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State of the Marine Environment Report for Australia: Pollution - Technical Annex 2

Edited by Leon P. Zann
David Sutton
Great Barrier Reef Marine Park Authority, Townsville Queensland

Ocean Rescue 2000 Program
Department of the Environment, Sport and Territories, Canberra, 1995

ISBN 0 642 17406 7


The problem of chlorinated compounds in Australia's marine environment

Bruce J. Richardson
School of Biological and Chemical Sciences
Faculty of Science and Technology
Deakin University, Geelong, Victoria 3217

Summary

A range of organochlorine compounds, including herbicides, insecticides, fungicides and polychlorinated biphenyls (PCBs) have been used in Australia. In addition, other compounds, including the dioxins and dibenzofurans, have been produced as a result of chlorination processes, or by combustion. Despite the fact that such organochlorines are recognised internationally as important contaminants in marine environments, few well designed studies have been implemented in Australia to elucidate local occurrence and distribution. Those which have been performed suffer from several problems, including the lack of adequate definition of monitoring objectives. At present, it is impossible to determine whether organochlorines are significant contaminants in Australian coastal waters, but the best evidence suggests that, as is the situation in Northern Hemisphere countries, organochlorines occur in highest concentrations close to urban and industrialised centres, or where sewage discharge and run-off from rural areas has a major influence. In order to develop and maintain an adequate level of environmental protection, there remains a need in Australia to embrace nationwide monitoring programs for the continued surveillance of organochlorine compounds, and to develop an analytical capability sufficient to allow the quantification of dioxins and dibenzofurans. Techniques for assessing the chronic toxicity of organochlorines in local waters also need to be developed.

Organochlorine contaminants: a brief overview

During the past two decades, the presence of organochlorine contaminants in the oceans of the world has caused considerable concern. The term 'organochlorines' is the name applied to a group of organic compounds which contain chlorine. Most of these compounds are synthetic, and during the last 50 years some 60 000 different organochlorines of industrial significance have been manufactured (ANZEC 1991). Organochlorines have achieved wide usage in Australia, especially as insecticides (e.g. DDT, lindane, chlordane, dieldrin, aldrin and heptachlor), fungicides (e.g. hexachlorobenzene and the chlorinated phenols such as pentachlorophenol), and herbicides (e.g. 2,4-D and 2,4,5-T). In addition to the pesticides, polychlorinated biphenyls (PCBs) were used extensively as dielectric, or insulating fluids in large transformers and capacitors, and as additives in hydraulic fluids, surface coating materials, plastics and lubricants. Organochlorine compounds such as the dioxins and dibenzofurans have also been produced unwittingly as by-products of chemical or combustion processes.

As well as the contaminants mentioned above, it is estimated that between 500 and 1000 new organic substances have been introduced worldwide each year, but their fate in the environment is largely unknown. As an example of this, concentrations of so-called 'bound chlorine' in fish fat (a representation of total organochlorine contamination) range from 30 to 200 parts per million (ppm), of which only 5-10 ppm can be attributed to the well recognised and researched contaminants such as DDT, PCBs, dioxins and chlorophenols (GESAMP 1990). The possible sources of the remainder are thought to be the result of industry-related activities, including chlorination processes (e.g. as a part of sewage treatment or pulp mill bleaching operations), metal smelting, and the burning of chlorine-containing compounds.

The key properties of organochlorines which cause concern are persistence and toxicity. Many organochlorines, such as the pesticides, were deliberately produced because of their toxicity; the fact that they were also persistent had advantages in that they remained effective against their targets for prolonged periods. Other compounds (such as the PCBs) were used in industry because of their stability, and were later found to produce toxic responses in many organisms.

