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Chlorine Accidents Take a Big Human Toll

Over the past 10 years, there have been hundreds of accidents involving chlorine nationwide, injuring thousands



U.S. Chemical Safety Board

Beverly Martinez was sitting at her desk in the office of a California scrap metal recycling plant when she felt the blast rattle her window.

One of her co-workers, Leonardo Morales Zavala, rushed through her door, struggling to breathe. “Run!” he yelled. He had just cut into a one-ton tank to recycle it in the yard – a football field away – and out poured a noxious substance. He didn't know what it was.

The workers ran as fast as they could toward the street. But they couldn't escape the giant, greenish-yellow cloud. A couple dozen people – workers and customers – dropped to the ground, gasping for air. Martinez fell, too.

"I couldn't get up. I felt like I was being strangled. I thought, 'I'm going to die. I'll never see my granddaughter grow up,’ ” Martinez said.

As she struggled to reach the building across the street, she heard a voice. "Bev, Bev, help!" It was Ricky Mejia, a 23-year-old inspector, calling to her from the ground.

"Ricky couldn't breathe, he couldn't walk. I'm stocky, and I told him to grab my side. Myrna Navarro was already hanging on my shoulder. She was praying enough for everyone. In my head, I was getting to the Firestone tire warehouse across the street. It seemed like an eternity,” she said.

“Then, I couldn't do it anymore. I said to Ricky, 'Your wife is pregnant. You've got a baby coming. Get up!' "  They finally made it to the warehouse, where Mejia collapsed.

More than a year later, the ghost of a chlorine cloud lingers like a vivid nightmare at Tulare Iron and Metal Inc., located in the heart of California’s Central Valley.

On that June afternoon in 2010, 23 people were taken to hospitals and six were kept for treatment, including Mejia, who was hospitalized for 11 days, two of them on life support. Sixteen months later, the workers are still beset with health problems, including lung, stomach and Post Traumatic Stress Disorders.

Over the past 10 years, chlorine has been involved in hundreds of accidents nationwide, injuring thousands of workers and townspeople, and killing some, according to federal databases. It is second only to carbon monoxide when it comes to the percentage of accidents that cause injuries, according to the newest federal data.

 Chlorine is one of the most widely used industrial chemicals in the world today, with 13 million tons produced annually in the United States alone. 

An element that is abundant in the Earth’s crust and oceans, the powerful, corrosive substance is considered essential to an array of products. It is used in manufacturing plastics, synthesizing other chemicals, purifying water supplies, treating sewage and making refrigerants, varnishes, pesticides, drugs, disinfectants, bleaches and other consumer products.

In recent years, accidents have occurred when chlorine leaked or spilled, pressurized tanks were punctured, train cars derailed or when other chemicals were improperly – and often unknowingly – mixed with it. In some cases, thousands of people have been evacuated after an accident at a factory or during transport of liquefied chlorine. Janitors, housekeepers and others also have been exposed when they mix acidic household chemicals with bleach or swimming pool chemicals.

The worst chlorine gas accident in the country occurred in 2005, when 18 freight train cars derailed and released 120,000 pounds of chlorine gas in the mill town of Graniteville, S.C. Nine people were killed and at least 1,400 people were exposed, resulting in more than 550 people treated at hospitals, including some with serious lung injuries. More than 5,000 people were evacuated from their homes.

Chlorine gas is particularly insidious. Even small exposures can trigger coughing, choking and wheezing, and burn the eyes, skin and throat. Inhaling large amounts constricts the airways by inflaming the lining of the throat and lungs. At the same time, fluid accumulates in the lungs, making it doubly hard to breathe. People can literally drown in their own body fluids. At high exposures, a few deep breaths are lethal.

In Tulare, Calif., the chlorine concentrations at the recycling plant were extremely high. Three hours after it happened, the Visalia Fire Department measured the gas at 328 parts per million near the tank. It was probably much higher when the workers were trying to escape. Studies show 40-60 ppm produces lung injury; 430 ppm usually causes death in 30 minutes, and 1,000 ppm is fatal within a few minutes. Under federal standards, workers are never supposed to be exposed to concentrations exceeding 1 ppm.

"Exposure to high levels of chlorine gas from a release can cause severe health effects, including death," said Mary Anne Duncan, an epidemiologist at the federal Agency for Toxic Substances and Disease Registry who has assisted with the aftermath of several chlorine accidents, including the one in Tulare.

Erik Svendsen, who studied the health effects of the Graniteville chlorine cloud, said researchers knew they would find pulmonary and other health problems in people exposed. But they found a lot of Post Traumatic Stress Disorders, too.

"Chlorine was used as a war gas for a reason. It was designed not just to kill the enemy but also to inflict fear in the enemy. You remember every second you were exposed to the gas. You don't know where to go. You see your clothes bleach before your very eyes. You see animals die,” said Svendsen, a Tulane University epidemiologist.

