It’s almost like Thriller. . .
Acid Rain has become a considerable problem on today's environment. The United
States Environmental Protection Agency (EPA) states that, "Caused by air pollution, acid
rain's spread and damage involves weather, chemistry, soil, and the life cycles of plants and
animals on the land and from acid rain in the water”. Acid rain can effect all parts of our
environment, as well as our lives.
Unpolluted rain has a pH of 5.6, as a result of natural carbon dioxide gases it picks
up in unpolluted air. Today, pH levels of rain are much lower as a result of industrial
pollutants in the atmosphere. Water droplets fall from clouds, picking up harmful particles
and chemicals on their way to the earth's surface. According to the EPA Acid Rain Web
Site, "When rain contains pollutants, especially sulfur dioxide and nitrogen oxides, the rain
water can become very acidic." Ohio alone is home to eighty thousand air contaminant
sources, and contributes two million tons of sulfur dioxide a year (White, 25). Thus, acid
rain is a direct threat to our environment and lives.
In studying the age, condition, and other properties of gravestones, it is possible
to determine the rate in which limestone is deteriorated as a result of acid rain and related
weathering. When acid rain comes into contact with materials, such as limestone, it
speeds up the deterioration process and leads to corrosion. In order to determine acid
rain's effects in a graveyard, we intend to compare the condition of limestone graves from
different time periods. We hypothesize that the older the gravestones are, the more
corroded they will be as a result of being exposed longer to acid rain and similar
weathering. We also think that the gravestones facing west will be more deteriorated
because weather usually travels from the west. Graves on hilltops will also be in worse
condition than others because they are less protected from rain and weathering.
B. Project Decisions/Questions
We decided on this project so that we could discover the dangers acid rain
pollutants have on materials in our environment. The effects of acid rain on limestone
graves, for instance, is similar to the effect it has on limestone buildings and monuments.
Are there certain ways to place limestone structures so that they will be least effected by
acid rain and weathering?
C. Planned Accomplishments
In determining the effects acid rain has on gravestones, we hope to encounter ways
in which limestone can be preserved, or ways in which acid rain could possibly be
decreased. We wish to discover the patterns of erosion on the graves in Oxford
Cemetery, which is a kind of historical log of data on rates of disintegration.
It will be interesting and informative to see the extent of damage acid rain causes
on limestone structures in our environment. Recently, laws to reduce air pollution have
gone into effect. By studying the information we collect and analyze, we can determine
whether more laws need to be created and if older laws need to be reinforced.
II. Relevance of the Research Question
A. Literature Review
There has been substantial study in the area of acid pollution, starting from the
1970s until the present day. The study we found to be most similar to ours is a United
States Geological Survey completed in 1989. Instead of observing limestone, as we are
doing, this study observed marble using glass as a reference. They found that the
dissolution rate of the stone doubled when the rain was moving slower and the pH was
higher. Schuster and Reddy, in the Geological Survey write, "The analytical results
presented in this report are intended to aid researchers in the assessment of the effects of
acidic deposition on building materials,"(2). Since we consider ourselves researchers in
this field of study, the survey will help our group better understand how limestone
Our group came across a countrywide survey of rainfall levels and pH
measurements. J.C. Simpson and A.R. Wilson for the Environmental Protection Agency
(EPA) conducted this study. It is relevant to our research because highly acidic areas
were mapped, and happened to include Oxford as a detailed location. Relating to our
conclusion, we found a study titled, "Industrial Pollution Prevention Opportunities for the
1990s." It contains detailed solutions for automotive and other industries, to minimize the
release of sulfur dioxide and nitrogen oxides, the two biggest chemical causes of acid rain.
This study will assist us because we have considered discussing possible prevention
methods for acid precipitation in our results, which we could develop during the
undertaking of our research project.
B. Relation of Research to the Larger Question
Our project has far reaching relevance for the community and the world. It is a
relatively small study, which is part of a larger inquiry into the damage humans have
caused to Earth. Our specific question deals only with acid rain, one of many types of
pollution. Even more specifically, we are studying how acid rain affects limestone, using
gravestones as a medium. By doing such a small study in the total encompassing topic of
pollution, our group has learned that the study of pollution is a vast field. It is so vast that
six college students cannot possibly cover all it entails. However, we realized that any
advances we can make are completely worthwhile, and our results will be useful to others
studying this topic. The results of this project, besides showing how quickly acid rain is
decomposing the limestone gravestones, will also show how limestone structures in
Oxford are holding up. With our data, we can determine when Oxford's limestone
gravestones will be completely eroded away. We will to discover solutions for preventing
the damage caused to limestone in the future. Now that the project has been expanded to
examine the orientation of tombstones, our group will have results concerning weather
direction and how this can affect damage by acid rain.
III. Materials and Methods
A. Experimental Design
We created a weathering scale for the tombstones that ranged from excellent,
good, fair, poor, and bad. The condition of the graves was determined according to the
decomposition of the limestone. The orientation of the graves was recorded to prove our
hypothesis that the graves facing west would be the worst. We measured the depth of the
inscription using a micrometer and recorded the location of each grave. The legibility of
each grave had a rating system with three ratings: legible, satisfactory, and illegible. The
names of those buried were not recorded, because the information was not relevant to our
experiment. Instead, we recorded the dates of each tombstone. We also did not complete
any chemical testing on the graves for we feel that would be damaging others’ property.
The group went to the Oxford Cemetery and recorded 177 graves. Ann and Danielle
photographed a small portion of the graves to use as examples for the scale and to create a
picture log of our specimens. Then all the results were compiled in StatView and we
made graphs in SuperNova.
