GRANITEVILLE -- Coughing, burning eyes and shortness of breath were the most common symptoms people who were exposed to chlorine gas in Graniteville reported immediately after the Jan. 6 incident, according to early results from an ongoing study of some victims.

Seventy-two people were hospitalized after the train collision and chlorine spill, and 527 others sought medical attention at hospitals or with a physician soon after the accident, the study by the South Carolina Department of Health and Environmental Control shows.

The agency interviewed 280 of the victims and asked a wide range of questions, from the symptoms they were experiencing to how they arrived at the hospitals where they sought help on the morning of the accident, said Mary Anne Wenk, an epidemic intelligence service officer with DHEC, who is assisting with the study.

The surveys, which Ms. Wenk discusĪsed Thursday night during a meeting with Graniteville residents at Leavelle McCampbell Middle School, were conducted in the days immediately after an estimated 60 tons of chlorine spewed from a train tanker , killing nine people and forcing the evacuation of about 5,400 others.

Ms. Wenk's agency is asking victims a second round of questions about long-term effects. The agency's ongoing studies could prove monumental because there is a lack of research on the long-term effects of chlorine gas.

But Ms. Wenk and her colleagues say the first round of interviews already has provided critical insight into what happened right after the train crash.

For example, 63 percent of the people who responded within the first 24 hours after the accident traveled to the hospital in a private vehicle, not an ambulance, the study found. That's important, researchers say, because victims started arriving in emergency rooms in Aiken and Augusta before physicians had any idea of what they were treating.

There was no way to route victims to alternate hospitals and control how many went where. Out of the 264 people who were treated in the first day, 42 percent went to Aiken Regional Medical Centers ; 55 percent went to University Hospital, the Medical College of Georgia Hospital, Doctors Hospital or St. Joseph Hospital; and 3 percent went to other medical facilities in South Carolina.

"We need to make sure our planning crosses borders," said Dr. James Gibson, state epidemiologist and the director of DHEC's bureau of disease control.

The study also shows a spike in hospital visits immediately after the release, which occurred just before 3 a.m., and other spikes 12 and 16 hours later. Part of the later spike could be attributed to the evacuation of thousands who had been told throughout the day to seek shelter in another place. Researchers credit part of the increase to symptoms of chlorine exposure that don't show up for more than 12 hours, like fluids that are released from mucous membranes in the lungs.

DHEC is asking detailed questions about each person's medical history. Though chlorine gas was used during World War I and leaked in previous disasters, researchers say there is still much to be learned.

"That's why it's so important to follow this," Dr. Gibson said.

Reach Josh Gelinas at (803) 648-1395, ext. 113, or josh.gelinas@augustachronicle.com.