic.
The concentration of lead in all home tap water samples was below EPA’s action level of 15
micrograms/liter (µg/L) for lead in drinking water (3).
ATSDR found no evidence of unusual exposures to the lead and arsenic found in soil on
residential and public property in Superior, MT for EI participants during the testing period. The
levels of lead and arsenic detected in the EI participants blood and urine samples were below
levels of health concern for exposure for all participants. This EI was conducted during the
summer (July 2010) when outdoor activity and the potential for exposure to soils are expected to
be at their highest. EPA is moving forward with plans for remediation of soil on residential and
public properties found to have highly elevated levels of lead and arsenic to further lessen the
likelihood that residents of Superior, MT will be exposed to soil contaminated with high levels of
lead and arsenic.

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C. Introduction
The town of Superior, MT (population of 893 in the 2000 census) is located in close proximity to
the IMM site. The IMM site was discovered in 1888 and produced silver, gold, lead, copper, and
zinc ore; it remained in operation until 1954. A large waste rock pile and some waste tailings
deposits (containing detectable levels of arsenic, antimony, lead, and manganese) still exist on
the mine property, although a majority of the waste tailings have been washed downstream onto
the Flat Creek floodplain. In the past, waste tailings from the IMM site were used as fill material
in Superior, resulting in high levels of metals in town soils.
In January 2002, the Montana Department of Environmental Quality (MDEQ) requested that the
EPA evaluate the town of Superior for a possible removal action based on data that reported high
levels of lead and arsenic in town soils. In June 2002, EPA conducted additional surface and
subsurface soil sampling and found multiple areas of Superior with soil containing elevated
levels of arsenic and lead. For lead, 10 of 27 residential properties in Superior were found to
have soil lead levels present above 400 parts per million (ppm) with a maximum concentration of
16,700 ppm. For arsenic, 11 of 29 residential properties were found to have arsenic
concentrations greater than 20 ppm with a maximum concentration of 2,620 ppm. In August
2002, EPA began a time-critical removal action in Superior. Contaminated soils and waste
tailings located in other areas, including rights-of-way and residential properties, were included
in the EPA removal action if the average surface soil concentration exceeded 400 ppm arsenic
and/or 3,000 ppm lead. Overall, EPA removed approximately 6,500 cubic yards of contaminated
tailings and soil from town locations (4).
Also in 2002, Mineral County Environmental Health and Planning (MCEHP) collected blood
lead and urinary arsenic samples from individuals living in Superior. In February 2002, 66
Superior residents were tested for lead exposure. All blood lead concentrations were less than 10
µg/dL. Among the 66 people tested were eight children below seven years of age with a range of
blood lead levels (BLL) between 1 – 2.6 µg/dL. In addition, seventeen Superior residents
provided a urine sample to test for urinary arsenic. No urine samples were taken from children
younger than six years of age. All 17 residents had urinary arsenic levels below the detection
limit of 5 μg/L (4). Based on the available sampling data, results show that these adult residents
of Superior showed no evidence of unusual exposure to arsenic during the 2–3 days prior to their
urine collection.
However, these blood and urinary samples were collected in February and may not represent
peak exposure levels to soil, sediment and waste tailings, which are more likely to occur in the
summer when outdoor activities occur and the ground is not frozen or covered by snow.
In February 2004, ATSDR received a petition for a public health evaluation of heavy metal
contamination in soil and water in Superior, Montana. Residents expressed concern regarding
exposures to waste tailings from the IMM site. Waste tailings from this mine site have washed
down along the banks and floodplain of Flat Creek. Additionally, some waste tailings were used
as fill material in the town. To address community concerns, ATSDR evaluated available data to
determine whether residents have had harmful health effects from exposures to heavy metal
contamination in soil and water.

