Health & Society Scholar Evaluates Effects of Chlorine Gas Disaster

    • February 26, 2009

Fours years ago, David Van Sickle, Ph.D., a Robert Wood Johnson Foundation Health & Society Scholar  at the University of Wisconsin, was working as an Epidemic Intelligence Service officer at the Centers for Disease Control and Prevention (CDC) in Atlanta, when a deadly chlorine gas accident occurred in the neighboring state of South Carolina. In January 2005, a freight train carrying three tanker cars—each loaded with 90 tons of chlorine—collided with a parked locomotive in the center of Graniteville, S.C., a 7,000-person town located 15 miles from Augusta, Ga. Van Sickle was part of a team from the CDC and the Bureau of Disease Control at the South Carolina Department of Health and Environmental Control (DHEC) that investigated the resulting health effects of the chlorine gas release.

As a Health & Society Scholar, Van Sickle analyzed the information that he collected while investigating the South Carolina accident. Van Sickle published a study examining the aftereffects of the South Carolina chlorine disaster in the January 2009 issue of the American Journal of Emergency Medicine. The study’s findings give larger metropolitan areas important insight into what to expect and how to prepare public health and emergency response systems for an accidental or terrorist release of the potentially deadly gas. “This is one of the largest community exposures to chlorine gas since World War I,” Van Sickle said. “It was a tragic disaster that shows us what a significant challenge a large-scale chlorine gas release poses to health care facilities.” 

Chlorine gas is an irritating, fast-acting and potentially deadly inhalant. It is also one of the most commonplace toxic chemicals, widely used in water treatment and industrial manufacturing. Much of the 13 million to 14 million tons of chlorine gas produced in the United States each year is transported by rail, often through densely populated areas.

The CDC and South Carolina DHEC team found that hospitals need to be able to recognize quickly the signs of chlorine gas exposure, and to have a plan to provide a sufficient number of mechanical ventilators in the event of another massive chlorine disaster. While small accidental and occupational exposures to chlorine gas occur regularly, the South Carolina disaster was a major community exposure. As a result, the CDC and South Carolina DHEC scientists sought to learn as much as possible about the health effects from this widespread chlorine gas exposure, Van Sickle said.

On the night of the South Carolina disaster, eight people died at the scene. At least 525 people were treated in emergency rooms and 71 were hospitalized at nine hospitals in South Carolina and Georgia. “We also wanted to understand how physicians treated the patients, how quickly they recovered and what resources hospitals would need to respond effectively in the future,” Van Sickle said.

Many hospitalized patients showed evidence of severe lung damage. More than a third were admitted to intensive care, and 10 percent required mechanical ventilation. But despite the severity of their injuries, the majority of patients recovered quickly and were discharged within a week, according to the study, Acute Health Effects After Exposure to Chlorine Gas Released After a Train Derailment. For this report, the investigators reviewed medical records of all individuals who were hospitalized or who died as a result of the chlorine gas release, analyzing information about the victims’ demographic characteristics, laboratory, pulmonary and radiographic studies, as well as medical treatment and diagnoses.

“Public health agencies and hospitals across the country can learn a lot from this disaster and be better prepared to help in the next emergency” said James J. Gibson, M.D., M.P.H., state epidemiologist and director of the Bureau of Disease Control at the South Carolina DHEC and a co-author of the report. “We continue to monitor area residents for any possible long-term health effects.” The South Carolina Department of Health and Environmental Control has established a registry of persons potentially exposed to chlorine gas and/or traumatic stress during the chlorine gas release and has offered free standardized medical screenings with referral for follow-up evaluation when necessary.

The U.S. Department of Homeland Security has identified a deliberate attack on a chlorine storage tank as a top concern. According to agency estimates, as many as 100,000 people would be hospitalized and 10,000 would die if a chlorine storage tank was attacked in an urban area, overwhelming public health systems and emergency response systems. In 2007, terrorists used chlorine gas in at least seven attacks on U.S. troops.

An editorial published by the Augusta Chronicle agreed that Van Sickle’s findings could help other communities prepare for chlorine disasters. “If studies of the Graniteville tragedy mitigate or lessen the impact of such an occurrence then at least something good will have come out of it,” wrote the paper.

While participating in the Health & Society Scholar program, Van Sickle has carried out research to better understand how pediatricians perceive common asthma symptoms. He also became interested in the potential of medical devices to improve population health. He was awarded a third year in the program (2008–2009) to evaluate a device he developed to improve the recognition of uncontrolled asthma and the timeliness and geographic specificity of public health surveillance. Van Sickle recently began work on a low-cost, open-source spirometer to improve the diagnosis and management of respiratory disease in global settings, and will be piloting a student-led epidemiological survey in Arizona high schools this spring.

As a CDC epidemic intelligence officer, Van Sickle was assigned to the Air Pollution and Respiratory Health Branch, where he provided epidemiological support to the National Asthma Control Program, and investigated the health effects of exposure to mold in post-Katrina New Orleans, to carbon monoxide in Florida and to ambient ozone among student athletes in Georgia. In addition, Van Sickle helped establish emergency illness and injury surveillance in coastal Mississippi after Hurricane Katrina.