This is the VOA Special English Health Report.

One of the largest health studies ever done in the United States will look at environmental influences on children.

The study will examine the many environmental and genetic factors that affect the health of children and the adults they become.

Dr. Steven Hirshfeld at the National Institutes of Health is the study director. Test projects have already begun, and he says the main part of the National Children's Study will begin next year.

STEVEN HIRSHFELD: "Our goal is to understand how you can get the healthiest, most robust child to develop into a healthy and contributing member of adult society."

Researchers want to study 100,000 children across America. The study will collect information from before they are born until they are 21 years old.

There are seven centers around the country where parents can join the study. Jennifer, three months pregnant, signed up for the study at the University of California, Los Angeles.

JENNIFER: "Well, living in Los Angeles, I'm concerned, like, obviously about the pollution and the smog and that kind of stuff. And, you know, I'm also concerned about what I put in my body, like is the food genetically modified? Like, is the food organic? Like, do they add chemicals or preservatives to things and, like, how do those things have an effect on an unborn child?"

Researchers at UCLA will consider questions like these as they study 4,000 children in the Los Angeles area. They also plan to study 1,000 children in a rural area. The aim is to see what effect pesticides used on nearby farms might have on the children's health.

Dr. Michael Lu is one of the lead investigators at UCLA.

MICHAEL LU: "We're examining a number of very important child conditions such as asthma and autism, pre-term birth and birth defects, obesity and diabetes and various behavioral and learning problems."

The researchers will also study mental health disorders.

MICHAEL LU: "I think this study has the potential to change the way we look at childhood health and development."

The goal of the National Children's Study is to create a database that researchers around the world can use. Dr. Hirshfeld, the study director, says this information could help solve some unanswered questions.

STEVEN HIRSHFELD: "We have knowledge gaps in many of the most important factors that influence not only the health and well-being and development of children, but that begin the foundations of what could turn into chronic conditions for adults."

Findings from the study will be released as they become available. The information could lead to new policies and changes in existing laws on child health and the environment. The hope is that children can live healthier lives and grow into healthier adults.

And that's the VOA Special English Health Report, by Caty Weaver and Carol Pearson. You can watch a video about the National Children's Study at voaspecialenglish.com. I'm Bob Doughty.

birth defects: 先天性畸形

obesity: 肥胖症

diabetes: 糖尿病

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（来源：VOA 编辑：实习生史莉萍）