Effect of 1940's Land Use On Arsenic
Levels in The Soil Today
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Researched by Amanda J.
2004-05 |
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PURPOSE
The purpose of this experiment was to compare the effects of land use
during the 1940’s the on arsenic level in the soil today.
I became interested in this idea when I became aware of the arsenic
problem in our community. I wondered how widespread arsenic
contamination was and what caused it.
The information gained from this experiment would show parents and
community leaders how much arsenic is in public school soil. This
information might be used to encourage clean up or find ways to protect
school children from exposure.
HYPOTHESIS
My hypothesis was that locations that were used during the 1940’s as
orchards would have the most arsenic in the soil.
I based my hypothesis on a statement by Norm Hepner, a Washington State
Department of Ecology engineer. He said, “The Intermediate School
is most likely the only school truly affected, though the results may
prove this incorrect because the soil was moved to create the design of
the campus.”
EXPERIMENT DESIGN
The constants in this study were:
- Depth in the ground at sampling (15 cm.)
- Amount of samples per school
The manipulated variable was the location the samples were taken from.
The responding variable was the amount of arsenic in the soil samples.
To measure the responding variable I used an Innovox system loaned by
the Washington State Department of Ecology.
MATERIALS
QUANTITY ITEM DESCRIPTION
15 plastic bags
1 Shovel
1 garden
rake
1 Testing
kit
1 Black
Permanent marking pen
1
Measuring cup
1 Innovox
system
PROCEDURES
1. Plan where to take samples
a) Plot on a map of each school where to take
samples
b) Repeat for every one of the three
schools
2. Take samples at one location
a) Dig a 15 cm. deep hole with a clean shovel
at location one
b) Remove 125 ml. of dirt from the bottom of
the hole
c) Put dirt in a plastic sandwich bag
d) Label bag with school and location number
3. Repeat step 2 for every one of the three locations on campus
4. Repeat steps 2-3 for each school
5. Test the samples with a innovox system
a) Place plastic sandwich bag on top of the
metal plate
b) Scroll down on the digital screen until you
come to the symbol “As.”
c) Record amount of arsenic in ppm. (Parts per
million) in the sample
on a data table
6. Repeat steps 5 for every sample in school one
7. Repeat steps 5-6 for every school
8. Analyze data
RESULTS
The original purpose of this experiment was to compare the effects of
land use in 1940’s the on arsenic level in the soil today.
The results of the experiment were that Selah Intermediate School had
on average 58.7 ppm. Of arsenic and it was the only school that was an
orchard in the 1947.
See my table and graphs
CONCLUSION
My hypothesis was that locations that were used during the 1940’s as
orchards would have the most arsenic in the soil.
The results indicate that this hypothesis should be accepted because
Selah Intermediate School had the most arsenic and it was the only
school that was an orchard in the 1940’s.
Because of the results of this experiment, I wonder if other school
districts would have different amounts of arsenic, if other toxins were
in the soil, and if the arsenic in the water affected the soil.
If I were to conduct this project again I would get the samples before
the ground froze and I would test more schools and samples I would also
test the samples more than once.
RESEARCH REPORT
Introduction
Soil is one of our most important resources. We cannot survive
without clean soil. Since over 95% of our food comes from the
soil one way or another, keeping soil clean so it remains healthy and
productive is an important survival issue. If the soil on school
playgrounds is contaminated with toxins and chemicals then children are
at risk of minor to serious health issues.
Arsenic
Arsenic is a naturally occurring chemical element. Pure arsenic
is grayish and metal like, but is rarely found in nature. Arsenic is
usually found combined with one or more other elements such as oxygen,
chlorine, and sulfur. When arsenic is combined with these, arsenic is
referred to as inorganic arsenic. When arsenic is combined with
carbon and hydrogen is referred to as organic arsenic. The organic
forms are usually less toxic than the inorganic forms.
The atomic number for chemical arsenic is 33 the atomic weight is
74.9216 the symbol is “As.”
Removal
Certain ferns remove arsenic from soil they are planted in. There
are also testing and removal kits available.
Effects
Organic arsenics cannot cause cancer, or DNA damage, but exposure to
high doses may cause certain effects to human health, such as nerve
injury and stomachaches. Exposure to inorganic arsenics can cause a
variety of health effects, such as less production of red and white
blood cells, irritation of the stomach and intestines, skin changes and
lung irritation. Large amounts of inorganic arsenic can increase the
chances of cancer, especially the chances of skin cancer, lung cancer,
liver cancer and lymphatic cancer. Plants absorb arsenic easily, so
that high concentrations may be in the plant tissue. So if animals eat
the plants, they ingest a great amount of arsenic. They will die as a
result of poisoning. They decomposed into the soil where other animals
live so the ground will be toxic. As a result plants grow and the cycle
starts again.
Uses
The most common uses of arsenic in the U.S. are wood preservatives
(74%), agricultural products (19%), glass (3%), nonferrous alloys (2%),
and other uses
(2%).
Soil pollution
Waste, and chemicals and many other things dumped and thrown out by the
carelessness of humans can cause soil pollution. Poisons
like gasoline, deicer, weed killers, and pesticides can soak into the
soil and pollute it so plants like grass cannot grow and develop
properly.
Source
Soil contamination results when chemical substances are either spilled
or buried. Another source of soil contamination could be water that
washes toxins from an area containing chemical substances and deposits
the contamination in the soil as it flows through.
Effects
Toxins in the soil can hurt plants when they try to grow or they can
and take up the toxic chemicals through their roots. Contaminants in
the soil can harshly impact the health of animals and humans when they
ingest, or touch contaminated soil, or when they eat plants or animals
that have already been affected by soil contamination. Animals ingest
and come into contact with contaminants when they burrow in
contaminated soil. Humans ingest and come into contact with
contaminants when they play in contaminated soil or dig in the soil as
part of their work. Certain contaminants, when they contact our skin,
are absorbed into our bodies.
Removal
There are three general ways to cleaning up toxic soil.
1) Soil can be moved from the ground and be either treated or disposed
2) Soil can be left in the area and treated in place
3) Soil can be left in the ground and contained to prevent the
contamination from becoming more widespread and reaching plants,
animals, or humans.
Summary
Arsenic is a toxic chemical element that is in our water and
soil. It is endangering the children of the world as a
toxin in the soil they play in and in the water they drink. Soil
pollution is an important factor to health because the toxins may be
ingested and may cause serious damage.
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BIBLIOGRAPHY
“Arsenic,” Britannica Encyclopedia inc. 2003
Bentor, Yinon “Chemical Elements.com - Arsenic” December 8, 2004
http://www.chemicalelements.com/elements/as.html.
Busch, Marianna. "Arsenic,” World Book Encyclopedia, 2004.
Chertow, Marian .R. "Environmental Pollution” World
Book Encyclopedia, 1998
Hepner, Norm personal interview
Johnston, Taylor .J. "Soil” World Book Encyclopedia, 2003
“The Mineral Native Arsenic” Amethyst Galleries, Inc. December 8, 2004
http://mineral.galleries.com/minerals/elements/arsenic/arsenic.htm.
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ACKNOWLEDGEMENTS
I would like to thank the following people for helping make my project
possible:
- My mom for helping me get the samples in freezing weather
- Mr. Newkirk for grading and correcting my project
- Mrs. Helms for helping me with my graphs
- Norm Hepner for helping test the samples and assisting me
in almost everything
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