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University of Wollongong Thesis Collections
University of Wollongong Thesis Collection
University of Wollongong Year
Trace metal contamination of soils and
sediments in the Port Kembla area, New
South Wales, Australia
Yasaman JafariUniversity of Wollongong
Jafari, Yasaman, Trace metal contamination of soils and sediments in the Port Kem-bla area, New South Wales, Australia, Master of Environmental Science - Research thesis,School of Earth & Environmental Sciences - Faculty of Science, University of Wollongong,2009. http://ro.uow.edu.au/theses/3133
This paper is posted at Research Online.
10
Chapter 2
Literature Review
2.1 Historical Development of Industry in the Illawarra Region:
In order to obtain an outlook on the possible sources of trace metal pollution in the Lake
Illawarra catchment, historical record of industrial activity within a 5-10 km radius from the
lake’s perimeter was garnered from Depers (1992) and Yassini et al. (1992).
Based on Depers (1992) and Yassini et al. (1992), there were five phases of anthropogenic
development from 1817 to 1992 in the area. The first anthropogenic activity occurred
between 1817 and 1896 and produced particulate material emissions (mainly carbonaceous
ash) prior to industrial development. During this period of time wheat farming and two
flour mills were operating in the region, however rusting of machinery changed the farming
practices to dairying. Also clearing and burning of the natural vegetation produced the first
significant particulate emissions in the area. In 1887 the railway line between Wollongong
and Dapto was completed, with trains being fuelled by locally produced coal and coke.
In 1876 the first coke ovens operating at Wollongong Harbour were established and in 1888
the Australian Coke Company established a large coke works at Unanderra, 3.5 km from
the lake. The latter company had 54 beehive structures that produced 300-400 tonnes of
coke per week (Bayley, 1963). Other sources of particulate emissions were the Mount
Pleasant Coke Works and the Wollongong Gas Works, both located in North Wollongong
(Smith, 2001).
Coal mining began within the lake’s catchment area at Mount Kembla in 1883. Other
collieries established in this period were Southern Coal Co. in 1888, South Kembla in 1888
and Tongarra near Macquarie Pass in 1893 The coal most probably was used in small
industries at Albion Park and elsewhere, e.g., the Tongarra creamery and for domestic fuel-
fired stoves and ovens. The burning dumps also created particulate material emissions, with
the by-product being coke. It was, therefore, by accident that the local coal was discovered
11
to produce a strong coke, suitable for industrial use (Depers, 1992; Yassini et al., 1992: 10-
11).
The second phase of industrial development in the area came about between 1896 and
1910. In 1896 the Smelting Company of Australia Ltd established a Pb-Zn-Cu-Ni sulphide
ore smelting plant on the western shore of Lake Illawarra. Sulphide ore from a variety of
mines was used while coal was used on site to fuel the boilers and the small power station
located there. The refining plant was closed in 1906 and moved to Port Kembla, where it
was later used by the Electrolytic Refining and Smelting Company of Australia Ltd. In
1899, the Mount Lyell Coke Works was established at Port Kembla, where coke was
produced and exported to Tasmania (Depers, 1992; Yassini et al., 1992).
The third phase from 1910 to 1954 is considered as a period of rapid industrial expansion in
the Port Kembla area. The base metal (Cu) refining plant was reopened in 1910, metal
Manufactures Ltd. commenced operation in 1918 and Australian Fertilizer Ltd began
producing superphosphate in 1921. Several other major industries were also opened during
this time. Many of the previously built coke works were demolished and a new coke battery
was built in 1910 at North Wollongong. Two steel strip mills were constructed during this
time, the first opening in 1936 at John Lysaghts (Aust.) Ltd and the second at the
Commonwealth Rolling Mills in 1939 (Depers, 1992; Yassini et al., 1992).
A power station was raised at Port Kembla in 1913 and fuelled by local coal supplies.
Wongawilli Coke Works was constructed in 1917 in the west, within the lake’s catchment.
It comprised six ovens initially and was expanded to 120 ovens by 1927 and was the largest
beehive type coke oven battery in NSW at the time. The coke was primarily sent by railway
to Lithgow, but when G and C Hoskins moved their Lithgow plant to Port Kembla in 1927,
the Wongawilli coke works became the main source of coke for the new steelworks
(Depers, 1992; Yassini et al., 1992).
In 1928 Australian Iron and Steel Pty Ltd (AIS) was opened, the no.2 blast furnace was
commissioned in 1938 and the no.3 in 1953. With the very rapid expansion of AIS Pty Ltd,
12
the no.1 power station was commissioned in June 1928. With the closure of the Lithgow
Works during the depression, equipment was transferred to the Port Kembla site (Anon
1969; Depers, 1992; Yassini et al., 1992). The production of pig iron increased gradually
from 130 000 tons in 1929 to 773 000 tons in 1953, the steel ingot production rose from 59
000 tons to 808 000 tons; however there was decreased production during the depression
and World War ІІ (Hughes, 1964; Depers, 1992; Yassini et al., 1992).
The Wongawilli Coke Works was closed in 1954, due to the age of structures and AIS Pty
Ltd installed its first battery of seventy two Wilputte by-product coke ovens in 1938. Forty
eight more ovens were commissioned in 1950 and another 24 ovens were commissioned
three years later (Hughes, 1964; Anon, 1969; Southern, 1978).
The fourth phase of industrial activity within the region occurred from 1954 to 1989 with
the commissioning of the Tallawarra Power Station in late 1954. Coal was initially supplied
from the Tongarra mine till 1955, when coal was sourced from the Huntley Colliery. In
1961 and 1962 two 100 MW generators were commissioned, however, the Tallawarra
Power Station was decommissioned in 1989 (Bayley, 1959; Depers, 1992; Yassini et al.,
1992).