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Between 2004 and 2009, ATSDR met with the petitioner to discuss the site, conducted site visits
and reviewed data collected from several on-going sampling events performed by the EPA and
others. ATSDR staff also met with county staff and toured the site and possible contamination
source areas (visible waste tailings along Flat Creek and on the mine property).
In April 2009, EPA listed the Flat Creek IMM site on its National Priorities List (NPL), and the
first phase of residential soil sampling occurred in the summer of 2009. This repeat testing by
EPA identified soil at 67 properties in Superior, MT greater than 400 ppm of lead and 19 of
those homes with soil lead levels greater than 2,999 ppm with the maximum concentration found
to be 12,576 ppm. In addition, soil arsenic levels were also noted to be greater than 20 ppm
(maximum of 2841 ppm) in a number of the properties with elevated lead levels(5).
In July 2009, ATSDR joined EPA staff at a public meeting held in Superior where ATSDR staff
discussed the findings of a public health assessment that was written based on this evaluation. In
this Public Health Assessment, which was published in January 2010 (4), ATSDR concluded that
coming into frequent contact with heavy metals in the waste tailings on the IMM site, the Flat
Creek floodplain, and the town of Superior could harm people’s health. Therefore, frequent,
contact-intense activities with the waste tailings may result in exposures that are a public health
hazard.
In November 2009, the MCHD requested ATSDR assistance to conduct an exposure
investigation (EI) to evaluate the potential for exposure of Superior, MT residents to lead and
arsenic. This community concern resulted from the presence of continued high levels of lead and
arsenic in the town soil. In addition, the previous blood and urinary results obtained in 2002
might not have represented peak exposure levels to soil, sediment and waste tailings, such as
those that might occur in the summer when outdoor activities occur. Finally, only a limited
number of children, who are at a higher level of risk of exposure to soil contamination, were
included in previous testing.
The potential for an exposure pathway for lead from the local water supply was also considered.
Since the early 1900s, the majority of town residents have been connected to the public water
supply (PWS). Previously, the PWS source for the town of Superior was a spring adjacent to Flat
Creek. However, the Mountain Water Company (former PWS owner) discontinued use of Flat
Creek Spring in 1997 when antimony was detected at concentrations above the EPA’s maximum
contaminant level (MCL). Currently, the spring is not in use, but it is maintained as an
emergency drinking water source.
Ownership of the PWS was transferred from the Mountain Water Company to the town of
Superior in October 2000. There are three production wells in the current system. All three wells
are located within the city limits of the town of Superior and each has its own treatment plant.
The town of Superior tests these wells for water quality in accordance with federal standards. 10
of 13 past samples of treated water from the PWS contained detectable lead levels but all were
less than EPA’s MCL of 15 ppb. The current PWS has a total of 430 service connections (6).
Information obtained from the Mineral County sanitarian (see Appendix A) indicate that the town
of Superior PWS applied for and received a full waiver for reduced monitoring for lead and
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copper from the MDEQ based on low levels in past sample testing and the non corrosive nature
of the current water supply in December 2005. It is not clear from this documentation whether
the last testing performed in August 2004 was performed at the water treatment plant or at home
spigots in the town. The next testing for lead is scheduled for the 2011-2013 period.

D. Purpose
ATSDR conducted biological monitoring for exposure to lead and arsenic in residents of
Superior, MT, with a focus on pregnant women and children between the ages of 9 months and
11 years of age. In addition up to 5 participants in the EI with children under the age of 11 were
asked to provide a home tap water sample for lead testing. Participation in the home tap water
sampling was on a voluntary basis and did not affect the ability of the participant to obtain blood
lead and urinary arsenic testing.
Sampling of home tap water (for lead), blood (for lead) and urine (for arsenic) occurred during
the week of July 12th, 2010 when outdoor activities were near their peak. This EI consisted of
two parts. First, a community education program was presented to residents and health
professionals to advise them of the potential risk of lead and arsenic in the community and to
encourage targeted residents to participate in the testing program. Based on age, participants
provided written consent, assent and parental permission. Biological and environmental
monitoring were conducted using validated, state-of-the-science analytical methodologies. The
results of this investigation provided the participants with accurate information on their current
level of exposure to lead and arsenic. In addition to biological and environmental sampling, EI
participants (or their parent/guardian) answered a brief questionnaire to assist ATSDR in the
interpretation of the results of biological sampling.

