Lead in Drinking Water : A Public Health Perspective

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Lead in Drinking Water A Public Health
Perspective

• Jim Reffle
• Director of Environmental Health Chronic
  Disease Prevention Services
• Middlesex-London Health Unit
• Ontario Municipal Water Association
• Western Section Education Day - Woodstock,
  Ontario
• October 25, 2007

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London Free Press Friday, April 20, 2007
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London Free Press, Tuesday April 24th, 2007
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Lead Absorption and Exposure

• Ingestion paint and dust, soil, food, water.
• Inhalation leaded gasoline,occupational, hobbies.

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Lead Toxicology

• Direct absorption
• Absorption varies with - route of exposure-
  age- nutritional status
• Distributed in blood, soft tissues, bones and
  teeth.

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Lead Toxicology

• Half life in blood 28-36 days
• Half life in bones/teeth gt25 years
• Retention of absorbed lead- lt 2 years retain
  33- adults retain 1

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Illness

• Varies with lead level, age of exposed
• Neurologic
• Hematologic
• Renal
• Gastro-Intestinal
• Endochrine

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Neurologic

• Developmental delay
• Loss of milestones ( e.g. language)
• Hearing loss (higher frequencies)
• Peripheral neuropathy
• Encephalopathy

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• Hematologic decreased hemoglobin synthesis,
  hemolysis
• Renal risk for hypertension in adulthood, some
  dysfunction of kidneys.
• Gastro-Intestinal lead colic, sporadic vomiting,
  intermittent abdominal pain, constipation.
• Endochrine effects on growth, maturation, tooth,
  bone development.

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Signs and Symptoms of Lead Toxicity

• Impaired abilities- decreased learning, memory,
  language- early signs of ADHD- decreased IQ-
  impaired speech, hearing functions.
• Mild toxicity- myalgias, paresthesias-
  fatigue, lethargy, irritability- abdominal
  discomfort

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Signs and Symptoms of Lead Toxicity

• Moderate Toxicity- anthralgia- difficulties
  concentrating- tremors- general fatigue-
  diffuse abdominal pain- headache- weight
  loss- constipation

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Signs and Symptoms of Lead Toxicity

• Severe Toxicity- paresis or paralysis-
  encephalopathy (e.g. seizures, coma, death)-
  lead line in gingival tissue.- colic.

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Occupations Exposed to Lead

• plumbers, pipe-fitters
• lead miners
• lead smelters, refiners
• auto repairs
• glass manufacturer
• printers
• plastic manufacturers
• police
• steel welders
• construction workers

• rubber product manufacturers
• gas station attendants
• battery manufacturers
• battery recyclers
• firing range instructors

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Hobbies and Behaviours

• glazed pottery making
• target shooting at firing ranges
• lead soldering
• painting
• preparing lead shot/fishing sinkers
• stained glass making
• car/boat repair
• home renovation

• tobacco smoking
• cosmetics
• moonshine whiskey
• gasoline sniffing

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Environmental Sources

• Lead-based paint
• soil/dust near lead industries, roadways,
  lead-painted homes.
• Ceramic ware
• leaded gasoline
• vinyl mini-blinds ( produced outside Canada/US -
  pre 1997)
• Consumer products (e.g. toys painted with leaded
  paint, jewelry)
• Water - lead water pipes common in homes
  before 1920.- solder contained 50 lead until
  1980s.- lead service pipes (common before 1950s)

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Lead Exposure Risk Reduction

• Canadian Drinking Water Standard for lead in
  drinking water reduced to 10 ug/L from 50 ug/L
  in 1992. ( same as US EPA, WHO)
• MAC based on consumption by infants as they are
  the most vulnerable population for lead
  exposure.
• Also takes into account other sources of daily
  lead exposure from dust, soil and food)
• London drinking water has consistently met this
  standard by being well below 10 ug/L(usually
  about 1 ug/L).