B. Statistically Sound
Our project is statistically sound because we measured each grave the same way,
paying close attention to accuracy, and worked in pairs to agree when classifying each
grave. The group entered the data into the computer and then rechecked to make sure we
had all of the information entered in correctly. (We made a list and checked it twice, so to
speak) We had quite a few extended conversations with our illustrious professor to ensure
we were following the correct steps. He was of vital importance in understanding our
results and calculating them accordingly.
1. Unbiased Results
We can ensure unbiased results by taking every precaution to have accurate
data, and to enter that data into StatView correctly.
2. Accurate Data
When we gathered data with the class, there was one group member for
every two classmates. The student-teacher ratio of was incredibly small, allowing us to
be with them at all times. For the presentation we devised a foam board with all of the
rating systems on the display so the class could see what we meant by good, poor, etc.
We stressed the importance of consistency through our presentation by telling the students
exactly what to look for and precisely how to classify the tombstones.
3. Important Materials
Chalk, 4 pieces used in class demonstration
Vinegar, 1 1/3 cups used in demonstration
Fishbowl, used in demonstration
Foam board, used to paste pictures on for demonstration
Plastic skeleton, used in presentation
Camera and film, to take pictures of the graves
6 Micrometers, for each group to measure inscription depth
Compass, to ensure accuracy for orientation
Data sheets, for the class to record data
4. Class Participation
The class was involved in our lab analyzing tombstones. The project was
presented with a simple vinegar and chalk experiment to show the effects of acid rain on
limestone. We discussed relevant research, our hypothesis, and how to record the graves.
A board displayed our scale with corresponding pictures, and the chemical equation for
acid rain. We divided the graveyard into six sections and had the groups record twenty
graves. The class was given a data sheet with all of the categories we needed preprinted.
They also mapped all of the graves but the information was not useful in our research.
After the presentation we immediately put the graves into StatView.
5. Data Sheet- see page 9
6. Timeline- see page 9
Our study of limestone tomb damage was divided into the categories of tomb condition
rating, location, orientation, inscription rating, inscription depth, and date. These six
categories, when grouped together in a variety of ways and plotted using StatView, gave
us interesting, although somewhat unexpected results. After collecting vast amounts of
grave data, we formulated several hypotheses concerning each rating category. These
included that tombs facing west would be damaged the most, since that is the direction
weather hits Oxford, and that tombs on hilltops would also be badly damaged. We were
unsure if inscription depth measurements would show any unity at all, since each tomb
could have been carved differently during its manufacturing. Also, we obviously
considered that the oldest tombs would have suffered the most damage.
B. Graph explanations (What we learned from each graph)
1) Location, Tomb Condition, and Inscription Depth-see page 10
-All tombs rated excellent are on hilltops (many of the newer graves were
-Tombs on slopes had increasingly lower inscription depths progressing
from good to bad tomb ratings.
-Tombs on slopes have the lowest inscription depths of the three location
-Tombs in valleys are of the worst condition.
2) Location, Tomb Condition, and Date- see page 11
-Location does not seem to affect tomb condition.
-The majority of graves from each rating category are found on hilltops.
-The older the tomb, the worse the condition.
3) Tomb Condition, Orientation, and Date- see page 12
-The only tombs rated excellent face west.
-All tombs facing northeast are in bad condition.
-All tombs facing southwest are in bad condition.
-All tombs facing southeast are in fair condition.
-Tombs facing west have the widest variation in condition ratings.
-All tombs facing up are either in poor or bad condition.
-Tombs facing north are in the best condition.
4) Orientation and Inscription Depth-see page 13
-Tombs facing southeast had the deepest inscriptions.
-Tombs facing west had the second deepest inscriptions.
-Tombs facing up had the shallowest inscriptions.
5) Orientation and Date- see page 14
-Tombs facing west were the most recently buried.
-Tombs facing north, northeast, and south were the oldest.
V. Summary of Results
Concerning location, our data showed that tombs on hilltops suffer the least
amount of damage, although this could have been skewed due to the fact that many of the
newer graves were on hilltops. We also learned that tombs in the valleys have suffered the
most damage. Concerning orientation, we noticed that tombs facing north suffer the least
damage, and tombs facing southwest and northeast suffer the most. Graves facing up
were even worse, but that damage can be attributed to the fact that older graves that have
been harmed more have fallen over. So, our hypothesis dealing with orientation was
disproven, since we had suspected tombs facing west would be the most damaged. Our
hypothesis concerning orientation was partially disproven because we thought hilltop
tombs would suffer the most weathering. Our general, basic hypothesis that the older
graves would have the most damage was proven correct.
How does this research fit in with the work of others? We’ve been exploring the
field of consolidants, the latest development in protecting national monuments from acid
rain. Michelangelo’s David used to be outdoors in the Santoria Square in Florence, but it
was moved indoors about ten years ago to protect it from acid rain. Other monuments,
however, cannot be moved so easily, and it is for these structures that consolidants were
invented for. Consolidants were developed in the 60s after a flood threatened the
buildings in Venice. The Sandia National Laboratories in Albuquerque, New Mexico have
been researching and working on the creation of a consolidant to cover limestone and
marble to protect them from weathering. In St. Paul, Minnesota, a testing session planned
for the next few years just begun when consolidants were applied to the dome of the state
capital. The problems with consolidants is that they are toxic, hard to apply, and it is not
known how long their protection lasts for. John Stubbs, director of programs for the
World Monuments fund, reflects on these problems, “We have to respond to a range of
stone damage, not just from building to building, but from stone to stone within a single
Further research could be done on different stones within a building, other
graveyards in different geographic areas, and on the effects of other pollutants on
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