E. Investigators and Collaborators
The ATSDR/Division of Health Assessment and Consultation (DHAC)/Exposure Investigations
and Site Assessment Branch (EISAB) was the lead agency for this EI.
EISAB:
(1) Worked with the MCHD and the community to recruit participants for the EI and provide
community health education for lead and arsenic exposure.
(2) Procured supplies for biological and environmental monitoring
(3) Contracted for local phlebotomists to draw blood samples
(4) Administered consent/assent and parental permission forms and questionnaires
(5) Collected biological/environmental samples and shipped them to the laboratory for
analysis
(6) Evaluated the analytical test results

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(7) Notified the participants of their individual test results
(8) Coordinated with EPA to conduct the EI at a time that will minimize impact on the EI while
also minimizing disruption of the planned remediation and additional soil sampling also
planned for the summer time period when the EI was conducted.
ATSDR/Division of Regional Operations (DRO)/Region 8/Montana Office:
(1) Worked in close cooperation with EISAB to complete the tasks assigned to it to include
providing input on development and implementation of the EI and the final EI report.
(2) Served as the primary liaison between ATSDR and MCHD to facilitate coordination with
local partners and the community.
MCHD:
(1) served as the lead local agency for the EI
(2) Led the effort in the community to recruit participants for the EI
(3) Served as the primary resource for education to the local community on the risks of exposure
to elevated lead and arsenic concentrations.
(4) Assisted in conducting the biological and environmental sampling conducted in Superior,
MT during the week of July 12th, 2010.
ATSDR/DHAC/Health Promotion and Community Involvement Branch (HPCIB):
(1) Assisted the MCHD with developing resource materials for the community education
program and providing health education to the community as requested by MCHD
(2) Worked with EISAB and the MCHD to develop recruitment materials
National Center for Environmental Health (NCEH) Laboratory:
(1) Provided supplies for collecting blood and urine samples
(2) Analyzed urine samples for the chemical of concern, arsenic, measured the urine creatinine
level and conducted speciated arsenic analysis for participants with an elevated level of
arsenic.
(3) Provided results from the urinary arsenic samples to ATSDR.

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(4) Reviewed and confirmed the results of blood samples for the chemical of concern, lead,
initially analyzed by the Montana Department of Public Health and Human Services
Laboratory (MDPHHSL).
MDPHHSL:
(1) Provided supplies for collecting home tap water samples for lead.
(2) Analyzed blood samples for the chemical of concern, lead.
(3) Analyzed home tap water samples for the chemical of concern, lead.
(4) Provided the individual water lead and blood lead results to ATSDR.
The Superior, MT health community, in cooperation with MCHD:
(1) Assisted ATSDR in identifying and recruiting participants for the EI.

F. Methods
1. Criteria for Participation
ATSDR worked with the MCHD to recruit residents with the highest potential exposures to lead
and arsenic, especially those who live in residences identified by the EPA as having a high level
of soil contamination. Exposure to lead and arsenic results primarily from waste tailings from the
mine used as surface soil fill on public and residential properties in the town of Superior, MT.
Participation in this EI was initially limited to pregnant woman and children but because
available appointments did not fill, participation was later opened to adult participants. Children
who currently live in or near the town of Superior, MT, aged 9 months to 5 years of age were
tested for blood lead; children 6 - 11 years of age and all older participants were tested for lead
and arsenic. Participants who made an advanced appointment and walk-in participants were seen
and enrolled in this EI.
The decision to include older participants was made two weeks prior to the planned EI because a
number of local residents requested testing for older residents of the community and because
available appointment spaces had not been filled by younger participants by that time.
2. Recruiting Participants
ATSDR staff worked with the MCHD and the community to identify and offer testing to all
families in Superior, MT with children meeting the recommended criteria and pregnant women.
Recruitment efforts included:
(1) ATSDR and MCHD met with community leaders approximately 10-12 weeks before the
EI to discuss the proposed EI and solicit community input and support in contacting
potential participants.

