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