ED5 - Lead Poisoning

7/29/2019 ED5 - Lead Poisoning

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Environmental Lead Ex osure

Jerold C. Woodhead, MD


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What is your opinion?

Anemia is the most common finding in children who haveelevated Blood Lead Levels.

1.True

2.False


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Blood Lead Level

What blood lead level identifies excessive lead exposurein a child?

1. 1 mcg/dl

.

3.10 mcg/dl

4.15 mcg/dl

5.25 m /dl


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What is your opinion?

Iowa ranks LOW nationally in % of the childpopulation with elevated BLL.

1.Strongly Agree

.

3.Neutral

4.Disagree

5.Stron l Disa ree


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Additional Topics

What is the 1o source of environmental lead?

Who is most at risk for lead poisoning?

What does chronic lead toxicity cause in adults? Which adults have risks for lead toxicity?

How does a pregnant woman put her newborn at

risk?


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Why Worry About Lead?

BUT

ea s a eurotox n

Disrupts cell migration/cell adhesion during braineve opmen

Interferes with neurotransmission

Behavioral concerns in 10-20% lead exposed children


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Impact of Lead on Intelligence


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Lead & Population IQ

Lead Education and

Abatement Design

http://www.lead.org.au/bblp/sld001.htm


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Blood Lead Levels Over Time

60

70

30

40Blood

Lead

10

20

0

up to

1970

1971-

1974

1975-

1985

1985-

1991

1991 to

now

considered

diagnostic of

excessive

lead exposure


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BLL > 10 mcg/dl US 1976-2000

MeanBLL BLL >=10 g/dLPrevalence Est. #

LEAD

REMOVED

1976 -

1980

14.9 88.2% 13,500,000

1960

Exterior paint

1988 -

1991

3.6 8.6% 1,700,00

-

1978

Gasoline

-

1994

. . ,

1999 - 2.2 2.2% 434,000


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BLL >10 mcg/dl - US 1997-2007

7.8%

1 %


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Thomas etal. Environmental Science and Technology33(22):3942-3947, 1999


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MMWR

May 27, 2005:

54(20);513-516


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Why Worry about Lead in Iowa? owa ran s g n or ea exposure

>50% of Iowa homes have lead-based paint

u e ore

Environmental lead is mostly from housing Dust contaminated with lead-based paint

All homes built before 1960 have lead-based paint on


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Iowa BLL 1997-2008

1500

600


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Screening

Lowa e7%

19%

High

23%

55%


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Poorly Maintained Housing


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Other Sources of Lead

Gasoline in the past Battery factory or other lead industry

Water supplies that use lead pipes

Parental job or hobby

, India

Mexico

Candy from Mexico Toys from China and India


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Lead Jewelry From

Child swallowed this and develo ed abdominal ain and

vomiting and later a seizure. BLL = 123 mcg/dl


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Recent additions

--Keychains at

--Pajamas at

Childrens Place

Stores


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How Should Iowa Respond?

Toxic CNS effects cannot be reversed

Develo local/count lead ro rams

Community awareness

Educate physicians and families Plan for lead abatement in housing

Screen all children for blood lead targeted to risk

Required for daycare and school entry

High risk populations (e.g. Medicaid eligible - 3X risk)


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Screening for lead exposure -

Who should be screened in Iowa?

Why are these children at risk?

Develo mental sta e: Hand-to-mouth behavior

Brain growth and development

What screenin method?

Questionnaire

Routine blood lead levels

Routine anemia screen (Hb or Hct)


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Screening Questions

Home, Daycare, or Visit (e.g. grandparents)? Chi ed or eelin aint?

Current remodeling?

Pica? Sibling or playmate with lead level 15 mcg/dl?

Job or hobby lead-related?

Live near battery plant, recycling plant, or smelter? Folk remedies, candy, cosmetics

Immigrant from Mexico or undeveloped country?


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Iowa Screening Guidelines


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CDC and AAPManagement of Elevated BLL

Blood Lead Level(mcg/dL) Action


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How Would You Manage?

2-year-old boy has a screening blood lead leveldone by capillary sample.

BLL returns 3 days later: 26.5 mcg/dl

What will you do?