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Lead Levels

• Blood lead levels of concern
• gt 10 µg / decilitre
• gt 100 µg / litre

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Health Effects of Lead
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Blood Lead Levels in Children

• Canadian studies done since phase out of leaded
  gasoline and other consumer products (e.g.
  paint).
• Ontario studies between 1974 and 2003 show
  declining blood lead levels over the years,
  where none of the studies since 1990 reported a
  mean blood lead level in children exceeding the
  blood lead action level of 10 ug/dL.
• Ontario studies in Ottawa-Carleton, Niagara
  County(2001) and parts of Northern Ontario(1995)
  found mean blood lead levels in children at below
  5 ug/dL.

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• CTFPHC (Canadian Task Force on Preventative
  Health Care,1994) reported insufficient evidence
  to recommend for or against universal screening
  of children in the general population.
• CTFPHC recommended that high-risk children be
  tested for blood lead.
• MLHU does not recommend universal screening of
  children in the general population for lead in
  blood because blood lead levels are generally
  below the actionable lead level of 10 ug/dL and
  have shown steady decreases.
• MLHU supports blood lead testing for individuals
  who may have been exposed to known sources of
  lead(e.g. lead-based paints). Consult
  physician.

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Blood Lead Levels in Quebec Children Over the
Decades
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Blood Lead and IQ
Canfield R.L. et al. Intellectual Impairment in
Children with Blood Lead Concentrations below 10
µg per Deciliter. 2003348(16)1517-1526.
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Correlation of Blood Lead and Drinking Water
Lead service
CDC Blood Lead Levels in Residents of Homes with
Elevated Lead in Tap Water District of
Columbia, 2004 MMWR 2004 53(12)268-270.
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MMWR Blood Lead Levels in Residents of Homes
with Elevated Lead in Tap Water - District of
Columbia - 2004

• 18 of homes had lead service pipes.
• EPA standard was 15 ppb.
• 163 ( of 6170) homes had lead levels of 300 ppb.
• Blood lead testing done- 100 of children
  tested had BLL lt 10 ug/dL- 100 of adults tested
  had BLL lt 25 ug/dL.

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Correlation of Blood Lead and Drinking Water Lead
Fertnann R et al. Lead exposure by drinking
water an epidemiological study in Hamburg,
Germany. Int. J. Environ. Health 2004207235-244
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Three-Pronged Approach to Addressing Lead Issues
in London Water

• Education Awareness campaign for homeowners
  with lead pipes and information replacement
  program.
• Investigation into Water Chemistry which could
  minimize the uptake of lead into water.
• Replacement of Lead Pipes, in conjunction with
  homeowners, as part of infrastructure renewal
  efforts.

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Lead Health Messages

• Vulnerable groups
• Children under 6 years old
• Formula-fed infants
• Pregnant women

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• Children less than 6 years of age Younger
  children are still developing and are therefore
  more sensitive to the neurological and blood
  effects of lead. As well, children less than 6
  years of age absorb lead more easily than adults.
  
• Particular recommendations are made for
  formula-fed infants because the water used to
  make the formula can contribute 40 60 of an
  infants lead intake, whereas drinking water in
  older children and adults only contributes
  approximately 10 of total lead intake.
• Pregnant women can pass lead in their blood to
  their fetus during pregnancy. Therefore
  particular recommendations are made to keep lead
  levels in pregnant women as low as possible.

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Lead Health Messages

• If house has lead water service line
• Flush
• 6 hours or more of not being used
• 5 minutes moderate flow
• Get water tested for lead.
• Vulnerable groups use lead-free bottled water or
  filters (NSF certified) until lead levels
  determined.
• Replace lead service line.

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MLHU Activities

• Receive residential tap lead results from the
  City.
• Those much greater than 10 will be contacted as a
  priority. ( gt20 ppb )
• Respond to callers who have received results.
• Inquire about vulnerable occupants.
• Cross link with other HU staff as clients.
• Healthy Babies/Healthy Children clients.
• Continue to work with City and MOE on issues.

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• Consider needs and access issues for bottled
  water/filters.
• Advocate for priority for lead line replacement.
• Advocate with City for possible financial
  subsidies for costs of replacing lead service
  line on owners property.
• Promote Lead Health Messages.
• Work with other local municipalities on assessing
  their local situation re this.
• Review HC Corrosion Control consultation
  document.
• Local Protocols and Provincial Guidance

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Provincial Legislation Changes Safe Drinking
Water Act

• Enactment of Ontario Regulation 243/07 Schools,
  Private Schools and Day Nurseries, June 7th and
  amended July 27th.
• Amendments to Ontario Regulation 170Drinking
  Water Systems, ( municipal community sampling and
  corrosion control ) July 26th.

