Jury Still Out on Chloramine Use in MWD’s Water Supply

Action last week by the Metropolitan Water District to switch from chlorine to chloramine as a disinfectant for the drinking water of 13 million Southern Californians has raised health issues that scientists cannot answer with certainty.

Both the water district and the California Department of Health Services have declared chloramine to be safe, but a small amount of research that has been conducted on bacteria and laboratory animals indicates that the chemical may have adverse health effects.

The water district made the change to maintain compliance with a federal regulation aimed at making drinking water safer by reducing the level of certain compounds that sometimes form in water when free chlorine is used. These compounds, known as trihalomethans, or THM, have been shown to cause cancer in laboratory animals.

Different Kind of Threat

But in attempting to protect the public from that threat, critics say water and health officials have substituted a chemical that also may be unsafe. They cite studies that indicate that chloramine, like chlorine, may also be carcinogenic and mutagenic.

But scientists on both sides of the argument agree that it is not possible at this time to say whether any of these findings apply to man.

Even the scientists who did the research that seems to incriminate chloramine admit that the experiments are small in number, often have not been repeated by other scientists and are difficult to interpret.

All of the scientists agree that the current incomplete understanding of the biological effects of chloramine--not to mention the biological effects of a multitude of other compounds that sometimes are present in water--has opened the door to lots of speculation but no proof as far as effect on humans is concerned.

Nevertheless, Los Angeles County Dist. Atty. Ira Reiner last week criticized the Metropolitan Water District for ignoring, in the literature it distributed, the research data that does exist and for claiming unequivocally that chloramines are safe.

Comments Called ‘Unfounded’

Reiner’s comments sparked the ire of state health director Kenneth W. Kizer, who branded them as “unfounded,” “regrettable” and “irresponsible.”

“The California Department of Health Services’ position is that chloramines are safe and effective as a disinfectant for public water systems and their use protects consumers from many infectious diseases,” Kizer declared.

Besides the Metropolitan Water District, about 70 other water agencies serving 26 million persons across the United States use chloramine to disinfect drinking water, said Michael McGuire, water quality manager for the MWD.

“If health problems existed with chloramine, they would have shown up in Portland or Denver, where chloramines have been used for 70 years to disinfect water,” McGuire said.

MWD delivers water to all or parts of Los Angeles, Orange, Ventura, San Diego, Riverside and San Bernardino counties, although in many communities its water is blended with that of other suppliers, which may or may not use chloramine, McGuire said.

The water district replaced chlorine with chloramine to comply with a U.S. Environmental Protection Agency regulation. That regulation was drawn up to reduce the level of THMs that are formed when chlorine interacts with organic materials, such as plant materials, when added to the water.

Although local water generally did not exceed the EPA’s standard for THMs, the district decided to make a change to chloramine in order to avoid violations in the future when THM levels might rise if the use of chlorine were continued.

The district began treating water with chloramine in November, but discontinued its use, until last week, when it was learned that some kidney dialysis facilities did not meet standards for removing chloramine from dialysis fluids. These fluids come into contact with a kidney patient’s blood, thereby placing the patient at risk of developing a serious form of anemia if chloramine is present.

Officials say that all dialysis centers have now taken proper steps to filter out chloramines.

Studies funded by EPA on humans who drank water containing very high levels of chloramine found no changes in the subjects’ blood chemistry. The researchers said that chloramines are destroyed in the intestinal tract and do not pass into the bloodstream.

Carolina Studies Cited

The EPA wrote the standards for THMs in 1978. Since then, much of the scientific basis for suspecting chloramines as a health hazard has come from J. Donald Johnson and James Jensen of the University of North Carolina.

According to those researchers, “the health effects of chloramine-treated water are nearly as severe as those of chlorine-treated water.”

“From a health standpoint, then, chloramines are by no means the perfect solution to the THM problem,” the researchers say in a paper soon to be published in a scientific journal. They say that the danger that chloramine can cause cancer, as well as mutations, in laboratory animals is about equal to that of chlorine.

The North Carolina researchers’ opinion is based on findings that a broad group of compounds called total organic halogens, or TOX, that include THMs, have an adverse health potential at least as great as that of THMs. The EPA, however, has no standards for regulating TOX.

