Environmental Toxins & Child Development
Walter J. Rogan, M.D.
Tel (919) 541-4578
Fax (919) 541-2511
P.O. Box 12233
Mail Drop A3-05
Research Triangle Park, North Carolina 27709
The Pediatric Epidemiology Group—led by Walter J. Rogan, M.D.—studies the effects of environmental chemicals on the growth and development of children. Rogan and his co-investigator, Beth Gladen, Ph.D., who retired from NIEHS in January 2007, studied about 850 North Carolina children born between 1978 and 1982. Their research showed that transplacental exposure to polychlorinated biphenyls (PCBs), which are widespread industrial pollutant chemicals, produced small delays in motor development detectable from birth to age two years (J Pediatr 119:58-63, 1991). The children’s development was tracked until they completed puberty. The adolescent boys with higher prenatal exposure to DDE-the most persistent form of the pesticide DDT, which is also still a widespread pollutant chemical—were taller and heavier than boys with low DDE exposure. Adolescent girls with higher prenatal PCB exposure were heavier than their counterparts with low PCB exposure, but there were no clear effects on the age at which they achieved puberty (J Pediatr 136:490-496, 2000).
In the same study, children with higher exposure to DDE were associated with markedly earlier weaning. That finding was replicated in Mexico (Am J Pub Health 85:504-8, 1995), and the investigators speculated that this was due to the estrogenicity and persistence of DDE. Rogan pursued the public health implications of this finding in an analysis of the use of DDT to prevent infant deaths from malaria (Emerging Infect Dis 9:960-4, 2003).
Rogan and his colleagues studied a complex food poisoning episode in Taiwan, in which children were exposed transplacentally to PCBs and polychlorinated dibenzofurans (PCDFs) that their mothers ate in contaminated cooking oil. The children had a syndrome of ectodermal defects, global persistent developmental delay and disordered behavior (Science 241:334-336, 1988). The oldest affected children were born in 1979, and their follow-up until 1995 has shown that the behavior disorder is becoming less severe, but that the cognitive defects remain (Arch Gen Psychiatr 59:61-66, 2002).
Rogan was project officer and one of the principal investigators for the four-site, randomized, controlled clinical trial of oral chelation therapy to prevent lead-induced disorders of growth, behavior and cognitive development in toddlers. The Treatment of Lead-exposed Children (TLC) trial randomized 780 children between 13-33 months of age with blood lead levels of 20-45 µg/dl and followed them after treatment with tests of cognitive ability, behavior and neuropsychological function. Despite lowering of their blood lead levels and relatively few drug side effects, the children given succimer scored no better than the children given placebo on any of the tests at about age five years (N Engl J Med 344:1421-1426, 2001) or 7 years (Pediatr, 114:19-26, 2004).
Rogan has now returned to his interest in infant nutrition and environmental estrogens by beginning a series of studies that should lead to a randomized trial of soy formula, looking for changes in neonatal sexual differentiation and estrogen metabolism. Two compounds in soy, genistein and daidzein, are plant estrogens, and infants fed soy formula as their sole source of calories have the highest relative exposure to these compounds. What effect, if any, this exposure has on the child is not well studied (Ann Rev Nutrition, 24:33-54, 2004).
Rogan received a B.A. from LaSalle College, an M.D. from University of California, San Francisco and an M.P.H. from University of California, Berkeley. He is licensed in North Carolina and Board Certified in General Preventive Medicine. Rogan came to NIEHS in 1976, served 20 years in the U.S. Public Health Service at NIEHS and has served as Epidemiology Branch Chief, Associate Director in the Division of Biometry and Risk Assessment, and Acting Clinical Director in his years at NIEHS.