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Common Killer

Chlorine, one of the world's most widely used chemicals, is the key link in a toxic chain which many activists feel is a grave threat to human health By Eric Johnson WHEN LOIS GIBBS HEARS about a study linking tap water to miscarriages in Santa Clara County, she is concerned but not surprised. Gibbs, formerly of Love Canal, N.Y., has been warning people for more than a decade that chlorine is poison. She first encountered its dangerous aspect in the late 1970s, when health officials discovered that her home had been built on top of 20,000 tons of buried chemical pollutants, including chloroform, dioxins and other chlorine-based compounds. Gibbs led her neighbors in a successful battle against Occidental Petroleum, winning relocation money and damages in what has become a textbook industrial pollution case. Now head of the Center for Health, Environment and Justice, Gibbs has been waging a decade-long campaign against dioxin. That fight, she says, "is all about chlorine." One of the most commonly used chemicals in the world, chlorine also is found at the root of thousands of chemicals that threaten the environment. Chlorine provides the "C" in deadly PCB, and it is the source of the "chloro" in ozone-destroying chlorofluorocarbons. And chlorine is a key ingredient in many of the world's nastiest poisons, including Agent Orange and DDT. Dioxin, a byproduct of the industrial use of chlorine, is considered by many scientists to be the deadliest chemical ever made. It has been linked to cancer, miscarriages, birth defects, reduced sperm counts and learning disabilities. It finds its way into the world when compounds which contain chlorine are burned or heated. The recent studies do not conclusively determine whether chlorinated solvents play a role in the increased miscarriages associated with drinking tap water. But for Gibbs--who remembers back almost 20 years, to the time when miscarriages became common among the 900 families in her Love Canal neighborhood--the study seems like one more charge to add to chlorine's growing environmental rap sheet. "When this whole issue came up in 1978, there was very little information," Gibbs says. "But now it's just overwhelming. This is a threat that just doesn't need to be. We don't need chlorine." Gibbs says that in most industrial uses, from bleaching paper to cleaning auto parts, alternatives to chlorine are cheap and available. Stephen Lester, science director for Gibbs' group, says that in his opinion, chlorine is "the most toxic and dangerous chemical in widespread use in the world." He explains that the very thing that makes chlorine so useful also makes it dangerous. In the language of chemistry, chlorine is "unstable." Like a very needy person, it is surrounded by an aura (in this case, an outer ring of electrons) that is chemically incomplete. That makes it "highly reactive," Lester explains. "It is constantly looking for other chemicals to react with." That's an excellent quality for something to bond with stains in a white blouse and dissolve them, or to bond with microbes and kill them off. But, as Lester explains dryly, this willingness to hitch up with every molecule on the block presents a real problem: "Chlorine's high reactivity, which is a great value, is also, from the point of view of a toxicologist, very dangerous." While Gibbs' group has focused on industry's use of the chemical, other citizens groups nationwide have been trying to get chlorine out of their drinking water. In recent years, the EPA has tightened its restrictions on chlorination, and water is being purified without chlorine in several cities using the "ozonation" process. "A wide range of dangerous chemicals are made when chlorine interacts with organic compounds [in drinking water]," Lester says. "From a public health perspective, then, it's a trade-off. It kills bacteria, but it may cause cancer." Or, as the recent studies suggest, miscarriages. Bleach Blackened THE RECENT STUDIES are not the only local case of chlorinated compounds wreaking reproductive havoc. In the early 1980s, the infamous Fairchild case linked chlorinated chemicals with an outbreak of birth defects in south San Jose. In that case, a compound called TCE, a byproduct of chip manufacturing, was identified as the culprit. Following the Fairchild incident, 24 sites throughout the county were placed on the national Superfund list of highly toxic areas. In a 1995 report, 32 "national priority cases" are listed--almost all associated with the microchip industry. The Regional Water Quality Control Board documents more than 400 contaminated sites. The following chlorinated solvents, all suspected carcinogens linked to many health disorders, are commonly found in ground water throughout the valley: Freon 113 (chlorofluorocarbon) Dichloroethane (DCA) Dichloroethene (DCE) Trichloroethane (TCA) Trichloroethene (TCE) Perchloroethene (PERC) More than 250 sites in the county are listed as "active" in the 1995 Water Quality Control Board report. Many leaked TCE, TCA, chloroform and other solvents. Several sites contaminated drinking water wells. The companies involved are mostly microchip plants, although dry cleaners, gas stations and paint companies are also listed. Rick Hind, who heads Greenpeace's national toxics campaign, says "there's no doubt" that chlorine is, environmentally speaking, public enemy No. 1. "Greenpeace's toxics campaign internationally has been focused on chlorine for the past 10 years," Hind says. As with Gibbs' group, most of Greenpeace's work has been directed at pulp and paper mills, as well as industrial solvents. But the group recently launched a project calling attention to children's toys made from PVC plastics, which, he says, contain lead, cadmium and other contaminants. Silicon Valley Toxics Coalition's Ted Smith says his group is cooperating in that campaign, along with many others nationwide as part of a concerted effort to "sunset" chlorine use. "The PVC campaign is good because plastic is ubiquitous, and it's a good consumer target," he says. "But really the overall strategy is to go after the chlorine industry itself, which is the source of so many problems." Smith says that while most local leaks in the soil have been patched, chlorinated compounds are still being released into the air throughout the South Bay. That poses a "significant health threat," he says. According to the Bay Area Air Quality Management District, more than 5.5 million pounds of toxic chlorinated substances are released in the area annually--including 13,000 pounds of chloroform, 1.4 million pounds of freon, 2 million pounds of perchloromethelyne and trace amounts of dioxin. While Smith has been calling for an end to the industrial use of chlorine for some time, he now questions whether it is even acceptable for the chemical to be used as a disinfectant. "Chlorine is the building block for so many different things, and everywhere you look, it causes problems," he says. "Now, with this study, it seems that in the one area where people thought its benefits might outweigh its risks, it is also causing problems." [ San Jose | Metroactive Central | Archives ]