Excessive Lead Exposure - CDCG
| Version | Date | Changes |
|---|---|---|
| 1.0 | December 2014 | Full revision of guideline. |
| 1.5 | December 2015 | Revision of guideline. |
| 2.0 | July 2017 | Revision of guideline. |
Infectious Agent
Not applicable.
Notification Criteria
Notifications of excessive lead exposure may arise from occupational and non-occupational settings.
Laboratory definitive evidence
Demonstration of a blood lead level of 0.24 µmol/L (~5 µg/dL) and greater.
Laboratory suggestive evidence
Not applicable.
Clinical evidence
Not applicable.
Community Outbreak Criteria
Not applicable.
Notification Procedure
Pathology laboratories
To notify on diagnosis of blood lead level that meets the notification criteria of 0.24 µmol/L (~5 µg/dL) and greater.
Following the notification of the elevated blood lead level by the pathology laboratory, the procedures outlined in the following document within the Health Protection Operational and Regulatory Toolbox are to be followed:
http://qheps.health.qld.gov.au/ehpom/documents/bloodleadprotocol.pdf (Health staff access only)
Public Health Significance and Occurrence
Exposure to lead can affect the health of children, unborn babies and adults. Children under the age of five are at the greatest risk due to the following:
- the brain in young children is still maturing and appears to be more vulnerable to lead
- the exploratory hand-to-mouth activity of children places them at a higher risk of ingesting lead from a contaminated environment
- very young children absorb a much higher proportion of ingested lead (up to 50 per cent compared to about 10 per cent in adults)
- the intellectual development of children can be affected by exposure to lead.
Clinical Features
Children
Typically asymptomatic unless the blood lead level is significantly elevated. Elevated exposure in early childhood has been found in population-based epidemiological studies to be associated with impaired cognitive development. Reported effects include poor development of motor abilities and memory, reduced attention span, reduced spatial skills, anaemia, poorer performance at school, constipation, abdominal colic and behavioural problems.
Pregnant Women
Exposure to lead while pregnant can result in elevated blood lead levels affecting the unborn baby. Complications from high levels of exposure include premature birth, low birth weight, miscarriage and stillbirth. The baby may also suffer impaired learning and cognitive development.
Adults
Symptoms, if any, depend on the level of exposure. High levels can cause joint and muscle pain, muscle cramps, anaemia, nausea, constipation, colicky abdominal pain, sleep problems, reduced concentration and headaches. At very high levels, lead may cause neuropathy, encephalopathy and convulsions. Prolonged high level exposure to lead can be associated with chronic renal damage many years later.
Reservoir
Not applicable.
Mode of Transmission
Excessive exposure can occur in occupational or non-occupational settings. Routes of exposure include:
- ingestion of lead-based materials eg. paint dust, contaminated soil, lead-based traditional medicines, etc.
- inhalation of lead-based dusts or fumes eg. dust or fumes from sanding or burning of lead-based paint, working in a lead smelter, welding or oxy-cutting of lead-based metals, etc.
Incubation Period
Not applicable. The level and duration of exposure affects time to onset of symptoms and/or identification of an elevated blood lead level.
Period of Communicability
Not applicable.
Susceptibility and Resistance
Not applicable. However, young children absorb ingested lead to a significantly higher degree than older children and adults. Further, children with poor nutrition absorb lead more efficiently from the gut and therefore are more at risk.
Management
Cases
Investigation
The aim of the investigation is to ascertain the source of exposure with the intent of providing advice on how future exposure can be minimised or averted, particularly where there is potential exposure to young children and women who are, or are planning to become, pregnant.
In association with the attending medical practitioner, verify and identify the source of exposure. Consider elevated lead levels in ambient air, paint, soil and dust, water, food, cosmetics, traditional medicines and occupational environments (both current and past).
If exposure is linked to a workplace (such as a shooting range, radiator repairs, battery manufacture) then consideration should be given to discussing the health risks with the exposed person including seeing recommending that he/she consult with his/her medical practitioner.Restriction
Ensure avoidance of further exposure to lead from any source until blood lead level has returned to an acceptable level and the risk of further exposure from the identified source is controlled. The effectiveness of the exposure control measures can be assessed by subsequent monitoring of the person’s blood lead level on a periodic basis.
Counselling
The case/parent/guardian should be advised of the nature of the condition and potential or identified sources of exposure. Advice on how to reduce exposure should be offered.
The case/parent/guardian should be advised to have follow-up testing of the blood lead level to ascertain the effectiveness of implemented exposure control measures.
Contacts
Contact Tracing
Investigate contacts for potential common exposure.
Definition
Any other person who might have been similarly exposed to lead as the case.
Investigation
Advise blood lead testing of any other person, in particular young children, who might have been similarly exposed as the case.
Prophylaxis
Not applicable.
Counselling Anyone with the same history of exposure as the case should be offered advice on how to reduce their exposure to lead and recommended to have their blood lead level measured.
Other control measures
Not applicable.
Community outbreaks/epidemics
Not applicable.
Preventive Measures
Educate community about sources of lead exposure.
Identify sources of exposure and ensure they are adequately controlled, if elimination is not practicable.
Feedback
Feedback should be given to the agency/person who notified the disease (if appropriate).
Summary
Complete the Enhanced Surveillance Form and fax back according to flow chart.