This is a final version submitted for publication. Minor editorial changes may have subsequently been made.
Sydney-siders were shocked earlier this year when they were told by the media that fish caught near their coastline were massively contaminated with organochlorines. The impact on the fish markets was immediate. Fish sales declined dramatically costing the industry an estimated $500,000 each week. Many people blamed the media for this. It was assumed that scientific studies had been sensationalised and distorted in order to sell newspapers or improve ratings. The director of the Southern California Coastal Water Research Project who was visiting Sydney at the time advised government scientists and engineers:
The recent events in Sydney indicate a route of communication to the public from the scientists should be developed. This may reduce the "scare" from the press and shield the fishing industry from impacts produced by false or inaccurate media reporting.
However the two studies that were the basis for media stories were reported accurately and did not overstate the results. The first study, which triggered the media attention, was the 1987 Malabar Bioaccumulation Study. The results of this study are shown in Table 1 & 2. The Sydney Morning Herald reported the results as follows:
FISH OFF SYDNEY BEACHES POLLUTED
Secret tests on fish caught near Sydney's main sewage outfall at Malabar have found dangerous levels of pesticides, up to 120 times above the recommended safety limits...
The red morwong had average concentrations of BHC of 1.22 parts per million, with the blue groper showing 0.20 parts per million. For HPTE, the red morwong showed average levels of 2.60 parts per million, with the blue groper 0.25 parts per million.
There were also traces of dieldrin in both fish, with the red morwong being slightly over the recommended maximum levels.
In fact the levels of BHC (Benzene Hexachloride) were on average 122 times the National Health & Medical Research Council (NH&MRC) maximum residue limits and the worst fish had much higher levels (250 times NH&MRC limits). The newspaper did not even mention the heavy metal contamination of the fish. What the scientists and engineers involved really objected to had far more to do with their loss of control of this information than the accuracy of the reporting. Various government bodies and politiicians had kept this study quiet for a year and a half. The Herald had not only published the information (which had been leaked to them) but interpreted the levels of pesticides in the fish as being "dangerous".
In this paper I would like to point out that dissatisfaction with the media's reporting of scientific studies is sometimes really a manifestation of a wider struggle over the control of information and its meaning. The results of studies which are commissioned for a purpose generally have political and social implications and various groups have an interest in how such studies are reported. These groups generally avoid presenting people with raw data that they can judge for themselves and dislike journalists making their own judgements or seeking the judgements of outside experts.
The two bioaccumulation studies undertaken in Sydney in 1987 and 1988 were at the centre of a wider controversy over sewage pollution in Sydney and as a result they were the focus of a just such a struggle to control the flow and interpretation of information to the public. Media reporters, far from being the villains of the piece, were pawns in a power struggle, praised by environmentalists and rebuked by government scientists who blamed them for the public protest that ensued.
The first study, the Malabar Bioaccumulation Study, was commissioned by the New South Wales State Pollution Control Commission (SPCC) and commenced in March 1987. Its stated aim was to determine the concentrations of organochlorines and metals in rocky reef aquatic organisms adjacent to Sydney's largest sewage outfall at Malabar and so determine the potential for bioaccumulation of toxic chemicals by these organisms. At the time this shoreline ocean outfall was being extended almost four kilometres into deeper water and there was some public debate over whether this was enough to prevent pollution problems.
Sydney Water Board  engineers and their consultants argued that toxic waste did not accumulate in the sediments off Sydney's coastline and the deepwater outfalls would provide sufficient dilution and dispersion to ensure toxic waste would not be a problem. The data obtained from the study was to help the Water Board select organisms for inclusion in their environmental monitoring programme for the deepwater outfalls and to enable the Board to evaluate the beneficial effects of diverting the effluent into deeper water.
In December 1987 results of the study, shown in Tables 1&2, were presented to the Clean Waters Advisory Committee which is an advisory committee to the State Pollution Control Commission. Various State government departments and statutory boards are represented on the Clean Waters Advisory Committee including the Sydney Water Board, the Department of Health, the Department of Agriculture and Fisheries, the Department of Planning and Environment. All would have received the business papers containing the results of the Bioaccumulation Study. The Minister was almost certainly informed.
