Water Officials Suggest Prudence, Not Panic

Reacting to a new study that suggests a possible link between drinking tap water and miscarriages by pregnant women in their first trimester, Los Angeles officials said Tuesday that the city’s water often contains amounts of the suspect contaminants exceeding the levels that have triggered concern.

But the officials advised prudence rather than panic.

Doctors faced a new barrage of questions from nervous patients, whose anxiety was stoked by frustration with state government, which oversaw a study of the problem and yet has not shared the findings with city officials because it is not scheduled to be published officially until next week.

At the city’s Department of Water and Power, General Manager S. David Freeman called a news conference to offer assurances about the city’s drinking water but also to note that any pregnant woman concerned about the new study can alleviate the problem by boiling drinking water for one minute. City officials did not encourage switching to bottled water, which is not regulated.

“It’s not anywhere close to proof positive,” Freeman said of the study, which he still had not received. “But it does suggest a risk. . . . If you boil water for just one minute and then put it in the refrigerator, that takes care of the risk.”

The study examined pregnant women served by three Kaiser Permanente facilities, in Fontana, Walnut Creek and Santa Clara. It found that those who drank five or more glasses of tap water per day with at least 75 micrograms per liter of trihalomethanes (TTHM)--about 2% of the study population--had an increased risk of miscarriage. Their risk was calculated at 15.7%, compared to 9.5% among women who received low exposure. In addition, the study found still higher risk for the Santa Clara-area women.

For women who drank water containing less than 75 micrograms per liter, there was no extra risk of miscarriage, researchers noted. Similarly, women who drank fewer than five glasses of cold tap water per day showed little increase in risk, even with high TTHM levels. Showering or swimming did not appear to add to the risk.

A companion study of women in the same three Kaiser service areas indicated that those using the Santa Clara medical center who drank a lot of water but consumed only bottled water had a little more than a third the miscarriage rate of women who drank only tap water. Puzzlingly, these differences were not seen in the Fontana and Walnut Creek groups. There was no claim that bottled water, in general, is safer than tap water.

In fact, Shanna H. Swann, an author of both studies, argued against switching to bottled water, noting that in Southern California the risk of miscarriage associated with bottled water was slightly higher than the risk with tap water.

In Los Angeles, Freeman noted that it was difficult, especially without having the full report, to evaluate the seriousness of any risks, but added: “I know there’s a difference between 15% and 9%, which suggests that there may be a cause and effect here. . . . If the risk is anything other than zero, I think people have a right to know about it.”

TTHM is created by the interaction of chlorine and plant matter. Chlorine is added to water to kill diseases, so simply discontinuing it is not feasible.

Chlorination has been widely used in the United States since it was introduced in 1908 to control a typhoid epidemic in Chicago caused by contaminated water from the city’s stockyards. It has virtually put an end to waterborne outbreaks of typhoid, cholera, dysentery and hepatitis in the United States.

But several studies have suggested that chlorination is associated with small increases in cancer risk and birth defects. It is not the chlorine itself that is the problem, but byproducts formed when it reacts with organic materials in the water.

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The most common of these byproducts are the trihalomethanes, such as chloroform. “But we are not sure if they are the problem or if they simply serve as surrogates for other problem chemicals,” said Frank J. Bove of the federal Agency for Toxic Substances and Disease Registry in Atlanta.

Freeman’s aggressive response to the issue put him in the awkward position of reacting to a report that has yet to be distributed, but the city’s water chief said he felt the public had a right to evaluate information about potential health hazards as it became available. He particularly bristled at the suggestion that he might cause pregnant women to overreact.

“I’m not one of those people who is going to withhold information because people might panic,” he said. “People are at least as smart as bureaucrats, probably smarter. . . . They concluded that there is a risk. It may be tiny, but let me ask you this: Don’t you feel as a human being that you’re entitled to information that your government developed?”

The primary study, led by investigators Kirsten Waller and Swann and scheduled for publication in the Feb. 18 issue of the journal Epidemiology, was based on Kaiser Permanente patients selected between 1989 and 1991 and served by 78 water utilities. Women were recruited when they made their first prenatal appointments. The TTHM levels were estimated by averaging routine measurements taken by the utilities during each subject’s first trimester.

The amount of TTHMs in water varies day to day, but is more common in water derived from above-ground sources such as rivers or lakes. The levels differ according to temperature, the amount of chlorine added to the water and other factors. State researchers found that 18% of the women in the study received water during their first trimester at or above the risk threshold of 75 micrograms per liter. And 13% had water at or above 90 micrograms.