McGuire, the MWD official, said he totally disagrees with Johnson’s statements. “He is in direct contradiction with the scientific literature on the subject,” he said. McGuire said that Johnson’s views were taken into consideration before the MWD made its decision in 1981 to switch to chloramine.

Washington State Research

Another piece of evidence that chloramine--but not just chloramine--may be mutagenic comes from R.J. Bull, a researcher at Washington State University, who asserts that all water disinfectants are mutagenic. Bull is a former EPA expert on the health effects of water disinfectants.

But scientists warn that the public should not be panicked by his assertion that all water disinfectants are capable of causing mutations. For one thing, so little research has been done by other scientists to confirm the biological effects of water disinfectants that lots of controversy exists.

Only two studies have been conducted to learn the mutagenicity of chlorine and chloramine, and both concluded that the chemicals are mutagenic. Both studies were on bacteria.

The lack of confirmation of such findings in laboratory animals leaves doubts about their validity for man, McGuire argues. Jensen, one of the North Carolina researchers, also said in a telephone interview that the limited amount of research done to date is “conflicting.”

Jensen said that while he is not convinced that chloramine is any safer than chlorine, he believes that “chloramine is the best way to go compared to other methods of disinfection” when all factors are considered.

No Change in Regulations

He added that the public can be assured that the EPA is aware of all the evidence pro and con on chloramines and that this means the agency does not feel the information is strong enough to change the regulations.

Dr. Joseph Cotruvo, director of drinking water standards for the EPA, said that the agency currently is reexamining its THM and other water standards.

Currently the EPA has contracts with research institutes to conduct the most extensive studies yet done on the biological effects of chloramine. These studies include a look at the compound’s effects on reproduction, organ toxicity, interactions with drugs and metabolism changes. The results of these studies are expected to be ready in 1986.

Critics of the switch to chloramine have also charged that the chemical may have undesirable effects on infants. This speculation rests on the knowledge that a baby’s intestinal tract is not fully developed and may allow some compounds to pass from the stomach into the bloodstream--something that scientists say does not occur in older individuals. If chloramine were one such compound--and there is no evidence that it is--it could destroy red blood cells and cause anemia.

Dr. Paul Fleiss, a Los Angeles pediatrician who is chairman of the American Academy of Pediatrics’ local committee on environmental hazards, is among those who voice concerns about an infant’s ability to handle chloramine.

No Specific Hazard

Fleiss admits, however, that his concern is over chemical contamination of all types in both air and water and that he has no data showing that chloramine specifically is a hazard to infants.

The problem of evaluating the possible hazards of chloramine consumed in water has recently been complicated by the discovery that chloramine is present in the body even if an individual drinks water that has been purified by some other method.

Chloramine, according to Dr. Joseph McCord, a University of Alabama biochemist, is not a foreign substance. The body manufactures it as a toxin to kill microbes that get into the bloodstream. The chemical is manufactured by phagocytes, a kind of white blood cell, and is released into the blood every time a phagocyte deactivates an invading germ.

Children who are born lacking the machinery to make chloramine die early in life of overwhelming infections.

The concentration of the chemical is the key to whether it may be causing damage to the body as well as to the bacteria, McCord said.

Depends on Concentration

“You can’t simply say that something is toxic so let’s eliminate it,” he said. “Oxygen is toxic, too, at only five times the level necessary to maintain life. By the same reasoning, I wouldn’t say that chloramine is necessarily bad. It depends on the concentration.”

One of the problems with evaluating the significance of findings that all water disinfectants may be carcinogenic or mutagenic, scientists say, is that they must be weighed against the health consequences of using no disinfectant to purify drinking water.

“We in the United States have forgotten that disease-causing bacteria and viruses once were the scourge of this country, killing thousands of persons annually from diseases caused by drinking impure water,” said Dr. Ellen Silbergeld, a senior scientist with the Environmental Defense Fund, a national public interest organization.

Even though disinfection may result in the production of toxic by-products in water, Silbergeld said, “the price is a small and acceptable one for the major benefit of nonpathogenic water.”