From BSE to Genetically Modified Organisms

Science, uncertainty and the precautionary principle.

How to Destroy the Beef Industry and Learn Nothing
Summary of Greenpeace report based on a report by Julie Sheppard:

"There is no reason to believe BSE will be any different from scrapie"
(John Gummer, Minister of Agriculture Fisheries and Food, 1990)

"There is no reason to believe that the genetic modification of the maize will give rise to any adverse effects on human health from its use in human food" (John Gummer, Secretary of State for the Environment, 1996)

*BSE showed how official decision-making fails to cope with scientific uncertainty. "No scientific evidence" was repeatedly taken to mean "no risk". Consequently risks that could and should have been avoided compromised the safety of the food chain.

*Fundamental questions about the nature of food production of major concern to the public were omitted by a decision-making process constrained by a narrow technical view.

*Risks from BSE and genetically modified organisms (GMOs) display striking similarities.

*Statements and mistakes identical to those made with BSE are already being made with GMOs.

*The Government is running political and economic risks in allowing the rapid commercialisation of genetically modified organisms for food production.

If in doubt...hope for the best?

As the BSE crisis developed, the authorities repeatedly cast the burden of proof as "prove it is unsafe" rather than "prove it is safe". Consequently decision-makers were always one step behind the progress of the disease through the food chain, as the chronology shows all too clearly.

In 1989 the Southwood Report stated:
"From present evidence, it is likely that cattle will prove to be a 'dead-end host' for the disease and most unlikely that BSE will have any implications for human health".

There was no evidence at the time as to whether cattle would prove to be a dead-end host. Southwood himself conceded that because of the long incubation period it would take at least another 10 years to determine whether the BSE agent could be transmitted to humans.

At a time when many major pet food manufacturers had voluntarily stopped using suspected offals in pet food, the Southwood working party did not even recommend a ban to stop these entering the human food supply via mechanically recovered meat, because, according to Southwood "we felt it was a no-goer" [with MAFF].

In 1990 the Tyrell Report stated:
"Many extensive epidemiological studies around the world have contributed to the current consensus view that scrapie is not causally linked with CJD. It is urgent that the same reassurance can be given about the effect of BSE on human health. The best way of doing this is to monitor all UK cases of CJD over the next two decades".

But rather than act cautiously, John Gummer, Minister for Agriculture asserted "we can say with confidence that beef can be eaten safely by everyone, both adults and children" and famously fed his 4-year old daughter Cordelia a beef-burger for photographers.

By 1994 CJD levels were double the late 1980s but in the absence of conclusive linkages Gillian Shephard, Minister of Agriculture stated "I should repeat that the Chief Medical Officer continues to advise that there is no evidence whatsoever that BSE causes CJD and, similarly, not the slightest evidence that eating beef or hamburgers causes CJD".

Only in 1996, too late, was the reality of the risk accepted:
referring to "ten cases of a new variant of CJD", Stephen Dorrell, Secretary of State for Health announced "the most likely explanation at present is that these cases are linked to exposure to BSE".

Decision-making in the face of scientific uncertainty

Scientific evidence has never excluded the possibility that BSE could be transmitted to humans.
Whilst scientists were insisting "there is no evidence so far" of BSE being transmitted to the human population, policy-makers preferred to talk of "zero" or "inconceivably low risk". These safe assertions were used to publicly justify limited precautionary action.

The evolution of new knowledge and evidence on BSE has important policy analogies with other areas of scientific uncertainty. The lack of scientific knowledge regarding the field behaviour and long-term impact of genetically modified organisms (GMOs), means that current risk assessments cannot be based on conclusive or quantitative evidence.

Despite these uncertainties, safety approvals for the marketing and growing of new GM crops are becoming routine in Europe. Official risk assessments of GMOs have tended to equate the absence of any evidence of risk with the conclusion of no or minimal risk.

We now know from the BSE case that this may prove to be a fallacious and dangerous assumption.

GMO risks mirror BSE risks

*Long latency

The link between BSE and CJD took a long time to show and was established only after active monitoring. Possible harm from GM foods, such as the commodity crops now entering the market, may take even longer to detect and establish.


As with BSE, the effects of GM could be serious and irreversible. Since genetically modified crops can out-cross with non-GM crops and wild relatives it may prove impossible to recall problem genes once released into the environment.

*Scientific uncertainty

As with BSE, there is considerable scientific uncertainty about the potential impacts of GM. GMOs mirror BSE in the way that scientific analysis assesses the risks as statistically small (unlikely or very unlikely) but the "improbable" case is potentially catastrophic.

The flawed response to BSE is being repeated with GMOs

*The pretence that the new practices and products are no different

The scientific and policy establishments made assumptions about BSE based on their knowledge of scrapie. These were subsequently shown to be misplaced.

