U.S. government researchers launched the biggest-ever study of children on Tuesday, saying they will track 100,000 children from birth through age 21 to see what makes kids sick.

The study, being launched at 96 centers, will follow the children as they grow up, looking at their environments, behavior, family and genetics.

“Together the children from these 96 locations will represent the face of all of America’s children,” the National Institute of Child Health and Human Development, which is sponsoring the study, said in a statement.

The National Institutes of Health, the Centers for Disease Control and Prevention and the Environmental Protection Agency will work together on the study, detailed on the Internet at http:/nationalchildrensstudy.gov/about/mission/overview.cfm.

No single comprehensive study has ever looked at U.S. children. Many studies, such as the Framingham Heart Study, and studies of tens of thousands of nurses and doctors, have followed adults through their lives.

The National Children’s Study will examine:

- Natural and human-made environment factors

- Biological and chemical factors

- Physical surroundings

- Social factors

- Behavioral influences and outcomes

- Genetics

- Cultural and family influences and differences

- Geographic location

“From the water we drink and the air we breathe to the foods we eat, it is important to know how environmental factors impact the health of our children. Only a study of this size and scope holds the promise of shaping the care of children for the next century,” said the EPA’s Paul Gilman.

Other groups said the research would help doctors better care for children, who are rarely included in medical studies.

“The American Academy of Pediatrics (AAP) and its member pediatricians believe the National Children’s Study will yield valuable information,” said AAP President Dr. Carol Berkowitz.

“It will ultimately enable us to learn much more about, and further improve, the care we give to our patients.”