Association between phthalates and attention deficit disorder and learning disability in U.S. children, 6–15 years

Center for Environmental Research and Children's Health (CERCH), School of Public Health, University of California Berkeley, Berkeley, CA 94720, USA. Electronic address: .
Environmental Research (Impact Factor: 4.37). 11/2013; 128. DOI: 10.1016/j.envres.2013.10.004
Source: PubMed


This study investigates the association between urinary phthalate metabolite levels and attention deficit disorder (ADD), learning disability (LD), and co-occurrence of ADD and LD in 6-15-year-old children.
We used cross-sectional data from the National Health and Nutrition Examination Survey (NHANES, 2001-2004). Phthalate metabolites with ≥75% detection in urine samples were examined. The study population comprised 1493 children with parent-reported information on ADD or LD diagnosis and phthalate concentrations in urine. Phthalate concentrations were creatinine-adjusted and log10-transformed for analysis. All models controlled for child sex, age, race, household income, blood lead, and maternal smoking during pregnancy.
There were 112 ADD cases, 173 LD cases, and 56 ADD and LD cases in the sample. After adjusting for potential confounders, we found increased odds of ADD with increasing urinary concentration of di-2-ethylhexyl phthalates (OR: 2.1; 95% CI: 1.1, 3.9) and high molecular weight phthalates (OR: 2.7; 95% CI: 1.2, 6.1). In addition, dibutyl phthalates (OR: 3.3; 95% CI: 0.9, 12.7) and high molecular weight phthalates (OR: 3.7; 95% CI: 0.9, 14.8) were marginally associated with increased odds of co-occurring ADD and LD. We did not find associations for any phthalate and LD alone. We observed stronger associations between phthalates and ADD and both ADD and LD in girls than boys in some models.
We found cross-sectional evidence that certain phthalates are associated with increased odds of ADD and both ADD and LD. Further investigations with longitudinal data are needed to confirm these results.

49 Reads
  • Source
    • "Huang, Tien, Sun, Hsieh and Lee (2008) reported high DBP and DHEP residues/burden in sediment and fish including Oreochromis miloticus niloticus (tilapia, known to be more sensitive to PCB contaminated sediment than to water) at high levels. Sewage plant effluents are another important source posing risk to wildlife and human health (in addition to effects depicted above in animal studies) exposure to PEs have been associated with attention and behavioural problems (Burridge & Haya 1995; Chopra et al. 2014): DBP and DHEP at lg L À1 level; some individual values reaching 40 and 80 mg L À1 despite international regulatory agencies permissible maximum water quality criteria in the range of 3–10 lg L À1 (Huang et al. 2008; Sun, Huang, Sun, Wang, Shi, Hu, Kameya & Fujie 2014; Zolfaghari, Drogui, Seyhi, Brar, Buelna & Dube 2014; Chi & Gao 2015). Some phthalates have been detected in cord blood, evidence for crossing the placental barrier, DBP one of the most frequently determined (Huang, Li, Garcia, Lin, Wang, Yan, Wang, Tan, Luo, Qiu, Chen & Shu 2014). "
    [Show description] [Hide description]
    DESCRIPTION: Phthalates such as di-n-butyl phthalate (DBP) and their esters are widely used plasticizers, their ubiquitous presence in daily life, inevitably leads to their restricted use due to important environmental pollution and health impacts and endocrine disruption potential. The aim of this study was to examine the effects of a sublethal concentration of 10 mg L �1 DBP on haematocrit (HCT) values, gills and liver histology, malondialdehyde (MDA, 2-thiobarbituric acid-TBA reactivity) and reduced glutathione (GSH) levels in gills and liver tissue as oxidative stress biomarkers in the aquaculture fish species Nile tilapia (Oreochromis niloticus) after 24 (DBP-24) and 96 (DBP-96) h exposure.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Ortho-phthalate diesters, or phthalates, are widely used synthetic chemicals found primarily in consumer products and polyvinyl chloride plastics. Experimental evidence suggests that several phthalates possess antiandrogenic properties and may disrupt endocrine pathways resulting in abnormal reproductive outcomes. Low-level exposure to phthalates has been well documented in humans, with higher levels found in children and women of childbearing age. Recent epidemiologic studies postulate that prenatal exposure to measurable urine phthalate concentrations may be associated with altered genital and pubertal development in infants and children. This review addresses the emerging evidence that some phthalates may have an adverse impact on the developing brain. The supporting animal studies and proposed mechanisms underlying the deleterious properties of phthalates in relation to neurodevelopmental outcomes are also discussed. While the observed associations are based on limited studies with a broad range of endpoints, the implications of such outcomes are concerning from a public health standpoint and merit further investigation given the widespread nature of the exposure.
    NeuroToxicology 03/2014; 41. DOI:10.1016/j.neuro.2014.01.007 · 3.38 Impact Factor
  • Source

    Environmental Health Perspectives 04/2014; 122(4):A108. DOI:10.1289/ehp.122-A108 · 7.98 Impact Factor
Show more