The study found large amounts of organochlorines in red morwong and blue groper caught near the Malabar outfall. The levels of metals in the fish caught at Malabar were mostly below NH&MRC limits but the Committee was told that this indicated that a negative correlation between organochlorines and trace metals in fish was likely. Evidence of a similar negative correlation had been obtained in fish off the Southern Californian coast.
The results were potentially very damaging to the Water Board. Not only did they indicate a failure of the Board's Trade Waste Policy but they suggested that toxic waste had in fact been accumulating in the seabed sediments. The SPCC could not avoid some blame for the situation as the agency that was supposed to be regulating what the Board was putting into the ocean.
There was disagreement over whether the results should be released. A meeting between senior officers of the Water Board and the SPCC was held in May 1988 to discuss the study. At the meeting, according to notes made of it by the SPCC, it was recognised that "spearfishermen consuming red morwong caught at Malabar could be at some health risk." The "question of public responsibility and the desirability of releasing the data" was discussed at length and the SPCC officers said that they thought the information indicated "potential health consequences".
The Water Board argued that the study should not be published because it was not conclusive and this view prevailed; the study was not released. The Board's planning manager later told the magazine Engineers Australia:
The criticism that by withholding the study results the board was potentially putting public health at risk had to be weighed up against the risk of causing unwarranted public concern and panic.
The first public indication that the study had been done came in September 1988 when the Herald received a tip-off and published a very small item reporting that two fish species off the coast of Malabar had been found to have traces of organochlorine pesticides in them. The deputy director of the SPCC, who had the advantage of interpreting data not available to the public, was reported as saying that "the concentration of the chemical [BHC] in the species was low and not a cause for concern." (This was the chemical that was on average 122 times the NH&MRC limit.)
"The point I would emphasise is that the levels are higher than we would like to see but only in a small number of samples taken," he said.
But we have been troubled by the detection of the chemicals in some of the samples, the very fact they are there is troubling us."
The Australian Underwater Federation immediately wrote to the SPCC to get the results of the study because of the ramifications for recreational fishermen, some of whom were members of their Federation. Their letter explained that they regularly held spearfishing competitions.
At these events, the competitors have found that certain species caught near outfalls have mushy, tainted flesh. The worst species is the red morwong, Cheilodactylus fuscus which they refuse now to eat.
The Federation was not informed of the results of the study despite the concerns of the SPCC officers about public responsibility. The SPCC annual report  mentioned the bioaccumulation study but, under pressure from the Minister for the Environment, gave no indication of any contamination.
Competing spearfishermen were not the only ones catching fish near the outfalls. Rock fishing is a popular pastime in Sydney and these people can catch large quantities of fish which they take home to their families and sell to fish shops and restaurants eager for freshly caught fish. It was not till the Herald was leaked the full results in January 1989, that these people were informed of the real extent of the contamination of the fish.
One person who was particularly concerned about this lack of public information was a woman whose husband had become a keen amateur fisherman. He had caught fish between North Head (site of Sydney's second largest outfall) and Long Reef and they had eaten fish three times a week for about three years until they read the Herald reports. The previous year her daughter had been born with severe and very rare abnormalities that were thought by two specialists to be genetically based, possibly a mutation caused by chemicals. The woman wrote to all Water Board members and State Pollution Control Commission members and various politicians to express her concerns. She said in that letter,
Because so few pregnant women in Sydney have eaten as much local fish as I did, it is impossible to establish whether there is an epidemiological link.
Cases such as my daughter's highlight the value of open public discussion and access to information. Had I known that Sydney's industrial waste went directly through the sewage system, or that there was evidence of toxins in fish caught in Sydney, I never would have eaten them. If I had not eaten them, the doubt about my daughter's abnormalities, however slight these may be, would not exist. If I had not eaten them, the concerns about the possible long term affects on my family's health would not exist.