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(2) ATSDR developed and distributed a fact sheet to the public that described the EI 10-12
weeks prior to the EI initiation in cooperation with MCHD. The fact sheet included a
toll-free number that participants could call to schedule an appointment for testing and a
separate toll free ATSDR Information line for residents to ask additional questions about
the EI. MCHD distributed the fact sheet to residents of Superior, MT through locally
established distribution methods to include local schools, local medical facilities,
community organizations and a local health fair on June 5, 2010. EPA provided
information to MCHD and ATSDR for the location of properties that were found to have
elevated soil samples for lead and arsenic. Those families known to have elevated lead
and/or arsenic soil samples on their property following the most recent EPA soil
sampling in 2009 were contacted by telephone or through one-on-one interaction by
MCHD personnel to encourage their participation in the EI if they had family members
who met the initial criteria for participation.
(3) Assuming that residents of Superior, MT are likely to respond more positively to
interaction with local public health officials in the recruitment effort, personnel from the
MCHD led the effort to contact and recruit residents to participate in this EI in the 8-10
weeks preceding the planned EI. MCHD personnel distributed flyers provided by
ATSDR and contacted residents who were pregnant or had children of the appropriate
age for the EI.
(4) A toll free ATSDR Superior, MT EI appointment line was established 8-10 weeks prior
to the EI to provide an opportunity for Superior residents to make an advance
appointment for blood lead and urinary arsenic testing. On making this appointment,
participants were advised of the opportunity to obtain urine specimen cups in advance
and were also asked to avoid consuming fish and shellfish for five days prior to the
testing appointment time.
(5) In addition to the toll free appointment line, a separate toll free ATSDR information line
was established 8-10 weeks prior to the EI to provide an opportunity for Superior
residents to contact ATSDR directly for additional information about the EI.
(6) The decision was made to expand participation two weeks prior to the sample collection
phase of the EI to residents of any age in Superior, MT. ATSDR worked closely with the
MCHD to inform the local community of this change. This information was disseminated
through flyers posted throughout the community and by contacting residents known to
have elevated lead and/or arsenic soil samples on their property by telephone or through
one on one interaction with the MCHD to advise them of the change in participation
criteria.
3. Field Activities
a. Community Health Education
ATSDR, in cooperation with MCHD, made presentations to the public, town and county

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commissioners, as well as area clinicians 8-10 weeks prior to the EI to provide information about
the potential risks of exposure to elevated levels of lead and arsenic and to encourage residents to
participate in the EI. In addition, ATSDR, in partnership with MCHD, developed informational
flyers and announcements that were distributed to local residents 8-10 weeks prior to the EI and
again approximately 4 weeks prior to the EI. These materials advised residents of the potential
health hazard from elevated lead and arsenic in the soil as well as the availability of testing
during this EI for eligible residents. The EI residents who had made an appointment for testing
were contacted one week prior to the sample collection to remind them of their appointment and
to remind them to avoid consuming fish or shellfish for the 5-day period preceding their EI
appointment.
b. Questionnaire
During the EI appointment ATSDR administered a questionnaire. The questionnaire solicited
contact and demographic information from the participants and also included questions to assess
potential exposures to lead and arsenic as a result of daily activities (See Appendix B).
c. Biological testing
ATSDR worked closely with MCHD personnel to identify and obtain permission to use the
Superior High School Multipurpose Room and several adjacent rooms as a central location in
this small community for collection of blood and urine samples from participants.
Each adult participant was asked to complete the applicable informed consent form. Parents or
guardians of children less than 18 years of age were asked for written permission to have their
eligible children/wards participate. Children ages 7-17 years old were also asked to grant their
assent to be in the investigation.
i. Blood Lead Collection
A phlebotomist collected a 3 ml blood specimen in tubes that were specifically determined to be
appropriate for use for blood lead samples as determined by the NCEH Environmental
laboratory. To maintain privacy, the tubes were labeled with a coded identification number. After
collection, ATSDR maintained the blood samples at refrigerator temperature (4° C) and shipped
them on ice packs to the MDPHHSL in a timely manner for analysis.
ii. Urinary Arsenic Collection
Children under 6 years of age were not included in the biological sampling for urinary arsenic
because there was no adequate reference value available to interpret the results. EI participants
for urinary arsenic sampling were children between the age of 6 and 17 years of age, pregnant
women and other adults. Because the participant population for this EI was primarily children, a
random “spot” sample of urine was collected due to ease of collection rather than a 24 hour urine
collection (the collection of all urine produced by an individual in a 24 hour period of time). An
effort was also made to provide an opportunity to pick up a urine specimen cup and plastic
storage bag the week prior to the participant’s appointment time for parents of young children

