Heavy metals or trace
metals (e.g. cadmium, copper, lead, mercury, and zinc) can pollute water supply
systems through natural deposits, waste discharged from mining, industrial and
agricultural activities. Water contaminated with heavy metals may be unsuitable
for irrigation, human consumption, livestock watering, aquatic ecosystems
protection and recreation and aquaculture. Metal pollution
can harm aquatic organisms through lethal and sub-lethal effects and can reduce
or eliminate species from an ecosystem through increased fish disease or
mortality or decreased fecundity.
Aquatic flora and fauna such as invertebrates (molluscs) and fish can
bioaccumulate heavy metal levels up to a thousand times higher, thereby posing
health risks to human and top predators resulting from eating heavy metal
contaminated aquatic organisms.
Irrigation water may transport dissolved heavy metals to agricultural
fields and accumulate in agricultural soils. The heavy metal transfer from
soils to plants is a key pathway to human health exposure to metal
contamination. ANZECC & ARMCANZ
(2000) has set guideline thresholds for heavy metals in raw water to be
supplied for irrigation, stock and domestic supply and aquaculture. Therefore, monitoring of heavy metals in the
environment is essential to safeguard the health of biota and humans and water
quality.
I : Trial of artificial mussel's technology for monitoring of heavy
metals - pilot study
Until
recently no reliable and time-integrated (continuous) monitoring techniques to
assess heavy metal concentrations in water were available. The ‘Artificial
Mussel' (AM) passive sampling method collects or accumulates pollutants
independently through a diffusion barrier onto a sorbent medium. The current work is part
of ‘global artificial mussels watch program' being run in eight countries
including Australia. The work was undertaken to trial the use of new and innovative
"artificial mussels" technology for heavy metals monitoring in G-MW water
supply systems as a pilot study for the first time in Australia. The ability to deploy and retrieve AMs in selected areas and analyse and interpret
AM results was confirmed for five sites within Goulburn-Murray Water Irrigation
District (including rivers and irrigation channels). AM deployed in waterways had accumulated both
targeted and non-targeted metals. The
targeted metals are cadmium, chromium, copper, mercury, and zinc, and the AMs
also accumulated some non-targeted metals such as iron, cobalt, and nickel.
For further information you can email Golam Kibria.
To download a copy of this study click here (3,159kb)
II: Monitoring of trace Metals in
North and Central
Victorian Waterways, Australia, Using Artificial Mussel (AM) Technology
(G-MW, DPI, Melbourne Water/CAPIM, North Central CMA, City University of Hong Kong and the University of Hong Kong collaboration)
During 2009-10, a monitoring study was conducted across
North and Central Victoria covering Goulburn Murray
Water catchments (GMW), several streams on the peri-urban fringe of Melbourne
managed by Melbourne Water (MW) and several ephemeral streams in the upper Loddon
River catchment managed by North
Central CMA (NCCMA) to assess the risks
posed by micro pollutants such as trace metals. The study used innovative
artificial mussel (AM) passive sampling technology called AM technology (or AM).
AMs deployed in waterways of three catchments (G-MW, MW and NCCMA) accumulated
all or some of the targeted metals (cadmium (Cd), copper (Cu), lead (Pb),
mercury (Hg), and zinc (Zn)). Copper and zinc were detected at most sites
within GMW, MW and NCCMA, however, cadmium, lead and mercury concentrations
were generally below the instrumental detection limits. Comparing the three
catchments, both copper and zinc concentrations in AMs were found at highest
levels at MW sites, lower at GMW sites, and lowest at NCCMA. Overall, the first
year of the study demonstrate the usefulness of using innovative technology
such as AM passive sampling techniques in monitoring metals in various
waterways such as rivers and irrigation channels (G-MW), peri-urban streams
(MW) and ephemeral streams (NCCMA).
For further information you can email Golam
Kibria.
To download a copy of this study click here (705 kb)