A ban on fishing within 500m of the sewage outfalls was announced on the 24th February by the Minister for Agriculture and the Government also increased fines for selling fish on the black market. The Herald reported that the Minister still maintained that there was "conflicting evidence" on the level of contamination off sewage outfalls and said that the ban was temporary whilst more evidence was collected.
Having suffered politically from accusations of secrecy, the government was not able to keep the second bioaccumulation study quiet. They were constantly pestered by reporters for the results of this study and it was released at a press conference by the Minister for the Environment. The second study had involved taking 8 samples of red morwong at varying distances from the three major Sydney outfalls and testing them for organochlorines and metals. This second study also showed high levels of organochlorines, although different ones (see table 3). Chlordane, a pesticide, was found to be on average 12 times the NH&MRC maximum limits for fish caught within 3.5 km of Malabar and Hexachlorobenzene, HCB, an intractable waste produced by the ICI chemical plant at Botany, was found to be on average 3 times the NH&MRC limit within 3.5 km of Malabar. The analysis for heavy metals which was being done by the Water Board was incomplete but an interim report on those was released at the same time.
The Minister for the Environment admitted that both the organochlorine report and the heavy metal report contained disturbing results and that the three sewage outfalls were directly implicated in the fish contamination. He said that the SPCC, the Health Department and the Department of Agriculture would hold urgent discussions on whether the fishing ban imposed by Agriculture Minister should be extended. (The ban covered 500m around the outfalls but the study had shown that fish were contaminated between 500m and 3.5km from the outfalls.) The ban was not extended.
The organochlorine report contained a page or two on the implications of the results written by a senior Health Department scientist. It described a major outbreak of HCB poisoning occurred in Turkey when people ate contaminated grain. It was estimated that these people had consumed 50-100 mg of HCB per day for a prolonged period. On this basis, it argued that fish would have to be far more contaminated than the NH&MRC limits to cause acute symptoms in humans.
The concentration of HCB and chlordane found in red morwong could not be expected to produce acute toxic effects and the effect of long term consumption is unknown.
The various government authorities were upset that this 'reassurance' was not reported by the media, which merely reported how many times the NH&MRC limits the concentrations of organochlorines in fish were. This was later cited as an example of the irresponsibility of the media, which had failed to ensure that official interpretations of the information were transmitted to the public. Different tactics were therefore adopted when it came to the release of the finalised heavy metals report from the same study.
The interim report on metals in the red morwong released at the same time as the organochlorine report had included the concentrations of mercury, zinc, cadmium and copper and showed that average levels of mercury in fish caught at each site were consistently above NH&MRC maximum limits except around the Bondi outfall (see table 4). This finding went largely unnoticed since it was overshadowed by the large amounts of organochlorines in the same fish. The final heavy metals report compiled by the Water Board was released in July at a press conference held by the Minister of the Environment. It now also contained analyses for Arsenic, Selenium, Lead and Nickel (see table 4). This time the Minister had an expert at the press conference to ensure the correct interpretations were conveyed to the media.
By this time the fish industry was just beginning to recover from the blows received earlier in the year and the government was anxious to reassure people that it was safe to eat fish. Despite the fact that most of the fish sampled were over NH&MRC limits for mercury the Minister stated that the study showed there was no toxicological threat to humans from heavy metals discharged in effluent from ocean outfalls. The report was reviewed by Professor Cairncross who was present at the press conference. Cairncross compared average levels of mercury in the Sydney fish to the highest levels found in fish from Minamata Bay in Japan where more than one hundred people died and hundreds more were sick from mercury poisoning after eating the fish there. He concluded that "treated sewage as presently discharged does not constitute a hazard in terms of heavy metal accumulation"  and he stated at the press conference that that one would have to eat 50 kg of red morwong a week continually "to get any real trouble".
The media left the press conference with the impression that the new report gave the fish a clean bill of health. On television that night news reporters asked why the ban on fishing at the outfalls was not to be lifted now and the Minister for Agriculture said he thought the ban should be lifted. The Minister for the Environment was even reported in the Herald the next day as saying that the "study proved that the effluent which was being discharged from treatment plants at Malabar, Bondi and North Head was not deemed to be a health hazard for the fish."
