Environmental lead (Pb) sources and exposure pathways to children in urban areas

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Environmental lead (Pb) sources and exposure
pathways to children in urban areas

• Ray W. Brown1, Chris Gonzales2, Andrew C. Bayat3,
  Ashley M. Fornerette4, Tobias J. McBride1,
  Michael J. Hooper1, Thomas Longoria5, Howard W.
  Mielke6
• 1Department of Environmental Toxicology, The
  Institute of Environmental and Human Health,
  Texas Tech University 2College of Pharmacy,
  Xavier University of Louisiana 3Biology
  Department, Austin College, Sherman, Texas
  4Department of Biology, Xavier University of
  Louisiana, 5Center for Public Service, Texas
  Tech University,, 6Center for Bioenvironmental
  Research, Tulane University
• Presented to the Air and Waste Management
  Association
• High Plains Chapter November 1st, 2007

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• The whole history of civilization is strewn with
  creeds and institutions which were invaluable at
  first, and deadly afterwards.
• Walter Bagehot English economist journalist
  (1826 - 1877)

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Measurement of Pb through the atmosphere (108g/yr) Measurement of Pb through the atmosphere (108g/yr) Measurement of Pb through the atmosphere (108g/yr) Measurement of Pb through the atmosphere (108g/yr) Measurement of Pb through the atmosphere (108g/yr) Measurement of Pb through the atmosphere (108g/yr)
Natural Natural Natural Anthropogenic Anthropogenic
Continental Dust Volcanic Dust Volcanic Gas Industrial Particles Fossil Fuel Ratio Anthropogenic/ natural
50 8.7 0.012 16,000 4,300 345.83
Lantzy, R. J. Mackenzie, F. T. (1979).
Atmospheric trace metals Global cycles and
assessment of man's impact. Geochimica et
Cosmochimica Acta, 43, 511-525
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Lots of potential Pb Sources

• Hobbies
• artist paint
• photography chemicals
• stained glass
• enamel, bronze or brass plating
• Colored newspaper print (comics)
• Hair dyes
• Culturally-specific products
• (Azarcon Coral, Rueda, Maria Luisa), Greta,
  Albayalde, Pay-loo-ah, Xyuuaj Fab, Tsuaj gais
  nyiaj, Ghassard, Bala Goli, Kandu, Kohl (Alkohl)
• Metal toys or toys with metal paint (wash toys
  and pacifiers frequently)
• Dishes (imported, handmade, bright colored
  pottery)
• Clothes (if a parent works around lead, he/she
  can bring lead home on clothing)
• Costume jewelry (many brands) especially those
  made outside the U.S.
• Candles with a metallic core
• Some insecticides

• Old paint on homes (pre-1980)
• Lead dust in the carpet
• Lead solder in joints
• Old bathtubs (metal)
• Marine paint
• Yellow stripes in roads
• Industrial Metals
• Lead putty in windows
• Brass candle sticks
• Old knife sharpeners
• Vinyl roll-up Venetian blinds
• Bullets
• Fishing sinkers
• Pool cue chalk
• Simulated pearls (coating has lead)
• Some Cosmetics
• Canned foods (imported) weld contains lead
• Candy wrappers

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Most everyone is aware thatPb is a poison.

• Question 1 What is the primary source of Pb to
  children?
• Pb-based paint.
• Question 2 How might we assess potential risk to
  children in a community like Lubbock?
• Determine the age of housing where children live

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• Age of housing is not correlated with childrens
  blood Pb levels in many urban environments that
  have been studied so far.