Persistence combined with toxicity implies that organochlorines are a long-term problem when they enter marine ecosystems, and this concern is compounded by the ability of organochlorines to accumulate in the tissues of living organisms (Phillips 1993). This phenomenon, known as 'bio-accumulation', may seem anomalous given that organochlorines (as a general rule) are poorly soluble in water. However, organochlorines are also very soluble in fats, including those which are found in the tissues of living organisms. Thus, relatively small amounts of organochlorines present in water may be preferentially transferred and accumulated in the fats of aquatic plants or animals, and the resulting concentrations may be as much as 500 000 times or more than in surrounding waters.

Living organisms may also accumulate organochlorines through their food via a process termed 'biomagnification'. This is a stepwise process, in which persistent contaminants such as organochlorines are transferred through food chains or food webs as successive organisms feed upon each other. As a result, concentrations of organochlorines may increase with trophic levels, the highest concentrations being observed in higher consumers including certain fish, marine mammals, birds, or in humans. There are some doubts that this process contributes significantly to the accumulation of organochlorines by all living organisms, but it may be a significant factor at the highest trophic levels (Phillips 1993).

Sources of organochlorines

The sources of organochlorines in the Australian marine environment have recently been reviewed by ANZEC (1991). Organochlorines enter marine systems from a variety of sources, which can be broadly defined as 'point sources' (arising from a single source or location) and 'diffuse sources', which are more widespread and hence more difficult to accurately define. Examples of point sources include sewage or factory discharges via pipelines, or rivers and streams discharging directly to the ocean. Point sources are relatively easy to recognise and manage, but measuring organochlorines in them is often difficult as the substances are poorly water soluble and hence difficult to detect using routine chemical techniques. Nonetheless, these low concentrations are often of toxicological significance, due to bio-accumulation. Diffuse sources include atmospheric fallout, run-off from land, and ground water leaching. Because of their widespread nature, diffuse sources of organochlorines are also difficult to measure, and are much more difficult to control than point sources.

In recent years, the use of many organochlorines in Australia has been limited, due to concerns over their persistence and toxicity. Table 1 summarises the situation of the commonest organochlorines which have been or are still being used in Australia. It can be seen from this table that the use and/or disposal of these substances has directly contributed to their widespread presence in the Australian environment.

Unlike the pesticides and PCBs, dioxins and their close chemical relatives the dibenzofurans are produced unintentionally during the manufacture of other organochlorines, during the chlorination of waste materials, or by combustion processes. Although there are many different dioxins and dibenzofurans, most concern has been directed towards 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD) and 2,3,7,8-tetrachlorodibenzofurans (2,3,7,8-TCDF), which are considered to be highly toxic. It should be noted, however, that dioxins and dibenzofurans are usually present in environmental samples at extremely low concentrations (in terms of parts per trillion or less), and that 2,3,7,8-TCDD and 2,3,7,8-TCDF usually make up only a small fraction of the total dioxins present.

The principle sources of dioxins and dibenzofurans in Australia have been reviewed by ANZEC (1991). Chemical processes producing the substances include pulp and paper mills where chlorine is used as a bleaching agent, and the manufacture of such substances as pentachlorophenols and 2,4,5-T (the latter has now ceased in Australia, although considerable waste remains to be disposed). Other industrial processes are also possible sources, and these include copper smelting, magnesium and nickel production, vinyl chloride production (or the use of recycled polyvinyl chloride in steel mills), and the regeneration of used petrochemical plant catalysts.

Combustion processes are also known to produce significant amounts of dioxins and dibenzofurans. For example, in Canada and Sweden incineration of wastes (especially municipal and industrial wastes) and the subsequent disposal of ash and sludge are the major sources of dioxins and dibenzofurans. In Sweden, the next most important sources are metals reclamation and pulp and paper mills. In the former West Germany, the major dioxin and dibenzofuran contribution to the environment arose from pentachlorophenol use, followed by municipal incinerators and emissions from motor vehicles running on leaded petrol (ANZEC 1991). In Australia, the various sources of dioxins and dibenzofurans have not been quantified, although it is unlikely that municipal incineration plays a key role as this process does not occur in Australia to the same extent as in Europe and Scandinavia.