What the public were not told was that these red morwong were the very same red morwong that had been analysed for organochlorines a few months earlier and far from being safe to eat or proving the sewage effluent was not a health hazard for fish had been a cause of the fishing ban being imposed in the first place. In fact, the tenor of the press conference and the declaration by Cairncross, caused the fact that NH&MRC maximum limits for mercury had been consistently exceeded to be given no significance by the media.
The government had almost succeeded in controlling the interpretation of the study but environmentalists stepped in the next day to point out what they saw as a deception. After this Cairncross was reported to have backed away from the statements he had made about the fish being safe to eat. Cairncross had said
I didn't mention the organochlorines because it was not in my brief and I wouldn't talk about them anyway...I made my comments on the basis that if there was no other contaminating factor, then the fish would be all right to eat... Obviously if there are organochlorines I think anyone who ate the fish from there would be very foolish.
SPCC officers were also annoyed at the way the heavy metals report had been released without them having a chance to review it. In an internal report by the manager of their chemistry laboratory the likely negative correlation between heavy metal and organochlorine bioaccumulation was again noted with references to support the concept. The report argued that the final metals report was poorly structured and should not have included the Cairncross review because he was ignorant of the organochlorine data available from the same fish samples. Because he did not examine "possible complex interactions between the bioaccumulation of different pollutants" it argued he was in no position to state that the sewage from the outfalls did not constitute a hazard in terms of heavy metal accumulation. Similarly, it argued, he was in no position to make recommendations concerning the threat to human health from eating fish caught at the outfalls.
The SPCC report also criticised the heavy metals report for only including mean levels of metals in fish caught at each site, since the mean could mask a large range. (Surprisingly, given the SPCC's regulatory role, it had not at the time been able to get the raw data from the Water Board although they had asked for it.) It argued that analysis of the fish livers should have been done since metals tend to be stored firstly in the livers as a detoxifying mechanism. The livers would therefore be a better indicator of bioaccumulation of heavy metals.
The heavy metals report was not the first report to be disputed in this way. Water Board officers had questioned the reliability of the analysis of the fish for organochlorines in the first Malabar bioaccumulation study. They stated "It is not unusual for studies of this nature to have high errors associated with them due to natural variations within the sample population." They claimed that the large amounts of Heptachlor Epoxide found in the study were really a sulphur compound. The SPCC officers had defended the results obtained. The second study had included an interlaboratory comparison study of four different laboratories so as to meet criticisms of the laboratory that had done the analyses for the first study. It concluded that only that laboratory and one other laboratory accurately detected a wide range of organochlorines. A third laboratory was found to be unsuitable for such analyses and a fourth was limited to accurate determinations of DDT compounds.
This interlaboratory study raised even more disputes. A senior chemist at the Department of Agriculture laboratories which was one of those included in the interlaboratory study was extremely critical of the second organochlorine report:
This report should not have been published because conclusions drawn from the findings are not supported by scientific evidence and lack credibility...I request that the SPCC be asked to retract those conclusions that suggest that our laboratory is unable to analyse fish for pesticide residues.
The Minister for Agriculture wrote to Tim Moore after both studies had been released to express his concern about the continuing publicity being given to the contamination of fish. He argued that very small errors in technique or measurement could seriously flaw the results when measuring minute amounts of chemicals in fish. He argued that reports of both studies were potentially erroneous because they had not been referreed "in the standard scientific manner".
I would appreciate it if you would ensure that media reporters are fully aware that these reports do not have the scientific standing that is being attributed to them... we should take all possible action to prevent the continuation of the unsubstantiated reporting which is doing so much needless damage to one of our State's most important industries.
An independent referees report subsequently procured generally approved of the studies saying that the "basic nature of the problem has been adequately identified and evaluated. Another review was made by the Director of the Southern California Coastal Water Research Project. He had no major criticisms of the studies. He commented that detection limits were very high so that some substances may have gone undetected and he suggested that polyethylene bags were not appropriate for storing samples in. Otherwise he agreed that both showed that red morwong were contaminated near the outfalls. He suggested, as a public relations strategy (and as a way of shaping perceptions of the meaning of the results):
After evaluating the best world-wide evidence for health risk from the various organochlorines, you might want to release to the press a comparative table to put the risks in line with others commonly accepted by the public.