“It's not just a toxic event. It's a traumatic event. You're powerless. You're being exposed to something you can't stop. You have a metabolic stress response that has effects on the body physiologically.”

Only four months before the accident in Tulare, five workers were injured at another California recycler, U.S. Metal in Indio, when a crane worker pierced a cylinder tank and set off an explosive chlorine gas release.

And in July, at Tyson Foods Inc., in Springdale, Ark., chlorine gas was released after the accidental mixing of two chemicals, exposing 173 people and sending 50 to hospitals, including five that wound up in intensive care. Chlorine is used in the company’s sanitizing washes.

Across the country, data going back to 1993 show that chlorine accidents occur in the United States at the rate of at least once every two or three days, and about one-third of them cause injuries.

In 2009 alone, chlorine was involved in 181 reported accidents with 56 resulting in injuries, based on the latest report from a federal database called Hazardous Substances Emergency Events Surveillance (HSEES). That amounts to 3.8 percent of all the reported chemical emergencies that year. Chlorine had a high percentage with victims, 30.9 percent, second only to carbon monoxide, which had 41.7 percent with victims. Roughly one-third of the states reported, and only for a part of the year, so the real number of accidents and injuries is much higher, experts say.

“Chlorine releases in fixed facilities resulted in victims and evacuations in more industry categories than any other substance," says a 2004 study by researchers from the Agency for Toxic Substances and Disease Registry. That study was based on HSEES data of 40,000 chemical incidents from 1996 through 2001.

Accidents involving chlorine "were more likely to result in events with victims, evacuations and decontaminations when compared with non-chlorine events,” according to another study by the same federal agency published in 2002.

Of 865 events involving chlorine alone between 1993 and 2000, 275 caused injuries, the study says. Of the 1,071 victims, 759 were workers, 235 were members of the public and most of the rest were first responders.

Transporting chlorine also poses more risks than other substances. The U.S. Department of Transportation issued a report last month weighting the most serious accidents in terms of deaths and major injuries from 2005 to 2009. Chlorine led the list with 83 major injuries and nine fatalities out of 48 rail and road accidents compared to gasoline, second on the list, which had 19 major injuries and 30 fatalities out of 1,306 rail and road accidents.

Estimating the number of hazardous materials accidents that affect the public is difficult. Many go unreported. There are at least five national databases of chemical spills, including one for worker accidents and one from the Department of Transportation, and they all have limitations.

For worker accidents, the database by the U.S. Department of Labor's Occupational Safety and Health Administration is considered the best available. Yet officials agree that a lack of consistent reporting among states leads to under-reported accounting. The numbers clearly are imprecise: While the HSEES database reported 56 chlorine accidents with injuries in roughly one-third of the states in just one year, the OSHA database reported only 45 chlorine accidents involving workers nationally over 10 years.

Representatives of the Chlorine Institute, the trade group most familiar with the chlorine industry, said it couldn't discuss the situations in which most chlorine accidents occur. They also wouldn't comment on the data showing the frequency of injuries and evacuations, saying they weren't familiar with the HSEES database or the studies.

"Incidents are rare" in the production of chlorine among Chlorine Institute members, said Frank Reiner, president of the national trade group of 220 manufacturers and distributors. In an e-mail, Reiner said, "the safety performance of the industry has been very good" and his group shares information among members to avoid future problems.

Chlorine is arguably the most essential chemical in use today, industry experts say. It is produced in such large volumes because it can be easily combined with other elements and molecules, transforming it into new classes of chemicals. Industry considers it vital to the synthesis of plastics, drugs, microchips and many other products around the globe. Though there are alternatives for some uses, there are few equally effective and viable substitutes for others, such as water disinfection.

About 93 percent of pharmaceuticals are manufactured with chlorine.

"Chlorine is not in the final product, but it is needed at an intermediate stage to direct reactivity and make sure you make the molecule you want. Being able to avoid the use of chlorine in these cases is a very intense area of current research in green chemistry," said Audrey Moores, an assistant professor in the Department of Chemistry at McGill University in Montreal.

In Tulare last year, the source of the poison released at the recycling plant was a one-ton pressurized cylinder, unmarked as hazardous and accepted in good faith as harmless scrap metal by a recycling inspector. County officials believe the chlorine inside had been used to disinfect food supplies.

Ron Rushing, owner of Tulare Iron and Metal, declined to comment about the accident. The California Division of Occupational Safety and Health has fined the company $15,000 for failing to make certain that containers do not contain hazardous materials and for failing to properly train workers. The company is appealing the fine. Records from Tulare County and federal courts do not show any lawsuits filed against the company related to the accident.

Most of the injured employees are back to work – but they are not back to normal.

Six months after the accident, "19 people were still seeing a physician for problems related to the chlorine release," said Dr. Rachel Roisman, a California Dept. of Public Health medical officer who worked on a health assessment of the workers with county officials.

People reported shortness of breath, change in sense of smell, headache, congestion or phlegm, dizziness, light-headedness and chest pain and tightness.

