Children & Lead, in the US, at the Border
Mychal L. Anderson Thomas
South Texas Environmental Education and Research
February 26, 2009
Outline
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History of Childhood Lead Poisoning
Lead Effects in Children
Mechanisms for lead neurotoxicity
Is there a Threshold?
Consumer Product Safety Commission
Sources of Lead Poisoning
Solutions & Conclusions
History of Childhood Lead Poisoning
• 1904 – Australian physician, Dr. Lockhard Gibson, links lead
based paint to childhood lead poisoning. He urges “use of lead
paint within the reach of children should be prohibited by law”
• 1914 – In Baltimore, Henry Thomas & Kenneth Blackfan
detail the case of a boy who died of lead poisoning after eating
white lead paint from his crib railing
• 1920’s, 1930’s – several countries, including Belgium, Cuba,
Great Britain, Greece, Poland, Spain, Sweden, Tunisia,
Yugoslavia ban/restrict lead paint use
• 1930 – Noted in the US that lead poisoning resulting from
paint on toys, cradles and woodwork is increasing in children
History of Childhood Lead Poisoning
• 1930’s – Lead industry publicly targets advertising to children,
advocates for interior lead paint while internally
acknowledging the danger lead paint poses to these children
• 1935 – researchers recommend prohibiting the use of leadcontaining paints for “toys, children’s furniture and for interior
work”
• 1952 – lead paint industry blames victims, says problem
rooted in “slums” and “uneducable” parents
• 1970 – federal legislation prohibits use of lead paint, the
following year NYC tests paints and finds them to have high
lead levels
Lead Effects in Children
• “Clinical evaluations indicate that the victim of lead
poisoning is brain damaged rather than simply a less
intelligent child”*
• Neuropsychological impairments decrease academic
potential and impair activities of daily living
• Different deficit patterns in different children
* Lidsky & Schneider, 2005
Mechanisms for lead neurotoxicity
• Direct neurotoxic actions:
apoptosis
excitotoxicity
influence on neurotransmitter storage and
release processes,
mitochondria,
second messengers,
cerebrovascular endothelial cells,
astroglia & oligodentroglia
Mechanisms for lead neurotoxicity
• Neurotoxicity is mediated by lead’s ability to
substitute for Ca++
• Lead crosses Blood Brain Barrier by substituting for
Ca++ ions
• Lead is taken up by excitable cells via interactions
with Ca++ mediated cellular functions
Is there a Threshold?
• >10µg/dL is currently considered elevated blood lead level
(BLL)
• Subclinical lead poisoning – lead produces a spectrum of
toxicity including subclinical counterparts, such as lowered
intelligence, impaired renal tubule function, elevated
erythrocyte protoporphyrin
• Cognitive deficits associated with BLL <5µg/dL
• There does not appear to be a detectable threshold for
adverse effects of lead exposure on cognitive
development/academic abilities
Consumer Product Safety Commission
• Created by the 1972 Consumer Product Safety Act
• Independent regulatory agency administered by commissioners
appointed by the president and confirmed by the senate
• Task of monitoring >15,000 types of consumer goods
• Has authority to ban hazardous consumer products, initiate
recalls, establish mandatory performance standards and warning
and instruction requirements
• Does not test products – this is left up to manufacturers,
importers, retailers
Glory and Decline of CPSC
• 1979: $44 million budget, 900 staff, 545 recalls
• 1981: Congress requires CPSC to wait for industry to write
standards, then prove industry standards wrong before
imposing any mandatory standards
• 1988: budget down 22%, staff cut almost in half, recalls <200
• 2007: $63 million budget (less than half of founding budget if
corrected for inflation), 400 staff (including only 15 import
inspectors).
Sources of Lead Poisoning
• Major source of childhood lead
poisoning continues to be
deteriorating lead-based paint
ingested from paint chips, leadladen dust, soil from pre-1978
housing
• For years the Lead Industries
Association (LIA) specifically
promoted white lead paint for use
in low-cost residential housing,
especially in urban areas
Lead in Toys from China 2007
• Toy Industry:
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Hasbro $161.6 million in profits, $1.14 billion in revenue 2006
Mattel produces 800million toys yearly
80% of the world’s toys made in China
Lead makes paint brighter and more durable
• Federal Hazardous Substances Act (FHSA)
– Household products exposing children to hazardous quantities of lead
under reasonable foreseeable conditions of handling or use are
“hazardous substances.” Household products not intended for children
but which create risk of injury because they contain lead require
precautionary labeling. A toy or other article intended for use by
children which contains a hazardous amount of lead that is accessible
for children to ingest is a banned hazardous substance.
