The Yale School of Public Health announced Thursday that it has received a $15 million contract from the National Institutes of Health to fund research on child health and wellbeing as part of the National Children’s Study.

Researchers at Yale and across the country will follow 100,000 children in both urban and rural areas from before birth until age 21 in the hopes of discovering how child development and health are affected by factors such as environmental conditions, family influences and genetics. The study will last for 20 years and is believed to be the largest of its kind ever undertaken, University officials said. Researchers said they hope the project will help increase knowledge of children’s entire developmental process in various environments.

“This project is different from our other research in that this is a longitudinal study that is planned to continue for 20 years,” head research scientist Kathleen Belanger said.

Belanger, along with professor of epidemiology and public health Michael Bracken, will oversee the study at Yale. The branch of the study being done at YSPH is one of 22 new additions to the project, which includes 105 sites across the United States and is a collaboration between the U.S. Department of Health and Human Services and the U.S. Environmental Protection Agency.

Researchers said they hope the study will shed light on areas of medicine that were previously unstudied in combination.

“The data from this path-breaking study will provide unprecedented information about how to protect and promote the health of individuals,” Paul Cleary, Yale’s dean of epidemiology and public health, said.

Because the scope of the study is so large, the data gathering, recording and analysis methods will be standardized to ensure uniform processing of data at all study centers across the nation, Belanger said. Using the prenatal studies included in the project, scientists will later be able to study data related to conditions that may not show up until much later in life, Belanger said.

She said the project is especially relevant because it encompasses such a large swath of society.

“It’s helpful to have a study that would be representative of the U.S. population,” Belanger said. “We certainly hope this will be an opportunity to enroll a cohort of families that we can look at for much longer term outcomes.”

The research included in the two-decade-long study is similar to work being done under projects currently being led by Yale researchers, Cleary said. He said the grant is an opportunity for Yale scientists to continue to expand their research because it places them in a leadership position within the National Children’s Study.

The length of the study will enable researchers to discover links between different genetic and environmental factors that would not have been evident from shorter projects, public health student Brian Wayda EPH ’08.

“Much of what we know about the etiology of rare disease — the effect of secondhand smoke on asthma incidence or the effect of television watching on autism, for instance — has been based on retrospective surveys,” Wayda said. “By tracking the subjects over 20 years, we can more precisely measure exposures and hopefully establish definite causation by controlling for lots of potential confounders.”