US EPA

2201270 

Journal Article 

Abstract 

Endocrine disruptors and disorders of neurobehavioral development 

Kato, N; Xu, X; Liu, L; Imai, H; Ushijima, H 

2003 

Yes 

Congenital Anomalies
ISSN: 0914-3505
EISSN: 1741-4520 

43 

3 

208 

English 

is part of a larger document 3230432 The Japanese teratology society 43rd annual meeting abstracts

Attention-deficit/hyperactivity disorder (ADHD) and infantile autism are both of special importance among neurodevelopmental disorders, in terms of their prevalence and severity. ADHD is known to affect 2-5% of grade-school children, and recent papers report infantile autism increasing year by year in Japan and the U.S.A. Meanwhile, environmental concomitants such as dioxin, polychlorinated biphenyls (PCBs) and bisphenol A are frequently warned to be a potential hazard to human and wildlife populations. These chemicals share similar characteristics, acting to disrupt gonadal functions, and so are known by the name of endocrine disruptors (EDs), or so called environmental hormones. In utero exposure to EDs has been found to induce intellectual impairment among infants born to women who had eaten Lake Michigan fish contaminated with PCBs. Experimentally, EDs impair auditory and thyroid functions besides having well-known estrogenic actions. We have long investigated the remote effect of neonatal mild hypothyroidism in rats and found the rats display audiogenic seizures, hyperactivity and spatial learning impairments after maturing. Also, a single peroral ingestion of trimethyltin, an organotin compound which is a byproduct of plastic manufacturing, can cause a set of behavioral abnormalities characterized by hyperactivity, aggression, seizure, and learning impairment with hippocampal damage. In this country, a nation-wide neonatal screening has revealed the prevalence of mild neonatal hypothyroidism (transient hyper- TSH-emia) increasing statistically in several prefectures. We here discuss the possible relationship of these epidemiological and experimental studies, and further present some new findings that perinatal exposure to bisphenol A at a dose equivalent to environmental pollution may induce hyperactivity as well as spatial learning impairment.