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soil analysis

Industrial contamination

in Australia’s backyards Industrialisation has left much of the urban environment contaminated with a variety of heavy metals, chemicals and pesticide residues. Macquarie University researchers have produced a series of maps that plot the concentrations of metal pollutants across cities like Sydney and Darwin, and towns such as Mount Isa and Port Pirie.

R

esults of the survey

The latest portable X-ray fluorescence

companies needing to determine what materi-

indicate the spread of

(pXRF) analysers, such as the Delta Pre-

contamination in many

mium from Olympus, have been developed

Macquarie researcher Marek Rouillon has

ways reflected the growth

specifically for complete environmental in-

been working to evaluate the reliability and

of major cities, with the

vestigations of metal contaminants in a wide

repeatability of XRF analysis on environmen-

als are in waste products,” he said.

highest concentrations

range of industrial and domestic materials.

tal samples. Professor Taylor and Rouillon

in older suburbs. The contaminant of most

The high-power, high-performance, rugged

regularly present their findings at seminars,

concern across Sydney backyards is lead.

unit allows in situ analysis in a wide range

outlining the spread of heavy metal contami-

It would be expected that there would be

of harsh environments from remote mining

nation in suburban gardens in addition to

contamination in a major city, explained the

and exploration sites to backyards in major

explaining the application and relevance of

director of the Macquarie team, Professor

urban centres.

the pXRF instrument for this project.

Mark Taylor. “We live in an industrial envi-

The latest model Delta unit offers in-

Typical ‘natural’ or ‘background’ con-

ronment. We have used lead-based petrol

creased speed and improved sensitivity.

centrations of lead for the Sydney region

and paint for most of the 20th century.”

It also lowers the limit of detection (LOD)

are in the range 20–30 mg/kg or parts per

for challenging elements such as cadmium,

million (ppm). However, due to the intense

barium, lead, mercury and tin.

use of lead-containing products, much of

One technique for measuring levels of contaminant metals that is key to the work being conducted by the Macquarie team is

According to Andrew Saliba, regional

Greater Sydney has been contaminated with

X-ray fluorescence spectrometry (XRF). Sim-

sales specialist with Olympus, the traditional

the metal. Their results indicate Sydney

ple screening for toxic metals is performed

use of pXRF has been for alloy identification,

residences have a mean soil lead concentra-

by placing an analyser directly onto soil or

grading ore, mineral exploration, metallurgy

tion of 220 mg/kg, which is approximately

dust. The analyser provides detection of

and mine site remediation. “The technology

10 times the typical natural background for

metals for site characterisation, contamina-

has been refined and is now often used by

Sydney’s soils and rocks.

tion tracking, remediation monitoring and

environmental consultancies specialising in

In 2012, the Centres for Disease Control

property evaluations.

contaminated land remediation and recycling

and Prevention in the USA stated that there

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Sustainability Matters is a bi-monthly magazine showcasing the latest products, technology and sustainable solutions for industry, governmen...