Lead poisoning



Last Review Date: December 30, 2018


What is it?

Lead poisoning is a preventable condition that results from environmental exposure to lead. This exposure can result in permanent health damage, especially among children.

Lead poisoning can affect almost all parts of the body, including the central nervous system, kidneys and reproductive organs. It commonly causes weakness and abdominal discomfort and less often causes abdominal pain, vomiting, constipation, foot and wrist drop and anaemia. In children especially, it impairs cognitive development, which can lead to learning disabilities and behavioural problems. At very high levels, it can even result in hallucinations, coma, seizures, and death.

Much lead exposure comes from inhaling or ingesting deteriorated paint containing lead found in older houses. Even household dust and soil can be contaminated with lead from paint chips, and children are especially vulnerable as they tend to put a lot of things in their mouth. As poisoning from lead became known as a problem, lead began to be removed from paint products and unleaded petrol was introduced. Following these and other measures, there has been a significant reduction in blood lead concentrations in the general population of Australia and many other countries.

Several work settings and certain hobbies may expose people to potentially high levels of lead:

Work Settings

  • lead smelting plants
  • construction work
  • painters
  • steel welding
  • bridge reconstruction
  • firing range instructors and cleaners
  • remodelling and renovating older houses
  • foundry work
  • scrap metal and battery recycling
  • car repair work
  • cable splicing
  • battery, glass and ceramic ware manufacture.

In Australia, it is a requirement that many workers be regularly monitored for lead poisoning.

Hobbies

  • casting bullets, lead shot or fishing sinkers
  • home remodelling
  • target shooting at firing ranges
  • lead soldering
  • car repair work
  • stained glass work, and
  • glazed pottery work.

Tests for lead poisoning

A simple blood lead test can be done to detect the level of lead in your body. Sometimes a second test, called a zinc protoporphyrin (ZPP) test, is requested in place of a blood lead test if the lead test is not available, or requested along with the blood test. The ZPP result increases when lead interferes with red blood cell’s ability to make haemoglobin. Some experts question the value of ordering both tests at once and the ZPP test is not reliable for screening children for lead poisoning.

The National Health and Medical Research Council in Australia has updated its information and policies regarding the effect of lead on human health. Average blood lead levels in the Australian population have fallen and the NHMRC now regards any blood lead level above 5 µg/dL (0.24µmol/L) in people who have no occupational exposure as abnormal. Affected people should be investigated to discover the source of the lead exposure.

In environments where lead is endemic, e.g. in communities where lead is mined or smelted, environmental aspects of lead are considered by enHealth (The Environmental Health Standing Committee—a subcommittee of the Australian Health Protection Principal Committee) which reports to the Australian Health Ministers’ Advisory Council.


Treatment

Depending on the results of the blood lead test, treatment may involve efforts to reduce exposure to lead, such as by wet mopping living areas frequently. Lead abatement is the process of methodically removing lead paint or other lead sources from a building or area. Workers exposed to lead in their jobs may have to wear respirators. If lead is still building up in their bodies, they may be transferred to a low-lead job, a procedure called medical removal. Abatement at the work site may be required if blood lead levels are very high among employees.

Chelation therapy is a last resort treatment to rid the body of high amounts of lead. Chelation involves giving the affected person a chemical, which lead will preferentially bind to, that then will be excreted in the urine. Sodium calcium edetate is effective but has to be given into a vein. Dimercaptosuccinic acid has the advantage that it can be given by mouth and is often used in small children. Chelation treatment can be dangerous, however, because the chemical-lead combination can damage kidneys.

For more information about lead poisoning, see the links on Related Pages


Related pages

On this site:
Tests: Lead; zinc protoporphyrin

Elsewhere on the web:
NHMRC Statement and Information Paper (2015): Evidence on the effects of lead on human health
NHMRC: Managing individual exposure to lead in Australia- a guide for health practitioners (2016)
Better Health Channel: Lead exposure and your health
Women's and Children's Health Network (SA): Eating things that are not food-pica
Centers for Disease Control and Prevention: Screening Young Children for Lead Poisoning (US)
CDC’s Lead Poisoning Prevention Program