CHILDREN'S HEALTH STUDY IMPERILED

A widely anticipated long-term study of childhood health problems and birth defects, under development for four years, is nearly ready for implementation. But there is concern that Congress will not appropriate the money needed to do the study properly.

The impetus for the study is the rapidly increasing incidence of serious childhood health problems recorded in recent years. For instance, the percentage of children and adolescents defined as overweight has more than doubled since the early 1970s. Also, the number of asthma sufferers has more than doubled since 1980. Now, about 6 million children have asthma, and asthma deaths per year have tripled over the past two decades. Roughly one out of 250 infants is born with the male birth defect hypospadias.

Over the past two decades, researchers have become aware that, during certain critical periods of fetal and childhood development, exposure to toxic agents can have more severe outcomes than would result from exposures later in life.

In 2000, such observations led to passage of the Children's Health Act, which had strong bipartisan support. The law authorized the National Institute of Child Health & Human Development (NICHD) to lead "a national longitudinal study of environmental influences--including physical, chemical, biological, and psychological--on children's health and development."

NICHD, the National Institute of Environmental Health Sciences, the Centers for Disease Control & Prevention, and the Environmental Protection Agency together have spent roughly $12 million each year from 2001 to 2004 to plan the study. Most of the planning has now been accomplished, and the study is nearly ready for implementation.

THE STUDY will follow a cohort of about 100,000 children from the womb to age 21. It will evaluate how low-level exposures to chemicals and how social and dietary factors interact with the genetic makeup of children to cause adverse health effects. It will be the largest and most lengthy study of children ever performed in the U.S.

One of the major potential benefits of the study is that it is longitudinal. That is, it has the potential to establish links between early fetal and childhood exposures and outcomes that may not happen until much later in life, says Carole A. Kimmel, senior scientist in EPA's National Center for Environmental Assessment.

However, for fiscal 2005, only $12 million is proposed for the program when $27 million is needed to begin implementing the study. "We've indicated that in order to go forward with the study, we need an additional $15 million in 2005, and that is not in the President's budget," says Peter C. Scheidt, director of the National Children's Study program office at NICHD.

This dearth of funding is hard to explain except by the fact that in most areas federal R&D funds are expanding little. Researchers in pediatric health and public interest groups all say the study is important and should go forward. For example, the American Chemistry Council and the Children's Environmental Health Network both consider the study crucial for understanding why certain health conditions are worsening in children.

"The American Chemistry Council has supported the study since the passage of the Children's Health Act, and we have been participating in the planning of the study," says Lee Salamone, director of ACC's public health team. "Because it is going to examine the environment broadly, it will help focus resources in areas that will have the most impact," she says.

Some of the health areas to be included in the investigation are asthma; obesity; premature birth; birth defects; autism and attention deficit hyperactivity disorder; injury; and nutrition, growth, and pubertal development.

For example, one key question investigators hope to answer is about the possible relationship between diabetes in pregnancy and malformations of the heart of the fetus. Another question is: Does a relationship exist between chronic low-level pesticide exposure and problems in central nervous system development? The real power of this study will be its ability to assess multiple classes of exposure and find relationships with children's health, Scheidt says.

Women in the study will be enrolled early in pregnancy so chemical exposures that might influence early fetal development can be studied, Scheidt says. A wide range of environmental and biological samples will be collected from parents, children, and their environment, he explains.

One of the challenges of the study is to design a repository where literally billions of samples can be stored, not only for current study but for follow-up work to investigate hypotheses that occur to researchers in the future, Scheidt says. "The study offers a rich opportunity for answering questions not posed at the outset," he explains.

Another challenge is to collect data in a way that does not burden people but is precise enough to maintain a high level of consistency. "We will need to be able to combine data from different sites around the country," Kimmel says.

Researchers worry that, if implementation of the study does not begin soon, momentum will be lost and the program will never be funded properly. "There is a real problem with keeping people interested who have dedicated a lot of time to planning the study and who don't see any steps toward actually implementing it," says Lynn R. Goldman, a professor at Johns Hopkins Bloomberg School of Public Health.

On April 28, briefings on the study will be held by committees in both the Senate and the House. Advocates hope that these efforts may result in more funding for the program.