"Some people were still very affected by the incident either physically and/or psychologically. It had been a significant event for them. For some people, it was definitely still with them," Roisman said.

Now, 16 months later, of four hospitalized workers, Ricky Mejia, who spent 11 days in the hospital – two breathing with the help of a mechanical ventilator – still is suffering from lung ailments and other health problems. He uses an inhaler, and misses some work because of his illness.

Morales Zavala, 48, the shearing machine operator who pierced the unlabeled cylinder tank and ran to warn the staff, is still on the job, suffering from poor health, including stomach problems. Fellow workers say he has lost 40 to 50 pounds, and has a hard time eating.

As for two other hospitalized employees, Danni Cuevas, 23, is back at work after recuperating for weeks, and Gladis Alaniz, 29, a clerk, has left the company.

The first responders were initially told that a 300-gallon tank had ruptured, perhaps containing ammonia, said firefighter-paramedic Karl Kassner with the Visalia Fire Department Hazardous Materials Response Team.

But when the firefighters in self-contained suits got close and sent camera images to the haz-mat trailer where Kassner and others waited, “we saw the one-ton cylinder and knew right away it was more than likely liquid chlorine that had been under pressure. We could hear the team's chlorine alarm going off,” Kassner said. When he called on the radio and learned the concentration was 328 ppm, they all knew that it remained at a level known to firefighters as “immediately dangerous to life and health,” even three hours after the original release.

Sometimes when Martinez looks at any cylinder, she feels a sense of panic. To the workers, the accident seems like yesterday. They can't shake the feeling of being unable to breathe.

Martinez recalls how the chlorine gas on their clothes made the ambulance drivers cough, and how people driving on the freeway a half-mile away could smell it. She remembers not breathing normally for days, and wanting to take showers every 20 minutes. "Sweat smelling like chlorine poured out of me. My husband said my coughs smelled like chlorine,” she said.

Working about 120 yards from the tank, John Espinola, shop supervisor, felt like his head had been covered in Saran wrap. "You felt like your breath was being taken away. You're engulfed in a yellowish cloud. I was just gasping for air. I couldn't get enough oxygen," he said.

Doctors say people who survive heavy chlorine exposure may suffer acute respiratory distress syndrome. Some people develop chemical pneumonitis, an inflammation of the lungs, from breathing in chemical fumes. They can recover or end up with permanent scarring of the lungs, which reduces their breathing capacity.

Even a one-time high-level exposure can lead to irritant-induced asthma. People develop bronchitis, or inflammation of the airways. In some, but not in all people, the bronchitis induces asthma, said Dr. John Balmes, professor at the University of California at San Francisco and division chief of occupational and environmental medicine at San Francisco General Hospital. Balmes’ laboratory has been studying the respiratory health effects of air pollutants for 25 years, and he reviewed parts of the U.S. Health and Human Services' toxicological profile for chlorine released last year.

What happens when a person breathes chlorine is that the corrosive substance splits hydrogen from water in moist human tissue, releasing oxygen and hydrogen chloride, which do the damage. Scientists say there are palliative remedies but no antidote.

Researchers believe that an injury from chlorine gas to the airway lining – or the epithelium – can somehow lead to persistent airway hyper-responsiveness, Balmes said. Smoking and allergies seem to increase the risk of permanent asthma after chemical exposures.

“Most people get better once they've recovered from the chemical bronchitis. Some don't," Balmes said.

Government agencies are ramping up programs to prevent future chemical accidents.

Within days of the accident in Tulare, federal, state and county public health officials turned to a new assessment tool in an effort to reduce chemical accidents. Called ACE, or Assessment of Chemical Exposures, the investigation focuses on circumstances surrounding a chemical accident, the health effects and recommendations for prevention.

As a result of the federal visit, the state mailed an alert urging 1,200 metal recyclers to take only containers that are cut open, dry or without a valve or plug; treat closed containers as potential hazardous waste, and develop and practice an evacuation plan to stay upwind of a hazardous gas release.

The Institute of Scrap Recycling Industries, a national trade association, sent the California alert to its 1,500 members in a weekly newsletter, said John Gilstrap, safety director. When he and his staff train employees in an OSHA 10-hour safety program, they warn that containers "are extremely hazardous unless they've been rendered incapable of holding pressure," he said.

Carrying out the practice of accepting only cut tanks may sound elementary, he said, but metal recyclers handle truckloads of scrap cargo and so monitoring is challenging.

In Tulare, Beverly Martinez, a Tulare native and seven-year employee of Tulare Iron and Metal, and the other workers now reject all uncut containers.

"We've turned away tons of tanks because they're not cut in half. I say, 'I don't care how good a customer you are. We're not taking it,'" said Martinez, an office manager.

"I can honestly say it was a life-altering event. I never came so close to death, or what you feel it would be. We all lived through it. That was the good thing.”

This article originally ran at Environmental Health News, a news source published by Environmental Health Sciences, a nonprofit media company.

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