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Assessing the joint effects of chlorinated dioxins, some pesticides and polychlorinated biphenyls on thyroid hormone status in Japanese breast‐fed infants
Author(s) -
Yanagawa Takashi,
Kobayashi Yosuke,
Nagayama Junya
Publication year - 2003
Publication title -
environmetrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.68
H-Index - 58
eISSN - 1099-095X
pISSN - 1180-4009
DOI - 10.1002/env.570
Subject(s) - chlordane , dieldrin , organochlorine pesticide , heptachlor , thyroid , medicine , hormone , endocrinology , bisphenol a , chemistry , pesticide , environmental chemistry , physiology , biology , epoxy , organic chemistry , agronomy
Abstract Joint effects of dioxin related chemicals (DXNs), hexachlorocyclohexanes (HCHs), DDT, dieldrin, heptachlor‐epoxide (HCE), chlordane and polychlorinated biphenyls (PCB) on the levels of triirodothyronine (T3), thyroxine (T4), thyroid stimulating hormones (TSH) and thyroid binding globulin (TBG) in the peripheral blood of 101 breast‐fed infants are studied. The statistical issue involved is how to estimate the effects based on data from volunteer subjects with possible measurement errors. A chain independent graph is applied for modeling the associations among factors, and dicotomizations of selected factors are performed for estimating the effects. Use of nonparametric methods with careful consideration of over‐adjustment is suggested. It is shown that the estimated odds ratios of DXNs∪DDT, the first principal component of DXNs and DDT, relative to TSH are 3.02 ( p ‐value=0.03) and 7.15 ( p ‐value=0.02), respectively, when PCB is not adjusted and adjusted for, respectively. Copyright © 2003 John Wiley & Sons, Ltd.