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who made an appointment for testing. Parents were given specific instructions on how to collect
and store the urine specimen until their appointment time. Parents were given the option to assist
their child to obtain a first morning void or spot void on the day of the scheduled appointment
prior to their scheduled appointment time.
Collection cups and handling instructions were made available for pick up in advance to all
participants who signed up for an appointment through the MCHD the week prior to the sample
collection. MCHD individually labeled the specimen cup with the participant’s name. The
participant or their parent was instructed on how to collect and properly store a first-morning
void or spot urine void of at least 30 ml by the MCHD. The participant or parent was requested
to note the time of collection on the urine sample cup and then was instructed that the urine cup
should be capped, bagged, and placed in a refrigerator until given to ATSDR.
Those participants unable to obtain a urine collection cup in advance and who were unable to
provide a spot void at the time of their appointment were given a urine collection cup and written
urine collection instructions. They were asked to obtain a first morning void or spot void sample
and return the following day with the urine sample.
d. EI Activities and Sample Collection Schedule
The EI activities and sample collection process was available to participants on the following
schedule:
Day 1:
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Day 2:
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Obtain consent/assent and/or parental permission
Administer questionnaire
Collect blood sample
Collect spot urine sample if obtained in advance by the participant
If no advance specimen obtain a spot urine sample if able to provide
If unable to obtain spot urine sample provide collection material and instructions for first
morning void or spot urine sample to be brought in the following day
Administer consent/assent form
Administer questionnaire
Collect blood sample
Collect urine sample if obtained in advance by the participant
If no advance specimen available obtain a spot urine sample if able to provide
Collect urine sample from Day 1 participants as needed

Note: Urinary arsenic testing was not done on Day 2 participants who did not collect a urine
specimen in advance and were unable to provide a spot urine specimen during their clinic visit.
Note: The protocol originally called for 3 days of sample collection but because not all available
appointments were filled only 2 days were required.

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e. Environmental Testing - Home Tap Water Collection
Five participants in the EI with children less than 11 years of age residing in the home who made
an advance appointment for testing were asked to provide a first morning draw home tap water
sample for lead testing. An adult from the residence was asked to complete the applicable
informed consent form. Water sample bottles appropriate for lead water testing were provided by
the MDPHHSL and made available in advance to participants through the MCHD along with an
instruction sheet on how to obtain a first draw tap water sample.
f. Sample Handling and Shipping
i. Blood Lead
The blood samples were maintained at an appropriate refrigerator temperature (4° C) after
collection during the EI and then at the end of the EI all collected samples were shipped by
overnight delivery to the MDPHHSL for analysis. To maintain privacy, the samples were labeled
with a coded identification number. In addition, a number of known blood lead specimens
provided by the NCEH environmental laboratory were provided to the MDPHHSL for analysis
to evaluate laboratory performance. All blood samples were then forwarded to the NCEH
laboratory for confirmatory analysis.
ii. Urinary Arsenic
ATSDR staff received the urine samples from participants and then aliquoted samples into three
separate cryovials (urinary arsenic, speciated urinary arsenic and urinary creatinine) and then
froze them on receipt from the participant using dry ice. Samples were maintained frozen until
the conclusion of the EI and then shipped frozen on dry ice by FedEx overnight to the NCEH
Environmental laboratory for analysis. To maintain privacy, the samples were labeled with a
coded identification number.
iii. Water Sample for Lead
ATSDR collected water sample bottles from the previously identified participants at the time of
their appointment for the EI. Sample bottles were stored at room temperature until the conclusion
of the EI and then were shipped overnight to the MDPHHSL for analysis. To maintain privacy,
the samples were labeled with a coded identification number.
4. Lab Processing and Analysis
a. Blood Lead
The MDPHHSL analyzed blood samples from 63 EI participants for lead concentration using
anodic stripping voltammetry (7). The lower detection limit was 1.0 µg/dL and the upper
detection limit was 63.2 µg/dL using the current calibrator with a variation range of +/- 2.0
µg/dL. Results were reported as micrograms of lead per deciliter of blood (µg/dL). In addition to
the EI samples, 10 blood specimens with known levels of lead were provided to the MDPHHSL

