PONTIAC -- Shawna Elmore, a Pontiac Township High School senior, read the marble gravestone of a child buried in Northwest Pontiac Cemetery.
"It makes me kind of sad, looking at stones about children," said Elmore, 17, an earth science student who was in the cemetery as part of a scientific study.
The students were learning how acid rain and atmospheric conditions can affect marble.
The Gravestone Project is part of the global citizen science program called EarthTrek, administered by the Geological Society of America in partnership with organizations around the world.
The students of teachers Paul Ritter, Brian Hitchins and Lisa Jennings visited cemeteries in Chenoa, Fairbury, Odell and Pontiac, measuring the gravestones to see the effects of acid rain.
In the last 100 years, students found, stones have decomposed between 13 to 20 percent, Ritter said. That says a lot about pollution in the area, he said.
Marble stones are among the best to gauge the chemical reaction caused by the atmosphere, Hitchins said. Gases, dissolved in rain, cause the marble to "weather."
By having volunteers take simple measurements of marble gravestones of different ages, scientists hope to produce a world map of the weathering rates and therefore monitor how the atmosphere has changed.
"Learning about pollution is a big thing," said sophomore Cody Chapman as he measured a stone. Sophomore Ian Beller joked it was warmer when the students learned -- indoors -- how to measure the stones.
Hitchins' 16 students were coached about measuring correct heights and locations, to record the family name, date of death and other details, and a cellphone photo to include as part of the record.
The students logged the information into a database, using GPS "addresses" of the cemeteries to map the results.
The teachers plan to continue the project with new students every year. The detailed records will help create accurate comparisons of the changing measurements.
"I hope our kids will inspire others to do great things," said Ritter, who would like to see the project picked up by other schools. "It's a real-world application in the hands of kids. It's true education."
On their own, several students later looked up names to learn more about the dead, which drew praise from Ritter.
Barb Graves of the Lexington Genealogical Society told students the importance of information on the stones. "It is the only record we have on some people," she said.
On the Web
Acid rain effects: For more information and to stay updated on the progress of the gravestone project, please visit: http://www.goearthtrek.com/Gravestones