‘Unusually Low’ Miscarriage Rate Linked to Drinking Bottled Water

A three-year study of nearly 5,000 women has found that those who reported drinking bottled water rather than regular tap water during pregnancy had an “unusually low” rate of miscarriages, state officials announced Monday.

The study also found that the incidence of birth defects was slightly lower in children born to women who drank bottled water instead of tap water, state Health Director Kenneth W. Kizer said.

“Three independent new studies carried out since 1985 have . . . shown unusually low rates of miscarriages in women who reported they had abstained from drinking tap water during their pregnancy,” Kizer said. “We welcome scientific comment on these findings. We know they are controversial.”

The state began investigating the incidence of miscarriages and birth defects in the San Jose area in 1982 after toxic chemicals from a leaking underground storage tank contaminated drinking water supplies in the middle-class Los Paseos neighborhood of south San Jose.

Inconclusive Study

Kizer said the latest study was unable to conclusively determine whether the birth defects and miscarriages were linked to the consumption of polluted tap water. Nor was the study able to explain what caused the unusual “cluster” of birth defects in the community.

State scientists, in their summary of the study, called the results on use of tap water “perplexing” and indicated that they were uncertain whether the findings showed that the bottled water, in fact, did result in fewer miscarriages and birth defects. “The most likely explanation” for the findings, they said, was that women who suffered miscarriages were more likely to remember what kind of water they drank than those who had normal pregnancies--a phenomenon called “recall bias.”

However, Department of Health Services researchers also found that the tap water in many homes contained much higher levels of “organic carbon” than expected. Further tests are needed to know what causes this organic carbon and whether it is related to the incidence of miscarriages and birth defects, they said.

Research Into Questions

“At this point, the department does not have enough information to warrant any public health advisories,” Kizer said.

Gov. George Deukmejian is proposing to spend $1.4 million next year to continue research into the questions raised by the latest study, including whether tap water poses a health risk and whether there is some beneficial substance in bottled water, the health director said.

The results of the study prompted environmentalists to call on the state to do a better job of protecting the public’s health.

“This seems to confirm that the public has good reason to worry about their drinking water and good reason to want a lot better information and protection than what they’ve been getting,” said David Roe, a lawyer for the Environmental Defense Fund and a co-author of Proposition 65. Beginning in October, the anti-toxics initiative will ban the discharge into drinking water supplies of chemicals that cause cancer or birth defects.

In the early 1980s, a well serving the south San Jose area was found to be fouled with toxic chemical solvents after a nearby computer chip plant run by the Fairchild Camera and Instrument Co. discovered that one of its underground solvent storage tanks had leaked. Later checks at an IBM factory in the area found that it, too, had leaky solvent storage tanks, as had other companies throughout the Silicon Valley.

In 1985, state health officials found that the incidence of serious heart abnormalities, birth defects and miscarriages was two to three times as high in the neighborhood of Los Paseos as in Santa Clara County as a whole.

Fewer Miscarriages

That study also suggested that fewer miscarriages and birth defects were associated with women who drank bottled water rather than tap water, a finding that helped prompt the state Health Services Department to conduct its latest research.

The latest three-year study of nearly 5,000 women included residents of San Jose near the original spill area, control groups elsewhere in Santa Clara County and women in San Mateo and Alameda Counties.

Based on detailed analysis of the health and diet of these women, state officials now say they are 90% certain the solvents found in tap water in the Los Paseos neighborhood were not responsible for the health problems that residents suffered.

As evidence, they cite the fact that the census tract with most of the health problems consumed less of the tainted water than an adjoining tract burdened with only an average number of reproductive disorders.

Conclusion Challenged

That conclusion, however, was challenged by a local lawyer, Ted Smith, who represents the Silicon Valley Toxics Coalition, a grass-roots environmental group. He said the state researchers did not properly analyze exactly how much tainted water was consumed in each neighborhood back to the very first suspected tank leak, at IBM, in 1981.

“If your underlying analysis of water distribution is wrong,” he said, “then so are the conclusions you draw from it.”

But even before the study was made public, Fairchild issued a written statement saying it was “gratified” by its conclusion.

Richard C. Paddock reported from Sacramento and Mark A. Stein reported from San Jose.