The Port Kembla Power Station was decommissioned in 1963, followed by the closure of
the Federal Coke Works in 1971 and the Mount Pleasant Coke Works in 1978. In 1959 the
Commonwealth Steel Company commenced operations to cater for the demand for
specialized steel. AIS Pty Ltd continued to expand operations by commissioning 96 coke
oven batteries in 1960 and a further 66 ovens in 1966 (Anon, 1969; Depers, 1992; Yassini
et al., 1992).
The fifth phase between 1989 and 2009 includes companies and industries which have
continued operations within the region. These include BHP Billiton-Steel International
Group, Slab and Plate Products Division (formerly AIS Pty Ltd and Commonwealth Steel
Co. Ltd); Incitec Ltd (formerly Australian Fertilizers Ltd.); Port Kembla Copper (formerly
13
Southern Copper ERS Ltd which was decommissioned in August 2003); John Lysaghts
(Aust.) and the Port Kembla Coal Loading Facility.
2.2 Selected studies of trace metal pollution and bioavailability on soils from
Australian and worldwide:
Soil is considered as an important and precious resource which supports and provides the
basis of all human and animal life. It is a very valuable and significant component of the
biosphere, acting as a natural buffer for the transport of chemical substances into the
atmosphere, hydrosphere and biota (Pacheco, 1999). Trace metals as naturally occurring
elements, could be dispersed in the environment by natural processes such as weathering of
the Earth’s surface and volcanic activity (Fernandez et al., 2001). Since the industrial
revolution, the soil environment has been used as a site for trace metal deposition and
accumulation, specifically acting as a chemical sink for toxic and hazardous wastes
(Pacheco, 1999). Some trace elements like Cu, Zn, As, Cd and Pb arise from various
industrial activities and waste products like tailing dams, emissions from metal processing
factories, oil combustion and power stations. Also urban and agricultural pollutants which
result from utilization of leaded petrol, lead based paints and utilization of fertilizers could
add to the metal concentrations in the environment (Pacheco, 1999; Fernandez et al., 2001).
Due to the possible health risks trace elements pose to humans, many communities have
become increasingly concerned by environmental soil pollution in relation to their daily
lives (Tiller, 1992; Fernandez et al., 2001). Government agencies have given more
significant attention to soil, considering its role as a repository of much pollution, as a
transmitter of undesirable materials to the groundwater and as a supplier of contaminants to
crops (Tiller, 1992). In Australia, public attitudes toward environmental issues had changed
slowly relative to North America and Europe, but they have shifted rapidly to higher levels
of concern during recent decades. Pollution rates in Australian cities would be expected to
be at lower levels than in European ones, but the upsurge of environmental pollution since
the industrial revolution has obviously caused significant pollution of major Australian
urban centres (Tiller, 1992).
14
2.2.1 Soil Formation:
Factors controlling the derivation of soils are divided into three components; lithogenic,
pedogenic and anthropogenic (Pacheco, 1999). Lithogenic soils are directly associated with
parent material, inherited from the lithosphere. The pedogenic component of soil includes
the concentration and distribution of materials resulting from natural weathering processes,
lithospheric and anthropogenic sources. Anthropogenic elements in soils are deposited
directly onto the soil as a result of human activities (Pacheco, 1999).
2.2.2 Background Trace Metal Concentrations:
Environmental and health authorities, in defining a yardstick to determine what levels of
soil contamination needs investigation, tend to use ‘normal’ background concentration
which monitors the amount of contamination in everyday life by most of the population.
These ‘normal’ background concentrations have been considered as contaminants scattered
by wind and water transport which are superimposed on the natural geochemical
contribution from rocks and sediments (Tiller, 1992). In previous studies, background
concentrations of some trace metals have been estimated using soil samples from non-
industrial and pristine areas or samples developed directly from parent rocks (Beavington,
1975; Tiller, 1992; Martley et al., 2004; Kachenko and Singh, 2006). Based on these
investigations background amounts of some trace metals in New South Wales are listed in
Table 2.1.
Table 2.1: Background concentrations of trace metals in surface soils from non-industrial sites in New South Wales.
Trace metal Concentration ranges(ppm)
As <0.3-11
Cd <0.05-0.7
Cr 1.3-380
Cu 2.1-72
Pb 2.7-170
Mn 20-3300
Ni <0.05-180
Zn 2.1-450
15
2.2.3 Sources of Urban Soil Contamination:
Urban environments have been influenced by a range of contaminants which pose different
impacts within and between different cities. Trace metals in urban soils have been
considered as useful tracers of environmental pollution (Tiller, 1992; Manta et al., 2002).
The various industries and land uses associated with soil contamination have been
summarized in Table 2.2 (Tiller, 1992).
Table 2.2: Sources of trace metal pollution in soils from (Tiller, 1992).
Acid/alkali plant and formulation Metal treatment
Airports Mining and extractive industries
Asbestos production and disposal Oil production and storage
Chemicals manufacture and formulation Paint formulation and manufacture
Defence works Pesticide manufacture and formulation
Drum re-conditioning works Pharmaceutical manufacture and formulation
Dry cleaning establishments Power stations
Electrical manufacturing Railway yards
Electroplating and heat treatment premises Scrap yards
Engine works Service stations
Explosive industry Tanning and associated trades
Gas works Waste storage and treatment
Iron and steel works Wood preservation
Land fill sites
2.2.4 Trace Metal Concentrations and Sources in Soils of the Port Kembla Area:
Anthropogenic emissions of metals from industrial sources such as smelters are an
international problem, but there is limited published information in Australia.