Table 1: Summary of past and present uses of organochlorines (after ANZEC 1991)

ORGANOCHLORINE USES
Insecticides  
DDT, Endrin, HCB No permitted uses
BHCs other than Lindane No permitted uses
Lindane ( -BHC)

Banned in WA.
Withdrawn in all states for use in control of insect pests in stored seeds.
Used to control white grubs & symphylids in pineapples (Qld), ectoparasites on food (all states except NSW, Tas. and WA), and head lice on humans (except in Vic. and WA).

Chlordane Quarantine purposes (Vic.).
Control of termites in all states except Tas.
Heptachlor Control of funnel ant in some cane growing areas of Qld, subject to permit.
Control of termites in all states except Tas.
Aldrin Control of termites in all states except Tas.
Currently being phased out in SA and WA.
Dieldrin Soldier Fly control in cane growing areas of Qld, subject to permit. Control of termites in all states except Vic., WA and Tas. Generally no longer available commercially for termite control.
Herbicides  
2,4-D Used to control broad-leaved weeds in crops, water weeds and vegetation near drains, and in domestic gardens.
2,4,5-T Used in the past as a herbicide against broad-leaved woody plants, and as a defoliant. Dioxins found present as a contaminant in some commercial preparations. Use and manufacture in Australia has ceased.
Fungicides  
Hexachlorobenzene (HCB) Use well controlled in the past. Does not present problems experienced with wide scale use in Northern Hemisphere. Now banned in Australia.
Chlorinated Phenols Widely used in Australia. Readily degrade in aerobic environments. Formulations of pentachlorophenol contaminated by dioxins and bibenzofurans.
Polychlorinated Biphenyls (PCBs) Never manufactured in Australia; imported for use. Use restricted from 1975 to 'closed system' uses where contact with the environment is unlikely.

Sewage discharge has been recognised as a potential source of organochlorine compounds to the Australian marine environment (Portmann 1974). Organochlorine compounds in sewage may arise from industrial or domestic sources, or new compounds may be formed in the sewage as the result of disinfection processes utilising chlorine. The latter processes give rise to many different (and largely unknown) organochlorine compounds, which are poorly understood both chemically and toxicologically (Koppermann et al. 1975). Similarly, chlorination processes in the pulp and paper industry give rise to a suite of organochlorine compounds (apart from dioxins and dibenzofurans) which are poorly understood. Such compounds are often measured in total as AOX, or 'adsorbable organic halide'. About 300 of the AOX components have been chemically characterised, but the higher molecular weight compounds are still not well understood. In Australia, pulp mill effluents are subject to primary and secondary treatment prior to discharge, but the fate of many of the chlorinated components upon passage through such processes has not been established, and it is possible that these compounds are being discharged to the marine environment. Process improvements, however, have lead to considerably less AOXs being formed during pulp and paper production.

Organochlorine concentrations in the marine environment

The concentrations of organochlorine residues in Australian marine waters, sediments and biota have been extensively reviewed by a number of authors (Connell 1981; Richardson & Waid 1982; Richardson et al. 1987; Farrugia 1986; Olsen 1988; Brodie 1989; Lincoln Smith & Mann 1989a, 1989b; ANZEC 1991; Thompson et al. 1992, Phillips et al. 1992). What is clear from these reviews is the lack of an integrated perspective on organochlorines in Australian marine waters, as most investigations have been undertaken in localised areas surrounding potential 'hotspots'. Indeed, most work on organochlorines has been conducted near Australia's major eastern seaboard cities, and only few data exist for what can be considered as 'baseline' or relatively pristine environments (Martin & Richardson 1991).

Pesticides

It is surprising that, given Australia's past (and present) usage of organochlorine pesticides and the propensity for run-off from rural and urban usage, there have been few definitive monitoring programs conducted in coastal waters. Thus, in comparison with the northern hemisphere, little is known about the extent of local contamination.

