Residential Lead

1
Residential Lead

• David Wallace

2
Overview

• Background
• History and uses
• Lead in paint and water
• Toxicity
• Children
• Adults
• Lead Exposure
• Controlling lead hazards
• Regulations

3
What is Lead?

• Plumbum
• Element 82
• 11.34 SpG
• 0.002 of the earth's crust (15 g/ton)
• Galena (PbS) Lead ore
• Lead is the end product of radioactive decay
• Lead properties
• Heavy, soft, gray, ductile metal
• Low melting point
• Many lead compounds are pigments

4
History

• Lead is one of the metals of antiquity
• Associated with silver ore and silver mining
• Lead ore is galena, or lead sulfide
• History of lead/silver mining in the west

• Tens of thousands of Utah miners suffered from
  lead poisoning in the late 1800s and early 1900s
• Plumbing
• Industrial uses

Galena (lead ore)
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History

• Chronology
• 6500 B.C.
• Earliest known object made of lead
• 2000 B.C.
• 160 tons per year produced
• 700 B.C.
• 10,000 tons per year produced
• Roman times
• 80,000 tons per year produced, extensively used
  for vessels, aqueducts, glasses.
• A possible factor in Roman empire decline.

Roman pig lead, ca. AD 150
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History

• Chronology (cont.)
• Industrial age occupational exposure
  accelerated
• Up to 1980 because of plasticity, softness and
  pigment properties it was commonly used in
  paints, construction materials, water and sewer
  pipes, chemical additives

Bonne Terre, Missouri. Mine Works, 1904
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Worldwide Lead Production
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USES OF Pb

• Storage batteries
• Automobile radiators
• Cable
• Brass and bronze production
• Radiation shielding
• Construction
• Galvanizing
• Ammunition
• Annealing

• Printing
• Plating
• Paint
• Plastics
• Soldering
• Television/electronics
• Glass
• Petroleum
• Insecticides

9
Lead in Paint

• Lead pigments are used to color paint
• Lead tetroxide, red lead
• Red lead primer controls rust
• Lead carbonate, white lead
• Promotes chalking of exterior paint
• Lead chromate, chrome yellow
• School-bus yellow, highway stripes
• Also used as a primer
• Lead oxide, litharge, yellow lead oxide
• Cream color, lemon yellow

Red lead
Chrome yellow
10
Lead in Paint

• Older Homes Contain Lead-Based Paint (LBP)
• Lead-based paint is more common and was used more
  extensively in homes built before 1950
• Residential lead-based paint was banned in 1978
• Most homes before 1978 contain some LBP
• Paint in older homes contains higher lead levels

11
Lead in Water

• Lead has been used in plumbing for a long time
• Plumbum is Latin for lead
• Old homes may have lead service lines
• From the water main to the house
• Lead pipes are no longer used

Roman lead pipe, Bath, England
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Lead in Water

• Lead plumbing (cont.)
• Copper pipes were joined with lead solder
• Now we use lead-free solder
• Brass plumbing fixtures contain lead
• New fixtures contain less lead

60 lead (40 tin) solder
Soldering copper pipe
Brass fixtures contain lead
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Lead Toxicity

• No known beneficial effect of lead in the body
• Effects from head to foot
• Behavior, IQ
• Low levels of lead affect development
• Higher levels associated with aggressive and
  erratic behavior
• Encephalopathy in extreme cases
• Peripheral neuropathy
• Hand and foot drop

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Lead Toxicity

• Lead toxic effects from head to foot (cont.)
• Lead colic
• Extreme abdominal pain
• Anemia
• Defective hemoglobin interferes with the bloods
  ability to carry oxygen
• Birth defects and infertility
• Male and female

15
Lead Toxicity

• Lead inhibits certain types of enzymes,
• Particularly enzymes dependant upon sulfhydryl
  groups.
• Organ systems affected include
• Neurologic
• Endocrine (including BP)
• Reproductive
• Musculoskeletal
• Blood
• Renal
• GI

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Lead Toxicity

• Lead in the Body
• Lead is absorbed into the bloodstream.
• Travels to soft tissue such as kidneys, lungs,
  brain, spleen, muscles, and heart.
• After several weeks, most lead moves into bones
  and teeth (and some into hair).
• About 94 of adults total lead burden is in bones
  and teeth
• Only about 73 for children
• Lead in bones and teeth equilibrates over time
  and circumstance with other compartments.