Beavington (1973) examined contamination of the Illawarra region by investigating Cu, Zn,
Cd and Pb levels in soils using acetic acid and EDTA extractions. The levels of these
metals were estimated at about up to ten times greater than those in rural control areas. A
significant concentration was observed in the Port Kembla area. The contaminants
accumulated in the surface horizons of the soils, indicating an airborne origin.
Using Pb isotopes, Chiaradia et al. (1997) identified historical Pb pollution in the roof dust
and recent lake sediments of the Illawarra region, indicating four major sources of
anthropogenic pollution and one natural source of Pb in the lagoon. The suggested
16
anthropogenic sources were an old disbanded base-metal lead smelter at Kanahooka, the
copper smelter, gasoline-air derived Pb and industries utilizing coal such as a thermal coal-
fired power station, while the natural source consisted of Permian rocks cropping out in the
catchment area (Chiaradia et al., 1997).
The long term environmental effects associated with modern development were assessed by
analysing the amount of Cu, Zn, Ni and Pb of the soil of the environment at and around an
abandoned Pb smelter located at Kanahooka, south of Wollongong (Pacheco et al., 2009, in
prep). Also the relatively wide dispersal of contaminants around the smelter site at
Kanahooka indicated that the main mechanism of trace metal dispersal was atmospheric
transportation and fallout (Pacheco, 1999).
In previous studies in the Illawarra region (Beavington, 1973; Chiaradia et al., 1997;
Chenhall et al., 2001) it was suggested that the Port Kembla copper smelter has been the
major source of metals to the surrounding environment. Therefore, a comprehensive
investigation on the regional metal distribution in soils (0-5 and 5-20 cm) in the vicinity of
the industrial complex in the Port Kembla area was done by Martley et al. (2004). Elevated
levels of Cu and As were mainly observed within 4 km from the industrial complex but
some Cu and As concentrations in the soils were probably related to the composition of the
parent rock. Moreover, there were no obvious differences of metal concentrations at depth
of 0-5 and 5-20 cm, except for Pb and Zn.
Overall, Port Kembla industries comprising the steelworks, closed copper smelter and other
associated industries seem to have contaminated the surrounding soils to a distance of 1-13
km depending on the element, but most likely to < 4 km (Beavington, 1973; Pacheco, 1999;
Martley et al., 2004; Kachenko and Singh, 2006). Also the extent of the pollution depends
on various factors such as the size and duration of the industrial operation, atmospheric
conditions, height of the stack, the amount of metals released to the atmosphere, physical
and chemical properties of the emitted particles and the sensitivity of detection of low metal
contamination which depends on factors like natural heterogeneity of metals in the soil, soil
properties, presence of multiple sources (Pacheco, 1999; Martley et al., 2004). In high
population density regions, the determination of fallout patterns around the smelter areas
may be complicated due to superimposed pollution from other industrial sources, car
exhaust fumes, urbanization and soil disturbance, thus many reports accentuate strong
17
dependence of fallout on distance from the smelter and climatic conditions (Tiller et al.,
1975). Rapid urbanization and agricultural activities could be considered as other lesser
sources of metal pollution in the area (Smith, 2001).
Before 1970s, no severe environmental pollution control measures were enforced in ore
handling or dust/ash distribution, so this resulted in extremely high contamination around
the area (Pacheco, 1999).
2.2.5 World-wide Contamination from Smelting Activities:
Smelting complexes are associated with anthropogenic metal pollution and release large
amounts of trace metals into the surrounding environments. These areas definitely become
vulnerable to the direct contribution of waste through slag, accidental spillage from
transportation, processing and refining in addition to fume, ash and dust released through a
smelter stack. Emissions from a stack could be transported through the atmosphere before
settling as particulate matter, thus affecting both close to and at great distances away form
the point source (Pacheco, 1999).
Due to the potential health risks posed by trace metals to humans, significant concern and
interest has focused on the impact of trace elements associated with smelter activities in
residential and agricultural soils (Fernandez et al., 2001).
Trace metal investigations in soils surrounding the Port Pirie Pb smelter, South Australia,
indicated that widespread dispersal of EDTA-extractable Zn, Cd and Pb in the area with
decline in concentration with increasing distance from the smelter. In close proximity to the
site, the fallout was consistent with surface winds, while major contaminants depend upon
the meteorology and topography of the region. Further, the Pb/Cd and Zn/Cd ratios in soils
decrease with distance from the smelter, indicating that over short distances soil
contamination resulted from the fallout of particulate emissions. Beyond about 15 km trace
metals would probably be dispersed mainly as aerosols. Also it was concluded that soil
leaching was negligible due to the high alkalinity, thus metal availability to plants was
relatively low (Cartwright et al., 1976).
Housedusts and garden soils were taken from an area of 2 km2 covering grounds and
surrounding residential areas near a secondary Pb smelter situated south-west of the Czech
capital, Prague, and analysed for concentrations of Pb, Zn, Cu, Cd, As and Hg (Rieuwerts
18
et al., 1999). Contour maps derived from the grid data suggested notable contamination in
the area with the maximum Pb concentrations of 58500 µg/g, particularly downwind of the
smelter grounds. Also there were no significant correlations between metal levels in garden
soils and housedusts while notable correlations were observed with distance from the
smelter; garden soil metal concentrations against each other; housedust metal
concentrations against each other; and house age against garden soil metal concentrations
(Rieuwerts et al., 1999).
A preliminary survey of metal concentrations was undertaken in the town of Zlatna, in
western Romania which is dominated by a large Cu smelter (Pope et al., 2005). Levels of
the elements Cu, Zn, Cd, As and Pb in soils and vegetables of the area were measured.