Because of the low concentrations of organochlorine pesticides found in waters, most analyses have been conducted on sediments and biota. Such surveys have been done for two purposes:

  1. to establish spatial and (to a far lesser extent) temporal differences in organochlorine distribution; and
  2. to measure organochlorines in organisms consumed as food to establish if acceptable health limits have been exceeded.

These two objectives are frequently confused in monitoring programs, and interpreting data accumulated for the latter objective in terms of spatial and temporal distribution is often fraught with difficulties. Many of the food species tested are mobile, and may not necessarily indicate that high concentrations are the result of contamination in the capture locality. In addition, meaningful comparisons between different species of organisms, and between the different analytical techniques utilised by various workers, are difficult to draw. Nonetheless some inferences are possible, but these highlight the need for monitoring programs with firmly established aims and methodologies if data are to be obtained which accurately indicate the extent of organochlorine contamination in Australian coastal waters.

Work to date indicates that although organochlorine pesticides can be found in Australia's marine organisms, concentrations are relatively low, except where discharges arise from urbanised areas or as a result of run-off from intensively-farmed rural areas. Thus, Olafson (1978) and Smillie and Waid (1984) were able to report low concentrations of organochlorine pesticides (DDT, DDE and lindane) in corals, fish and molluscs obtained from the Great Barrier Reef. However, studies undertaken in Moreton Bay, which receives discharge from the Brisbane River, indicate considerably higher concentrations of organochlorines, including DDT and its metabolites (ANZEC 1991).

In South Australia, HCB, lindane, dieldrin and DDTs were measured in 79 fish samples during the 1970s (ANZEC 1991). Only six specimens were pesticide free, and analyses indicated that maximum residue limits (MRLs) for dieldrin and total DDTs (the sum of DDT and its metabolites) were exceeded in some samples. A survey of organochlorine contamination in waters and sediments in Western Australia (ANZEC 1991; Thompson et al. 1992) indicated that river flushing following rainfall contributed relatively high loadings of chlordane, total DDTs, dieldrin, heptachlor and heptachlor epoxide, and that Environment Protection Authority (EPA) criteria for the maintenance and preservation of marine aquatic ecosystems were exceeded in 63% of waters sampled.

In Victoria, few studies on organochlorine pesticide contamination of coastal waters have been undertaken (Thompson et al. 1992). Measurement of DDTs in sediments from Port Phillip Bay and the Yarra River showed relatively low concentrations in comparison with international data (Murray 1987), although concentrations of these substances in Australian fur seals were at least as high as those reported in Northern Hemisphere species (Smillie & Waid 1987).

Most work on the organochlorine pesticides in Australian waters has been conducted around sewage outfalls in the Sydney area (see Thompson et al. 1992; Lincoln Smith & Mann 1989a, 1989b; ANZEC 1991). Fish caught off Sydney's sewage outfalls (in particular the Malabar outfall which contains the highest proportion of industrial waste) contained high concentrations of organochlorine pesticides. For example, red morwong (Cheilodactylus fuscus) flesh exceeded the MRLs for BHC and heptachlor epoxide by 122 times and 52 times, respectively. Chlordane and hexachlorobenzene concentrations were also found to exceed MRLs in some samples taken off the Sydney coast, and other organochlorine pesticides including dieldrin, oxychlordane and the DDTs were also detected. In 1989, fishing was prohibited within 500 m of the main outfalls. Further studies around the new deep water ocean outfalls (Mann & Ajani 1991) have indicated the presence of organochlorine pesticides in the flesh of rubberlip morwong (Nemadactylus douglasii), and 65% of the samples taken from 30m depth contained organochlorines higher than the National Health & Medical Research Council's MRLs [see NH&MRC (1988) for details of MRL standards applying to pesticides, agricultural chemicals and noxious substances in food].

