The largest human health study ever conducted in the United States is about to be launched. The study aims to discover the incipient causes of topical health issues including autism, attention-deficit/hyperactivity disorder, asthma, birth defects, diabetes, heart disease and obesity.

The National Children’s Study will enroll 100, 000 children and pregnant women from across the country. The children will be followed from before birth to age 21 to identify genetic and environmental factors that contribute to health disorders and conditions of childhood and adulthood. Researchers will collect a variety of information from participants, such as air samples, dust samples, medical records and survey information. They will study the environmental influences that affect them, including toxins, nutrition, physical living conditions and socioeconomic factors.

The study won a $57-million grant from the National Institutes of Health. Officials said more than $200 million has been spent already into the forming of the study from 2000 to 2007.

The National Children's Study will be conducted at 105 different locations throughout the United States and it will cost an estimated $3.2 billion.

"By following children from before birth and studying their environment, we will be able to seek out ways to prevent many of the diseases children now suffer from," said Nigel Paneth, Michigan State University epidemiologist and principal investigator in Michigan.

Michigan State University will lead the study overall with project collaborators from Wayne State University, the University of Michigan, Children's Hospital of Michigan, Henry Ford Health System, Michigan Department of Community Health, Wayne County and city of Detroit Health Departments.

Beginning in January, the University of North Carolina and the Mount Sinai School of Medicine in New York will start recruit pregnant women whose babies would then be followed to age 21. The first data from the study could be available in 2012 or 2013.