The notion of "substantial equivalence" is the principle criterion deployed for assessing the safety of GM foods. If conventional chemical analysis and short-term toxicity tests on a GM food show similar results to its non-GM 'equivalent' then it is assumed to be as safe.

This framework would not have picked up the scrapie prion in sheep offal and is equally inadequate for GM foods.

*No evidence, no risk

Throughout the BSE crisis "no evidence" was equated, implicitly, with "no risk". This implicit assumption of safety is now echoed in official reassurances over GM crops and foods.

"There is no reason to believe BSE will be any different from scrapie"

(John Gummer, Minister of Agriculture Fisheries and Food, in letter to Lady Wilcox, Chairman National Consumer Council, dated 15 May 1990)

"The Scientific Committee on Food have confirmed that there is no reason to believe that the genetic modification of the GM maize will give rise to any adverse effects on human health from its use in human food"
(John Gummer, Secretary of State for the Environment, in letter to Peter Melchett, Executive Director Greenpeace, dated 23 Dec 1996)

*An experiment on the public and the environment

Laboratory tests or field trials leave considerable uncertainty. "Proof" will only come after GMO release into the environment when the long term effects on consumers can be assessed. The BSE crisis showed that waiting for this "proof" is not a defensible policy.

"The observations that 'nothing happened' in these hundreds of tests do not say much. In many cases, adverse impacts are subtle and would almost never be registered in scanning a field...the field tests do not provide a track record of safety but a case of 'don't look, don't find'."
(M Mellon & J Rissler (1995) Transgenic crops: USDA data on small-scale tests contribute little to commercial risk assessment, Bio/Technology 13:96)

*Saying 'NO'

Because science cannot give proof of safety, judgements have to be made about risk and its acceptability. But fears about undermining consumer confidence or damaging economic interests during the BSE crisis led to reassurances disproportionate to the degree of certainty which then existed.

With GMOs too, there is a temptation to deny any risk at all: "The information should state explicitly - There is no risk inherent in the technology itself. Thus, there are fool-proof safeguards that modified micro-organisms cannot engender diseases in man or the environment."
(DM Conning (1993) Biotechnology - influencing public opinion. BCPC Monograph No 55: Opportunities for molecular biology in crop protection pp299-304)

Even technical decision-making about GMOs is value-laden. There is a "taken-for-granted" assumption in the regulatory community that GM technology is the basis for future economic growth and, therefore, desirable. Those who advise governments on the risks of GMOs tend to be already working actively in the field of gene technology. Whilst the assessment is able to take advantage of their experience, it is also likely to be blinkered by their inability to question the underlying assumptions of GM.

*Who answers the 'Big Picture' questions?

The public were largely unaware, and subsequently shocked to discover, that animal remains were being fed to cattle and were responsible for causing BSE.

There was an implicit assumption that the public would be broadly supportive of measures that improved productivity. Subsequent outcry demonstrated that the public did not accept that the risks of such an "unnatural" practice were justified by the increased "efficiency" of meat production.

A similar disparity between public and official perceptions of GMOs is beginning to emerge. There is mounting evidence that the public is anxious about genetic modification. Many applications are seen as trivial and not justified in terms of the risks involved. Questions are raised about alternatives to GM and about whose interests are being served by developments.

Policy-makers ignore such societal sentiments at their peril. If subsequent problems do arise with the technology then it is not only the environment and public health at risk but the political, industrial and economic institutions which have under-written its development.

The analogies between the BSE crisis and the introduction of GM foods highlight a number of critical scientific, economic and political risk factors:

*the potential for serious harm which is unpredictable, irreversible and unmanageable

*a strong commercial dynamic driving rapid innovations

*official assertions of safety based on incomplete knowledge

*disparity between the basis on which the public and official institutions determine safety

*narrow risk assessment which fails to address the complex interactions between the technology and society

*public distrust in risk assessment and the institutions responsible for it

*a scientific and political culture incapable of responding to unforeseen outcomes

These factors represent a formidable political challenge to the existing risk culture, and show that current decision-makers and the UK Government are running considerable political risks in allowing GM food into the system.

Risk avoidance

A re-evaluation of the risks, need and justification for GM foods, one that extends beyond what is normally thought of as "risk assessment" is urgently required. Public health and the environment should be at the forefront. The approach adopted must be one of risk avoidance, not to hope that risks from GMOs will prove manageable once permitted into the system.

The lessons of the BSE crisis reverberate wider. The relationship of scientific expertise/advice to public policy is now under scrutiny. Scientific uncertainty should never again be so publicly disavowed nor the limitations to knowledge so actively concealed. Commercial excitement should not over-ride public concerns. Nor should safety assertions be clouded by political or commercial calculation.

We must learn from the BSE fiasco.

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