Polychlorinated Biphenyls (PCBs)

The presence of PCBs in Australia's coastal environment has been reviewed by Richardson et al. (1987). The major regional study of PCBs in Australia was undertaken in Port Phillip Bay, Victoria during the mid to late 1970s (Richardson & Waid 1982; Richardson 1983). This survey utilised the U.S. 'Mussel Watch' approach, which uses mussels (e.g. Mytilus edulis) as 'sentinel' (or nonmotile, indicator) organisms. Bivalve shellfish (such as mussels and oysters) have been used as indicators of contamination in many studies worldwide. The successful use of bivalves is based upon the sedentary nature of the organisms and their ability to accumulate contaminants from the water column in proportion to that in surrounding waters.

In Port Phillip Bay, PCBs were found in all 87 samples of shellfish and in 27 sediment samples. Highest concentrations occurred near the densely populated and industrialised areas of Melbourne and Geelong, whilst lowest concentrations occurred offshore or near localities distant from urbanised areas. Little follow-up work has been done on PCBs in Victoria, but limited sampling (see Richardson et al. 1987; Phillips et al. 1992) has shown that PCB concentrations in Corio Bay, near the city of Geelong, have fallen markedly whilst those in Hobsons Bay near Melbourne have remained similar to those recorded in the late 1970s. The explanation for the fall in Corio Bay concentrations is believed to be related to the closure of an industrial tip in the locality (Richardson et al. 1987).

In other areas of Australia, few surveys of PCBs have been conducted. In Queensland, PCBs have been detected in fish samples from the Brisbane River (Shaw & Connell 1980), and in low concentrations in corals, fish and dugong from the Great Barrier Reef and the Gulf of Carpentaria (Smillie & Waid 1984). These latter data are representative of the low levels of contamination in remote areas. However, in the Sydney area PCBs have been detected in mullet (Mugil cephalus) caught in Port Jackson and Botany Bay (Woollard & Settle 1978; State Pollution Control Commission 1979), and in red morwong off Malabar. It is notable that more recent surveys of the Sydney sewage outfalls (Lincoln Smith & Mann 1989a) have recorded a continued decrease in PCB concentrations, presumable due to the restrictions placed on the use of PCBs in the mid 1970s and efforts to more appropriately dispose of the substances in recent years.

PCBs have been measured in Australian surface waters by Tanabe et al. (1982). Concentrations were highest in near-shore waters, but overall the levels measured were less than those in the Atlantic.

Dioxins and dibenzofurans

Although dioxins and dibenzofurans are recognised as significant waste problems in the Australian environment (see Thompson et al. 1992), few studies of these substances have been made in the marine environment. This is largely due to the lack of local analytical capability and the expensive nature of analyses, which require high resolution gas chromatography/mass spectrometry to detect extremely low concentrations. At present, the only published studies have been in urbanised areas, or associated with pulp and paper mills.

In Sydney, dioxins have been measured in Homebush Bay, adjacent to contaminated landfill sites. Dioxins (including 2,3,7,8-TCDD) were measured in fish and sediments, and as a result fishing has been banned in the area (Rubinstein & Wicklund 1991). In Melbourne, dioxins and dibenzofurans have been measured in association with the sewage system and in the sediments of Port Phillip Bay (Thompson et al. 1992; Phillips et al. 1992). In general, the more toxic forms of dioxins and dibenzofurans were present in low concentrations.

Low concentrations of 2,3,7,8-TCDD and its related dibenzofuran (2,3,7,8-TCDF) have been found in effluents to marine receiving waters from 3 of 4 pulp mills in Australia using chlorine bleaching processes (Thompson et al. 1992). Due to the risk of contamination associated with the pulp and paper industry, Australia is currently increasing its research capability with regard to dioxins and dibenzofurans through the National Pulp Mills Research Program , and a more definitive picture of the influence of this source of dioxins and dibenzofurans is expected in the future.

Other chlorinated contaminants

Little work has been undertaken to date on other, unknown chlorinated compounds in marine waters. Total AOXs are measured in pulp mill effluents and in certain sewage discharges, but at the moment few data are available for review, and no statement can be made about their status in the Australian marine environment. This is an area in which further research is urgently required in this country.