Concentrations of trace metals in the soils in Zlatna were significantly high and exceeded a
number of soil guideline values. Also the soils seemed to be phytotoxic, with toxic
elements entering the food chain. Lead and cadmium intake by people from home grown
vegetables and other diet sources may be high and needs further investigation. Trace
element concentrations in the area and in school grounds in particular, could cause a
concern from a children’s health perspective. The metal levels at five sampling sites in the
grounds were unacceptably high, especially when taking into account the amount of time
children spend in the school, the vulnerability of the exposed population, its close
proximity to the smelter and children’s activities in the area like digging around in the dirt
leading to ingestion and skin contact (Pope et al., 2005).
2.2.6 Trace Metal Extractability and Bioavailability in Soils:
Trace metals in soils and sediments may exist in various chemical forms. In unpolluted
soils or sediments trace metals have been found to bind to silicates and primary minerals
forming relatively immobile species, while in polluted areas trace metals are generally
more mobile and bound to other soil or sediment phases(Rauret, 1998). From an
environmental point of view, determination of the different ways of binding provides more
information on trace metal mobility and also bioavailability and toxicity. To do this,
various approaches have been used for soil and sediment analysis, many of them focused
on pollutant desorption from the solid phase; others aimed to detect the pollutant adsorption
from a solution by the solid phase. There are two types of extraction: (single and sequential
19
extraction methods) widely used in soil science. Single extraction procedures usually
dissolve a phase whose elemental content is associated with the availability of the element
to plants. Such extraction methods are well designed for major elements and nutrients as
well as studies of fertility and quality of crops, to predict the uptake of essential elements,
to diagnose deficiency or excess of one element in a soil and studies of the physical-
chemical behaviour of elements in soils (Rauret, 1998). To a lesser extent they are applied
to determine trace and trace metal pollutants. The use of these extraction procedures is
mainly focused on the potential availability and mobility of pollutants for both soil-plant
transfer and metal migration in a soil profile, which are usually connected with
groundwater problems (Rauret, 1998).
The content of mobile trace metals also depends on the nature of the metal ion, the nature
of extractant and the pH (Sabienë et al., 2004). For example, the mobile forms of Cd, Cu
and Pb were investigated by using ammonium nitrate, ammonium acetate (pH 7 and 4.8),
0.1 M HCl and 0.05 M NH4-EDTA (pH 7). The lowest amounts were extracted with
ammonium salt solutions ever through the content of trace metals extracted with
ammonium acetate (pH 4.8) was greater than those extracted with ammonium acetate (pH
7). Even more significant contents of trace metals were extracted with 0.1 M HCl while
0.05 M NH4-EDTA (pH 7) was capable of extracting not only the trace metals participating
in the exchange processes, but also trace metals in carbonates and organic complexes in the
soil. In addition, a comparison of the mobile forms of trace metals extracted from clean and
highly polluted soils has indicated that in the polluted soils a higher portion of trace metals
exists in a mobile form (Sabienë et al., 2004).
In Western Europe, policy makers have shifted their attitudes towards a major integrated
risk-based approach of soil contamination assessment to determine trace metal mobility and
bioavailability by single extraction procedures (Meers et al., 2007). The notion behind this
is the fact that total soil content of metals by itself is not an appropriate measure for
assessing their bioavailability and not a very useful tool to determine potential risks from
soil and sediment contamination.
The levels of Cu, Zn, Pb, Cd, Ni and Fe were investigated in leaf vegetables and their
supporting soil in the vicinity of a copper smelter and steelworks in Wollongong, Australia
by Beavington (1975). Mean levels of Pb, Cd and Ni in lettuce were 23, 4.5 and 2.7 mg/kg,
20
respectively, while extractable levels of metals in the supporting soil were also found to be
high. Notable correlations were found between distance from the Port Kemble copper
smelter stack and the levels of easily-extractable Cu, Zn, Pb and Cd in soils. The low
correlation between Fe and other trace metals in lettuce was related to the basalt-derived
soil or the steelworks as the main sources of Fe in the area. In addition, notable correlations
observed among the levels of most other trace metals in both soil and vegetables indicated
the ‘blanket effect’ of fallout coating both vegetation and soil. Also when compared to the
World Health Organization (1972) recommended maximum Provisional Tolerable Weekly
Intake levels for adults, the levels of Pb, Cd and other trace metals in leaf vegetables
prepared for human consumption, especially lettuce, grown around the smelter are a matter
of concern (Beavington, 1975).
Sources and the extent of trace metal contamination in soil and vegetable samples across
four vegetable growing regions, namely Boolaroo, Port Kembla, Cowra and the Sydney
Basin in New South Wales, were investigated by Kachenko and Singh (2006) since the
dietary exposure to trace metals like Cd, Cu, Zn and Pb has been suggested as a risk to
human health through the consumption of vegetable crops. The amount of metal
contamination in soil samples located in the neighbourhood of smelters like Boolaroo and
Port Kembla was greatest, decreased with depth at these two sites, reflecting contamination
due to anthropogenic activities. Also contamination of vegetables with trace metals was
observed in samples from the residential regions of Boolaroo and Port Kembla with
samples from Port Kembla having the highest mean levels of Cu in all vegetable types. At
Boolaroo, nearly all the vegetable samples exceeded the Australian Food Standard
maximum levels for Cd and Pb whereas all vegetable samples from Cowra, which is a
relatively pristine site, had Cd and Pb levels below these guideline values. Thus, these
findings suggest that the cultivation of leafy vegetables for human consumption near
smelters should be avoided (Kachenko and Singh, 2006).
