Workshop to identify critical windows of exposure for children's health: immune and respiratory systems work group summary.
Fetuses, infants, and juveniles (preadults) should not be considered simply "small adults" when it comes to toxicological risk. We present specific examples of developmental toxicants that are more toxic to children than to adults, focusing on effects on the immune and respiratory systems. We describe differences in both the pharmacokinetics of the developing immune and respiratory systems as well as changes in target organ sensitivities to toxicants. Differential windows of vulnerability during development are identified in the context of available animal models. We provide specific approaches to directly investigate differential windows of vulnerability. These approaches are based on fundamental developmental biology and the existence of discrete developmental processes within the immune and respiratory systems. The processes are likely to influence differential developmental susceptibility to toxicants, resulting in lifelong toxicological changes. We also provide a template for comparative research. Finally, we discuss the application of these data to risk assessment.
Dietert
R R
RR
Department of Microbiology and Immunology and Institute of Comparative and Environmental Toxicology, Cornell University, Ithaca, New York, USA. rrdl@cornell.edu
Etzel
R A
RA
Chen
D
D
Halonen
M
M
Holladay
S D
SD
Jarabek
A M
AM
Landreth
K
K
Peden
D B
DB
Pinkerton
K
K
Smialowicz
R J
RJ
Zoetis
T
T
D002648:Child; D002657:Child Development; D002669:Child Welfare; D002675:Child, Preschool; D004781:Environmental Exposure; D004785:Environmental Pollutants / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007107:Immune System / Q000187:drug effects* / Q000196:embryology / Q000254:growth & development; D007223:Infant; D007231:Infant, Newborn; D011247:Pregnancy; D012137:Respiratory System / Q000187:drug effects* / Q000196:embryology / Q000254:growth & development; D013997:Time Factors
D004785:Environmental Pollutants