EIU Media Relations

EIU Professor Aims to Solve Mystery of Acid Rain's Formation

So, you don’t understand what causes acid rain? Don’t feel too bad – scientists don’t quite get it, either.

But Rebecca Peebles, an assistant professor in Eastern Illinois University’s chemistry department, hopes to change that.

Peebles has received a competitive $30,000 grant to allow her to study the destructive phenomenon. Only nine similar grants were awarded throughout the nation by the Camille and Henry Dreyfus Foundation this year.

In simple terms, Peebles wants to find out where acid rain comes from so scientists will be better able to predict the future health of the atmosphere and to reduce harmful chemical reactions in the future.

“I think the better an understanding we have of the world around us, the better chance we have of protecting the world we live in and not destroying ourselves through pollution and acid rain,” she said. “Knowledge is our best weapon.”

Her work should help scientists understand what chemical reactions are happening to create acid rain.

Most of the world’s nations, minus the United States and Australia, adopted the Kyoto treaty in February. The treaty, which was drawn up in 1997, aims to reduce greenhouse gas emissions in an effort to control global warming.

Now, as U.S. legislators wrestle with domestic proposals for limiting greenhouse gas emissions, forecasts for the atmosphere’s health become a key component of the debate.

“It becomes very important to try to predict how acid rain will build up,” Peebles said.

Peebles studies the interaction between individual molecules to better understand the process by which two molecules combine to form an acid. For example, when sulfur dioxide, a significant industrial pollutant, interacts with water, it creates sulfuric acid, one of the main culprits in acid rain.

Molecules have to come together in a particular way to create a certain reaction. She wants to take a closer look at that tendency.

People have theorized that the number of molecules involved makes a difference in how the interaction takes place.  “Nobody’s done an experiment to try to decide if they’re right or not,” she said. “I want to see if we’re just completely wrong in what we’ve been thinking all along.”

She also wants to study the way individual pollutants, like sulfur dioxide and nitrogen oxide (known for its role in creating smog) interact not only with water, but with each other in the atmosphere. A lot of pollution is caused by such reactions, she said.

In her research, which will be conducted at EIU, Peebles will use infrared radiation to study the reactions, and therefore the structures, of chemicals’ molecular bonds.

The equipment Peebles needs isn’t commercially available, so she’ll have to buy parts and assemble them herself.

“The spectroscopic technique I want to use is still relatively new, and not many people are doing it yet, especially at small schools,” she said.

The grant will pay for five years of work. Peebles intends to involve students who show an interest in the project.