Air quality fact sheet
Department of the Environment and Heritage, 2005
Lead is a soft metal that is found in air in the form of very small particles. Lead can get into the air through soil erosion, volcanic eruptions, sea spray and bushfires. The natural concentration of lead in the air is less than 0.1 microgram per cubic metre.
Lead smelters, mining operations, waste incinerators, battery recycling and the production of lead fishing sinkers are other sources of lead in the air. Because many older houses were painted with lead-based paint, lead from unsafe house renovations can be an important source of lead indoors and builders and renovators need to be aware of the dangers. Further information about lead in paint is available in the Department's publication 'Six Step Guide to Painting Your Home'.
Lead used to be added to petrol and this was the source of high levels of lead in the air of major cities. Significant reductions in the levels of air-borne lead were achieved over recent years as the result of national legislation introduced to remove lead from petrol. (For more detail, refer to: Diesel Fuel Quality Standard.)
Lead is absorbed if dust or fumes that contain lead are swallowed or breathed in. Although small amounts of lead do not cause any specific symptoms, as much as 10% of the lead that enters an adult's body stays there, and so even small amounts can gradually build up in the body.
Large amounts of lead in the body can cause pain in joints and muscles. Other symptoms of lead exposure include anaemia, nausea, gastric problems, sleep problems, concentration problems, headaches, and high blood pressure. In children, the symptoms of lead exposure can be poor development of motor abilities and memory, reduced attention span, and colic and gastric problems.
Small children and unborn babies are most at risk because they are smaller and their bodies are still growing and developing. They also store in their bodies as much as 50% of the lead that they swallow. In addition, children can be exposed to more lead than adults because they swallow more dust from their hands and toys.
Any amount of lead can be a health risk for pregnant woman because the unborn baby is exposed to lead in the mother's blood. A large amount of lead in the mother's body can cause premature birth, low birth weight, or even miscarriage or stillbirth.
There has been less and less lead in Australia's air since the introduction of unleaded petrol in 1986. Lead levels in major cities and towns are now very low, in some instances less than 10% of the level specified in the national air quality standard. Lead remains a problem where smelters are located close to urban areas and the national standard is still exceeded on occasions in these locations.
Because lead is heavy, 80% of it does not stay in the atmosphere for very long, so most lead is found close to where it was produced. For example, lead can still be found in soil close to roads and in the ceiling dust of older houses.
Because of the significant health impacts of high levels of lead, the Australian Government has taken steps to manage and reduce the amount of lead pollution produced. Most significantly, the Australian Government phased out the sale of leaded petrol nationally by 1 January 2002.
The Australian, State and Territory Governments have also agreed on a National Environment Protection Measure for Ambient Air Quality. The Measure contains national air quality standards for six key air pollutants, including lead. (See factsheet on National Standards for Criteria Air Pollutants in Australia.) The Measure aims to keep the concentration of lead in outdoor air to less than 0.5 micrograms per cubic metre averaged over one year. This goal has already been met across most of Australia as the result of the phasing out of leaded petrol. However, lead in air remains a problem in several locations close to smelters.
Related publications are available from the Community Information Unit of the Department of the Environment and Heritage, phone 1800 803 772. These include the State of the Air Report: Community Summary 1991–2001 and Air Quality fact sheets on:
- National Standards for Criteria Air Pollutants in Australia;
- carbon monoxide, nitrogen dioxide, ozone, particles, sulfur dioxide, air toxics;
- woodheaters and woodsmoke; and
- smoke from biomass burning
See also our website at Chemicals management.
Fact sheets on other lead issues such as lead in house paints, ceramics and pottery are also available from the Department's website (www.environment.gov.au/publications) and from the Community Information Unit.