Immigrant Health Service

Lead - further information

  • Lead is a heavy metal. Routes of exposure to lead include contaminated air, water, soil and food.(4) Hand-to-mouth activities in young children increase their risk of lead exposure. Well described sources include lead-based paint from imported toys and in older houses.(6) Toxicity has also been linked to lead-contaminated traditonal remedies (2), imported candies/condiments, and fashion accessories.(6) 

    Elevated blood lead concentrations have been reported in up to 7 - 13% of African(5, 6) South Asian(7, 8) and Burmese(2, 9) refugee children, especially in those aged < 6 years; although rarely to a concentration requiring chelation therapy. Blood lead screening is now recommended for all refugee children (aged 6 months - 16 years) arriving in the United States(10). Blood lead screening is not part of Australian refugee guidelines, but should be considered in any child with developmental delay, pica, or where there is a history suggesting exposure.

    Clinical features of lead toxicity

    Clinical features vary depending on level of exposure and age of the child; they may be non-specific.

     Low level exposure
     Moderate exposure
     High level exposure
    Decreased learning and memory, lowered IQ, cognitive dysfunction
    Behavioural disturbance (more marked in children) - irritability, restlessness, sleeplessness
    Myalgia/paraesthesias
    Fatigue, lethargy
    Abdominal discomfort

    Arthralgia
    Vomiting, weight loss, constipation, abdominal pain
    Headache
    Poor concentration
    Muscle fatigue, tremor

    Lead line (blue discoloration) on gum margins
    Anaemia
    Paralysis
    Encephalopathy, seizures, coma, death

    Investigations

    • FBE (microcytic hypochromic anaemia, basophilic stippling, sideroblasts)
    • Whole blood lead concentrations (specimen collection handbook)
     Blood lead concentrations
     Associated outcomes
    <10 mcg/dL (normal)
    >10 mcg/dL
    >25 mcg/dL
    >45 mcg/dL
    >70 mcg/dL
    >100 mcg/dL

    Normal
    Impaired cognitive development (children)
    Anaemia
    GIT symptoms - consider chelation
    CNS symptoms - consider chelation
    Life threatening (encephalopathy, seizures, coma) - chelation

    Treatment

    • Prevention of further lead exposure
      • Patient/family education
    • Blood lead concentration 10 - 45 mcg/dL, patient well
      • Supportive therapy (treat any associated iron deficiency)
      • Recheck blood lead concentration at 1 and 3 months to ensure it is decreasing
      • If concentration not decreasing, consider ongoing exposure and look for source
    • Blood lead concentration > 45 mcg/dL, and/or patient acutely unwell with signs of lead toxicity
    • Notify cases of lead toxicity: online notification.

    Further information

    References

    Immigrant health resources. Authors: Dr Anthea Rhodes and Dr Georgie Paxton. Initial April 2012. Last review May 2015. Contact: georgia.paxton@rch.org.au