The relationships between the trace metal concentrations of vegetables, agricultural soil and
airborne particulate matter were investigated in the industrial area of Thessaloniki, northern
Greece (Voutsa et al., 1996). Despite the airborne particulate matter that was significantly
enriched with Zn, Cd, Pb and Mn, trace metal contents of agricultural soils were found to
be relatively low; however, elevated concentrations of these metals were observed in leafy
21
vegetables. Also the main pathway for most trace metals to vegetable roots was from the
soil, while trace elements in vegetable leaves seemed to originate from the atmosphere.
Significant accumulation of Pb was found in lettuce and Cr and Cd are concentrated in the
leafy vegetables generally as a result of atmospheric deposition. In contrast root vegetables
appeared to accumulate soil Cd much more efficiently than other trace metals (Voutsa et
al., 1996).
Generally, the high metal concentrations observed in soil and vegetable samples in the
vicinity of industrial and urbanized activities could cause serious environmental problems
which in turn affect human life (Fernandez et al., 2001; Fytianos et al., 2001; Sponza and
Karaoğlu, 2002; Manta et al., 2002; Krishna and Govil., 2004; Liao et al., 2005).
2.2.7 Soil Quality Guidelines:
Following the recognition of contaminated soils in Europe and the USA in the early 1970s,
guidelines were designed in order to estimate the extent, spread and risk of exposure to
humans, as well as the immediate and surrounding ecosystems. Thus, each set of guidelines
was essentially developed to suit the needs for detecting a specific problem in a particular
region. One of the most widely used guidelines to assess contaminated soils and
groundwater are the Dutch Guidelines (Tiller, 1992; Pacheco, 1999). Other soil guidelines
established by other environmental organizations have comprised and adapted many
aspects of the Dutch values for their own purposes, such as the Australian and New Zealand
Environment and Conservation Council and National Health and Medical Research Council
(ANZECC/NHMRC, 1992).
The Dutch Approach:
In response to the estimated 100 000 contaminated sites which required cleanup, the
Netherlands has carried out much research in order to assess and cleanup the
contaminated soils. Their approach aimed to define three indicative levels, an A-
value (reference value) which defined the upper limit of the natural background
range but was not based on ecotoxicological effects. A second indicative level, B-
value, was the trigger value for further investigation. This investigation would be
applied to the affected site and soil factors to determine bioavailability, transport of
22
pollutants and critical pathways in relation to the desired land use. A third indicative
value, C-value, defined a limit which required cleanup. The Dutch indicative
C-values for cleanup consider human-toxicological arguments but are not based on
any accepted risk assessment methodology. Cleanup provisions should aim to return
the site to the A value which would allow a flexible, unrestricted or multifunctional
use of the land. Overall the Dutch approach has had immense impacts world-wide
(Tiller, 1992). Table 2.3 shows the concentrations pertaining to these three
indicative levels for several trace metals.
A = Reference value (top of background range). B = Indicative value for further
investigations. C = Indicative value for cleaning up.
Table 2.3: Dutch standards for soil contamination assessment (Tiller, 1992). (Total concentrations in soil: mg/kg)
Metal A B C
Cr
Co
Ni
Cu
Zn
As
Mo
Cd
Sn
Ba
Hg
Pb
100
20
50
50
200
20
10
1
20
200
0.5
50
250
50
100
100
500
30
40
5
50
400
2
150
800
300
500
500
3000
50
200
20
300
2000
10
600
ANZECC/NHMRC Guidelines:
In Australia, control and remediation of contaminated sites has been conducted by
different state health and environmental departments and agencies. Some of these
agencies have had interim regulations under State legislations pending the moves
towards national Australian and New Zealand guidelines for contaminated sites
developed under the auspices of the Australia and New Zealand Environment and
23
Conservation Council (ANZECC) and the National Health and Medical Research
Council (NHMRC; Tiller, 1992).
ANZECC/NHMRC provided modified guidelines from research and knowledge
based on international information in order to develop guidelines for investigation
as information become available. Figure 2.1 illustrates the recommended approach
for initial evaluation of potentially contaminated sites (ANZECC/NHMRC, 1992).
Figure 2.1: Recommended approach to the assessment and management of a
potentially contaminated site (ANZECC/NHMRC, 1992).
Initial Evaluation
Site history/ Site description/ Preliminary sampling
Apply Soil Investigation Guidelines
No problem Potential Problem
Second Stage Investigation
Assess nature and extent of problem
Assess potential public occupational health risks (toxicology)
Assess environmental impacts
No problems for agreed land use
No action
Unacceptable impacts detected Determine criteria for site cleanup Determine options for site management Determine cleanup methods
Action
Monitoring
24
2.3 Selected studies of trace metal contamination on sediments from local and world-
wide previous investigations:
The distribution of trace metals in aquatic systems has been widely studied during the last
two decades for reasons of environmental concern. The geochemistry of aquatic
environments like rivers, lagoons, estuaries and creeks is governed by a complex interplay
of hydrodynamic factors, industrial and municipal wastewater discharges and
biogeochemical processes (Smith, 2001). Also several studies in Australia have indicated
instances of noticeable metal pollution of estuarine waters (Eustace, 1974; Furzer, 1975).
Some previous studies chose to investigate metals in sediments instead of water due to
higher concentrations of metals in sediments (within the range of direct determination by
atomic absorption spectroscopy without preconcentration) and also because sediments are
less susceptible to short term variations as a result of lateral mixing, wind direction,
flushing by rainwater, etc. (Ellis and Kanamori, 1977). Also sediments are important
because they are both a source and a sink for contaminants.
