Environmental Chemical Exposures and AutismSpectrum Disorders: A Review of the EpidemiologicalEvidenceAmy E. Kalkbrenner, PhD, MPH, Rebecca J. Schmidt, MS, PhD,Annie C. Penlesky, MPH

Environmental Contributors to Autism:The Pediatrician’s RoleLeonardo Trasande, MD, MPP

Curr Probl PediatrAdolesc Health Care, November 2014

Foreword: Environmental Chemical Exposures andAutism Spectrum Disorders: A Review of the

Epidemiological Evidence

Autism spectrum disorders exact a tremendous

toll emotionally, physically, socially, and econom-

ically. In the United States, on average, for children

with autism spectrum disorders compared to

children without autism spectrum disorders, health

care costs were $3020 higher and aggregate non-

health care costs were $14,061 higher, including

$8610 higher school costs.1 In a statistical model

assuming a prevalence of concomitant intellectual

disability of 40%, the national cost of supporting

children with autism spectrum disorders in the

United States was found to be $61 billion per year,

while the national cost of supporting adults with

autism spectrum disorders in the United States

was found to be $175 billion per year.2

Given the enormous personal, family, and soci-

etal costs, early intervention and prevention of

autism spectrum disorders are very important.

The American Academy of Pediatrics recom-

mends that all children be screened for devel-

opmental delays and disabilities during regular

well-child doctor visits at 9 months, 18 months,

and 24 or 30 months.3 Also, the American Acad-

emy of Pediatrics recommends that children be

screened specifically for autism spectrum disor-

ders at 18 and 24 months.4 A toolkit designed to

assist clinicians in the recognition, diagnosis, and

management of children with autism spectrum

disorders is available at www.aap.org/autism.

More than 70 tools are included.

The Federal government also is making a

coordinated effort to encourage healthy child

development, universal developmental and

behavioral screening for children, and provision

of support for patients’ families and providers.

The Birth to 5: Watch Me Thrive campaign is

available at hhs.gov/WatchMeThrive.

With regard to prevention, there is evidence that

folic acid supplementation during the pericon-

ception period is associated with a decreased

risk for autism spectrum disorders.5–7 This evi-

dence provides yet another justification for the

recommendation that all women of childbearing

age should follow the U.S. Public Health Service

recommendation to take folic acid.8 The American

Academy of Pediatrics has endorsed the U.S.

Public Health Service recommendation that all

women capable of becoming pregnant consume

275

400 mg of folic acid daily to prevent neural tube

defects, particularly for adolescent, sexually active

women who do not plan to use effective contra-

ception or abstain from sexual intercourse.9,10

Clinicians should advise patients that prevention

of autism spectrum disorders may be yet another

benefit of folic acid supplementation.

References1. Lavelle TA, Weinstein MC, Newhouse JP, Munir K, Kuhlthau

KA, Prosser LA. Economic burden of childhood autismspectrum disorders. Pediatrics 2014;133(3):e520–9.

2. Buescher AVS, Cidav Z, Knapp M, Mandell DS. Costs ofautism spectrum disorders in the United Kingdom and theUnited States. J Am Med Assoc Pediatr 2014. http://dx.doi.org/10.1001/jamapediatrics.2014.210:[Published online].

3. Council on Children With Disabilities, Section on Develop-mental Behavioral Pediatrics, Bright Futures Steering Com-mittee and Medical Home Initiatives for Children With SpecialNeeds Project Advisory Committee. Identifying infants andyoung children with developmental disorders in the medicalhome: an algorithm for developmental surveillance and screen-ing. Pediatrics 2006;118(1):405–20.

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4. Johnson CP, Myers SM, American Academy of PediatricsCouncil on Children with Disabilities. Identification andevaluation of children with autism spectrum disorder. Pedia-trics 2007;120(5):1183–215.

5. Schmidt RJ, Hansen RL, Hartiala J, et al. Prenatal vitamins,one-carbon metabolism gene variants, and risk for autism.Epidemiology 2011;22:476–85.

6. Schmidt RJ, Tancredi DJ, Ozonoff S, et al. Maternal peri-conceptional folic acid intake and risk of autism spectrumdisorders and developmental delay in the CHARGE (Child-hood Autism Risks from Genetics and Environment) case–control study. Am J Clin Nutr 2012;96:80–9.

7. Suren P, Roth C, Bresnahan M, et al. Association betweenmaternal use of folic acid supplements and risk of autismspectrum disorders in children. J AmMed Assoc 2013;309:570–7.

8. Centers for Disease Control. Recommendations for the use of folicacid to reduce the number of cases of spina bifida and other neuraltube defects. Morb Mortal Wkly Rep 1992;41:[No. RR-14].

9. American Academy of Pediatrics. Folic acid for the preventionof neural tube defects. Pediatrics 1999;104:325–7.

10. Klein JD, American Academy of Pediatrics Committee onAdolescence. Adolescent pregnancy: current trends and issues.Pediatrics 2005;116:281–6.

Ruth Ann Etzel, MD, PhD

Editor

Curr Probl PediatrAdolesc Health Care, November 2014