NEHA Conference 2005

1
Developmental Disabilities and Environmental
Toxics

• NEHA Conference 2005
• Michele N. Gagnon, Director
• Environmental Health Initiative
• American Association on Mental Retardation
• Acknowledgements to Ted Schettler, MD, MPH of
  Greater Bostons Physicians for Social
  Responsibility and the Science and Environmental
  Health Network for parts of this presentation.

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Outline

• The Concern
• Brain Development
• Exposures that cause DD
• Special concerns of the DD community
• AAMR Environmental Health Initiative

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Neurodevelopmental Status of US Children

• Nearly 12 million children (17) under age 18 in
  the US suffer from one or more learning or
  developmental disability
• Learning disabilities alone affect 5-10 of
  children in public schools
• ADHD conservatively affects 3-6 of all school
  children may be higher
• Marked increase in autism reported in CA and
  elsewhere
• Increasing trends ? explanation ?

4
Unknown Causes

• The causes of mental retardation are unknown in
  30 to 50 of all cases.
• The cause of mild MR is unknown in more than 75
  of cases.
• Most LD/DD Unknown Causes

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Are Developmental Disabilities on the Rise?

• Researchers estimate that between 3 and 8 percent
  of the babies born in the US each year will be
  affected by neurodevelopmental disorders
• LBW on the rise

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Mental Retardation Rates in CA
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Autism Rates in CA
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Autism Diagnosis Receiving Services Under IDEA
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Causes of Autism Spectrum Disorders

• No consensus
• Theories include
• Genetic
• Environmental
• Gene-environment interaction

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Cerebral PalsyRates in CA
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Epilepsy Rates in CA
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Environmental Factors Attributable to DD

• 25 of developmental and neurological deficits in
  children are due to the interplay between
  chemicals and genetic factors
• 3 of DD can be attributed to chemical exposure
  alone

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Three-Step Process
Chemical Exposure
Low Birth Weight Prematurity
Developmental Disability
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Economic Costs to Society

• The potential costs due to environmental factors
  couldbe anywhere from 4.6 18.4 billion

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Brain Development

• Begins early in fetal life is not complete for
  years
• Under control of neurotransmitters, hormones,
  other neurotrophic chemicals susceptible to
  alteration by environmental agents
• Depends on an orderly sequence of events that can
  be disrupted at many different points

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Mechanisms of Impact

• Single agents may have different and multiple
  mechanisms of toxicity
• Multiple agents may interact
• Nutritional and genetic factors may interact
  with chemical exposures

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Cellular Events in Neurodevelopment

• Each of these events is subject to disruption by
  environmental agents
• Division
• Migration
• Differentiation
• Formation of synapses
• Pruning of synapses
• Apoptosis
• Myelination

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Known Causes of Developmental Disabilities

• Lead
• Alcohol
• Nicotine
• Mercury (High dose exposure)
• PCBs

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Lead, Alcohol and Nicotine DD Effects

• Lead IQ, learning, attention deficits
  hyperactivity, impulsiveness, aggression failure
  to complete school, trouble with the law
• Alcohol hyperactivity, cognitive deficits,
  behavioral problems
• Nicotine IQ, learning, and attention deficits

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Mercury Exposure Prenatal High-Dose Effects

• Mental retardation
• Seizures
• Cerebral palsy
• Disturbances of vision, hearing, sensation
• Abnormal gait
• Abnormal speech
• Disturbances of swallowing and sucking
• Abnormal reflexes

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Mercury ExposureLow Dose Prenatal

• Impairments (at age 7-9) of
• motor skills
• attention
• visual spatial skills
• language
• memory
• Blood pressure, heart rate variability

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PCB ExposureDevelopmental Effects

• Infant
• Birth weight
• Head circumference
• Performance on Brazelton Neonatal Behavioral
  Assessment (BNBA) - motor immaturity, inc.
  startle
• Early Childhood
• Memory, attention, verbal ability, information
  processing
• Delayed psychomotor development changes in play
  behavior
• Hyperactivity
• Preteen
• Word and reading comprehension
• Full scale and verbal IQ
• Memory and attention

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Special Concerns of the DD Community

• What is the DD Community Concerned About?
• Unique Behaviors
• Co-morbidity
• Environmental Justice Community?

