Airborne lead
Health effects of lead
Air quality standard
Measuring lead concentrations
Lead is a heavy metal which can exist as an air pollutant in the form of vapour or as particles. In recent decades the dominant source of lead exposure to humans has been from emissions of motor vehicles operating on leaded petrol.
Many houses built before the 1970s may have been painted with paints containing lead. If you are renovating, repainting or living in a house that may contain lead paint the department can send you a guide about what precautions to take to protect your family.
Mining, casting and other industrial processes also contribute lead emissions to the atmosphere.
Health effects of lead
Lead occurs naturally in small quantities in the air, water and soil. Humans can inhale lead particles or ingest lead via the food and water we consume. Although lead can enter the body in a number of ways people living in urban areas are most likely to ingest it by inhaling airborne particles containing lead. Lead can be found in all tissues of the body and tends to accumulate in the bones where it is immobilised. Ingested lead is only slowly eliminated by the liver and kidneys.
Lead effects the human central nervous system. In young children, lead can impair neurological and intellectual development and can cause learning difficulties. In older people lead can cause high blood pressure and (in high concentrations) kidney disease or anaemia.
Air quality standard
Symptoms of lead exposure have not been observed at blood lead concentrations below 0.1 µg/mL. For the protection of human health the EPP 2008 (Air) goal for airborne lead is now set at 0.5 µg/m3 (0.0000005 grams per cubic metre of air) based on annual average time to take account of the slow rate of excretion from the body. This level is considered low enough to maintain blood lead levels below 0.1 µg/ml.
In the past the major source of lead in most areas of Queensland was from emissions of motor vehicles operating on leaded petrol. The phase out of the sale of leaded petrol in Queensland was completed by March 2001. The introduction of unleaded petrol in the mid-1980s and continued reductions in the lead content of leaded petrol have resulted in decreased lead concentrations in Queensland in the last two decades (see graph). Lead levels in Queensland are now less than 0.02 microgram per cubic metre even next to major roads.
Measuring Lead
Airborne lead is part of the particulate matter collected by TSP and PM10 high-volume air samplers. The particulate matter is collected on a filter paper by the sampler. The lead concentration in the sample is determined by performing a chemical analysis on the filter paper.
Last updated: 15 May 2009