By Donella Meadows

–May 12, 1994–

“Now the enviros want to ban chlorine!” say the outraged anti-enviros. The outrage would be appropriate if the charge were true. Chlorine is a chemical element, a component of the planet. You might as well ban gravity, or granite, or the salt in the sea. In fact salt, sodium chloride, is made of chlorine. Anyone who talks of a chlorine ban must be nuts, which is what the anti-enviros want you to believe about the enviros.

There may be extremists who talk of banning chlorine — every movement, religion, and political party has its lunatic fringe. But I have never heard an environmentalist advocate a “chlorine ban.” The only folks I’ve known to use those words are a few excitable members of the press, and the Chlorine Institute and other organs of the chemical industry, which have launched a letter campaign to Congress, asking it not to ban chlorine.

Behind the hyperventilation, here’s what’s really going on.

In the 1960s people found robins dying on lawns after DDT spraying. In the 1970s fish hatchlings were poisoned by PCBs in river mud. In the 1980s scientists discovered that CFCs were eating up the ozone layer. A pattern was becoming clear. Those trouble-making chemicals and a lot of others — not all, but a lot — contain chlorine atoms bonded to carbon atoms.

They are called organochlorines. You don’t have to be a chemist, you just have to listen to the names to know that there’s chlorine in PCBs (polyCHLORinated biphenyls), CFCs (CHLORO-fluorocarbons), and pesticides such as alaCHLOR, CHLORdane, methoxyCHLOR. In the names of the herbicides 2,4-D and 2,4,5-T the numbers show where chlorine atoms are attached. DDT stands for diCHLORO-diphenyl-triCHLOROethane. PCP means pentaCHLOROphenol.

These chemicals are used for different purposes, and they have different effects in nature. But in some ways they are similar, which accounts both for their usefulness and their troublesomeness. The carbon-chlorine bond is strong. PCBs and CFCs don’t burn, don’t corrode, don’t break down easily. Up in the ozone layer or deep in the groundwater they last for decades.

Many organochlorines are volatile; they evaporate and travel with the winds around the globe. They are found in Arctic ice, penguin livers, Great Lakes waters, egg shells, and human breast milk. They are soluble in fat, so when they enter a living creature, they tend to stay in its tissues and get passed up the food chain. Top predators such as eagles, seals, and people can accumulate high organochlorine concentrations in their bodies.

That’s no problem, industry has said for decades, because organochlorines are not very toxic to people. Sure, pesticides mow down bugs and an occasional bird or fish, but it takes huge quantities to kill a person. A DDT maker once swallowed a spoonful of his product on television to make that point.

But there are more subtle ways of doing harm than outright, knock-em-dead poisoning. What many organochlorines do is interfere with neurotransmitters and hormones — chemicals that carry messages between the nervous system, the immune system, and the endocrine system. These messengers are, in effect, the intersections in the body’s information highway. A surprising number of organochlorines jam those intersections either by blocking cell receptors so messages can’t get through, or by acting like hormones and sending false messages.

Some of the most pernicious organochlorines, such as the dioxins, mimic or block the hormones estrogen or testosterone, the central controllers of reproduction. Unbelievably tiny amounts of these substances can interfere with the production of eggs or sperm, with conception, or with the development of embryos.

Anyone who is worried about unborn humans should be worried about these hormone-disrupters — as should be anyone who is worried about unborn birds, whales, turtles, seals, or fish. If that’s not enough of a political hot button, organochlorines are known to masculinize females and feminize males in many species, and they may be the cause of the otherwise unexplained 50 percent drop in the sperm count of men.

We can’t ban chlorine from the periodic table of elements, any more than we can ban radon or plutonium. What we can do is stop sloshing these destructive elements around unnecessarily. That is what the enviros are calling for. Chlorine is a hyper-reactive gas; when it comes in contact with organic matter, it produces organochlorines. Therefore we should, as much as possible, keep chlorine away from organics.

We can start by phasing out the use of chlorine as bleach in paper plants. Alternative oxygen-based processes cost less and use less energy. Then we can greatly reduce our use of the plastic polyvinylchloride (PVC), which spews out organochlorines at every stage of its manufacture and disposal, especially when it is burned in trash incinerators, where it makes dioxins. Paper and PVC account for 50 percent of industrial chlorine use in the United States.

Next in order of importance would come tighter controls on the use and disposal of chlorinated pesticides, solvents, and bleaches. You can already buy chlorine-free laundry bleach.

When they want to make enviros look really dumb, industry PR people say they want to remove chlorine from municipal water systems and cause a cholera epidemic. Only about one percent of the chlorine we use goes into drinking water. About 90 percent of that could be replaced by other disinfecting techniques. Another four percent of the national chlorine budget goes into sewage treatment. It could be replaced by more natural treatment methods — not immediately, but eventually.

It is not necessary to substitute one public health risk — pathogens in drinking water — for another — hormone-deranging organochlorines — and no one’s recommending it. If you hear that environmentalists want to spread cholera in order to save polar bears, consider the motivations of whoever is delivering that news. It’s always easier to discredit people by claiming they hold a crazy position than to deal with what they’re really saying.

Copyright Sustainability Institute 1994