17
Lead Toxicity

• Lead in the Body (cont.)
• Lead Excretion
• Urine
• Stool
• Sweat
• Breast milk
• Hair, nails, teeth (very slow turnover)
• It takes over 10 years to turn over half the
  bodys stored lead.

18
Lead Toxicity

• Children are affected differently
• Adults absorb about 6 of ingested lead.
• Fasting adults absorb more
• Children absorb much more lead
• 30-50 if well fed, and more, if fasting or
  malnourished
• CNS development in children
• IQ, behavior
• Special concern for children lt 6 years of age

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Lead Toxicity

• Treatment
• Stop the lead exposure!
• Industrial
• Residential
• Chelation therapy
• Allow the body to secrete metals
• For serious cases only
• Usually requires hospitalization

EDTA (chelating agent)
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Sources of Lead Exposure

• Pathways of exposure
• Adults occupational exposure
• Children household dust and soil
• Exposure generally arises from man-made processes
  and products

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Sources of Lead Exposure

• Major current exposure sources
• Manufacture of electrical batteries
• Chemicals
• Major exposure sources of the past
• Mining
• Paint additives
• Gasoline additives
• Solder, pipes

22
Sources of Lead Exposure

• Environmental sources of exposure
• Lead-based paint (LBP)
• Urban soil and dust
• Lead-based paint
• Leaded gasoline
• Industrial sources
• Drinking water
• Solder
• Brass fittings and fixtures
• Service lines
• Food

23
Lead in Paint

• Tens of millions of houses contain some LBP
• Deteriorating paint/paint chips source of lead
  dust
• Dust and soil are major routes of exposure
• Young children ingest through normal hand-mouth
  activity
• Poor diet can increase absorption

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Lead in Surface Dust and Soil

• Dust-lead and childrens blood-lead are linked
• Types of dust
• Surface dust
• Household and street dust
• Surface dust has high potential to expose
  children
• Soil
• Top soil and below top layer soil
• Lead below the soil surface has less exposure
  potential

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Lead in Surface Dust and Soil

• How household dust becomes contaminated
• Weathering and chipping of LBP
• Scraping and sanding LBP (refinishing)
• Renovations that break surfaces painted with LBP
• Abrasion on doors and windows
• Dust from the outside
• Atmospheric fallout from leaded gasoline
• Factory emissions
• Dust carried in by workers from occupational
  exposures
• Dust carried in by pets

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Lead Dust Problem

• 14 of pre-1980 housing dust levels exceed HUD
  Guidelines
• Chance of home having excessive dust lead is
  twice as large if home has high levels of LBP
• 16 of pre-1980 homes have adjacent soil lead
  concentrations exceeding 500 ppm
• Chance of home having lead concentrations of 500
  ppm in soil adjacent to the home is 4 to 5 times
  greater if house has exterior LBP

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Childhood Risk Factors for Elevated BLLs
(gt10µg/dl)
Pre-1946 Housing Non-Hispanic Black
21.9 Mexican American 13.0 White
5.6 Low Income 16.4 High Income
0.9 NHANES III, and CDC Recommendations for BL
Screening of Young Children (Dec. 2000)
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• Blood lead levels in children lt6 years old
  showed an approximately 80 decline from the
  1970s to 1994, and a continuing drop from
  1994-1998.
• with elevated BLLS
• Geometric Mean gt10 gt15
  gt20 µg/dL
• 2.7 10.5 3.9 1.9
• 8.6 3.2 1.5
• 2.0 7.6 2.7
  1.2
• Approximate of children tested 1.2 million
  yearly
• MMWR 2000491133-1137

