out of harm's way: preventing toxic threats to child development
TRANSCRIPT
Oregon Physicians for Social
Responsibility
www.oregonpsr.org
Out of Harm’s Way: Preventing Toxic Threats to
Child Development
•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.
Today’s Presentation
Introduction
“When an activity raises threats of harm
to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.”
Wingspread Conference, 1998
Precautionary Principle
Image: http://www.flickr.com/photos/tkneen/319265454/
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
Introduction
Economic Implications
$81.5 – $167 billion/yr - Neurodevelop-mental 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.
Introduction
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.
The Significance of Small EffectsExample: population of 260 million
160140120100806040
70 130I.Q.
mean 100
6.0 million "gifted"
6.0 million "mentally retarded"
5 Point Decrease in Mean IQ
160140120100806040
70 130I.Q.
9.4 million "mentally retarded" "gifted"
2.4 million
mean 95
57% INCREASE IN "MentallyRetarded”
Population
What causes developmental syndromes?
• Genetic traits & susceptibility
• Exposure to toxins • Nutrition • Social environment
Multiple factors interact in complex ways during fetal development.
Internal factors
External factors
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.
Leonardo da Vinci
Measurable Impact
Windows of VulnerabilityEmbryonic Development & Vulnerability
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
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.
Introduction
Problem:Problem: Data available for just a few chemicals. No data available for majority!
0.4%
66.5%
33.1%
Lack of Testing for Developmental Effects
No DataOn DevelopmentalToxicity
Only 12 Tested for NeurodevelopmentalToxicityAccording to EPAGuidelines
Some DataOn DevelopmentalToxicity
Introduction
PROVEN HARM
PARTIALLY PROVEN
NOT YET RECOGNIZED
FOREVER UNRECOGNIZED
THE TOXIC ICEBERGIntroduction
Synergistic Effects
• Adverse effects of toxins are often synergistic
• Advisories based on analysis of a single chemical are unlikely to protect public health
Parental Concern vs. Pediatrician Advice
01020304050607080
pediatrician advisesoftenparents worry "a lot"
Stickler GB, Simmons PS., Clin Pediatr 1995
Introduction
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
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.
Lead
lead
0.1
1
10
100EX
PO
SU
RE –
blo
od
lead
, u
g/d
l
DECLINING THRESHOLD OF HARM - LEAD
ReportedHarm (CDC)
?New Level?
YEAR REPORTED
1960 1970 1980 1990 2000
Effects of Lead on Cognitive and Behavioral
Traits
OTHERfine motorvisual motoraggressiveantisocialoff-task
Lead
ADHD hyperactivity impulsivity distractibility diff. w instructs conduct problems executive function attention/vigilance social skills
LDreading, math spellingpattern recognition word recognition
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
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/
Lead
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
Methyl mercury
Coal-fired power plant in Cheshire, Ohio from http://www.flickr.com/photos/dshea/2089737103/
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.
Methylmercury
The Mercury CycleMercury
Toxic Effects of Methyl mercury
Mercury
http://www.flickr.com/photos/nirak/206930221/
Methyl mercury
• Mental retardation and developmental disabilities
• Learning impairments• Behaviors associated with
– Autism Spectrum Disorder (ASD)– Attention Deficit Hyperactivity
Disorder (ADHD) • Hearing loss, balance problems• Visual impairment• Peripheral neuropathy• Seizure disorder• Abnormal reflexes & muscle tone
Mercury
Basic Toxicology: Exposure Concepts
• Persistence PCBs, heavy metals, pesticides
• Bioaccumulation Heavy metals, pesticides
• Transient exposures Ongoing and prenatal exposures
Breastfeeding is Best for Baby
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.
Mercury
Mercury:Declining Threshold of
Harm
20001990198019700.01
0.1
1
10
100
YEAR
Level associated with
harmful effectRegulatory standard
(maximum safe exposure or high end exposure from allowed fish
contamination)
FDA WHO
EPA
ATSDR
DA
ILY
IN
TA
KE
(mic
rogr
ams/
kg/
day
Hg)
Mercury
Benefits of Maternal Fish Consumption Lessened by Mercury
Exposure
Fish is a good food source:- protein, iron, vitamin E,
selenium, and long chain n-3 polyunsaturated fatty acids
Higher fish consumption associated with improved infant cognition
However...Higher mercury exposure (even very low dose) associated with reduced cognition
Oken E et al., EHP 2005
Mercury
Eat more fish with less 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: 1-800-RECYCLE
Mercury
Guide to Healthy Fish• 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.
CHECK LOCAL AND STATE FISH ADVISORIES at
www.healthoregon.org/fishadv
Mercury
How Much Fish is Safe?
•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.
Enter your body weight in pounds:
Select the species of fish you eat:
Get your Results!
IATP Fish Calculator
www.iatp.org
www.ewg.org
Mercury
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.
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
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.
Pesticides
Organophosphate Pesticides
Occurrence and distribution of 11 types in surface & ground water of the United States, 1992-97
http://ga.water.usgs.gov/publications/abstracts/ofr00-187.html
Pesticides
Anthropological Study of Children Exposed to
Pesticides
Pesticides
Children from villages practicing organic agriculture
Children from villages practicing non-organic
agriculture
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
Pesticides
• 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
Transient Hypertonia in an Infant
Wagner SL, Orwick DL., Pediatrics 1994
Pesticides
Anticipatory Guidance Card Pesticides
http://www.flickr.com/photos/andreasbalzer/433048027/
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
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
Pesticides
Lu et al. 2006 EHP
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 non-
organic produce;• Store food in secure nontoxic containers.• Select lawn care & pest control companies
which use IPM and nontoxic products.
Pesticides
Advice for Buying Organic: Pesticide Guides
Institute for Agriculture and Trade Policy
Pesticides
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.
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.
Conclusions
• Be aware of environmental toxins & possible effects.
• Provide education on prevention and minimizing exposures - use the Pediatric Environmental Health Toolkit in your practice
Conclusions
What Can You Do?
http://www.flickr.com/photos/cursedthing/2198948816/
• Advocate for a healthier environment
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