Out of Harm's Way: Preventing Toxic Threats to Child Development
1. Out of Harm’s Way:
Preventing Toxic Threats to
Child Development
Oregon Physicians
for Social Responsibility
www.oregonpsr.org
2. Introduction
Today’s Presentation
•Scope of the problem of neurodevelopmental
& learning disabilities.
•Human vulnerability to toxic chemicals,
focusing on children.
• Current chemical environment, focusing on
mercury & pesticides in Oregon.
• What you can do to help your patients
minimize exposures.
4. Introduction
Prevalence of
Learning and
Behavioral Disabilities
•Total: 17%, 12 million children
•Learning disabilities: 5-10%
•One in eight Oregon children use
special education services
•Autism: 0.3- 0.66%; 1 in 150 young
children
5. Introduction
Economic Implications
$81.5 – $167 billion/yr - Neurodevelopmental deficits & related disorders.
$9.2 billion/yr - Attributable to
environmental pollutants.
Over $8000/yr – Special education costs
for a child with autism.
$800 million/yr - OR special ed costs.
6. AMA Resolution
In June, 2008, the American Medical Association
issued a resolution stating that there was a need for
toxics reform:
• To implement new, federal regulation to test and
update all chemicals in use today;
• To restructure the 1976 Toxic Substances Control Act
(TSCA) to effectively achieve these goals;
• To adopt safer production and uses of all
chemicals;
• To encourage the training of medical students,
physicians, and other health professionals about the
human health effects of toxic chemical exposures
with the help of the AMA.
7. The Significance of Small Effects
Example: population of 260 million
mean 100
6.0 million
"gifted"
6.0 million
"mentally retarded"
40
80
60
70
100
I.Q.
120
140
130
160
8. 5 Point Decrease in Mean IQ
mean 95
57% INCREASE IN
"Mentally
Retarded”
Population
2.4 million
"gifted"
9.4 million
"mentally retarded"
40
80
60
70
100
I.Q.
120
140
130
160
9. What causes developmental
syndromes?
Multiple factors interact in complex ways
during fetal development.
Internal factors
• Genetic traits &
susceptibility
External factors
• Exposure to toxins
• Nutrition
• Social environment
10. Leonardo da Vinci
Measurable
Impact
The result can be any
one or combination
of the traits and
behaviors we identify
in developmental
syndromes including
learning disabilities,
Attention Deficit
Hyperactivity
Disorder (ADHD),
Autism Spectrum
Disorders (ASD) and
others.
12. Introduction
Children are More Vulnerable to
All Toxins
• Eat, breathe & drink more per pound
• Mouth breathers
• Immature brain and blood-brain
barrier
• Gastrointestinal tract & skin have two
times the surface area of adults
• Outside more & closer to ground
• Hand-to-mouth behaviors
• Lower enzyme levels
13. Introduction
Our Chemical Environment:
The State of Knowledge
• >81,000 chemicals, estimate
700 new chemicals/year.
• 62,00 chemicals
grandfathered in with no
testing requirements.
• >4 billion lbs per year,
including 72 million lbs
carcinogens.
Problem: Data available for just a few
chemicals. No data available for majority!
14. Introduction
Lack of Testing for Developmental
Effects
Some Data
On Developmental
Toxicity
0.4%
33.1%
66.5%
No Data
On Developmental
Toxicity
Only 12 Tested for
Neurodevelopmental
Toxicity
According to EPA
Guidelines
15. THE TOXIC ICEBERG
PROVEN HARM
PARTIALLY
PROVEN
NOT YET RECOGNIZED
FOREVER UNRECOGNIZED
Introduction
16. Synergistic Effects
• Adverse effects of toxins are
often synergistic
• Advisories based on analysis of a
single chemical are unlikely to
protect public health
17. Introduction
Parental Concern vs.
