Late-term miscarriages and spontaneous abortions occurred at an unusually high rate among Washington women from 2000 through 2003 — during the same time frame that lead levels were dangerously high in the city’s drinking water, a study has found.
The increase in fetal deaths was an anomalous spike for the District, and the rate of women losing advanced pregnancies returned to average levels in 2004. That is the year that a Washington Post story alerted the public to the widespread lead problem in tap water, and federal health officials began urging children and pregnant women to instead drink filtered or bottled water.
The study findings, which are scheduled to be published in the journal Environmental Science and Technology, do not prove that the city’s lead crisis caused fetal deaths or miscarriages. But the results show a significant correlation between the two events.
Lead is an extremely toxic metal, and ingestion of lead paint dust and high doses of lead in water have been traced to brain damage, behavioral problems and developmental delays in children. Exposure to lead has also been linked to miscarriages. In the early 1900s, lead-laced pills were used to induce abortions.
The study, by Virginia Tech environmental engineer Marc Edwards, contrasts sharply with government-led health studies that were released amid an outcry after people learned of hazardous lead in the water in 2004. Those studies largely rejected the notion that the water had harmed public health.
The data seem “to confirm the expectation, based on prior research, that about 20 to 30 extra fetal deaths occurred each year that the lead in water was high,” Edwards said.
One rushed and disputed analysis by the Centers for Disease Control and Prevention asserted in April 2004 that there was no indication of health trouble from the water problem, even among children in homes with the highest lead levels in the water. Under repeated criticism, the CDC published a corrected analysis in 2010, acknowledging that this overarching statement had been misleading and based on incomplete data.
Today, the city’s drinking water has historically low levels of lead. But Edwards’s study looks back at that period when the city had some of the highest lead spikes in water ever recorded in the United States. The study tracks the rate at which pregnant Washington women suffered miscarriages known as fetal deaths — losing a pregnancy after 20 weeks — and charted the data before, during and after the city’s experience with unusually high levels of lead in drinking water.
Like many urban areas in the 1990s, Washington was experiencing a gradual decline in the rate of women losing babies late in pregnancy. The fetal death rate had dropped from 9.7 deaths per 1,000 births in 1997 to 7.9 deaths per 1,000 births in 1999.
But in 2000, as cities such as Baltimore and others continued that slow decline, the District’s rate increased by 37 percent. It rose to 10.9 deaths per 1,000 in 2000, and to 12.9 deaths in 2001.
In 2000, the D.C. Water and Sewer Authority had made a chemical disinfection change in its water treatment that started sending hazardous levels of lead through faucets. The chemical change made the water more corrosive on lead pipes and plumbing and continued for three years before the public was alerted to the problem.
When a Post story reported the problem in 2004 and residents began using filters and taking other preventive steps, the miscarriage and fetal death rate fell again to 7 deaths per 1,000.
George Hawkins, the new director of the water authority, said Edwards’s study provides helpful research and raises worrisome questions about the impact of the lead spike on public health. Today, he said, the city’s lead levels are at historic lows. He said the agency also closely monitors homes when pipes are being replaced and encourages the use of filtered water.
“We generally believe lead in water is a great risk to human health, and that’s why we have an extremely proactive program to respond to it,” he said. “We know it’s a serious issue . . . and we work with our customers if we think there is a risk.”