Related Experiment Video
Updated: May 24, 2026
Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
Published on: August 25, 2014
Prenatal exposures to environmental chemicals and birth order as risk factors for child behavior problems
Nozomi Tatsuta1, Kunihiko Nakai, Katsuyuki Murata
1Environmental Health Sciences, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan.
Insights
Prenatal exposure to polychlorinated biphenyls (PCBs) may influence internalizing behaviors in children. However, parental child-rearing attitudes, particularly related to birth order, appear more critical for behavior problems at low exposure levels.
Area of Science:
- Environmental Health
- Developmental Psychology
- Toxicology
Background:
- Prenatal exposure to environmental toxins like polychlorinated biphenyls (PCBs), methylmercury, and lead is a growing concern.
- Understanding the impact of these exposures on early childhood behavior is crucial for public health.
- Parental child-rearing attitudes are also recognized as significant factors influencing child development.
Purpose of the Study:
- To determine the relative importance of prenatal exposure to PCBs, methylmercury, lead, and parental child-rearing attitudes in relation to maladaptive behavior problems in young children.
- To investigate the associations between specific environmental toxins and behavioral outcomes using validated assessment tools.
Main Methods:
- A cohort of 306 Japanese children was followed from pregnancy to 30 months of age.
- Behavioral problems were assessed using the Child Behavior Checklist (CBCL).
- Associations between cord-blood levels of total PCBs (ΣPCB), total mercury (THg), lead, and CBCL subscales were analyzed using multivariate and multiple regression analyses, controlling for potential confounders.
Main Results:
- Cord-blood ΣPCB showed a significant correlation with the internalizing score on the CBCL (r=0.113), while THg and lead did not show significant correlations.
- This correlation between ΣPCB and internalizing scores became non-significant in multiple regression analyses that included confounders such as birth order, home environment, and maternal IQ.
- However, a significant partial correlation between internalizing scores and ΣPCB (r=0.175) was observed in later-born children after adjusting for confounders except birth order. First-born children exhibited higher CBCL scores and ΣPCB levels compared to later-born children.
Conclusions:
- Low-level prenatal exposure to PCBs may be associated with internalizing behaviors in children.
- Parental child-rearing attitudes, particularly those influenced by birth order, may play a more significant role in shaping behavior problems than low-level exposures to these hazardous chemicals.
Objectives:
To assess whether polychlorinated biphenyls (PCBs), methylmercury, lead, or parental child-rearing attitudes was most crucial for maladaptive behavior problems, we examined Japanese 30-month-old children followed up from pregnancy.
Methods:
The Child Behavior Checklist (CBCL) was used to assess the behavior problems in 306 children. The associations of cord-blood total PCBs (ΣPCB), total mercury (THg), and lead with each CBCL subscale were examined by multivariate analyses.
Results:
The median values in cord blood of the 306 children were 48.3 (5 and 95 percentiles, 18.6-116.3) ng/g-lipid for ΣPCB, 10.2 (4.1-24.5)ng/g for THg, and 1.0 (0.5-1.7)μg/dl for lead. The internalizing score of the CBCL was significantly correlated with ΣPCB (r=0.113) in the children, though no significant correlation was seen between any CBCL score and either THg or lead. The significant correlation disappeared when conducting multiple regression analysis with possible confounders; at that time, the birth order, home environment, and maternal intelligence quotient were significantly related to the internalizing score. Three CBCL scores and ΣPCB levels were significantly higher in the first-born children than in the second-born or following children, and the partial correlation coefficient with the adjustment for all confounders except birth order was significant between the internalizing score and ΣPCB in the latter children (r=0.175).
Conclusions:
Internalizing behavior appears to be affected by prenatal exposure to PCBs at low levels. Under lower-level exposures, however, behavior problems may be more strongly associated with parental child-rearing attitudes involved in birth order, than with such hazardous chemicals.
Related Concept Videos
01:28Causes of Social Behavior III: Biological and Environmental Influences
01:30Attention-Deficit/Hyperactivity Disorder
Diagnostic Criteria and Symptoms
To diagnose ADHD, symptoms must manifest before age 12 and be evident across multiple settings.
01:23Behavioral Genetics and Its Designs
The primary methodologies used in behavior genetics include family studies, twin studies, and adoption studies, each providing unique...
01:29Environmental Influences on Intelligence
01:20Gene-Environment Interactions
01:28Conduct Disorder