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by the NCEH environmental laboratory to evaluate laboratory performance. Initial results
provided by the MDPHHSL found all samples to be below the lower detection limit of 1.0
µg/dL. However results of analysis of the 10 blind samples provided by the NCEH Laboratory
suggested the possibility of a poor correlation with NCEH laboratory analysis. As a result all
samples were forwarded to the NCEH laboratory for confirmatory analysis using electrothermal
atomic absorption spectometry (ETAAS), the same analytical procedure used in the NHANES
testing.
b. Urinary Arsenic
The urine samples were analyzed using published methodologies by the NCEH laboratory.
NCEH analyzed the urine samples for total urinary arsenic, speciated urinary arsenic when
indicated and creatinine (1).
c. Water Sample for Lead
The MDPHHSL analyzed the home tap water specimen for lead concentration. The action level
for water samples is based on the current EPA recommended action level of 0.015 mg/L (15 ppb)
as defined in the EPA Lead and Copper Monitoring and Reporting Guidance for Public Water
Systems (3). The MDPHHSL analyzed the home tap water specimen for lead concentration in
accordance with the recommendations of this EPA Guidance. The Method Detection Limit (MDL)
was 0.001 mg/L.

G. Results
1. Participants in the Exposure Investigation
ATSDR conducted the field activities for this EI on July 13-14, 2010. During this time, we
collected blood samples from 63 residents of Superior, MT. The 2007-2008 National Health and
Nutrition Examination Survey (NHANES) provided reference levels for blood lead, total and
speciated arsenic in urine in adults and children 6 years old and older (2). Prior NHANES reports
had only provided reference levels for total arsenic. Because there were no adequate reference
values for arsenic in urine in this age group it was not collected from children under 6 years of
age. As a result only 48 of the 63 participants that had blood lead testing also had urinary arsenic
testing.
The age of the participants ranged from 11 months to 74 years of age, with thirty (47.6%) of the
participants being under the age of 18. Twenty three participants met the initial criteria for the EI
of children under the age of 12. In addition one participant was pregnant. The average age of the
test population was approximately 29.8 years old.
Based on information provided from the questionnaires, 5 (7.9%) of the participants self-reported
their ethnicity as being Hispanic or Latino. The remainder self-reported their ethnicity as NonHispanic. The self-reported race of the participants was White for all 63 participants.

14

2. Environmental Testing – Home Tap Water
Tap water samples were collected from five homes. Three homes reported that the main source
of drinking water in the home was from a private well and two reported that the main source of
drinking water in the home was from city public water. The level of concern for water samples in
the EI was based on the current EPA recommended action level of 0.015 mg/L (15 ppb). No
sample concentration exceeded this value. The results are presented in Table 1.
Table 1: Home Tap Water Lead Concentrations in homes of EI participants

Lead (mg/L) 

Water Samples (n=5) 
EPA Action Limit (mg/L) 
Range 
0.015  
<0.001 ‐ 0.0031 

Mean 
0.0017 

(1) Lead concentrations below the Method Detection Limit (MDL) of <0.001 mg/L were 
calculated as MDL/√2  

3. Blood Lead Testing
The MDPHHSL initially analyzed blood samples from all 63 EI participants for lead
concentration using anodic stripping voltammetry. As previously noted, analysis of 10 blind
samples provided by the NCEH Laboratory suggested the possibility of a poor correlation with
NCEH laboratory analysis. As a result all samples were forwarded to the NCEH laboratory for
confirmatory analysis. The results of the NCEH confirmatory analysis are presented in Table 2.
Table 2: Blood Lead concentrations (µg/dL) in EI  participants 

1

NHANES Blood Lead  

EI Blood Lead (n=63) 

Age (years) 
1‐5 (n=15) 
6‐11 (n=8) 
12‐19 (n=7) 
20+ (n=33) 

GM2  
1.51  
0.99  
0.80  
1.38  

95th % 
4.10 
2.50 
1.90 
3.90 

GM2 
1.27 
1.034 
0.834 
1.09 

N>95%3 
0 
0 
0 
0 

Range 
0.60 ‐ 3.01 
0.51 ‐ 2.28 
0.58 ‐ 1.47 
0.31 ‐ 2.79 

Total 

1.27  

3.70 

1.09 

0 

0.31 ‐ 3.01 

(1)
(2)
(3)
(4)

95th percentile of NHANES Reference Range (CDC 2009)  
GM = Geometric Mean 
Number of samples greater than the NHANES 95th percentile 

Although participant geometric mean is slightly higher than NHANES geometric mean it 
is within the 95% confidence interval. 

