Everything You Always Wanted to Know About

Childhood Lead Poisoning (but Were

Afraid to Ask)

Everything You Always Wanted to Know About

Childhood Lead Poisoning (but Were

Afraid to Ask) June 21, 2007

Steven Rosenberg, M.D., M.P.H. Public Health Medical Officer

Childhood Lead Poisoning Prevention BranchCalifornia Department of Health Services

“Why should I screen?” “What difference

does it make anyway?” “ Is it going to take up

too much time?”

“Why should I screen?” “What difference

does it make anyway?” “ Is it going to take up

too much time?”

ObjectivesObjectives Toxicology of lead Sources and risks Effects of lead at low levels Screening requirements Illustration with a case study Case management

The Basics of LeadThe Basics of Lead

Whole blood in micrograms per deciliter Venous blood sample is gold standard CDC level of concern >/= 10 mcg/dL * Most children BLL <2mcg/dL No known safe levels

–IQ Effects below “Level of Concern” **

*MMWR 5/27/2005

** Confirmed by meta-analysis by Koller et al. EHP, Jun 2004

Main absorption in children is gastrointestinal Similar to iron & calcium 70% total body lead is stored in bone*

–Half-life in blood is weeks–Half-life in bone is decades

Metabolism of LeadMetabolism of Lead

*Environmental Health Perspectives 1993, 101:598-616

Health Effects of LeadHealth Effects of Lead Sub-clinical

Iron deficiency associated with elevated blood lead level *

Interferes with hemoglobin synthesis– Free erythrocyte protoporphyrin– Basophillic stippling

Neuro-developmental toxin

* Wright, et al, J Pediatr, 2003; 142: 9-14

Prolonged IQ EffectsProlonged IQ Effects

After early childhood exposure IQ can drop 5-8 points Multiple studies Even at levels < 10 mcg/dL

Bellinger, 1992, decrease of 5.8 IQ pointsPocock & Smith, 1994, ReviewNeedleman, 2004, Lead Poisoning

Graph Illustrating Inverse Relationship Between IQ and Lead

Level

Graph Illustrating Inverse Relationship Between IQ and Lead

Level

Source: Bellinger, et al. Pediatrics (1992)

Blood Lead Level at 24 Months of Age (µg/dL)

125

120

115

110

105

00-4.9 5.0-9.9 10.0-14.9 ≥15.0

WISC-R Full-scale IQK-TEA Battery Composite

Adjusted Intelligence Test Score at Age 10

“What’s the impact of an average drop of 5 IQ points?”

“What’s the impact of an average drop of 5 IQ points?”

Effects of a Small Shift in IQ Distribution in a

Population of 260 Million

160140120100806040

70 130I.Q.

Normal: mean = 100

6.0 million "gifted"

6.0 million “special health &educational needs"

Adapted from Pediatric Environmental Toolkit

5 Point Decrease in Mean IQ

160140120100806040

Mean 95

70

2.4 million "gifted"

9.4 million

57% INCREASE57% INCREASE

I.Q.130

57% DECREASE57% DECREASE

Adapted from Pediatric Environmental Toolkit

“special health &educational needs"

In economic terms:In economic terms:

Economic savings to society for the decrease of lead in US population from 17.1ug/dL to 2ug/dL = $319 billion

Grosse et al, Environmental Health Perspectives, June 2002, 110:563-569

Rothenberg & Rothenberg, Environmental Health Perspectives, Sept 2005, 113: 1190-1195

Poor academic achievement 1

Juvenile delinquency 2

Elevated school drop-out rate 3

Direct effect on behavior 4

ADHD 5

Even at low levels 6

Studies Correlate Lead in Childhood With:

1. Bellinger DC, et al. Pediatrics 1992; 90(6):855-61

2. Dietrich KN, et al. Neurotoxicol Teratol 2001; 23(6):511-8 Needleman HL, et al. Neurotoxicol Teratol 2002; 24(6):711-73. Needleman, et al. NEJM 1990; 322(2):83-84. Chen, et al. Pediatrics 2007; 119:e650-85. Braun, et al. Environ Health Perspect 2006; 114:1904-96. Canfield et al. NEJM 2003; 348(16):1517-26

How much lead is hazardous?

How much lead is hazardous?