“Because the geochemical processes that influence metal accumulation in the environment
are reversible it is important to realize that the environmental sink for today may become
the pollutant source of tomorrow. “ (Clark et al., 1997)
2.3.1 Background Trace Metal Concentrations:
Background concentrations of trace metals in soils from the Port Kembla area have not
previously been reported in the literature. These soils have mainly developed in situ and
would reflect the composition of the parent rocks from which they were derived. Parent
rock compositions have therefore been analysed as part of this study.
Background concentrations of trace metals in Lake Illawarra have been estimated in a
number of previous studies (Ellis & Kanamori, 1977; Payne et al., 1997; Chenhall et al.,
2004). Concentrations of Cu, Zn and Pb exhibit a notably uniform distribution with depth
therefore, providing the basis for determination of background (pre-industrial) values for
these elements. Despite the different methods of sample collection and analysis, the
background concentrations of Cu and Pb have been in reasonable agreement in previous
studies and were estimated at about 33-38 ppm and 15-18 ppm respectively (Ellis and
25
Kanamori, 1977; Payne et al., 1997 and Chenhall et al., 2004). Significant differences
between the Zn background values in these studies could be probably due to different
analytical factors and the unusual grain size normalization applied by Ellis and Kanamori,
(1977) which included a portion of the fine sand sediment fraction. Also a more feasible
explanation is that the deep (10-20 m) sediments investigated by Ellis and Kanamori,
(1977) were in fact part of the geochemically distinct underlying Pleistocene succession.
Sediment grain size factors and different sample preparations have been considered as other
factors for different background values of Zn concentration (Chenhall et al., 2004).
Background concentrations of Zn were estimated at about 44 ppm by Ellis and Kanamori,
(1977) and 84 ppm in a study by Chenhall et al., (2004).
Further, in a later study by Gillis and Birch (2006), background concentrations of Cu, Zn
and Pb have estimated around 19, 87 and 39 ppm, respectively.
2.3.2 Trace Metal Abundant in Lake Illawarra:
To have a better idea about the extent to which contaminant concentrations exceed
background values and also the impact of anthropogenic activities on the catchment,
enrichment factors of some trace metals have been calculated using the expression below
(Payne et al., 1997):
Enrichment Factor: mean concentrations of trace metal in the top 20 cm of sediment background concentration (below 45 cm)
Previous studies indicated that the enrichment of some trace metals like Cu, Zn and Pb in
the upper 50 cm of sediment profiles in Lake Illawarra could be equated with European
(industrial) impact on the lake. The maximum enrichments for Cu, Zn and Pb were
estimated at about 4, 34 and 11 respectively, at Griffins Bay in the north-east corner of the
lake, which is closest to the Port Kembla industrial complex (Roy & Peat, 1974; Ellis &
Kanamori, 1977). Also in studies by Chenhall et al. (1994) and Payne et al. (1997) the
enrichment factors of Cu, Zn and Pb were calculated around 1.8, 5.9 and 3.5 respectively.
Gillis and Birch, (2006) indicated that in Griffins Bay, Cu and Zn were elevated above
background values by more than 3 times while the enrichment factors for Pb and Cd were
just less than 6.
26
Trace metal concentrations in Lake Illawarra are higher than in less polluted or pristine
areas such as Burrill Lake, NSW, or Bells Creek catchment, Queensland, (Jones et al.,
2003; Liaghati et al., 2003) and significantly lower than heavily polluted areas like Port
Pirie, South Australia, Derwent River, Tasmania, Lake Macquarie, NSW; Parramatta River
catchment, NSW, and Deule- canal sediments, France (Cartwright et al., 1976; Batley,
1987; Birch et al., 2000; Jones et al., 2003; Boughriet et al., 2007).
2.3.3 Sediment Chronology:
Increased sediment supply to estuaries can be caused by natural phenomena like flood
cycles, but additional sedimentation can also be the result of anthropogenic activities,
comprising industrial practices, initial deforestation, clearing of the catchment and also
increased rates of erosion and transportation of sediment as a result of urban expansion,
construction of roads and housing developments.
Accelerated sedimentation in shallow coastal lagoons poses significant environmental
impacts like shoaling, degradation of seagrass beds, and increased turbidity with
consequent loss of aesthetic appeal (Chenhall et al., 1995).
Pre-European sedimentation rates in Lake Illawarra were estimated at less than 1 mm/year
by radiocarbon dating methods on shells (Notospisula trigonella) preserved in the
sediments (Chenhall et al., 1995). This method is not without limitations including its
limited applicability to sediments less than 200 years in age and also the potential for
erroneous 14C ages if older carbon, in the form of reworked, redeposited shells is
incorporated in the sediment (Chenhall et al., 1995). Modern (< 200 years) radiocarbon
ages have been estimated from shells at a depth of 1 m around the sandy deltaic margins of
the lagoon, indicating that the rates of sediment accretion since the European settlement
would be >5 mm/year (Chenhall et al., 2001).
The chronology of sediments deposited in the last 120 years can be detected using the
modelling of 210Pb and 137Cs depth-decay curves (Chenhall et al., 2001). However these
techniques are not without their limitations including availability of facilities, costing and
in the southern hemisphere the very small quantity of 137Cs in the samples (Smith, 1982;
Loughran and Campbell, 1983). Furthermore, sediment-age profile constructed using 210Pb
data may not coincide with the profile generated by site-specific markers such as trace
27
metals (Killby and Batley, 1993). 137Cs dating results on Lake Illawarra in 1990 were
somewhat disappointing, mainly due to non-measurable 137Cs activity in some cores,
because of low clay content and very rapid sediment accumulation rates (Chenhall et al.,
2001).