Pediatrician Advice
ea
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i m c ti
mu on
niz s
a ti
tel on
ca evis
ra
i on
cci
ea dent
tin s
gr
en ight
v.
to x
ins
80
70
60
50
40
30
20
10
0
Stickler GB, Simmons PS., Clin Pediatr 1995
pediatrician advises
often
parents worry "a lot"
18. Taking An Environmental
History
• Activities –
school, daycare, after
school, sports, grandparents, church, etc.
• Community – industry, agriculture, dump
site, water pollution, water source
• Household – dwelling, age, condition,
heating, sources, pesticides use, SHS
• Hobbies – arts, crafts, fishing
• Occupation – known exposures, fumes,
dusts, vapors, Material Safety Data
Sheets
• Oral behaviors – pica/mouthing
20. Lead
Lead (Pb): a Persistent Problem
• Nationally: 2.2% have BLL predictive of lower IQ.
• New data: BLL<10 may reduce IQ proportionally
more than higher levels, affecting up to 16%
children.
• Oregon: 2% homes high risk & 1% tested kids<6yo
have elevated BLL.
• Multnomah County: 4% homes high risk.
• Lead phase out: paint 70s; gas 80s; plumbing
1985.
• Lack of OR regulation: 19/48 industries air & 5/18
water have permits – we know nothing about
the rest.
21. EXPOSURE – blood lead, ug/dl
DECLINING
lead
THRESHOLD OF HARM - LEAD
100
Reported
Harm (CDC)
10
?New
Level?
1
0.1
1960
1970
1980
1990
YEAR REPORTED
2000
22. Effects of Lead
on Cognitive and Behavioral
Traits LD
ADHD
hyperactivity
impulsivity
distractibility
diff. w instructs
conduct problems
executive
function
attention/vigilance
social skills
reading, math
spelling
pattern recognition
word recognition
OTHER
fine motor
visual motor
aggressive
antisocial
off-task
Lead
23. Health Effects
• Developmental effects:
•
•
•
•
•
•
•
•
– ADHD
– learning disabilities
– Lowered IQ
Chronic renal disease, nephritis
Dementia
Atherosclerosis
Peripheral neuropathy
Behavioral changes
Reduced sperm count and libido
Miscarriages
Hypertension
Lead
24. Lead
Sources
• Toys, plastic nipples and baby
bottles
• Old paint & water pipes
• Home renovation (in dust)
• Gasoline (soil contamination)
• Industrial/workplace emissions
• Hobbies-lead solder
• Bone release during pregnancy if
calcium deficient
• Breast milk
• Costume jewelry & under-fired
terra cotta
• Folk remedies (greta, azarcon,
rueda)
• Vinyl and non-glossy mini-blinds
http://www.flickr.com/photos/wayneandwax/119879781
/
25. Advise Patients
• Regularly clean areas where children play;
• Clean/remove shoes outside;
• Limit use of toys, bottles & pacifiers which may
contain lead in paint or plastics, wash often;
• Test homes built before 1978, esp. if being
remodeled;
– Clean up paint chips, keep paint in good condition;
• Test drinking water & replace Pb solder-if
unable, use COLD water;
• Testing for all immigrants, Medicaid patients &
low SES;
Call the Multnomah Co Lead Line 503-988-4000:
free tap water testing, BLL clinics, safe home
remodeling, risk assessment help
Lead
27. Methylmercury
Methyl mercury (H3C-Hg+)
• Nationally: EPA estimates that 160 tons
released annually.
• In Oregon: 4,500 lbs released from
human sources annually.
• Lack of OR regulation: 10 facilities
report Hg release, but Oregon does not
require emissions monitoring.
• Poisonings: Minamata 1950s & Iraq
1971.
33. Mercury
Mercury Exposures
• 5-8% of women of reproductive age
exceed recommended Reference Dose
(RfD) of 0.1mcg/kg/day.
• 50% of women who eat fish exceed RfD on
any given day.
• Higher risk: Children (estimated 300,000 per
year) of women with higher mercury intake;
Subsistence fishers, immigrants, Native
Americans.