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O.Regulation 243/07

• Applies to all Ontario Schools, Private Schools
  and Day Nurseries.
• Requires daily flushing and annual sampling for
  lead in drinking water.
• Sampling period for schools is June 15 to August
  15th
• Sampling period for day nurseries is May 1st to
  October 31st.

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Corrective Action
Section 7 (O.Reg. 243/07) the operator of the
school, private school or day nursery shall take
steps as are directed by the medical officer of
health.
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Local Development of Protocol For Implementation
of O.R. 243/07

• July 13th - MLHU, Oxford HU, Elgin-St Thomas HU,
  TVDSBd, LDCSBd, Municipal Water System Operators
  (London and Central Elgin), MOE.
• July 26th - Private School Operators, MLHU, MOE.
• August 1st - Day Nursery Operators, MLHU, MOE,
  City of London.

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Local Development of Protocol For Implementation
of O.R. 243/07

• September 11th - Finalized the Protocol at
  meeting with the school boards and other health
  units.
• Developed recommendations for amending the
  legislation that was sent to Ministry of the
  Environment.
• Shared drafts of the Protocol with MOHLTC and all
  Ontario health units.

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Local Protocol Contents

• Purpose To assist staff of local boards of
  education, private schools, day nurseries and
  area health units in complying with the
  Regulation.
• Emphasis placed on response to reports of adverse
  water sample results.

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Local Protocol Contents

• Regulatory Requirements
• Mandatory Flushing
• Mandatory Lead Sampling
• Notification Requirements
• Recording of Results
• Duration of Flushing
• Lead Sample Results and Action Required

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Other Activities

• MOHLTC Expert Panel for developing Lead in
  Drinking Water Guidance Document for Ontario
  Boards of Health.
• Regulation 170 activities with local
  municipalities (community residential lead
  surveys and corrosion control programs).
• Regulation 243 follow-ups.
• Advocate for regulatory changes to Reg. 243/07
• Contributed to the City of London Information
  Brochure

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Key Public Health Messages

• Heightened awareness and concern regarding lead
  in our environment (e.g. drinking water and toys)
  and of the negative health effects associated
  with lead.
• Intake of lead is a concern at all levels and
  especially for young children and pregnant
  women.
• The current level of lead found in drinking water
  is a minor contributor to our overall lead intake
  and does not constitute any immediate concerns or
  health risks for children or adults.
• Provincial standard threshold level, not a toxic
  level.

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MLHU Response to Lead levels in Flushed Drinking
Water - gt 10 to 30 ug/L

• Lead from food sources reduced.
• School as source of drinking water minimal.
• Action based on impact to children lt6 and
  pregnant women and formula-fed infants.

• Continue access to water.
• Continue flushing.
• Continue monitoring.
• Reduction of consumption to children lt6 yrs and
  pregnant women.
• Advise against use for baby formula preparation.
• Cold water for food preparation, not hot water.

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MLHU Response to Lead levels in Flushed Drinking
Water - gt 30 ug/L

• Not safe.

• Discontinue access to water system.
• Post signs at faucets Do Not Drink.
• Do not use for food preparation.
• Provide alternative water supply, filtration to
  reduce lead.
• Continue longer term monitoring and
  investigations of source.
• Implement long term solutions.

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Summary

• Lead is throughout the environment.
• No safe threshold for lead.
• Standards and other efforts have reduced
  population blood lead levels.
• There are vulnerable groups.
• The health risks of exposure lead in drinking
  water at observed concentrations are minimal.

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Acknowledgements

• Dr Bryna Warshawsky - Associate Medical Officer
  of Health Middlesex-London Health Unit
• Dr Sarah Wilson - University of Toronto
  Communuity Medicine Resident
• MOHLTC Expert Panel
• City of London - Pat McNally, John Braam, Dan
  Huggins

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Contacts

• jim.reffle_at_mlhu.on.ca
• www.healthunit.com
• www.london.ca