The fate of a much-anticipated long-term study on the effect of the environment on children's health is in jeopardy, a potential victim of the tight federal budget.

The $3.2 billion National Children's Health Study, launched with much fanfare in 2000, was intended to follow 100,000 children over 20 years, and was set to begin recruiting in late 2007.

We've been funded out of pocket change for the last five years. Sarah Keim, National Children's Study

But the president's budget request for fiscal year 2007 directs the US National Institute of Child Health and Human Development (NICHD), the lead agency in the study, to shut down all operations, including a pilot study of 900 expectant mothers that is already under way.

At the same time, the NICHD is operating under the 2006 funding bill, which directs the agency to continue preparations.

“We're kind of schizophrenic doing both at the same time,” says study director Peter Scheidt.

The study is intended to track the effects of different environmental factors—from chemical exposures to parental nurturing styles and television viewing—from the womb through adulthood. The vast database would then help researchers fathom the causes of birth defects, autism, diabetes and a host of other childhood disorders. The data would be made freely available to researchers.

Because the study would recruit children even before their birth, the first research questions address prenatal risks, such as whether low thyroid activity in the mother leads to cognitive defects and autism in her child, and whether inflammation or infection of the uterus can lead to premature birth.

Smaller studies could address some of these questions, but “there are a large number of conditions that are so infrequent that you can't study them unless you collect a very large sample,” says Scheidt. For common conditions, such as obesity or asthma, he adds, a large sample also allows researchers to examine which of the many risks contribute to the disease.

“Ending the study before it begins would be a tragedy for our children,” adds Nancy Chuda, president of the Children's Health Environmental Coalition, a Los Angeles–based nonprofit advocacy group. “The only way we can prevent these illnesses is to learn what causes them.”

Democratic Senator Tom Harkin is trying to revive the study, which has already consumed five years and $50 million for study design, database development and pilot research. That amount includes $7.4 million awarded to seven recruiting centers that are gearing up to enroll expectant mothers.

Language in the House version of the funding bill directs the agency to continue the study but provides no specific funding. Deputy study director Sarah Keim says this approach is unworkable. “We've been funded out of pocket change for the last five years,” she says. “Big science can't be done like that—we can't keep scraping pennies out of the couch.”

The fate of the study will remain in limbo until Congress passes a spending bill; at press time, neither chamber had scheduled a vote on the bill.