Moreover, using trace metal-depth concentration profiles and anthropogenic markers in
conjunction with the time of industrial development, near surface sedimentation rates
ranged between 3 to 5 mm/year at Griffins Bay to more than 16 mm/year at Macquarie
Rivulet. Sedimentation rates of approximately 10 mm/year seemed to be typical of the
western and southwestern portions of the lagoon (Chenhall et al., 1995; Payne et al., 1997).
Trace-metal concentration-depth and ash concentration-depth profiles indicated the typical
rates of sedimentation of between 3 to 5 mm/year over the last 70-90 years for the northern
and north-central parts of the lagoon (Chenhall et al., 2001). It should be noted that
limitations attached to this method are potential trace metal mobility, and biogenic and
physical distribution of the sediments. Thus, sites far from known point sources could not
be assessed by trace metal profiling mainly due to uncertainties about the dates of
introduction of trace metals into the sediment profiles depending on selection of 1910
(Southern Copper) or 1928 (BHP Steel) as the starting date (Payne et al., 1997).
Based on other estuarine investigations, rates of sediment accretion in Lake Illawarra have
been identified as higher than Burrill Lake, which is about 1.7 mm/year, but lower than
Lake Macquarie, NSW, Australia (Batley, 1987; Jones et al., 2003).
2.3.4 Trace Metal-Sediment Grain Size Relationships:
Fine-grained, clay-rich sediments generally have significant metal retention due to
increased specific surface area and the strong adsorptive properties of clay minerals. Clay
particles, i.e., aluminosilicates, are negatively charged since at the end of silicon-oxygen
chains, oxygen atoms carry an extra electron because they are only bonded to one atom
instead of the usual two, and aluminium atoms are bonded to four oxygens instead of the
usual three (Smith, 2001). Therefore, clays are regarded as anions and metals like Cu, Pb
and Zn are positively charged cations. Because of this affinity, trace metals are
preferentially bonded with fine-grained sediments (clays and silts) and colloidal materials
due to particularly strong cation exchange potential upon clay surfaces (Smith, 2001).
28
Rubidium is also a cation and is geochemically coupled to potassium, a component
associated with illite and smectite clays, therefore, can be used as a proxy indicator for
grain size (Payne et al., 1997). As a result, the Rb distribution in Lake Illawarra sediments
is directly associated with the content of fine silt and clay and can be applied as a useful
measurement of grain size variation in relation to retention of trace elements by silt and
mud particles (Payne et al., 1997).
Also like clays, organic matter shows the ability to bind different metal ions to its surface;
the strength of the bound created between organic matter and metal ions is directly related
to factors such as pH, influx of sediment and redox potential. The organic material forms
metallic complexes readily (Smith, 2001).
As a result of the above, the distribution of Cu, Pb and Zn in the upper 20 cm of sediments
in Lake Illawarra is directly related to the proportion of mud-dominated (> 50 % silt &
clay) sediment while high organic matter content and biogenic processes (bacterially-
mediated sulphate reduction) assist trace metal retention via sulphide formation in the
sediment (Payne et al., 1997). In contrast, sand dominated (> 50 % sand) sites in Lake
Illawarra are characterised by lower concentrations of metals like Cu, Pb and Zn (Payne et
al., 1997).
2.3.5 Sediment Quality:
Lake Illawarra sediments are generally identified by low (< 2.5) enrichment factors for
trace metals like Cu, Pb and Zn with the maximum concentrations of these metals in the
upper 20 cm of sediment profiles. However, a remarkable exception is the sediment from
southern Griffins Bay with enrichment factors of 3 to 6 for these metals (Chenhall et al.,
1994 and 2001; Payne et al., 1997; Gillis and Birch, 2006). Higher enrichment factors of
trace metals in this part of the lake reflect the close proximity of this site to the Port Kembla
industry and its associated surface runoff (Chenhall et al., 2004). Trace metal data for Lake
Illawarra have been assessed against the ANZECC & ARMCANZ (1992 and 2000)
sediment quality guidelines in previous studies (Ellis & Kanamori, 1977; Payne et al.,
1997; Chenhall et al., 2004; Gillis & Birch, 2006) that suggested the sediments in Lake
Illawarra could be generally classified as low risk. However, sediments from Griffins Bay
may exceed the high trigger value (ISQG-high) for Zn and the low trigger value (ISQG-
29
low) for Cu and Pb indicating that sediments from this embayment may be having an
adverse effect on benthic populations (Chenhall et al., 2004; Gillis & Birch, 2006).
2.3.6 Trace Metal Bioavailability and Toxicity:
Contaminated sediments have the potential to release metals into the water column and be a
source of bioavailable contamination to benthic biota and enter the food chain (ANZECC &
ARMCANZ, 2000).
Trace metals in sediments can be divided into three fractions based on geochemical
associations between the metals and constituents in the sediment. Fraction 1: refers to
metals which are exchangeable or loosely adsorbed, bound to carbonate, aluminium, iron
and manganese oxyhydroxides. This is generally referred to as the ‘bioavailable fraction’.
Fraction 2; refers to metals which are bound to organic matter and sulphides. Fraction 3;
refers to the detrital or lithogenic fraction (Smith, 2001).
Using dilute HCl and EDTA indicated that a large amount of Cd, Pb and Zn may be
available to benthic species in Griffins Bay sediments: however, it is believed that
sediments in Griffins Bay and northern Lake Illawarra are unlikely to be toxic to benthic
organisms because the acid-volatile sulphide simultaneously extracted metals (AVS/SEM)
are > 1 (Gillis & Birch, 2006).