• Fish Advisories: in 2004, 44 states had over
2000 warnings; OR lists 16 water bodies with
mercury advisories.
34. Mercury
Mercury:
Declining Threshold of Harm
100
Level associated with
harmful effect
Regulatory standard
(maximum safe exposure or high
contamination)
end exposure from allowed fish
(micrograms/kg/day Hg)
DAILY INTAKE
10
1
FDA
WHO
ATSDR
0.1
EPA
0.01
1970
1980
YEAR
1990
2000
35. Mercury
Benefits of Maternal Fish Consumption
Lessened by Mercury Exposure
Eat more fish with
less mercury
Oken E et al., EHP 2005
Fish is a good food source:
- protein, iron, vitamin E,
selenium, and long chain n3 polyunsaturated fatty
acids
Higher fish consumption
associated with improved infant
cognition
However...Higher mercury
exposure (even very low dose)
associated with reduced
cognition
36. Mercury
Advise Patients
• Recommend children <6yrs and women of
child-bearing age avoid fish high in mercury.
• Provide pregnant women copies of Healthy Fish,
Healthy Families (PSR) and An Expectant
Mother’s Guide to Eating Fish in Oregon (DHS)
• Have car checked for mercury switches at
participating auto shop (free replacement with
nonHg switch).
• Use digital thermometers & thermostats.
• Recycle old mercury thermometers, thermostats
& compact fluorescent bulbs or tubes: 1-800RECYCLE
37. Mercury
Guide to Healthy Fish
CHECK LOCAL AND STATE
FISH ADVISORIES at
www.healthoregon.org/fishadv
• AVOID: Mackerel-King, Shark,
Swordfish, Tilefish; In OR, also
Bass (large & smallmouth),
Brown Trout.
• <2 servings/month (Hg &/or
PCBs): Salmon, Sardines,
Herring, Bluefish.
• <1 serving/wk: Lobster, Tuna,
Mackerel-Spanish, Marlin,
Orange Roughy, Grouper; In
OR, also Walleye, Carp,
Catfish, Sturgeon.
38. Mercury
How Much Fish is Safe?
IATP Fish Calculator
Enter your body
weight in pounds:
Select the species of
fish you eat:
Get your Results!
www.iatp.org
www.ewg.org
•Do not feed children swordfish,
shark, mackerel (King), and tilefish.
•“Chunk light” vs “solid white”
albacore (limit amt based on weight)
•Serve a variety of fish and seafood Haddock, pollock and shrimp are
among the low fat, low mercury
choices.
40. Pesticides
Pesticides: a Persistent Problem
• Definition: Physical, chemical or biological agent
intended to kill an undesirable plant or animal
pest.
• Major classes: insecticides, fungicides, herbicides.
• Market: in 1997, USA $11.9 billion & World $37
billion.
• History: new to humans & environment since
1940s; over 800 licensed as “active” ingredients
by EPA.
• Inherent toxicity: 140 pesticides considered
neurotoxic, 37 used on food &/or feed.
41. Pesticides
Pesticides and Health
Associations noted with:
– Neurodegenerative disorders
• Parkinson's Disease
– Birth defects
– Neurodevelopmental disorders
–
–
–
–
• Autism Spectrum Disorder (ASD)
• Attention Deficit and Hyperactive Disorder
(ADHD)
Leukemia
Non-Hodgkin’s lymphoma
Soft tissue sarcoma
Brain tumors
• Same tumors repeatedly found in adult studies.
Zahm SH, Ward MH., EHP 1998
42. Pesticides
Background Pesticide
Exposures Widespread
• Reported use: 98% of families, 80% during
pregnancy.
• In Humans: detectable chlorpyrifos metabolites in
92% children’s, 82% adults’ urine.
• Food: detectable residues of at least 1 pesticide
on conventionally grown 72% fruits & vegetables.
• In Homes: 3 to 9 pesticide residues found; 70% of
infant levels from dust.
