Prenatal phthalate exposure is associated with childhood behavior and executive functioning

Abstract

Background: Experimental and observational studies have reported biological consequences of phthalate exposure relevant to neurodevelopment.

Objective: Our goal was to examine the association of prenatal phthalate exposure with behavior and executive functioning at 4-9 years of age.

Methods: The Mount Sinai Children's Environmental Health Study enrolled a multiethnic prenatal population in New York City between 1998 and 2002 (n = 404). Third-trimester maternal urines were collected and analyzed for phthalate metabolites. Children (n = 188, n = 365 visits) were assessed for cognitive and behavioral development between the ages of 4 and 9 years.

Results: In multivariate adjusted models, increased loge concentrations of low molecular weight (LMW) phthalate metabolites were associated with poorer scores on the aggression [beta = 1.24; 95% confidence interval (CI), 0.15- 2.34], conduct problems (beta = 2.40; 95% CI, 1.34-3.46), attention problems (beta = 1.29; 95% CI, 0.16- 2.41), and depression (beta = 1.18; 95% CI, 0.11-2.24) clinical scales; and externalizing problems (beta = 1.75; 95% CI, 0.61-2.88) and behavioral symptom index (beta = 1.55; 95% CI, 0.39-2.71) composite scales. Increased loge concentrations of LMW phthalates were also associated with poorer scores on the global executive composite index (beta = 1.23; 95% CI, 0.09-2.36) and the emotional control scale (beta = 1.33; 95% CI, 0.18- 2.49).

Conclusion: Behavioral domains adversely associated with prenatal exposure to LMW phthalates in our study are commonly found to be affected in children clinically diagnosed with conduct or attention deficit hyperactivity disorders.

Figure 1

Adjusted mean BASC T-score and 95% CIs for aggression (A), attention problems (B), conduct problems (C), depression (D), externalizing problems (E), and BSI (F), plotted at the median creatinine-based phthalate biomarker concentration by tertile of exposure to assess linearity in dose response. LSMEAN, least-square mean. Means were adjusted for race, sex, educational level of the primary caretaker, and marital status of the primary caretaker. All affected domains appeared to be monotonically associated with phthalate biomarker level, with the exception of attention problems, which appeared to plateau at 2 μM.