Newcastle’s toxic legacy: soil metals and hydrocarbons pose health risk

25 January 2017

  • Contaminating metals and hydrocarbons could be posing a significant health risk to residents of the industrial city of Newcastle
  • Lead was found to be the most common contaminant in the city and exceeded Australian Health Investigation Levels in 88 per cent of private residency soils
  • Dangerous polycyclic aromatic hydrocarbons were also detected in the city’s soils

Contaminating metals and hydrocarbons could be posing a significant potential health risk to residents of the industrial city of Newcastle a study from Macquarie University has found.

The study found that the most abundant metal contaminant found in the city’s soil was lead, which was found to exceed Australian Health Investigation Levels (HIL) in 88 per cent of private residency soils.

“We found evidence indicating that the city’s historic copper and steel industries contributed to most of the measured soil contaminants, mainly by being spread though atmospheric dust and when slag waste, a by-product of the metal mining process, was used as filling material in mining areas,” explained Paul Harvey, lead author on the study.

The findings also indicate that the lead in the soils around Newcastle is highly ‘bio-accessible’, meaning that it could be readily absorbed by our intestines.

“Using simulated gastric fluid, much like that found in our own stomachs, we saw that the lead in Newcastle’s soils was very easily taken up by these liquids. Around 45 per cent of the lead in these soils was able to be turned into a form that could potentially be absorbed by our bodies,” said Professor Mark Taylor, who oversaw the research project.

In addition to the metals, the researchers also tested for polycyclic aromatic hydrocarbon (PAH) compounds, discovering the presence of the carcinogenic compound benzo(a)pyrene in soils across the city, as well as other types of PAHs, which were found to exceed HIL guidelines in a number of regions.

“While we have strong evidence linking the presence of contaminating metals in Newcastle’s soils to the city’s legacy industrial activities, the source of these other PAH contaminants is still unclear. They could be present due to steel manufacturing and coal transport practices, as well as incomplete combustion of motor vehicle emissions,” said Professor Taylor.

The authors warn that the PAHs in the Newcastle soil environment, combined with the metal contaminants, is likely to generate a significant burden of disease to residents.

“Regardless of whether we know where the contaminants have come from, this study and others like it, are helping close the knowledge gap when it comes to soil contaminants, and highlight potential environmental contamination risks associated with living in an industrial city,” concluded Harvey.

Harvey, P J; Rouillon, M; Dong, C; Ettler, V; Handley, H K; Taylor, M P; Tyson, E;Tennant, P; Telfer, V; Trinh, R. Geochemical sources, forms and phases of soil contamination in an industrial city. Science of the Total Environment. January 2016.

Filed under: Research Science & nature