Identification and measurement of contemporary sources and exposure risks from lead emissions and depositions in Australia

Lead emissions in Australia have been occurring for almost two centuries. In that time, environmental quality and human health have been greatly affected. As a result, lead contaminated soils are widespread in Australian urban and industrial locations and lead emissions are ongoing in lead industrial locations. The removal of primary sources, leaded petrol and paint, as well as the decline in blood lead levels in mining and smelting communities has led to complacency that much of the problem has been resolved. However, elevated childhood blood lead levels are still being measured in lead towns. Despite the global abundance of studies on environmental lead sources, emissions and human health consequences, relatively little research has been undertaken in Australia following the removal of lead from petrol in 2002. In light of this knowledge gap, this thesis includes twelve papers that present research into the current state of lead emissions in Australia. The papers address multiple and interconnecting aspects of lead emissions: identification of major sources emitting large volumes; measurement of lead in the environment and ongoing exposures; the impacts on the environment and consequences to human health. Additionally, this thesis examines the role of regulations and guidelines in protecting children from the harmful effects relating to the toxicity of lead. The outcome of the studies in this thesis demonstrate that environmental lead emissions, depositions and exposures remain a cause for serious public health concern in Australia. Current lead emissions from mining and smelting operations continue to expose children to dangerous levels of toxic metals that result in blood lead levels above current guideline values. Quantification of lead emitted from petrol, at a quarter million tonnes, has revealed the enormity of this legacy source, even in relation to mining and smelting emissions. Although petrol emissions form an historical source, the findings in this thesis reveal its impact prevails in the environment. By providing a contemporary analysis on the issue of lead emissions, this thesis demonstrates that reliance on outdated regulations and guidelines are ineffective at reducing exposure to both historic and ongoing lead emissions in Australia. Therefore, in light of the globally accepted paradigm that there is no safe level of lead exposure, this thesis highlights the urgent need to revise existing strategies and regulations to limit preventable exposures.