TECHNOLOGY EDUCATIONMr. Sabur – Tech Systems
NEW YORK TIMES
When Brain Trauma Is at the Other End of the Thrill Ride
Deborah Lee Benagh was at SixFlagsElitchGardens in Denver when her sons coaxed her onto its daring new attraction, a giant serpent of loops and inversions ominously called Mind Eraser. It was among the first suspended roller coasters in the world, a new breed of rides that dangled people in harnesses beneath the tracks. Plunging down the first hill, Ms. Benagh felt something go terribly wrong. She said the harness loosened to the point that her head began to whip around as the ride zoomed up, down and around. "At the bottom of the hill my head was forced back and hit the back of the seat," she said. "On the loops, my head knocked against the sides of the headrest. I passed out briefly. When the ride halted, I was dazed. I had to steady myself against a pole in order to stand." Though she was able to drive home, she felt tired and nauseated. Two days later, her left eye filled with blood. In the weeks that followed, she had dizzy spells and blacked out periodically. Her vision went blurry. She could not remember things, like what someone had just told her. She saw a neurologist, who diagnosed traumatic brain injury with short-term memory loss, vertigo and ocular damage. Two months after riding Mind Eraser, Ms. Benagh filed an accident report at ElitchGardens and later sued the park. Six Flags confirmed that it settled with Ms. Benagh out of court, but the settlement prevents the company from commenting, said Debbie Nauser, a spokeswoman. Though Ms. Benagh's head injury occurred five years ago and she has fully recovered, she is one of 58 people cited last month in a report by the National Institute of Neurological Disease and Stroke in Bethesda, Md. All of them suffered brain trauma after being on thrill rides that operated normally. Eight people died. Injuries on amusement park rides in the United States increased 60 percent from 1996 to 2000, when 10,580 injuries needed emergency room treatment, according to the Consumer Product Safety Commission, an independent federal regulatory agency. While most of the injuries were caused by accidents, a growing number were associated with rides that did not malfunction, suggesting that the increasing intensity of the rides themselves might have played a role. A decade ago, there was no such thing as a hyper-coaster, a roller coaster that reaches 200 feet or higher. Now, the record is 400 feet. Until a few years ago, roller coasters gained momentum purely by gravity. Now many are catapulted from zero to 70 miles an hour in less than four seconds by motors originally designed to launch rockets. Some doctors and policy makers think some of the rides may be dangerous, pushing and pulling the body with greater force than many people can tolerate. In October, New Jersey will become the nation's first state to limit the gravitational force, or G-force, on rides. This is the force in addition to gravity that is imposed on the body by acceleration, deceleration and speed. G-force is what pins you to your seat as a roller coaster hurtles forward, lifts you off your seat when it plunges downhill and tosses you sideways as it rounds a curve. G-force is just one of many powerful forces that people encounter on thrill rides. Other forces are jerk, the rate of change of the G-force; roll, the force that rotates the rider diagonally; yaw, the left-right rotation, and pitch, the front-back rotation on the ascent and descent of a hill. The interplay of these forces constitutes the secret formula that produces the singular thrill of a ride and influences its safety, said Steve Elliott, an engineer in Madison, Wis., who inspects and test rides around the world. Mr. Elliott heads a group formed by the amusement park industry that will take all of these forces into account and then set voluntary limits on G-force. Those standards should be approved by early next year, he said. No one knows whether brain injuries suffered by people on thrill rides were caused by the rides themselves. But at least two studies are under way to see whether a cause-and-effect relationship exists. The American Association of Neurological Surgeons is doing one study, commissioned and financed by the Six Flags amusement park chain. The other study is being done and financed by the Brain Injury Association of America, an organization of doctors, lawyers and people with brain injuries. The most detailed account of neurological injuries from amusement park rides appeared in The Annals of Emergency Medicine in January. The study documented 16 injuries, including bleeding in the brain, leaking of cerebrospinal fluid and stroke. One person died of a subdural hematoma, bleeding from a ruptured blood vessel in the brain. For some of these people, the only symptom was a bad headache that started during or soon after a ride and did not go away, said Dr. Robert Braksiek, the lead author and a resident in emergency medicine at HennepinCountyMedicalCenter in Minneapolis. Even with treatment, the study found, many of those