Although Los Angeles was not part of the study, women who drank water on peak days in the city last year could have received water with as much as 100 micrograms.

That issue, the level of TTHMs in city water, was of particular interest to local officials as they gauged their response to the report. Freeman and others stressed that on most days, city water does not contain the levels of TTHM that might trigger concern.

According to DWP statistics, the amount of TTHM varies slightly from region to region of the city, depending on the source of the water and time of year. Last year, the peak recording in the region that includes the west San Fernando Valley and Westside was 100 micrograms per liter. In the central area of the city, it was 99.78 micrograms per liter. Both of those peaks exceed the 75 micrograms per liter analyzed in the study.

Only the Harbor region of Los Angeles did not exceed the 75-microgram level in 1997. Its highest reading last year, according to the DWP, was 65 micrograms per liter.

“We are above 75 quite a bit of the time,” Freeman acknowledged.

Local officials have not decided on a long-term response to the issue, but for the time being agreed that it was prudent for pregnant women in their first trimester to boil water rather than risk any potential problems, no matter how remote the possibility.

Council members Mike Feuer and Ruth Galanter co-authored a proposal, swiftly and unanimously approved by the council, requiring the DWP and the MWD to report back on the issue, including the activities and programs being implemented to deal with the potential problems.

Meanwhile, doctors said they already were hearing from patients alarmed by the reports of possible hazards. Dr. Tamerou Asrat, an obstetrician and perinatologist at Long Beach Memorial Medical Center and Hoag Memorial Hospital Presbyterian in Newport Beach, was hit with questions by his patients Tuesday.

“I’m not alarmed by this, but my patients are,” Asrat said. “And when someone is pregnant, the least bit of concern is amplified.”

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The study analyzing a possible link between miscarriage and TTHMs is the latest in a long line of looks at the health effects associated with chlorinating water.

A 1992 study by Dr. Robert D. Morris of the Medical College of Wisconsin showed that people who drank chlorinated water had a 21% greater risk of getting bladder cancer and a 38% greater risk of rectal cancer than people who drank non-chlorinated water.

Other studies, including one from the Agency for Toxic Substances and Disease Registry, have confirmed the increased risk for bladder cancer, but not for rectal cancer.

A study of Iowa women reported last August by epidemiologist Wei Zheng and his colleagues at the University of Minnesota found that women who had the highest concentrations of chloroform in their water supply had an 86% greater risk of developing colon cancer and a 28% greater risk of developing cancer of any kind than women whose water contained little or no chloroform.

If the problem really is caused by trihalomethanes, Bove noted, switching to bottled water is probably not going to solve it. Because the compounds are very volatile and evaporate into the air from sprayed water, “You get a bigger dose from showering than from drinking it,” he said. “The other problem is that bottled water isn’t regulated, so we don’t know what is in it.”

Bove said water purification processes should be changed so that these chlorination byproducts are not formed. Better filtration before chlorination will remove organic materials, so that fewer byproducts are formed. Another answer would be to use ozone as a disinfectant--admittedly a more expensive approach--which would eliminate their formation.

“There is really nothing any individual can do, but as a society we can certainly do something,” he said.

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Times staff writers Beth Shuster, Julie Marquis and Shari Roan contributed to this story.

* EXPECTANT WOMEN WORRY

Women study latest warning; doctors are cautious. B1

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Trihalomethane Levels

The Environmental Protection Agency requires the concentration of trihalomethanes (TTHM) in water average less than 100 parts per billion over the course of a year. Levels are usually much lower in winter and substantially higher in summer.

Concentrations of TTHM in L.A.-Area Water Supplies (parts per billion)

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Water System City Avg. Level City of Santa Ana Santa Ana 43 City of Anaheim Anaheim 43 City of Huntington Beach Huntington Beach 26 Foothill Municipal Water Dist. La Canada Flintridge 34-67* Suburban Water Dist.-Whittier La Mirada 64 Long Beach City Water Dept. Long Beach 64 Dept. of Water and Power Los Angeles 72 Metropolitan Water District Los Angeles 40-73*

Water System Max. Level City of Santa Ana 68 City of Anaheim 109 City of Huntington Beach 31 Foothill Municipal Water Dist. -- Suburban Water Dist.-Whittier 97 Long Beach City Water Dept. 107 Dept. of Water and Power 177 Metropolitan Water District 108

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* Quarterly averages

Source: Natural Resources Defense Council