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What Self-AdvocatesAre Saying

• We want to know what toxic chemicals in the air,
  water and products we use might harm us.
• Since a lot of us are moving into our own place,
  we want to learn how to be safe and protect
  ourselves from toxic substances.
• We want our direct support staff to know about
  harmful chemicals and how to protect us from
  them.
• We want our work place to be safe from toxic
  chemicals.
• We want to know if you having a developmental
  disability makes us more susceptible to harm from
  toxic substances.
• Joe Medours, Self Advocate, Alabama

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Unique Behavioral Attributes

• Pica- engage in hand to mouth activity past a
  developmentally appropriate age.
• Self-restrict Diet
• Crawl, sit or lie on grass past a
  developmentally appropriate age.

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Behavioral Attributes Cont.

• Sit for long periods in a car seat, special
  adaptive equipment, or wheelchair seat
• Spend longer periods of time indoors year round
• Have difficulty communicating symptoms of
  exposure or context of exposure to others

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Co-morbidity

• Depression 28 vs. 7
• Diabetes 87 vs. 28
• Hypertension 32 vs. 27
• Obesity 30 vs. 23 (1991)
• Asthma??

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A New Environmental Justice Community?

• Poverty
• Lower Education
• Low Political Power
• High Unemployment
• Health Disparities
• Increased vulnerability from exposure to
  environmental stressors

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Resources

• Greater Boston Physicians for Social
  Responsibility www.igc.org/psr
• Collaborative on Health and the Environment
  www.cheforhealth.org, www.protectingourhealth.org
• Science and Environmental Health Network
  www.sehn.org

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AAMRs Environmental Health Initiative

• Promoting Good Health
• Collaborating for Action
• Reducing Toxic Exposure

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Overarching Theme

• Disability is a natural phenomenon of the human
  condition
• Disability due to toxic chemical exposure is not
  natural, unnecessary, and most importantly -
  preventable

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AAMRs Environmental Health Initiative

• Raise awareness about the complex connections
  between exposure to neurotoxic chemicals and
  developmental disabilities
• Raise awareness that those living with
  developmental disabilities may be more likely to
  suffer secondary health effects than individuals
  without disabilities

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The Initiative Workgroups

• Education, Outreach and Training
• Policy and Legislative Issues
• Research and Science

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Education Outreach and Training

• Journal Articles
• Environmental Health Manual
• Fact Sheets
• Exceptional Parent Magazine
• Environmental Health Series
• Developmental Disability Training Workshop

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Policy and Legislative Workgroup

• National Childrens Study
• DNT Testing For New Chemicals
• Model State and Local Legislation
• Healthy/High Performance School legislation
• Congressional Briefing Chemical Exposure,
  Childrens Health and Disability

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Research and Science

• Study the Effects of Chemicals on People with
  Developmental Disabilities
• Include People with Developmental Disabilities in
  Research Studies
• Research Multiple Chemical Exposures
• Science and Research Lecture Series
• Develop a research agenda with NICHD, NIEHS and
  CDC to address special concerns of the DD pop.

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Ultimate Goals of the Project

• To prevent prenatal, infant and childhood toxic
  exposures that cause, trigger, or are associated
  with the manifestation of developmental
  disabilities
• To identify the special concerns of the DD
  community and prevent toxic exposures from
  exacerbating their health

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AAMR Environmental Health Initiative

• Promoting Good Health
• Collaborating for Action
• Reducing Toxic Exposures
• For more information visit the AAMR website at
  www.aamr.org
• Thank You!