injured suffered long-term side effects, like difficulty speaking, writing or swallowing. The study said forces that could tear blood vessels in the brain and cause subdural hematoma could be "direct or indirect and usually involve acceleration, deceleration, or both." The study likened the effect to that of brain injuries from shaken baby syndrome. There are few published studies on the health effects of thrill rides. What is known comes mainly from research on G-force conducted by NASA and the military. The research shows that when G-force gets high enough or lasts long enough, it causes a decrease in blood flow to the brain. First there is a loss of peripheral vision, then of color vision. This is called grayout. Then there is blackout, or temporary blindness. In the extreme, high G-force causes loss of consciousness. The margin of safety is fairly small. Anything over 3 G's lasting 4.2 seconds can cause loss of consciousness, military research shows, but 5 G's lasting just 2 to 3 seconds is usually harmless. Space shuttle astronauts experience less than 4 G's in launching and re-entry. By contrast, more than 18 roller coasters operating in the United States today exert more than 4 G's. They include Taz's Texas Tornado (6.5 G's) at Six Flags AstroWorld in Houston, RunawayMountain (5.2 G's) at Six Flags Over Texas in Arlington, and Batman and Robin (5 G's) at Six Flags Great Adventure in Jackson, N.J. Ms. Nauser, the spokeswoman for Six Flags, said the maximum G-force on its rides lasted only a fraction of a second. But this crucial information is difficult to confirm because ride manufacturers consider it intellectual property, Mr. Elliott said. After reviewing industry data and published medical reports, the Six Flags panel found insufficient evidence that the G-forces on thrill rides could cause neurological injuries, said Dr. Richard Gliklich, a surgeon from Boston on the panel. It is possible that the reported brain injuries occurred because the victims had conditions, like aneurysms, that made them vulnerable, said Dr. Stan Pelofsky of Oklahoma City, another panel member. "Aneurysms can rupture with exercise, while having sex or for no reason," he said. Other experts are not convinced that the high G-forces on thrill rides are benign for healthy people. "I would be concerned about amusement park rides with a force of 6 G's," said Dr. Russell Rayman, executive director of the Aerospace Medical Association, a professional organization in Alexandria, Va. "That's considerable; it's what a fighter pilot is exposed to. And fighter pilots have anti-G suits and other protective equipment." A concern of Dr. Rayman is that studies on the biological effects of G-forces represent best-case situations because they have been done on pilots and astronauts, who are trained and in excellent health. In contrast, the people who go to amusement parks are not necessarily in peak condition. Another concern is that amusement park patrons typically go on several rides in a day. "The more you ride, the more you increase the risk," Dr. Rayman said. Research shows that G-force poses the lowest risk when it presses people down, as gravity does, because the body is adapted to withstand this pressure. The greatest risk occurs when it shoves people to the side. Therefore, New Jersey's limits on G-force will depend on its direction as well as duration. Bill Connolly, director of the New Jersey Division of Codes and Standards, the office that regulates amusement parks, said the threshold would be 6 G's pushing riders down into their seats for up to 1 second to 1.5 G's side to side for 10 seconds. In addition to setting voluntary G-force limits, the amusement park industry subcommittee is trying to determine which people are most vulnerable to harm from the forces on rides, so that parks can post better warnings, Mr. Elliott said. Many parks now have signs that caution people who are pregnant or have heart disease from braving the monster rides, but he said warnings might also need to include people with aneurysms or arthritis, and perhaps even smokers. Children under 14 may also need special warnings, said Kathy Fackler, a consumer advocate on the industry subcommittee. She said the subcommittee reviewed research earlier this year that suggested that G-forces that were safe for adults were unsafe for children under 14. Of all people, children ages 10 to 14 are most often injured on amusement park rides, according to the Consumer Product Safety Commission. But, Ms. Fackler said, there was not enough information to determine G-force thresholds for these children or, for that matter, which rides should be off limits to them. "We lack specific data on the effects of high G-forces, acceleration and abrupt starts and stops that all may contribute to brain injury in otherwise healthy individuals," said Dr. Braksiek of Minneapolis. "We are assuming roller coasters with speeds over 100 miles per hour and G-forces higher than the space shuttles are safe for our children, rather than testing them and proving they are safe before we use them for entertainment."