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Lead in Water

• Exposure to lead in water
• 20 of lead exposures for average 2-year old
• 5 to 50 lead exposure from water
• Infants on formula could receive 85 of their
  lead from drinking water
• Lead contamination due mainly to corrosion of
  lead-containing materials in household plumbing
• Factors affecting extent of contamination
• Temperature of the water
• Acidity of the water
• Softness (extent of dissolved solids) of water
• Duration (how long water stands in the pipe)

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Lead in Air

• Once released in environment by use of leaded
  gasoline (4-5 million tons used prior to ban)
• Tetra ethyl lead
• Anti-knock gasoline additive (boosts octane
  rating)

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Lead in Air

• Impact of EPA phase-down of leaded gasoline
• Lead removed from gasoline to avoid damaging
  automobile catalytic converters (used to reduce
  hydrocarbon emissions)
• Total atmospheric lead emissions dropped 94 from
  1978 to 1987
• Reduction of lead in air correlates with decline
  in childhood blood lead levels (1975 - 1980)

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U.S. Leaded Gasoline Phase-out and Blood Lead
33
Lead in Air

• Other environmental sources of lead in air
• Smelters/batter factories
• Combustion of oil, coal, waste oil and municipal
  wastes
• Occupational airborne exposures are still a
  problem
• LBP abatement
• Bridge repair (bridges are often coated with LBP)
• Construction
• Painting
• Mining
• Etc.

34
Lead in Food

• Sources
• Lead from solder in cans
• Phased out in domestically manufactured cans in
  1970s
• Banned in imported cans since the mid 1990s
• Lead from glazes on ceramic cookware and dishes
• Usually a problem only with poorly fired imported
  items, i.e., old fiesta ware
• Current EPA and California regulations limit the
  leachable lead
• Lead is allowed in glazes, but the amount that
  can leach out is restricted

35
Lead in Food

• Sources (cont.)
• Intentional lead contamination
• 50 Hungarians hospitalized with lead poisoning
  from adulterated paprika in 1994
• Red lead pigment added to enhance the color
• From airborne lead on crops or water during
  transportation or processing (historical)
• Some (ethnic) home remedies

36
Other Sources of Lead Exposure

• Certain industries (adult occupational exposure)
• Battery manufacturing
• Smelting, mining
• Auto body repair
• Printing
• Construction
• Hobbyists (working with stained glass or pottery)
• Sportsmen (making their own bullets or fishing
  weights)

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Controlling Lead Hazards

• Paint
• Identify LBP hazards
• Testing and inspections
• Assume for older homes
• Keep paint intact
• Cover with non-lead paint
• Protect surfaces from abrasion
• Use special precautions during repair
• Remove lead-based paint
• Expensive and hazardous!
• EPA certified workers, inspectors

38
Controlling Lead Hazards

• Dust and Soil
• Restrict child access
• Cover contaminated areas
• Grass
• Pavement
• Clean topsoil
• Remove contaminated soil
• Dust control
• Vacuum sweeping
• Wet methods

Testing for lead in soil
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Controlling Lead Hazards

• Water
• Water testing
• Replace lead service lines, fixtures
• Newer products are lead-free or low-lead
• Corrosion control of water source
• Abrupt lead increase in Washington DC water after
  treatment changes in 2001
• Problem solved by adding anti-corrosion
  compounds
• Flush lines before drinking
• Dont drink hot water

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Regulations

• OSHA
• Protects workers
• EPA/HUD
• Residential Lead Regulations
• Disclosure upon housing sale or lease
• Certified contractors/workers/inspectors
• Residents notified before renovation

EPA/HUD required pamphlet