4. Urinary Arsenic Testing
NHANES provides reference levels for total and speciated arsenic in urine for adults and
children 6 years old and older (2). There are no standard reference levels available for children
under 6 years of age. For this reason the 15 children under 6 years of age are not included as
participants in this EI for urinary arsenic evaluation. The NCEH laboratory analyzed urine
samples from 48 of the 63 participants in the EI. To correct for urinary dilution NCEH analyzed

15

the urine samples for urinary total arsenic and creatinine. This is the common method to
determine a creatinine corrected total urinary arsenic result. For participants with a creatinine
corrected total urinary arsenic greater than 10 μg/g of creatinine, a creatinine corrected total
speciated urinary arsenic level was also determined to differentiate between levels of inorganic
and organic urinary arsenic species. NCEH analyzed the urine specimens using the same
analytical procedures used in the NHANES testing. For methodology see Appendix C of the
Fourth National Report on Human Exposure to Environmental Chemicals (1). The results of the
NCEH analysis are presented in Table 3.
Table 3: Creatinine corrected total urinary arsenic (µg/g of creatinine) in EI participants. 

Age (years) 
6‐11 (n=8) 
12‐19 (n=7) 
20+ (n=33) 
Total 

1 

NHANES Urinary Arsenic
2 

 GM
8.87 
5.49 
9.01 
8.47 

th 

95 % 
37.2 
22.5 
59.4 
49.8 

EI Urinary Arsenic (n=48) 
GM2 
8.47 
5.614 
7.57 
7.38 

N>95%3 
0 
0 
0 
0 

Range 
5.4 ‐ 21.0 
4.0 ‐ 9.1 
2.9 ‐ 42.3 
2.9 ‐ 42.3 

(1) 95th percentile of NHANES Reference Range (CDC 2009) 
(2) GM = Geometric Mean  
(3) Number of samples greater than the NHANES 95th percentile 
(4) Although participant geometric mean is slightly higher than NHANES geometric mean it 
is within the 95% confidence interval. 

Ten of the 48 participants sampled had creatinine corrected total urinary arsenic greater than 10
μg/g of creatinine. The urine samples of these 10 participants underwent further analysis by the
NCEH Laboratory to determine the sum of urinary inorganic-related urinary arsenic species
(arsenous acid, arsenic acid, dimethylarsonic acid [DMA] and monomethylarsonic acid [MMA])
present in their specimen. The limit of detection (LOD) for the sum of inorganic-related urinary
arsenic species was 4.8 μg/L. The results of the NCEH analysis are presented in Table 4.
Table 4: Urinary Inorganic‐related Arsenic Species (µg/g of creatinine) in EI participants with creatinine 
corrected total urinary arsenic >10 µg/g of creatinine. 

