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Early prenatal exposure to suspected endocrine disruptor mixtures is associated with lower IQ at age seven

Tanner, Eva M. ; Hallerbäck, Maria Unenge ; Wikström, Sverre ; Lindh, Christian LU orcid ; Kiviranta, Hannu ; Gennings, Chris and Bornehag, Carl Gustaf (2020) In Environment International 134.
Abstract

Background: Endocrine disrupting chemicals (EDCs) are xenobiotics with the ability to interfere with hormone action, even at low levels. Prior environmental epidemiology studies link numerous suspected EDCs, including phthalates and bisphenol A (BPA), to adverse neurodevelopmental outcomes. However, results for some chemicals were inconsistent and most assessed one chemical at a time. Objectives: To evaluate the overall impact of prenatal exposure to an EDC mixture on neurodevelopment in school-aged children, and identify chemicals of concern while accounting for co-exposures. Methods: Among 718 mother-child pairs from the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy study (SELMA) study, we used Weighted... (More)

Background: Endocrine disrupting chemicals (EDCs) are xenobiotics with the ability to interfere with hormone action, even at low levels. Prior environmental epidemiology studies link numerous suspected EDCs, including phthalates and bisphenol A (BPA), to adverse neurodevelopmental outcomes. However, results for some chemicals were inconsistent and most assessed one chemical at a time. Objectives: To evaluate the overall impact of prenatal exposure to an EDC mixture on neurodevelopment in school-aged children, and identify chemicals of concern while accounting for co-exposures. Methods: Among 718 mother-child pairs from the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy study (SELMA) study, we used Weighted Quantile Sum (WQS) regression to assess the association between 26 EDCs measured in 1st trimester urine or blood, with Wechsler Intelligence Scale for Children (IV) Intelligence Quotient (IQ) scores at age 7 years. Models were adjusted for child sex, gestational age, mother's education, mother's IQ (RAVEN), weight, and smoking status. To evaluate generalizability, we conducted repeated holdout validation, a machine learning technique. Results: Using repeated holdout validation, IQ scores were 1.9-points (CI = −3.6, −0.2) lower among boys for an inter-quartile-range (IQR) change in the WQS index. BPF made the largest contribution to the index with a weight of 14%. Other chemicals of concern and their weights included PBA (9%), TCP (9%), MEP (6%), MBzP (4%), PFOA (6%), PFOS (5%), PFHxS (4%), Triclosan (5%), and BPA (4%). While we did observe an inverse association between EDCs and IQ among all children when training and testing the WQS index estimate on the full dataset, these results were not robust to repeated holdout validation. Conclusion: Among boys, early prenatal exposure to EDCs was associated with lower intellectual functioning at age 7. We identified bisphenol F as the primary chemical of concern, suggesting that the BPA replacement compound may not be any safer for children. Future studies are needed to confirm the potential neurotoxicity of replacement analogues.

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author
; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Chemical mixtures, Multipollutant, Neurodevelopment, Repeated holdout validation, Replacement analogues, Uncertainty plot
in
Environment International
volume
134
article number
105185
publisher
Elsevier
external identifiers
  • pmid:31668669
  • scopus:85075991242
ISSN
0160-4120
DOI
10.1016/j.envint.2019.105185
language
English
LU publication?
yes
id
96affffc-8e22-4fa5-b5e0-b451332c0287
date added to LUP
2019-12-19 10:48:16
date last changed
2024-04-02 22:39:10
@article{96affffc-8e22-4fa5-b5e0-b451332c0287,
  abstract     = {{<p>Background: Endocrine disrupting chemicals (EDCs) are xenobiotics with the ability to interfere with hormone action, even at low levels. Prior environmental epidemiology studies link numerous suspected EDCs, including phthalates and bisphenol A (BPA), to adverse neurodevelopmental outcomes. However, results for some chemicals were inconsistent and most assessed one chemical at a time. Objectives: To evaluate the overall impact of prenatal exposure to an EDC mixture on neurodevelopment in school-aged children, and identify chemicals of concern while accounting for co-exposures. Methods: Among 718 mother-child pairs from the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy study (SELMA) study, we used Weighted Quantile Sum (WQS) regression to assess the association between 26 EDCs measured in 1st trimester urine or blood, with Wechsler Intelligence Scale for Children (IV) Intelligence Quotient (IQ) scores at age 7 years. Models were adjusted for child sex, gestational age, mother's education, mother's IQ (RAVEN), weight, and smoking status. To evaluate generalizability, we conducted repeated holdout validation, a machine learning technique. Results: Using repeated holdout validation, IQ scores were 1.9-points (CI = −3.6, −0.2) lower among boys for an inter-quartile-range (IQR) change in the WQS index. BPF made the largest contribution to the index with a weight of 14%. Other chemicals of concern and their weights included PBA (9%), TCP (9%), MEP (6%), MBzP (4%), PFOA (6%), PFOS (5%), PFHxS (4%), Triclosan (5%), and BPA (4%). While we did observe an inverse association between EDCs and IQ among all children when training and testing the WQS index estimate on the full dataset, these results were not robust to repeated holdout validation. Conclusion: Among boys, early prenatal exposure to EDCs was associated with lower intellectual functioning at age 7. We identified bisphenol F as the primary chemical of concern, suggesting that the BPA replacement compound may not be any safer for children. Future studies are needed to confirm the potential neurotoxicity of replacement analogues.</p>}},
  author       = {{Tanner, Eva M. and Hallerbäck, Maria Unenge and Wikström, Sverre and Lindh, Christian and Kiviranta, Hannu and Gennings, Chris and Bornehag, Carl Gustaf}},
  issn         = {{0160-4120}},
  keywords     = {{Chemical mixtures; Multipollutant; Neurodevelopment; Repeated holdout validation; Replacement analogues; Uncertainty plot}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Environment International}},
  title        = {{Early prenatal exposure to suspected endocrine disruptor mixtures is associated with lower IQ at age seven}},
  url          = {{http://dx.doi.org/10.1016/j.envint.2019.105185}},
  doi          = {{10.1016/j.envint.2019.105185}},
  volume       = {{134}},
  year         = {{2020}},
}