MISCARRIAGE: Tap Water Cited For High Rates
"Two new studies by the California Department of Health Services link drinking large amounts of tap water in Santa Clara County to incidents of miscarriage," the San Jose Mercury News reports. One of the studies found that pregnant women "who drank more than five eight-ounce glasses" of Santa Clara County tap water "had a 17.9% miscarriage rate -- nearly twice the county's average and close to three times the rate for women who drank the same amount of bottled water." The other study found that pregnant women in Santa Clara, Contra Costa and San Bernardino counties who drank tap water with a high percentage of "potentially cancer-causing chemicals called trihalomethanes" (TTHMs) had a 15.7% miscarriage rate, versus a rate of 9.5% for women "who drank the same amount of tap water in districts with lower average levels of the chemical" (Puzzanghera, 2/10). The findings will be published in the February 18 issue of the journal Epidemiology.
The Los Angeles Times reports that while the findings are already "stirring political and scientific debate," local officials were quick to point out that "the study is not definitive," but rather "one part of a large-scale effort by the U.S. Environmental Protection Agency to balance the need for protection against microbes ... with the need to keep the dangers of disinfection itself to a minimum." The authors of the study, Kirsten Waller and Shanna Swann, "emphasized that only about 2% of the 5,144 women in their study were found to have been exposed to the highest risk levels" (five or more glasses of water containing at least 75 micrograms of TTHMs per liter). However, the California Department of Health Services "described the findings as particularly disturbing because pregnant women are often advised by physicians to drink a lot of fluids."
Los Angeles Mayor Richard Riordan (R) said "he was seeking more information on the seriousness of the threat." While Los Angeles was not specifically studied, the Times reports the city's tap water "exceeds the level that triggered concern in the study, leading local officials to debate whether city leaders should be warning pregnant women about possible risks." Health official Jim Stratton said, "We are in that awkward in-between stage between when something starts showing up (as a possible problem) and when we have definitive proof." And as LA Department of Water and Power General Manager S. David Freeman noted, the situation is "particularly difficult" because it is not possible to remove the hazard since TTHM is a bi-product that is formed when chlorine is added to the water. "You can't just take the bad stuff out. The bad stuff is what makes the water safe," he said (Newton/Marquis/Yi, 2/10). The Sacramento Bee reports that "the state's top health officer, Dr. James Stratton, suggested that pregnant women may choose to take precautions to minimize the potential risks of drinking tap water," such as boiling the water for one minute or allowing the water to sit for several hours.
The 5,144 California women studied were Kaiser Permanente patients in Santa Clara, Walnut Creek and Fontana (Griffith, 2/10). The San Jose Mercury News reports that "the studies raise as many questions as answers." For example, the studies "used data collected between 1989 and 1991," a time when Santa Clara County was forced by drought to use more surface water -- which has a higher percentage of TTHMs than ground water. And, the Mercury News notes, miscarriages are "difficult to study because they are not tracked by health officials the same way cancers and some birth defects are." A North Carolina study found no link between miscarriages and TTHMs (2/10).