“LEAD DUST”

• 1 gram packet of lead dust spread over 10,000 ft2 gives lead level of 100 μg/ft2

• Current EPA acceptable Current EPA acceptable level: 40 μg/ftlevel: 40 μg/ft22

• FDA recommended maximum consumption: 6 μg per day

What are the common sources of lead?

What are the common sources of lead?

Top Ten States with pre-1950 HousingTop Ten States with pre-1950 Housing

0

0.5

1

1.5

2

2.5

3

3.5

4

NY PA CA IL OH MI MA NJ TX WI

Top Ten States

Number ofpre-1950

Housing Units

(in millions)

Change in Blood Lead Levels in Relation to Decline in Use of Leaded Gasoline 1976-1980

Source: Annest JL, 1983

Lead in soil remainsLead in soil remains

What are other, less common, sources of lead?

Occupational Sources Brought Home

Occupational Sources Brought Home Storage battery manufacture/repair/recycling

Painting/soldering/remodeling Heavy construction/abatement Smelting/brass/bronze working Firing ranges/metal work

At Risk HobbiesAt Risk Hobbies Stained Glass Making Furniture Painting/Refinishing Ceramic Glazing Soldering Jewelry Lead fishing weights Firearms Collectibles

Imported CeramicsImported Ceramics

Eating Dirt: ww.cdc.gov/ncidod/eid/vol9no8/pdfs/03-0033.pdf

Lead in Imported Candy*

*& other foods & spices

Lead in Imported Jewelry

Lead in Imported Jewelry

Lead in Folk Remedies

Lead in Folk Remedies

Ayruvedic medications Sindoor Pay-loo-ah

Who is at risk?Who is at risk? Toddlers 1-2 years old Hand mouth behavior Pica Government-assisted programs:

–Medi-Cal–CHDP*–WIC**–Healthy families

*Child Health & Disability Prevention Program

**Woman & Infant Care program

Source: US GAO Report 1999, NHANES III, Phase 2, data early 1990’s

BLL≥10 mcg/dL

Prevalence of EBL by Funding Source

insurance

Why aren’t high-risk kids being screened?

Why aren’t high-risk kids being screened? Not ordered by physician Families don’t go to get blood drawn High-risk kids aren’t getting well child visits

“Maybe my population is not at-risk — at

what incidence should a disease occur before

it is worthwhile to screen?”

“Maybe my population is not at-risk — at

what incidence should a disease occur before

it is worthwhile to screen?”

0.000%

0.100%

0.200%

0.300%

0.400%

0.500%

0.600%

0.700%

0.800%

0.900%

1.000%

Incidence

Galactosemia PKU CongenitalHypothyroidism

Lead Level ≥10mcg%

Screening Test

Inc idence of Screened Inborn Errors vs Lead Screening

1:25,000 1:12,000 1:3,000

≥

Incidence of Screened Inborn Errors of Metabolism

~600,000 children received blood lead testing in 2006

Average BLL < 2 mcg/dL 0.7% had results reflecting CDC level of

concern

Childhood Lead Poisoning Prevention Program:

Childhood Lead Poisoning Prevention Program:

0.000%

0.100%

0.200%

0.300%

0.400%

0.500%

0.600%

0.700%

Incidence

Galactosemia PKU CongenitalHypothyroidism

Lead Level ?10mcg%

Screening Test

Incidence of Screened Inborn Errors vs Lead Screening

1:25,000 1:12,000 1:3,000

≥

1:140

“Is lead poisoning a serious enough illness

to warrant screening?”

“Is lead poisoning a serious enough illness

to warrant screening?”

Early Clinical SymptomsEarly Clinical Symptoms Anorexia Abdominal pain Constipation Anemia

Case Report: MMWR 3/23/2006

Case Report: MMWR 3/23/2006

Feb 2006: 4 year old dies in Minnesota of undiagnosed lead poisoning (BLL 180)

Reebok recall Pediatrics, Dec 2006, 2548-51

Rare Clinical SymptomsRare Clinical SymptomsBlood lead >70 µg/dL

–Changes in mentation (encephalopathy)–Ataxia–Seizures–Coma–Death

Most Common Clinical Finding

Most Common Clinical Finding

Neuro-developmental compromise Clear reduction in IQ inversely correlated

with rising lead levels –  approximately 1/4 to 1/2 point decrease

for every 1µg/dL rise in BLL

“What am I required to do?”

“What am I required to do?”