Environmental effects of organochlorine contaminants

Connell (1981) and ANZEC (1991) have summarised the effects of organochlorines in the marine environment. These include, for example, fish kills associated with waters near agricultural areas receiving organochlorine pesticide treatment; peregrine falcon eggshell thinning associated with DDT concentrations; sublethal effects on crabs as a result of DDT in surrounding waters; and possible synergistic effects of DDTs and PCBs on algae. It is notable from these reviews that there have been very few studies of the effects of organochlorines on Australian species, and it is fair to assume that this is more a reflection of a lack of research effort rather than a lack of contamination in local waters (ANZEC 1991).

Consideration of the effects of organochlorines in the Australian marine environment is mainly based on the results of overseas investigations, and local evidence of specific effects relies more on anecdotal evidence than hard, scientific fact. Studies in Australia have mostly defined the occurrence and distribution of organochlorines in marine biota rather than investigating possible effects. Furthermore, in contrast to the routine chronic toxicity testing (using local species) of effluents discharged to the marine environment in such countries as the United States, there remains a lack of specific tests which can be applied to the Australian marine environment. This is a situation which urgently requires attention, and should be the subject of an intensive research effort in this country (Martin & Richardson 1991).

With regard to the possible effects of persistent organochlorines on human health, ANZEC (1991) notes that the majority of fish eaten by Australians is taken from waters which contain relatively low concentrations of organochlorine contaminants. This statement is based on the results of regular market basket surveys by the National Health and Medical Research Council (NH&MRC), which examine the concentrations of such organochlorine compounds as aldrin, BHC, DDT and its metabolites, dieldrin, heptachlor, HCB, lindane and PCBs in foods including fish. Of these contaminants, only DDE and PCBs were detected in locally caught or imported fish samples, and dietary intakes have been estimated to be below the Food and Agriculture Organisation and World Health Organisation acceptable daily intakes.

Monitoring programs related to organochlorines

The relative paucity of data relating to organochlorines in the Australian marine environment is a direct result of the lack of monitoring activities which have been undertaken to date. Of particular note is the lack of consistent nationwide data upon which a definitive statement may be made regarding the status of organochlorine contamination. Such data are unlikely to be based on analyses of waters alone, given the analytical problems associated with the very low concentrations usually encountered in waters. Rather, a network of sites at which bio-accumulator organisms (e.g. bivalve shellfish) are analysed seems a more reasonable alternative, despite the fact that different organisms may have to be used to cover the range of environments found around the Australian coastline. A monitoring network of this nature has been suggested to the Federal Government by Bremner and Richardson (1986).

Martin and Richardson (1991) have recently reviewed marine contaminant monitoring practices in Australia, relating them to those in California. They note that there are many similarities between the two localities, and that monitoring activities in both California and Australia have suffered (to a greater or lesser extent) from the same deficiencies. These include:

Martin and Richardson (1991) note that current practices of marine contaminant monitoring in many parts of Australia are in need of a thorough review, and that new programs with well defined aims and objectives need to be developed. Perhaps most importantly, a commitment needs to be made to these programs such that they deliver long-term, reliable information upon which future policy in Australia can be established or refined.

Management of organochlorines in Australia

Thompson et al. (1992) have reviewed the current management practices and legislative requirements relating to hazardous wastes (including organochlorines) in Australia. They note that the Australian regulation of chemicals and hazardous wastes is extremely complex due mainly to:

As an example of the multitude of legislation which confounds the regulation of organochlorines in Australia, Thompson et al. (1992) cite New South Wales, where 72 pieces of legislation administered by 19 departments relate to the control of toxic and hazardous chemicals. They discuss aspects of the Federal regulation of organochlorines in the areas of control of agricultural and veterinary chemicals, the control of industrial chemicals, the management of intractable wastes, the regulations surrounding sea dumping, and highlight areas where improvements are being made, including:

Summary

Despite the fact that organochlorines are recognised internationally as important contaminants in marine environments, few well designed studies have been implemented in Australia to elucidate local occurrence and distribution. Those which have been performed suffer from several problems, including the lack of adequate definition of monitoring objectives. At present, it is impossible to determine whether organochlorines are significant contaminants in Australian coastal waters, but the best evidence suggests that, as is the situation in Northern Hemisphere countries (see GESAMP 1990), organochlorines occur in highest concentrations close to urban and industrialised centres, or where run-off from rural areas has a major influence. In order to develop and maintain an adequate level of environmental protection, there remains a need in Australia to embrace nationwide monitoring programs for the continued surveillance of organochlorine compounds, and to develop an analytical capability sufficient to allow the quantification of dioxins and dibenzofurans. Techniques for assessing the chronic toxicity of organochlorines in local waters also need to be developed.

References

ANZEC (Australian and New Zealand Environment Council) 1991, Persistent Chlorinated Organic Compounds in the Marine Environment. Public Information Paper, Australian and New Zealand Environment and Conservation Council, Canberra.

Brodie, J.E. 1989 (unpub.), The State of the Marine Environment in the South Pacific Region -- A Review for the SPRGP Region as a Contribution to the GESAMP Global Review of the State of the Marine Environment 1989, report to the United Nations Environment Program.

Bremner, A.J. & Richardson, B.J. 1986, Australian National Bioaccumulator Network: Final Report., Internal Report no. 139, Marine Science Laboratories, Queenscliff, Australia.

Connell, D. 1981, Water Pollution. Causes and Effects in Australia and New Zealand, 2nd edn, University of Queensland Press, St Lucia, Queensland.

Farrugia, A.J. 1986, Assessment of Organochlorine Pesticides in the Urban Environment, Especially Aldrin, Chlordane, DDT, Dieldrin, Heptachlor and Lindane, Assessment Report 86/3, State Pollution Control Commission, NSW.

GESAMP 1990, The State of the Marine Environment, IMO/FAO/UNESCO/ WMO/WHO/IAEA/UN/UNEP Joint Group of Experts on the Scientific Aspects of Marine Pollution, Blackwell Scientific Publications, London.

Kopperman, H.L, Kuehl, D.W. & Glass, G.E. 1975, Chlorinated compounds found in waste treatment effluents and their capacity to bioaccumulate, in Water Chlorination, Environmental Impact and Health Effects, eds R.L. Jolley, H. Gorchev & D.H. Hamilton Jr., vol. 1, Ann Arbor Science Publishers Inc, Ann Arbor, Michigan.

Lincoln Smith, M.P. & Mann, R.A. 1989a, Bioaccumulation in Nearshore Marine Organisms. I. Organochlorine Compounds and Trace Metals in Rocky Reef Animals Near the Malabar Ocean Outfall, State Pollution Control Commission, Sydney.

Lincoln Smith, M.P. & Mann, R.A. 1989b, Bioaccumulation in Nearshore Marine Organisms. II. Organochlorine Compounds in the Red Morwong, Cheilodactylus fuscus, Around Sydney's Three Major Sewage Ocean Outfalls, State Pollution Control Commission, Sydney.

Mann, R.A. & Ajani, P. 1991, Sydney Deepwater Outfalls, Pre-Commissioning Phase. Volume 11. Contaminants in Fish, State Pollution Control Commission, Sydney.

Martin, M. & Richardson, B.J. 1991, 'Long term contaminant biomonitoring: views from southern and northern hemisphere perspectives', Marine Pollution Bulletin, vol. 22, pp. 533-537.

Murray, A.P. 1987, Hydrocarbons and Chlorinated Hydrocarbons in the Sediments of Port Phillip Bay (Australia), MSc thesis, Deakin University, Geelong, Australia.