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Adapted from Mielke HW, Reagan PL. 1998. Soil Is
an Important Pathway of Human Lead Exposure.
Environmental Health Perspectives Supplements
106217.
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Some Factors that have been correlated with
childrens blood Pb levels

• Proximity to high traffic areas
• Use of hot water
• Use of leaded personal products
• Season (summer vs. fall)

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Exposure to Exterior Soils Indoors

• Exterior soil accounts for 31 of interior dust
• Children ingest 9-40 mg/soil/day

Calabrese et al. Reg Tox Pharm 198910123-137
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Dust, Soil, Blood Lead Relationships
with BLL ?10 ?g/dL
Soil/exterior lead, ppm
Interior dust lead loading, ?g/ft?
Lanphear et al. Env Research 19987951-68
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• The source of Pb in 70 of gardens studied in
  Massachusetts was a mixture of paint and
  gasoline.
• The maximum average contribution of interior
  paint to floor and window sill Pb was 50
• In determination of sources of interior dust Pb,
  exterior sources contributed as much as or more
  than interior lead-based paints.

Clark, H. F., Brabander, D. J. Erdil, R. M.
(2006). Sources, sinks, and exposure pathways of
lead in urban garden soil. Journal of
environmental quality, 35, 2066-2074
Adgate, J. L., Rhoads, G. G. Lioy, P. J.
(1998). The use of isotope ratios to apportion
sources of lead in Jersey City, NJ, house dust
wipe samples. Science of the Total Environment,
221, 171-180
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• Soils are the best indicator of potential Pb
  exposure (e.g. as opposed to age of housing)
  since they integrate not only exposure from
  lead-based paints, but also other sources
  (incinerators, Pb-added gasoline, other wastes).

Mielke HW, Reagan PL. 1998. Soil Is an Important
Pathway of Human Lead Exposure. Environmental
Health Perspectives Supplements 106217.
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Pb Concentrations of Concern

• ?Soil
• 400 mg/kg hazard in childrens play area
• 1200 mg/kg hazard for the rest of the yard
• - 40 CFR Part 745, Lead Identification of
  Dangerous Levels of Lead Final Rule
• 310 mg/kg soil concentration predicted to
  result in child blood level of 9 ?g/dL
• - Mielke, H. W. Reagan, P. L. (1998). Soil is
  an important pathway of human lead exposure.
  Environmental Health Perspectives
  Supplements, 106 217-229

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• A concentration of 80 ppm in soils may provide a
  margin of safety for children given that median
  blood lead levels in this range are 6.0 ?g/dL.

Jones, C., Elert, M., and Christiansson, A. 1998.
Fördjupad miljöoch hälsoriskbedömning avsende
Falu Tätort. Kemakta Konsult AB, Falu kommun. 51
pp. Mielke HW, Gonzales CR, Smith MK, Mielke PW.
1999. The urban environment and children's
health Soils as an integrator of lead, zinc, and
cadmium in New Orleans, Louisiana, USA.
Environmental Research 81(2)117-129.
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Pb Concentrations of Concern

• ?Childrens Blood
• gt 10 ?g/dL lead poisoning
• -National Center for Environmental
  Health/Centers for Disease Control Prevention
• gt 5 ?g/dL neurotoxicity in children
• - Canfield et al. 2003, Min et al. 2006

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Canfield RL, Henderson CR, Cory-Slechta DA, Cox
C, Jusko TA, Lanphear BP. 2003. Intellectual
impairment in children with blood lead
concentrations below 10 ?g per deciliter. New
England Journal of Medicine 348(16)1517-1526.
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• There is now sufficient and compelling
  scientific evidence for the CDC to lower the
  blood lead action level in children.
• no threshold for the health effects of lead is
  demonstrable (although) a blood level of 2 ?g/dL
  provides a benchmark for successful prevention.