1. Provide anticipatory

guidance

1. Provide anticipatory

guidance At each periodic health assessment from 6 months - 72 months

Inform parents of risk of lead exposure to young children– especially deteriorating/disturbed

lead-based paint & paint dust –particularly after begins crawling–particularly because of hand-mouth

behavior

2. Statewide Targeted Screening

Policy

2. Statewide Targeted Screening

Policy Test all children who receive services from

publicly funded programs–Medi-Cal–Healthy Families–CHDP– WIC

@ ~12 months & ~24 months of age

2. Statewide Targeted Screening

Policy

2. Statewide Targeted Screening

Policy Test children not in publicly funded programs who answer “yes” or “don’t know” to the following question:–Does your child live or spend a lot of time in

a place built before 1978 that has chipped or peeling paint or has been recently renovated?

Any child not appropriately tested Parent requests Obvious risk factors present

“Doesn’t screening increase my paperwork?”

“Doesn’t screening increase my paperwork?”

Guidance & CounselingGuidance & Counseling At each well baby and pre-school check Provide simple written information Follow BLL >/= 5 mcg/dL

–? Risks present– Interventions:

»Hand-washing

»Good nutrition

» Infant stimulation

Other environmental interventions:

Other environmental interventions: Check cans & cookware

Wash toys/ Wipe windowsills/ Wet mop Remove shoes at door Adult exposed from job: shower & change clothes Close off area if remodeling

“Even if I find a child who is

lead poisoned, can we do anything to improve the clinical outcome for

this child or is the damage already done?”

“Even if I find a child who is

lead poisoned, can we do anything to improve the clinical outcome for

this child or is the damage already done?”

Case study from Kaiser

Vallejo

Case study from Kaiser

Vallejo

Found: New 18 mo. old male (Medi-Cal) BLL=17.4

Initiate environmental intervention:

Case management:– Automatic referral to county CLPPP– BLL > 10 mcg/dl

– Child Lead Poisoning Prevention Program does the work:

» Risk/exposure queries» Environmental investigation» Identify other affected children/family members» Tailored education

– Referral to WIC

– Feedback from CLPPP

_ Prevent further neuro-developmental compromise:

» Arrange for developmental evaluation

» Referral DDS/Early Start if needed

» Follow-up by CLPPP (including family)

Am I complying with the standard of care?

Am I complying with the standard of care? Provide anticipatory guidance about lead

hazards to all parents Lead test all publicly assisted children Ask screening question of other children Remove source(s) of lead when possible Request assistance of local county CLPP

when BLL≥ 10mcg/dL

Results: compliance with current standard of care regulations in California

What should I do if I need to chelate?What should I do if I need to chelate?

Very rare Discuss with experienced consultant See DHS internet site

–Current list of consultants–Treatment matrix

Special Recommendations:Special Recommendations:

Screen new immigrants and refugees–esp. adopted toddlers from developing countries–exposed to unknown risks

Consider screening pregnant women–household member works in occupation with

significant risk of lead exposure– lead poisoned child living in household–pica/other risks–refugee or new immigrant

Why be concerned about lead in the perinatal period?

Why be concerned about lead in the perinatal period?

Lead readily transferred to the fetus during pregnancy Developing fetus especially vulnerable to effects of

lead Fetal blood lead levels estimated to be 80%-90% of

maternal levels based on umbilical cord lead level Studies have found a correlation with prenatal lead

exposure and:

- Reduced intelligence

- Behavior problems

- Developmental delays

So what else can I do?So what else can I do? Identify & eliminate lead sources to prevent further

exposure to the mother and baby If occupational source: refer to Occupational Lead

Poisoning Prevention Program If mother < 21 & meets case definition: eligible for

case management services thru DHS CLPPP Refer family members for blood lead test Encourage good nutritional practices Recommend avoiding tobacco/alcohol during

pregnancy

California DHS Website Information:

California DHS Website Information:

http://www.dhs.ca.gov/childlead/html/POpapers.html (provider references)

http://www.dhs.ca.gov/childlead/html/faq.html (fact sheet)

http://www.dhs.ca.gov/childlead/html/POmatrix.html (treatment matrix)

http://www.dhs.ca.gov/childlead/html/POhome.html (home page)

E-mail address: srosenbe@dhs.ca.gov

Estimated Losses in IQ if Lead Had Remained in Gasoline 1970–1990

(Gilbert & Weiss, NeuroToxicology 2006, 27:693–701)