FALLON, NEVADA, CHILDHOOD LEUKEMIA: A CASE STUDY IN

MEDICAL GEOLOGY

Paul Sheppard

Laboratory ofTree-RingResearch

(dendrochronology)

But Wait, There’s More …

• AHSC colleagues

– Dr. Mark Witten, Pediatrics (ret.)

– Dr. Clark Lantz, Anatomy (admin.)

• Joint faculty, Zuckerman Public Health

• ACC

– CPC

• Huh?

Medical Geology

• (Re)-emerging interdisciplinary scientific field

• Study of exposure to, or deficiency of, trace elements, e.g., in dust, water, food

• Effects on human health

Hydrobiogeochemoepidemiopathoecology

• Ron Fuge: Editor,Applied Geochemistry

• Olle Selinus: My working editor

Lovelock

Fern ley

Yerington

Reno Fallon

Ne

vada

Califo

rnia

80

50 km

Fallon Leukemia

• 17 cases, 1997-2004

• 27x national rate

• 1 in 232 million

• “Most convincing cluster ever reported”

Environmental Analysis

• Ecologic study vs. case-comparison

• Multi-element analysis

• Controls

• Multiple lines of evidence

• Replication

• Airborne environment

Airborne Dust

Fallon Airborne Dust

• Many samplers

• Many days

• Five towns

• Project repeated

− New equipment

Lovelock

Fernley

Yerington

Reno Fallon

Ne

vad

a

Californ

ia

80alt95

alt50

50 km

0

5

10

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llon

(1

0)

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llon

(5

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ove

lock

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llon

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ern

ley

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llon

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eri

ng

ton

(5

)

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llon

(2

)R

en

o (

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llon

(2

7)

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ers

(1

8)

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ng

ste

n (

ng

m–3

)

0

1

2

Co

ba

lt (n

g m

–3)

0.0

10

.01

0.0

1

0.1

5

0.0

20

.06

0.0

7

0.3

0

0.0

01

0

.00

1

a

Fallon W Other W Fallon Co Other Co

Tungsten and cobalt

• Elevated in Fallon

• Variable through time

Surface Dust

Tungsten, cobalt

• Variable across space, mostly low

• Elevated neartown center

• Hard-metal industry

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95

95

117

Tungsten Concentration (ppm)

0 3 km

N

0 - 1010 - 20

20 - 30

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a

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Station Fallon

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117

Tungsten Concentration (ppm)

0 3 km

N

0 3 km

N

0 - 1010 - 20

20 - 30

934

0 - 1010 - 20

20 - 30

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a

Fallon

Naval Air

Station Fallon

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95

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117

5 - 1010 - 15

15 - 25

98

Cobalt Concentration (ppm)

b

Fallon

Naval Air

Station Fallon

0 3 km

N

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117

5 - 1010 - 15

15 - 25

98

5 - 1010 - 15

15 - 25

98

Cobalt Concentration (ppm)

b

Fallon

Naval Air

Station Fallon

0 3 km

N

0 3 km

N

Fallon Surface Dust

Lichens

Fallon Lichens

• 10 in town

− Rattlesnake Hill

• 20 out of town

− All directionsNavalAirStation

Fallon

East

South

West

North

10 km

alt50

95

Table 1: Element concentrations and standard errors in lichens and rock substrates. Cobalt and tungsten are shaded for lichens as the only elements with significant differences within Fallon versus outside of Fallon.

Lichens

Within Fallon (n = 10) Outside Fallon (n = 20)

Element Median (ppm)

Standard Error

Median (ppm)