EI Urinary Inorganic‐related Arsenic Species 

NHANES Urinary 
(n=10) 
Inorganic‐related Arsenic 
N>95%2 
Range 

Age (years) 
Species 95th %1 
6‐11 (n=2) 
14.7 
0 
7.6 – 14.7 

12‐19 (n=0) 
16.7 
N/A 
N/A 

20+ (n=8) 
19.4 
0 
numher 00339
:'I){)l) \\'(/la (jill/lin I\cjl(Ji'/

III \.'()1l1pll~1I11'e \\ Ith the EPXs S~ltc Drlllkill~ Water :\l't ami III all eli()rt t(l keep youllll()rJllL'd ah(lut
the LJLldiity (ll \\~Iter ,IIlLi senil'l''i \\e prmlLie tu you c~lch lia:-, \\ e're pleased t() pr()\ Ilk Y(IU \\ Ith (lUI'
Annual W~lter Quality Report, This repurt IS a sn,lpshut 01 thc LJu~t1lty 01 \\ ater \\c pr()\lded you 1:I\t
ye'lr. It IIlL'ludes liet,lIis rcgarlilllg the souln:: of yuur \\atcr, \\ h~lt your \\,Iter L'olltalll') ~l1ld hu\\ It
cnmpare') to EP,\ allll the State ll! \julltcllla st:lTlli,lrlis,
w,lter sourl'es are three \\ells th,lt lir,I\\ w,lter from the one hundred alld filly feet deep ,i1IUVI,1i
the south silie of the Clark Furk Ri\er, Flat Creek Spring h:ls not been used ,IS a S()Uln:: for
the public \\,atcr supply sincc 1997, due to high levels of antimony. Howe\er, gra\ity flow from thc
Flat Creek Spring collector could be used as an emergency backup source of water. The \\ells and
spring are conllected to a~OO,OOO gallon resen'oir for storage, and the system has a backup generator
to maintain the water supply in the event of a loss of po\\er. To ensure its punty, we treat Ollr \\'ater
with chlorine. We ha\e -+ 11 sen'ice connections and have added three ne\\' connections this year. We
installed approximately 12,000 feet of new water mains, and6 new hydrants, This \\as financed by
stimulus money, loans and grants.
QUI'

~Iquiferon

We \\'ant you, our valued customers, to be informed about your water utility, If you want to leam
more, please attend any of our regularly scheduled meetings held on the second Monday of each month
at 7::~O p.m. at 305 Mai n Street.
We are pleased to report that our drinking water is safe and meets all federal and state requirements.
If you have any questions about this report or conceming your water utility, please contact Roger
Wasley or Tony Lapinski at (..J-06) 822-..J-672. Roger and Tony are our certified operators with 10
years of experience each, They attend periodic training sessions to meet continuing education
requirements. The most recent traIning was in March of 2009 the topics Included water and waste
water.
DiD YOU KNOW') The sources of drinking water (both tap and bottled water) include ri\ers, lakes,
~trcams, ponds, reservoirs, and \vells, :-\s \\ater tra\'el:; o\er the surface of I~md or through the ground
it dissol lies naturally occulTing minerals and in some cases radioactive elements, Water can al so pick
up substances resulting from the presence of animals or from human acti vity,

CunLlminants that Tllay he prcsent In \\ ater includc:
I)
Microbial contaminants such as \'iru:-,es and hacterl,1 \\hlch may come frnm SC\\ ,Ige tl'catlllent
plants, septic systems, agricultural II\estock operations and \\ildlifc,
.2)
Inorg,lIllc cUlltalllin,lIlts, such as s,lits and mctals \\ hlch em he n~ltLlrally (lCCUITin~ or rc')ult
from urh,1Il storm \\Clter rUlloff. industrial or domcstlc \\,Iste \\atcr dlsl'klrgcs, oil and gas
pruductlllil. minlllg and Llrlllillg.
,~)
Pestlcldcs and hcrhlcldes, \\hil'h may come from a \ ariel:- of S()UrL'eS such ,IS d~riL'ulturL'.
urhall storm \\ ,Iter 1'Llno!T and reslLientl,1i uses,
-t)
\'olatiic nrganic chemIL',lis, \\hlch are hYllroducts ()f IIldustn,1i processes. petroleum
produL,tiClIl, and call also comc from geLS stations, urhan storm \\,Iter runoff. ~Illd septic systems,
:'i)
Radl()Clctivc cont,llllln,lTlts, \\ hil'h L'all he IlCltLIr,lily occurring ur he the result uf oil ~l1lcl
production and Tllilling actl \ Ities,

45

In (IrLiCI to 1'1l~1I1C that tap \\ atl'l IS s~lk to drlll~. the EPA plnLTlhL'~ 1<~~ltlatl(Hh \\ hlL'1l 1II111t till'
()f L'LTt~1I11 L'llntal11lll~l11h III \\ ~Itcr prm ideli h) puh IiL' \\ ~ltL'r~) ~te111\. FD.\ Il' ~ ul atll Ilh l'~ta hll~h

~lIn(lunt

limits forc()nt~IJllin~lIlh III huttled \\ atl'l which l11ust plm ide thc S~ll11e protcctlon 1m public hl'~ilth. Thl'
Superior W~lter System rDutlT1cly T1lllnlt(lIS for c()nstltuents in your drinking \\'File Typeapplication/pdfFile TitleMicrosoft Word - Superior EI report FINAL 31MAR11 _2_.docxAuthorrlm6File Modified2014-10-08File Created2011-04-05