The NH&MRC maximum residue limits also came under attack since it was those limits which were enabling the media to interpret the concentrations of organochlorines in fish as dangerous. When the red morwong in the second bioaccumulation study were found to have levels of mercury above NH&MRC maximum limits, those limits were described by various groups as being too low. For example, the Fisheries Division of the Department of Agriculture argued that background levels of mercury were naturally high in Sydney waters and the Health Department representative on the Water Board's environmental monitoring steering committee argued that the NH&MRC limits should not be interpreted as health limits.
The NH&MRC maximum residue limits are based on Australian dietary habits and what little is known about the toxicology of the substances in question. For example, for mercury, it has been estimated that an "average" human of 70 kg (which seems to imply an average adult male) can consume 0.3 mg of mercury each day and just be on the borderline of showing clinical symptoms of toxicity. It is assumed that such a person would eat no more than 59 g of fish a day or 410 g per week. From these assumptions the theoretical blood levels are calculated. A safety factor of ten is applied (and these safety factors vary for each toxic substance) and the maximum residue limit for mercury in fish is thereby worked out. The safety factor is necessary because many people, particularly children weigh a lot less than 70kg, because people may eat more than 410g of fish per week, because some people may be more sensitive than others and because little is known about long-term effects of eating mercury contaminated fish.
The Fisheries Research Institute has regular discussions with the Department of Health on this subject and the Institute Director noted that in those discussions
it normally becomes obvious that the health limits for some metals have been set far too low and even though it normally takes time we have managed to get these levels changed in some cases, again zinc levels in oysters is a good example.
Mercury was one of the limits that the Institute together with the Fish Merchants Association had been trying to get changed, yet it is difficult to see what basis these changes are made on, especially when, in the case of mercury, the safety factor is so small. The safety factors are larger for organochlorines, sometimes more than 100.
The larger safety factors for organochlorines have been used to argue that the fish sampled in the bioaccumulation studies were in fact not so bad. An SPCC information bulletin reassured the public:
The Department of Health considers that very large quantities of contaminated fish (e.g. a tonne) would have to be eaten before a person suffered pesticide poisoning. However the long-term effect of consuming fish and invertebrates containing organochlorines is not known.
In answering the letter from the woman whose daughter had been born with abnormalities, the Environment Minister's senior policy advisor, used similar reasoning to argue that the NH&MRC limits, "if just exceeded", were unlikely to produce symptoms in humans if ingested because of safety factors of at least 100 times. One would have to consume many thousands of kilograms of fish that had NH&MRC limits in them in order to acquire a lethal dose, she was told. This was of course of no comfort to the woman who was concerned about subtle reproductive effects not immediate toxic symptoms and who knew that the NH&MRC limits had been grossly exceeded, in some cases by more than 100 times.
The letter also included other 'reassurances' such as: chlordane has "not been shown" to be teratogenic in humans, HCB has "never been proven" to be a terotogenic compound (no mention of whether BHC or heptachlor expoxide were terotogenic), traces of pesticides occur in other foodstuffs, aldrin and deildrin are imported, heptachlor (found as heptachlor epoxide in fish), is imported and repackaged in Sydney, the discharge of HCB into the sewerage system "is strictly controlled". The woman naturally felt that the letter did not really address the issues and concerns she raised.
Clearly, various players in the debate over whether Sydney fish are contaminated chose to interpret the two bioaccumulation studies according to their own interests and to further those interests by restricting (or increasing) the flow of information and attempting to ensure that their interpretations of the studies were accepted.
Each participant in this controversy implicitly acknowledged that the truth did not automatically emerge from the data obtained in the studies but was up for grabs to whomever could successfully get their own interpretation accepted as the 'truth'. Science is a resource in the political arena and those who have best access to it and most control over it can shape interpretations and meanings. Criticisms of the media for false, inaccurate or distorted reporting are often made by disgruntled players who have lost power over interpretation or those who do not understand the game.