Gilbert, SG, Weiss B. 2006. A rationale for
lowering the blood lead action level from 10 to 2
?g/dL. NeuroToxicology. 27 693-701.
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Mielke HW, Gonzales CR, Smith MK, Mielke PW.
1999. The urban environment and children's
healthSoils as an integrator of lead, zinc, and
cadmium in New Orleans, Louisiana, USA.
Environmental Research 81(2)117-129. Mielke HW,
Powell ET, Gonzales CR, Mielke PW, Ottesen RT,
Langedal M. 2006. New Orleans soil lead (Pb)
cleanup using Mississippi River alluvium Need,
feasibility, and cost. Environmental Science
Technology 40(8)2784-2789
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West Texas Lead Study

• A comprehensive assessment of Lubbock area soil
  contamination in concert with an assessment of
  housing with Pb-based paint.
• Assessment of blood Pb concentrations in
  populations at risk.
• A determination of child populations at risk from
  exposure to Pb-based paint, Pb-contaminated soil
  and/or other risk factors.
• Immediate implementation of simple steps parents
  and educators can take to reduce Pb exposure to
  children in at-risk populations.
• Education of all citizens of Lubbock on both
  short-term and long-term solutions to reduce
  exposure of all Lubbock children to Pb in their
  environments.

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West Texas Lead Study

• A comprehensive assessment of Lubbock area soil
  contamination in concert with an assessment of
  housing with Pb-based paint.
• Assessment of blood Pb concentrations in
  populations at risk.
• A determination of child populations at risk from
  exposure to Pb-based paint, Pb-contaminated soil
  and/or other risk factors.
• Immediate implementation of simple steps parents
  and educators can take to reduce Pb exposure to
  children in at-risk populations.
• Education of all citizens of Lubbock on both
  short-term and long-term solutions to reduce
  exposure of all Lubbock children to Pb in their
  environments.

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1930
1950
1970
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Soil Pb Concentration (mg/kg)
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Soil Pb Concentration (mg/kg)
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Soil Pb Concentration (mg/kg)
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West Texas Lead Study

• A comprehensive assessment of Lubbock area soil
  contamination in concert with an assessment of
  housing with Pb-based paint.
• Assessment of blood Pb concentrations in
  populations at risk.
• A determination of child populations at risk from
  exposure to Pb-based paint, Pb-contaminated soil
  and/or other risk factors.
• Immediate implementation of simple steps parents
  and educators can take to reduce Pb exposure to
  children in at-risk populations.
• Education of all citizens of Lubbock on both
  short-term and long-term solutions to reduce
  exposure of all Lubbock children to Pb in their
  environments.

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Demographics Blood Lead Data

• Under Age 5 (2000) - 14,272
• Births
• 2001 - 3,826
• 2002 - 3,947
• 2003 - 4,064
• 2004 - 4,049

• Blood Lead Data Reported for Children Under Age 5
• 2000 - 884
• 2001 - 729
• 2002 - 921
• 2003 - 1,155
• 2004 - 1,112
• 2005 - 1,017

• Percent Children Tested
• 2000 - 6.2
• 2001 - 5.1
• 2002 - 6.4
• 2003 - 8.1
• 2004 - 7.8
• 2005 - 7.1

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Blood Lead Data for Children Ages 0 - 3
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79403
79415
79401
79411
79412
79404
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Hypotheses
Blood Pb concentrations are a function of age of
housing
Blood Pb concentrations are a function of
culturally-specific behaviors
Blood Pb concentrations are a function of
geography
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you will observe with concern how long a useful
truth may be known and exist, before it is
generally received and practiced on Benjamin
Franklins recollections from his boyhood on the
prohibition of the use of lead in rum
production, causing people to lose the use of
their hands
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Project Supporters/Partners

• Texas Tech University
• The Institute of Environmental and Human Health
  (TIEHH)
• Center for Public Service
• Honors College
• Child Development Research Center
• Department of Psychology
• Department of Human Sciences
• Department of Mass Communications
• TTUHSC Department of Pediatrics
• TTUHSC School of Nursing
• University of Texas - Arlington
• UT Austin School of Nursing
• Success by 6/United Way
• Lubbock Housing Authority
• Lubbock Independent School District
• Early Childhood Intervention/Early Childhood
  Intervention Developmental Education Birth to 3
  (ECI/DEBT)
• LISD Early Head Start
• Faith-based Organizations
• St. Johns UMC