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Elevated Capillary BLL

Obtain a venous sample to repeat BLL

Venous sample allows confirmation that the sample

reflects true BLL Patient results:

Capillary BLL 26.5 mcg/dl

Venous BLL 2.4 mcg/dl Child lives in a new home and plays outside in the dirt

aren s ave ca e e con rac or


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Adult Lead Exposure

Environmental lead exposure before public health

Adults mostly asymptomatic at levels < 25 mcg/dl

CNS dysfunction and Renal failure >80 mcg/dl

Low-level Chronic lead toxicit

Hypertension

Cognitive Decline

Atherosclerosis


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2002 Adult BLL 25 mcg/dl

Iowa

,

With BLL 25 mcg/dl


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2004 Adult BLL 25 mcg/dl

Iowa

10-19/100,000 with

Note decline in rate

with improvedsurve ance


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u mcg


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What affects Adult BLL? Continued ex osure: Occu ation or hobbies

Mobilization of stored lead from bones Pregnancy

Hypertension/Toxemia

Spontaneous abortion Exposes the fetus to possible CNS developmental

abnormalities

Fractures

Immobilization

Osteoporosis/Menopause


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Prenatal Lead Poisoning ot er use an er a preparat on ur ng pregnancy

Lead and Mercury

, ,

BLL 102 mcg/dl

Chelated for 2 months w/ succimer Infant born when maternal BLL = 36 mcg/dl

Cord blood BLL 54.5 mcg/dl

Infant BLL 59 mc /dl

Infant BLL 62 mcg/dl on day 10, Despite chelation w/succimer

At 18 months infant BLL was still 21 mcg/dl

Mothers BLL was 11.3 mcg/dl


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Cord

BLL

54.5

BLL

Mcg/dl

10 mcg/dl = Cut Off for excessive exposure

Date


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and Cord

BLLLOW < 3 mcg/dl

MED 6-7 mcg/dl

HIGH > 10 mcg/dl

(Needleman 1991)


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Elevated BLL pregnancy > -

BLL 10 mcg/dL1990 estimate 4.4 million women ofchildbearing age

13% (400,000) pregnant women

1% with BLL >15 mcg/dL

2005 BLL in women of child-bearing age: 1.78

mcg/dL

or oo ec ne s nce 1999 study in Quebec: cord BLL = 1.5 mcg/dL


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Screening of Pregnant Women?

No controlled clinical trials

Low prevalence of BLL > 15 mcg/dl

Fair evidence that BLL > 15 mcg/dl Elevated

BP NO evidence for other adverse events in

pregnancy

THUS no data to support for or againstscreening


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Blood Lead and Menopause

during

menopause

into plasma.

Am J Epidem. 2004, 160:901-911.


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Lead Toxicity in Elderly

onger ura on o ea exposur e Higher bone lead levels than younger individuals

function

Osteo orosis releases lead into the blood BLL associated with toxicity unclear

BUT, even low BLL may be associated with

Hypertension Renal impairment

Co nitive disorders

Atherosclerosis


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Adult Lead Toxicity

Adults who might be at risk for lead toxicity

Judicious use of testing blood lead levels.

,

prevent low-level Pb toxicity such as hypertension

or even cognitive decline.


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Beethoven Had Lead Poisoning

lead salts used

after paracentisis


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Beethovens Lead Poisoning

Chronic lead exposure and absorption

Elevated lead levels in skull bone fragments

x o ea po son ng s ar e n a o escence

Change of personality

Both persisted throughout his adult life

poisoning. There is no solid evidence that lead poisoningwas a cause of Beethoven's deafness.


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Key Points: Lead Toxicity y

Low level and chronic: Neurodevelopmental delay

, , ,

Adult

, ,

High level and acute: anemia, GI, renal, CNS

Pregnant women: eclampsia

Fetus and newborn: CNS developmental delay

Geriatric: Dementia


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Centers for Disease Control and Prevention

Iowa Department of Public Health Lead Exposure in Children: Prevention, Detection, and

Management, PEDIATRICS Vol. 116 No. 4 October 2005, pp.

1036-1046 on-line article

Nash etal: Am J E idem. 2004 160:901-911 Needleman HL, Bellinger D: Health effects of low level

exposure to lead. Ann Publ Hlth. 1991, 12:111-140.

, , .

caused by use of health supplements presenting as acute

abdominal pain during pregnancy. Obstet Gynecol. 2009;114

ar : - .


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Resources, continued Shih RA etal: Environmental lead ex osure and co nitive

function in community-dwelling older

adults. Neurology 2006; 67:1556-1562

. .

Stewart WF etal: Past adult lead exposure is linked to

neurodegeneration measured by brain MRI. Neurology 2006;66:1476-1484

http://www.neurology.org/cgi/content/full/66/10/1476

. , -

Balser B: Lead Poisoning. Lead Education and Abatement

Design Group (LEAD) http://www.lead.org.au/bblp/sld001.htm

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ED5 - Lead Poisoning