Joint Effects of Air Pollution Mixtures and Psychosocial Factors on Child Psychopathology in a South African Birth Cohort Restricted; Files Only
Christensen, Grace (Fall 2023)
Abstract
Risk of childhood psychopathology is complex and includes both environmental and social risk factors. A majority of the current literature on psychosocial stress and air pollution’s effect on child psychopathology focuses on outdoor air pollution exposure and stress in high-income countries with relatively low exposures. Very little is known about the effects of indoor air pollution (IAP), especially in low- and middle-income countries where many children and pregnant women are exposed to high levels of IAP as well as psychosocial stressors.
The overarching goal of this dissertation is to investigate the individual and joint effects of prenatal and early-life exposure to IAP mixtures and psychosocial factors (PF) on child psychopathology. We leverage data from a unique birth cohort from South Africa, the Drakenstein Child Health Study.
AIM 1: We investigated the effect of prenatal exposure to IAP and PFs on trajectories of childhood psychopathology symptoms at 24, 42, and 60 months. We found externalizing behavior trajectory was associated with particulate matter and smoking, while internalizing behavior trajectory was associated with volatile organic compounds.
AIM 2: We investigated the pre- and early postnatal periods as sensitive periods of exposure to IAP and PFs on childhood psychopathology at 6.5 years. Prenatal exposure to IAP and PFs, as well as the total prenatal mixture was associated with increased psychopathology. Analyses also indicated that the prenatal period is a sensitive period for IAP exposure, while PFs, including depression and alcohol, were associated with childhood psychopathology in both periods.
AIM 3: We investigated inflammation during infancy as a potential mediator of the association between prenatal exposure to IAP and PFs and childhood psychopathology. IAPs were associated with increased inflammation, while the association with PFs did not have a consistent pattern. We did not find evidence of mediation by inflammatory markers, possibly due to the small sample size and evidence of effect modification by HIV status and ancestry.
Overall, our findings add evidence that prenatal exposure to IAPs and PFs are associated with psychopathology during childhood. These findings can be used to target interventions to reduce exposure to IAPs and PFs and prevent childhood psychopathology.
Table of Contents
Chapter 1 : Introduction and Background. 1
Overarching Goal and Specific Aims. 1
Background. 3
Childhood Psychopathology. 3
Indoor Air Pollution. 4
Maternal Psychosocial Factors. 8
Joint Effects of Air Pollution and stress. 11
Biological Pathways and Inflammation. 12
Critical Periods of Exposure. 13
Data Source. 14
Chapter 2 : Joint Effects of Indoor Air Pollution and Maternal Psychosocial Factors During Pregnancy on Trajectories of Early Childhood Psychopathology. 15
Abstract 16
Introduction. 17
Methods. 19
Data Source. 19
Indoor Air Pollution Assessment 20
Assessment of Psychosocial Factors. 21
Outcome Assessment 21
Statistical Analysis. 22
Results. 29
Study Population. 29
Trajectories. 32
Single-exposure models. 33
Joint effects models. 34
Sensitivity analyses. 45
Discussion. 49
Chapter 3 : Sensitive periods for exposure to indoor air pollutants and psychosocial factors in association with symptoms of psychopathology at school-age in a South African birth cohort 54
Abstract 55
Introduction. 57
Methods. 60
Study Population. 60
Exposure Assessment 60
Outcome Assessment 62
Statistical Analysis. 63
Sensitive Periods of Exposure. 70
Results. 71
Study Population Characteristics. 71
Prenatal Exposure Analyses. 73
Postnatal Exposure Analyses. 89
Sensitive Period Analyses. 90
Discussion. 108
Chapter 4 : Joint Effects of Prenatal Exposure to Indoor Air Pollution and Psychosocial Factors on Early Life Inflammation. 115
Abstract 116
Introduction. 118
Methods. 120
Study Population. 120
Indoor Air Pollution Assessment 121
Assessment of Psychosocial Factors. 122
Assessment of Inflammatory Markers. 122
Statistical Analysis. 124
Results. 129
Single-Exposure Analyses. 131
Joint Effects Analyses. 140
Discussion. 145
Chapter 5 : Mediation of the prenatal indoor air pollution and psychosocial factor association with CBCL at 6.5 years by inflammation at 6 weeks old. 149
Introduction. 150
Methods. 151
Study Population. 151
Outcome Assessment 155
Statistical Analysis. 155
Results. 159
Exposure-Outcome Analyses. 159
Mediator-Outcome Analyses. 168
Mediation Analyses. 170
Discussion. 174
Chapter 6 : Summary of Findings, Future Directions. 177
Summary of Findings. 177
Overall Findings. 177
Findings from AIM 1. 178
Findings from AIM 2a. 179
Findings from AIM 2b. 180
Findings from AIM 3a. 181
Findings from AIM 3b. 181
Strengths and Limitations. 182
Strengths. 182
Limitations. 183
Future research. 184
References 186
About this Dissertation
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File download under embargo until 10 January 2026 | 2023-10-30 10:59:17 -0400 | File download under embargo until 10 January 2026 |
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