2.3.7 Sediment Quality Guidelines:
The Australian Water Quality Guidelines for Fresh and Marine Waters (ANZECC and
ARMCANZ, 2000) established the framework for managing water quality. It was indicated
that total load and fate of contaminants should be considered. Sediments are important
because they are both a source and a sink for contaminants (ANZECC and ARMCANZ
2000). The development of Sediment Quality Guidelines can be used to evaluate the extent
of sediment contamination, or to implement measures designed to limit or prevent
additional contamination (McCauley et al., 2000). The ANZECC and ARMCANZ (2000)
sediment quality guidelines have outlined three categories in which the determination of the
sediment quality is assessed for the aquatic ecosystems. For an aquatic ecosystem to be
considered as: Condition 1: chemicals from human activities should be undetectable, i.e.,
trace metal concentrations should not be elevated above background concentrations;
30
Condition 2: moderately contaminated by anthropogenic activity; and
Condition 3: highly disturbed and contaminated aquatic ecosystems.
The principal philosophies behind the ANZECC and ARMCANZ (2000) sediment quality
guidelines are to recognize contaminated sites which could cause adverse effects to
ecological health, to establish the potential for remobilization of contaminants into the
water column and the aquatic food chain and to indicate areas which have not been affected
by anthropogenic practices (ANZECC and ARMCANZ 2000). The ANZECC and
ARMCANZ (2000) Sediment and Water Quality Guidelines involve a decision tree
approach, where the guidelines should not be used on a pass or fail basis. Therefore, if
trigger values are exceeded, further action as defined by the decision tree should be
undertaken (Figure 2.2; ANZECC & ARMCANZ 2000). The first level screening compares
the total metal contaminant concentration in the sediment to the trigger values set in
ANZECC and ARMCANZ (2000) Sediment Quality Guidelines. If contaminant levels
exceed trigger values, then either management and/or remedial action are triggered or
further investigation is required to consider the fraction of contaminant that is bioavailable
or can be transformed and mobilized into a bioavailable form. The decision making process
is illustrated in Figure 2.2 (ANZECC and ARMCANZ 2000).
2.3.8 Sources of Pollution in Lake Illawarra:
Although trace metals arising from different sources, for instance, Zn from galvanized iron,
Pb from the combustion of petrol-Pb additives and trace metals associated with domestic
discharges, probably contribute to the trace metal loading in Lake Illawarra, a noticeable
correlation between fine fraction sediments, Cu, Pb and Zn indicated that these trace metals
have had a common but not unique source of pollution (Chenhall et al., 2004; Gillis &
Birch, 2006). The Port Kembla industrial complex has been suggested as an important
source of trace metals in the area and concentrations of these elements have been observed
to decrease rapidly with distance from the complex (Roy & Peat, 1975; Ellis & Kanamori,
1977; Chiaradia et al., 1997; Gillis & Birch, 2006).
31
Define primary management aims
Determine appropriate guideline trigger values for selected indicators.
Sediment contaminant characterisation. Measure total then dilute acid-soluble metals, organics
plus TOC, grain size
Test against guideline values. Compare contaminant/stressor concentration with lower and
upper guideline values
Below low value
Low risk No action
Between upper & lower values
Check backgroundconcentrations
Below
Low risk (no action)
Above
Examine factors controlling bioavailability (optional) e.g. AVS: pore water concentrations
sediment speciation organic carbon
Test against guideline value Compare bioavailable concentration with lower guideline value
Above upper value
Low risk (no action)
Acute toxicity testing
Chronic toxicity testing Highly contaminated (Initiate remedial action)
Low risk (no action)
Moderately contaminated (initiate remedial action)
Not toxic Toxic
Toxic Not toxic
Below Above
Figure 2.2: Decision tree for the assessment of contaminated sediments
(ANZECC and ARMCANZ 2000)
32
Potentially, a main contributor to trace metal contamination in the Port Kembla area is
aerosols generated by the Port Kembla industrial complex since1910. Previous studies have
indicated that the greatest concentrations of trace metals like Cu, Pb and Zn occur in both
lagoonal and salt marsh sediments on the south side of Griffins Bay, adjacent to the
complex (Ellis & Kanamori, 1977; Payne et al., 1997; Chenhall et al., 2001, 2004). Also
sediments in creeks discharging into Griffins Bay contain higher trace metal concentrations
than sediments mantling Griffins Bay, indicating that these creeks, which drain sub-
catchments related to urban and industrial areas adjacent to the complex, are a source of
trace metals to the embayment (Gillis & Birch, 2006).
Urban runoff can also be considered as a source of trace metals to these creeks since metals
like Cd, Cu, Pb, and Zn are common constituents of urban stormwater runoff from vehicle
wear and exhaust emissions, corrosion of plumbing, roofs, etc. (Sutherland, 2000). Due to
limited water exchange between Griffins Bay and the main body of the lake, Griffins Bay
acts as a sink for sediment and affiliated trace metals entering the embayment (Gillis &
Birch, 2006). Sediment resuspension in Griffins Bay occurs during strong wind conditions
and northeast winds may result in an exchange of water between Griffins Bay and the main
body of the lake (Yassini & Depers, 1995). Also strong southerly and westerly winds in
summer and winter, respectively, would probably restrict resuspended material within
Griffins Bay due to the orientation of the embayment in the northeast corner of Lake
Illawarra (Gillis & Birch, 2006).
Significantly, near surface sediments in this portion of the lagoon contain abundant
anthropogenic ash uniquely sourced from both the steelworks and the copper smelter
(Payne et al., 1997). Little published analytical data are available for the aerosols generated
either by the smelter or the steelworks.
Historical industrial sources of trace metals existed on the western foreshore of the
catchment including the Smelting Company of Australia Ltd at Kanahooka (1896-1906)
and the Tallawarra Power Station (1954-1989) but these make a negligible metal
contribution to north eastern portion of the lake due to their locations and short periods of
operation (Gillis & Birch, 2006).