Lead in Toys from China 2007
“It has been all about price, and it is that very desire for lower
prices that creates the problem” ~ Charles Hinnant, president,
Charkit Chemical
• Large toy companies dependent on cheap Chinese production
for most of their wares
• Limited regulatory environment in China, Quality control a
significant issue, Chinese feel bullied by foreign companies to
cut costs, thus squeezing their own suppliers
• Bargaining – “you get what you pay for”, price negotiation
may implicitly negotiate quality
• Some companies had products more affected than others,
depending on how stringent company testing and inspection
policies were
The US-Mexico Bi-National Community
& Lead Risks for Children
• High risk
– Ceramics
– Tamarind & Other dulces
– Chapulines
– Folk Remedies (greta, azarcon)
Ceramics – Study in Oaxaca City
• In Oaxaca state, small family businesses produce traditional lead-glazed
ceramic-ware. Oaxaca city chosen to look at non-occupational exposures
outside of Mexico City.
• Questionnaire administered & blood lead levels drawn on 220
8-10 year olds
– Mean blood lead level 10.5µg/dL
• Mean value for mothers was 13.4µg/dL
• Lead-glazed pottery was the most predictive questionnaire item of blood
lead levels
Ceramics & Tamarind
• Lead glazed ceramic pots used to package some tamarind candy/jelly
• Tamarind candy is acidic, increasing lead leaching
• Chili, often in candies, can be lead contaminated through air or fuel assisted
drying
• 1999 Oklahoma City-County Health Dept tested 2 types of tamarind suckers and
their packaging for lead. >50% exceeded the FDA Level of Concern
• 1993 case in California
– 6 year old boy identified via routine screening at well-child exam. BLL
59µg/dL. He required 7 chelation therapy tx to reduce his BLL
– 5 siblings, age 11-17, tested the same year and found BLL 35-46 ug/dL
– BLLs coincided with return of maternal aunt from Mexico. She brought
tamarind candy jam products in personal baggage
Chapulines
• Chapulines – toasted grasshoppers, popular snack, famous in Oaxaca
• Grasshoppers bioaccumulate
• 2000 – Seaside clinic, Monterey County, CA, excess elevated BLL cases
noted, linked to imported chapulines sold locally
• 2003 – FDA warning issued against eating chapulines,
found to contain as much as 2,300µg lead per gram
of product (federal guidelines for children <6yo,
6µg from all food sources)
Traditional Remedies – tx for “empacho”
• greta and azarcon (lead tetroxide)
– fine powders
– total lead content 70% to > 90%.
– large surface area for potential absorption
– administered to infants and children
• 1982 case
– 15 month old & 3 year old treated with multiple doses azarcon for
chronic diarrhea refractory to ampicillin
– Taken to San Diego hospital, 15 month old had BLL 124µg/dL, 3 year
old expired with seizures, azarcon-induced lead encephalopathy
suspected cause of death
• From Dec 1, 1991- Dec 31, 1992, CA Dept of Health Services received
reports of 40 cases of BLL >= 20µg/dL in children who had received
traditional ethnic remedies, 89% Hispanic
Solutions and Conclusions
• Education – of families on both sides of the border
• Bi-National Cooperative Efforts – between US and Mexican
government and health ministry
• Healthcare Providers – know what to ask, know risks
• Target producers – 2001 Dulmex tamarind candy roll recall
• Routine screening
• Role of the FDA – has banned some tamarind imports,
greta/azarcon
Solutions and Conclusions
• CPSC needs teeth:
– Readapt law code to allow for CPSC to more easily create mandatory
standards
– Funding for enforcement of standards
– Increase staffing in import inspection role
• Companies working with international suppliers:
– due diligence, including direct visits and reference checks
– Evaluate quality through the 10th shipment (quality may decline after
first few shipments)
– Ultimate responsibility lies with the US company purchasing foreign
products
Solutions and Conclusions
• Lead poisoning is a serious issue:
– 12.8 million US children born from 1972-1988
adversely affected by lead exposure (BLL>2.5µg/dL)
– Nearly 1 million US children continue to have BLL at
or > 10µg/dL, millions more have levels between 2.5
and 10µg/dL
• The major concern is still lead paint in old houses
References
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