Standard Error

Ratio Within: Outside

lithium 8.02 0.82 5.37 3.61 1.49 beryllium 0.32 0.06 0.19 0.07 1.71 vanadium 21.65 3.88 13.40 5.52 1.62 chromium 8.52 1.56 6.21 2.26 1.37

manganese 137 52 118 43 1.16 iron 8122 1403 6290 1852 1.29

*cobalt 3.59 0.73 1.79 0.65 2.01 nickel 4.38 0.94 4.40 0.99 0.99

copper 8.99 0.72 7.73 1.43 1.16 zinc 43.55 2.31 34.60 4.58 1.26

arsenic 4.83 0.72 3.07 0.99 1.57 strontium 251 20 179 20 1.40

molybdenum 0.63 0.06 0.60 0.12 1.05 silver 0.17 0.01 0.14 0.01 1.26

cadmium 0.30 0.01 0.32 0.02 0.94 tin 0.61 0.07 0.44 0.08 1.40

antimony 0.77 0.08 0.71 0.13 1.09 cesium 1.44 0.14 0.93 0.44 1.54

tantalum 0.09 0.02 0.06 0.02 1.47 ***tungsten 24.95 1.91 1.99 0.30 12.54

thallium 0.12 0.01 0.08 0.03 1.55 lead 13.70 1.15 17.45 5.13 0.79

thorium 2.28 0.33 1.35 0.31 1.69 uranium 0.96 0.11 0.52 0.19 1.85

Rock Substrates

Within Fallon (n = 3) Outside Fallon (n = 12)

Element Median (ppm)

Standard Error

Median (ppm)

Standard Error

Ratio Within: Outside

cobalt 24.00 0.58 23.00 0.47 1.04 tungsten 2.40 0.17 2.45 0.06 0.98

* Significance at the 0.06 level, *** significance at the <0.001 level. Differences in medians were tested using the two-tailed Mann-Whitney test of medians (Sokal and Rohlf, 1981).

• Most Elements

– Slightly higher in Fallon

• Tungsten, cobalt

– Much higherin Fallon

Fallon Lichens`

`

– Not higher in Fallon rocks

Tree Leaf Chemistry

1. Clip a branchlet of leaves

2. Rinse leaves in water, save water

3. Measure rinsate for contaminants

4. Divide through by mass of dried leaves

5. Map out concentrations

6. Repeat every year,citizen science

Fallon Leaf Chemistry

Fallon Leaf Chemistry

Tree rings

Fallon Tree Rings

• Trees in Fallon

• Trees in other towns

• Last 15 years

50

95

Lovelock

Fernley

Yerington

Fallon

Ne

vad

a

Ca

liforn

ia

80alt95

alt50

50 km hard-metalfacility

250 m

A B

Fallon Tree Rings

• Tungsten increased since mid 1990s

• Cobalt high through-out

• Other metals not noteworthy

0

100

200

1990 1992 1994 1996 1998 2000 2002 2004

A:

Tun

gste

n0.01 0.04 0.06>0.50

0

70

140

1990 1992 1994 1996 1998 2000 2002 2004

B:

Cob

alt

0. 0. 0. 0.

0.01 0.02 0.06 0.01

1,500

2,500

3,500

1990 1992 1994 1996 1998 2000 2002 2004

C:

Cop

per

>0.50 >0.50 >0.50 >0.50

0

100

200

1990 1992 1994 1996 1998 2000 2002 2004

D:

Cad

miu

m

>0.50 0.02 0.09>0.50

0

125

250

1990 1992 1994 1996 1998 2000 2002 2004

E:

Lead

>0.50 >0.50 >0.50 >0.50

Con

cent

ratio

n (p

pb)

• Environmental Research (me)

• Fallon distinctive environmentally

– Tungsten and cobalt elevated relative to other towns, outlying desert

– Airborne particles

• Biomedicalresearch (Witten)

• Public health theory• Research by others

Biomedical Side• Tungsten can’t be linked to

leukemia from en-vironmental data alone– Biomedical research

suggestive– IARC: W and Co probably

carcinogenic

• Relevant title

• Appropriate journal

• Independent authors

• High tungsten burden in Fallon

• Tungsten exposure in Fallon

• Leukemia cluster in Fallon

• Tungsten biomedical treatment level based on environmental finding

• Tungsten of high interest in cancer research

EPA Earmark: Fallon

What’s next?

• Other sites with illness

• Other sites with pollution

Funding

• Cancer Research & Prevention Foundation

• Gerber Foundation

Funding Dilemma

• NIEHS: Understand how combined environmental exposures affect disease pathogenesis

• EPA: Protect human health and the environment

• Research, or mere monitoring?

Thanks for having me.

Comments, questions?