Do workplace environmental exposures affect the health of children? Over the next several years more than 50,000 pregnant workers, their partners, and the pregnant workers’ workplaces in 96 counties across the United States are expected to be monitored in the National Children’s Study (NCS) to help answer this question. Data from the NCS might eventually impact all employers through new prevention strategies, health and safety guidelines, and educational approaches to improving children’s health.

What’s the NCS?

The NCS (, at a projected cost of $2.7 billion, will study the effects of environmental exposures (chemical, biological, physical and psychosocial) as well as gene-environment interactions on pregnancy outcomes, child health and development, and precursors of adult disease of 100,000 children from before birth to age 21.

The lead agencies for the NCS include the National Institutes of Health, Centers for Disease Control, and the U.S. Environmental Protection Agency. The initial study groups are pregnant women and their partners, couples planning pregnancy, and women who are of child-bearing age but who are not planning a pregnancy. The main subject of the study, however, is the “subsequent children.”

Ninety-six (96) study locations across the U.S. were announced in November 2004. The study groups in the NCS will come from these locations and will be a cross-representation of “America’s children.” The randomly chosen Vanguard locations (e.g. pilot sites) are Orange County, CA; Orange County, FL; Lincoln, Pipestone, and Yellow Medicine Counties, MN; Duplin County, NC; New York City (Queens), NY; Montgomery County, PA; Salt Lake County, UT; and Waukesha County, WI.

Critical factors

A major premise of the NCS is that the health and safety of a child depends on factors that occur before birth. The NCS seeks to enroll participants into the study as “early in the pregnancy as possible, with a target of enrolling at least 25 percent of pregnancies prior to conception and a cumulative total of 90 percent within the first trimester of the pregnancy.”

The NCS will collect a wide variety of biological and environmental samples. Anticipated biologic samples include blood, urine, hair, nail clippings and saliva from mothers; blood, urine and hair from fathers; cord blood, placental tissue and meconium collected at/around the time of delivery; vaginal and cervical swabs; breast milk from mothers; and semen sample from fathers. What constituents will be initially measured is yet to be determined, but plans call for freezing some biological samples to be analyzed in the future as technology expands and allows for a closer examination.

Household environmental samples including dust, air, water, paint and soil will be obtained with each change in residence. Environmental samples will also be obtained from “the mother’s place of employment during her pregnancy.” The kind of samples to be obtained is yet to be determined but should be a case-by-case decision. As the research children grow, environmental samples will also be collected from their day-care centers and schools.

Given that more than one-half of all babies born in the U.S. are born to working mothers, and even a higher percentage of working fathers, the planned population of more than 100,000 NCS participants should draw in approximately 50,000 employers having one or more employees in the study. Employers in the study locations may want to prepare as early as practical for the coming media blitz and their possible involvement in the NCS. But other employers should get ready, too.

SIDEBAR: Future regulations?

U.S. employers who want to know what actions might be necessary to protect a pregnant worker and children should review the regulations in the European Union that require all employers to conduct risk assessments for workers who are pregnant, have recently given birth, or are breastfeeding. The rationale and concepts for the risk assessments, as a worldwide effort, are covered in the International Labor Organization (specialist agency of the United Nations) 2004 publication, “Healthy beginnings: Guidance on safe maternity at work” (

SIDEBAR: To learn more

The topic will also be covered in an eight-hour Professional Development Course “Implementing Reproductive and Developmental Health Programs” (PDC 415) on Sunday, May 22, 2005, at the American Industrial Hygiene Conference and Exhibit in Anaheim, Calif. Registration information for the PDC is available at