NHMRC is responsible for ensuring that Australians receive the best available, evidence-based advice on matters relating to improving health and preventing disease. The NHMRC Strategic Plan 2013-15 includes particular focus on investigating new and emerging health issues, particularly through environmental hazards and changes in the human environment.
Lead is a naturally occurring metal found in the earth’s crust and has a wide variety of uses in manufacturing due to its properties of being soft, malleable and corrosion resistant. Unlike many other naturally found metals, lead and lead compounds are not beneficial or necessary for human health, and can be harmful to the human body. Infants, children and pregnant women are at the greatest risk of harm from lead.
Reducing people’s exposure to lead remains an important health issue in Australia because lead can be found in various sources throughout the environment. NHMRC has reviewed the evidence on the health effects and management of lead exposure in humans. The review has a particular focus on low level lead exposure (blood lead levels less than 10 micrograms per decilitre) as there has been increasing recent evidence suggesting that health effects may occur at blood lead levels lower than previously thought.
NHMRC Statement and Information Paper on the health effects of lead
The NHMRC Statement: Evidence on the Effects of Lead on Human Health was released on 19 May 2015 and was prepared based on the advice of the Council of NHMRC. It provides advice to the community and to policy makers on this issue.
In developing the Statement, the Council of NHMRC considered the findings of a comprehensive independent evaluation of the evidence on the health effects of lead (see Evaluation of evidence related to exposure to lead). The Evidence Review found an association between blood lead levels less than 10 micrograms per decilitre and health effects, including reduced Intelligence Quotient and academic achievement in children, behavioural problems in children, increased blood pressure in adults and a delay in sexual maturation in adolescent boys and girls. However, there is insufficient evidence to conclude that lead at this level caused any of the health effects observed.
The Statement advises that a blood lead level greater than 5 micrograms per decilitre suggests that a person has been, or continues to be, exposed to lead at a level that is above what is considered the average ‘background’ exposure in Australia. If a person has a blood lead level greater than 5 micrograms per decilitre, it is recommended that the source of exposure should be investigated and reduced, particularly if the person is a child or pregnant woman. Identifying and controlling the source of lead exposure will reduce the risk of harm to the individual and to the community.
The accompanying Information Paper: Evidence on the Effects of Lead on Human Health summarises the findings of the Evidence Review and describes the approach taken by NHMRC’s Lead Working Committee to interpret the findings of the Evidence Review. The Information Paper also provides information on testing individuals for exposure to lead and the available evidence on managing individual exposure to lead.
Before being finalised, the Draft Information Paper: Evidence on the Effects of Lead on Human Health was open for public consultation from 16 July until 15 September 2014. The draft Information Paper was also considered by expert reviewers in the fields of environmental health, epidemiology and paediatrics. During the public consultation period, seven public consultation submissions and three expert reviewer comments were received. The Lead Working Committee gave due regard to all submissions and, over several meetings, carefully considered the issues that were raised.
Details of key issues that were raised during public consultation and expert review can be found in the Public Consultation: Summary of Key Issues and Expert Review: Summary of Key Issues. Non-confidential public submissions are available on the NHMRC Public Consultations website.
Evaluation of evidence related to exposure to lead
The NHMRC Statement and Information Paper are based on the findings of a comprehensive evaluation of the evidence on the health effects of lead, conducted by the Cochrane Public Health Group at the University of Melbourne. The final report of the review, titled Evaluation of evidence related to exposure to lead was completed in February 2014 and released as a background document to accompany the draft Information Paper during public consultation. The evidence review comprises:
- a non systematic review of the literature examining the health effects of exposure to lead; routes of lead exposure in non-endemic areas; clinical indicators for testing for exposure to lead; blood markers; availability and accuracy of testing for exposure to lead; and management strategies to reduce exposure to lead at an individual and at a population level;
- an overview of evidence (i.e. a systematic review of systematic reviews) of health effects associated with blood lead levels (i) less than 5 micrograms per decilitre and (ii) 5 to 10 micrograms per decilitre in children and adults; and
- a systematic review of evidence for the effectiveness of strategies for reducing blood lead levels in children and adults in non-endemic lead environments.
NHMRC Lead Working Committee
NHMRC’s Lead Working Committee was established in 2012 to consider the available evidence on lead toxicity and management strategies for minimising individual exposure to lead. The Lead Working Committee comprises jurisdictional representatives, clinicians, public health, environmental health and toxicology experts as well as a consumer representative.
The Lead Working Committee assisted the NHMRC in developing the scope of the Evidence Review and interpreting its findings to develop the Information Paper. The Lead Working Committee also considered all of the public consultation submissions and feedback received from the expert reviewers.
Further details on the development of the NHMRC Statement, Information Paper and background documents can be found in the NHMRC Administrative Report - NHMRC Information Paper: Evidence on the Effects of Lead on Human Health.
NHMRC has also developed a Frequently Asked Questions resource containing practical information that people can consider to reduce their risk of lead exposure.
For further information please contact NHMRC at firstname.lastname@example.org.