• In Air: indoor levels 10 to 100X higher than
outdoor.
• In Water: >90% stream samples, 50% of wells.
44. Pesticides
Anthropological Study of
Children Exposed to Pesticides
Children from villages
practicing organic agriculture
Children from villages
practicing non-organic
agriculture
45. Pesticides
Case: Transient Hypertonia in an
Infant
• 7lbs. 14 oz. term female, jaundice peak bili
12.6
• Normal physical exam at 12 weeks except
lower extremity and hypertonicity
• Pediatric consult at 16 weeks - upper and
lower extremity hypertonicity, ankle clonus
with diagnosis of cerebral palsy
• Physical therapy begun
• No environmental history was taken
Wagner SL, Orwick DL., Pediatrics 1994
46. Pesticides
Transient Hypertonia in an Infant
• Diazinon 1% sprayed by
unlicensed pesticide applicator
• Levels still high six months after
spraying
• Serum cholinesterase normal
• Urine metabolites high, similar to
post-shift urine of applicators
• Six weeks after removal from
house, muscle tone returned to
normal
Wagner SL, Orwick DL., Pediatrics 1994
48. Pesticides
Urban Exposure to Pesticides
During Pregnancy Ubiquitous
• NYC women wore
backpack air samplers for
48 hrs during 3rd trimester
• 266/314 reported pest
measures at home (90%
for cockroach)
• ALL tested positive for
exposure to at least 4
pesticides
• Cord blood levels =
maternal
• Chlorpyrifos associated
with decrease in BW and
length
Whyatt et al. Envir. Health Persp. 2002
49. Pesticides
Organic Diet Reduces Exposure to
Common Agricultural Pesticides
• 23 children monitored for metabolites before/after organic
diet
• Levels of urinary metabolites reduced to non-detectable
for malathion (left) and chlorpyrifos (right)
• Again elevated on re-introduction of conventional diet
Lu et al. 2006 EHP
50. Pesticides
Advise Patients
•
•
•
•
•
Regularly clean areas where children play;
Practice Integrated Pest Management (IPM)
Use nontoxic products in yard;
Clean/remove shoes outside;
Buy organic food or, when unable, clean nonorganic produce;
• Store food in secure nontoxic containers.
• Select lawn care & pest control companies
which use IPM and nontoxic products.
52. Conclusions
Emerging Themes
• The more we learn about chemicals, the
lower we shift the toxic “thresholds”.
• Subtle effects carry profound impacts
when expressed over a population (IQ).
• Adverse effects of toxins are often
synergistic-advisories based on analysis of
a single chemical are unlikely to protect
public health.
53. Conclusions
Guiding Principles
•
Disabilities are widespread. Toxic exposures
are preventable contributors.
•
Apparent toxicity at high doses is a red flag
for possible harm from low dose exposures.
•
Since “proof” of harm materializes slowly,
generations are being put at risk before
adequate regulatory response occurs.
•
To protect public health, we need a flexible
regulatory system capable of preventing (as
well as responding to) exposures.
54. Conclusions
What Can You Do?
• Be aware of
environmental
toxins & possible
effects.
• Provide
education on
prevention and
minimizing
exposures - use
the Pediatric
Environmental
Health Toolkit in
your practice
http://www.flickr.com/photos/cursedthing/2198948816/
• Advocate for a
healthier
environment
55. Acknowledgments
• Greater Boston
Physicians for Social
Responsibility
• Washington Physicians
for Social Responsibility
• Oregon Physicians for
Social Responsibility
• Ted Schettler, MD, MPH
• Steven G. Gilbert, PhD,
DABT
• Richard Grady, MD
• Catherine Thomasson,
MD
• Michelle Gottlieb
• Jenny Pompilio, MD
• Maria Valenti
• Jill Stein, MD
• David Wallinga, MD
• Margie Kircher
Editor's Notes
Image is of toys (not necessarily containing lead) from: http://www.flickr.com/photos/justanuptowngirl/2249080112/