NH&MRC (National Health and Medical Research Council) 1988, MRL Standard. Standard for Maximum Residue Limits of Pesticides, Agricultural Chemicals, Feed Additives, Veterinary Medicines and Noxious Substances in Food, AGPS, Canberra.

Olafson, R.W. 1978, 'Effects of agricultural activity on organochlorine pesticides in hard corals, fish and molluscs from the Great Barrier Reef', Marine Environmental Research, vol. 1, pp. 87-107.

Olsen, A.M. 1988, Pesticide Levels in Some Marine and Freshwater Fish of South Australia, Fisheries Research Paper no. 19, Department of Fisheries, South Australia.

Phillips, D.J.H. 1993, 'Bioaccumulation', in Handbook on Ecotoxicology, ed P. Calow,Blackwell Scientific Publications, London.

Phillips, D.J.H., Richardson, B.J., Murray, A.P. & Fabris, J.G. 1992, 'Trace metals, organochlorines and hydrocarbons in Port Phillip Bay, Victoria: a historical perspective', Marine Pollution Bulletin, vol. 25 (5-8), pp. 200-217.

Portmann, J.E. 1974, 'Persistent organic residues', in Discharge of Sewage From Sea Outfalls. Proceedings of an International Symposium, ed A.L.H. Gameson, Pergamon Press, London.

Richardson, B.J. 1983, Polychlorinated Biphenyls (PCBs) in the Victorian Environment and their Interactions with Micro-organisms, PhD thesis, La Trobe University, Melbourne, Australia.

Richardson, B.J. & Waid, J.S. 1982, 'Polychlorinated biphenyls: an Australian viewpoint on a global problem', Search, vol. 13, pp. 17-25.

Richardson, B.J., Smillie, R. & Waid, J.S. 1987, 'Case history: the Australian ecosystem', in PCBs and the Environment, vol. 3, ed J.S. Waid, CRC Press, Boca Raton, Florida, pp. 241- 263.

Rubinstein, N. & Wicklund, J. 1991, Dioxin Contamination of Sediment and Marine Fauna in Homebush Bay, State Pollution Control Commission, Sydney.

Shaw, G.R. & Connell, D.W. 1980, 'Polychlorinated biphenyls in the Brisbane River Estuary, Australia', Marine Pollution Bulletin, vol. 11, pp. 356-358.

Smillie, R.H. & Waid, J.S. 1984, 'Polychlorinated biphenyls and organochlorine compounds in Great Barrier Reef biota', inWorkshop on Contaminants in Waters of the Great Barrier Reef. Report of Proceedings, Great Barrier Reef Marine Park Authority, Townsville, Australia.

Smillie, R.H. & Waid, J.S. 1987, 'Polychlorinated biphenyls and organochlorine pesticides in the Australian fur seal, Arctocephalus pusillus doriferus ', Bulletin of Environmental Contamination & Toxicology, vol. 39, pp. 358-364.

State Pollution Control Commission 1979, Toxic Chemicals. Environmental Control Study of Botany Bay, State Pollution Control Commission, Sydney, Australia.

Tanabe, S., Kawano, M. & Tatsukawa, R. 1982, 'Chlorinated hydrocarbons in the Antarctic, Western Pacific and Eastern Indian Oceans', Trans. Tokyo Univ. Fish., vol. 5, pp. 97-109.

Thompson, G.B., Chapman, J.C. & Richardson, B.J. 1992, 'Disposal of hazardous wastes in Australia: implications for marine pollution', Marine Pollution Bulletin, vol. 25 (5-8), pp. 155-162.

Woollard, P. & Settle, H. 1978, 'PCB residues in mullet, Mugil cephalus, fed to captive Eastern Australian water rats, Hydromys chrysogaster ', Bulletin of Environmental Contamination and Toxicology, vol. 20, pp. 606-612.

This technical contribution by Dr B. Richardson was reviewed by G. Shaw, National Research Centre for Environmental Toxicology, University of Queensland, Queensland.