Precaution

The precautionary principle

What is the precautionary principle?
How much evidence do you need to trigger the precautionary principle?
How do you then apply the precautionary principle?
Has a precautionary approach been adopted for EMFs?
What is happening in the UK?
What is the World Health Organization policy on precaution and EMFs?
Other applications of the precautionary principle

What is the precautionary principle?
There are lots of different definitions of the precautionary principle (and no single agreed one), but the essence is captured in the 1992 Rio Declaration on the Environment:

“Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.”

We list here some other definitions of the precautionary principle from various international statements.

How much evidence do you need to trigger the precautionary principle?
The European Commission suggest the precautionary principle may apply when:

“preliminary objective scientific evaluation indicates that there are reasonable grounds for concern”

The World Health Organization are moving away from the idea of “triggering” or “invoking” precaution at all, rather seeing it as an approach that should underpin all risk assessment.

How do you then apply the precautionary principle?
There have recently been two detailed discussions of the precautionary principle and how it might be applied in practice: one by the European Commission and the other by a UK Government committee. The European Commission summarise the application of the precautionary principle:

Where action is deemed necessary, measures based on the precautionary principle should be, inter alia:

• Proportional to the chosen level of protection
• non-discriminatory in their application
• consistent with similar measures already taken
• based on an examination of the potential benefits and costs of action or lack of action (including, where appropriate and feasible, an economic cost/benefit analysis)
• subject to review in the light of new scientific data, and
• capable of assigning responsibility for producing the scientific evidence necessary for a more comprehensive risk assessment. More on what these actually mean

Has a precautionary approach been adopted for EMFs?
Neither the UK Government nor the European Union has recommended precautionary actions over power-frequency EMFs. (This is different to mobile-phone frequencies, where the UK Government and NRPB have both accepted some of the recommendations of the Independent Expert Group on Mobile Phones for a precautionary approach.)

Some individual countries have adopted precautionary measures: Switzerland and Italy have precautionary exposure limits, and some of the Scandinavian countries have general precautionary policies. In parts of America and Australia, “prudent avoidance” measures are sometimes taken.

What is happening in the UK?
In March 2004, the NRPB recommended to Government:
“The government should consider the need for further precautionary measures in respect of exposure of people to EMFs. In doing so, it should note that the overall evidence for adverse effects of EMFs on health at levels of exposure normally experienced by the general public is weak. The least weak evidence is for the exposure of children to power frequency magnetic fields and childhood leukaemia.” more

The Government response says:
“Government has recently engaged in preliminary stakeholder discussions to consider power lines and NRPB advice suggests that this process should be continued, focussing on the possible health effects of continuous low level exposure to power frequency electromagnetic fields.
The Government will be exploring further the practical applications of precautionary measures within a stakeholder engagement process. This will be the subject of wide consultation and will explore any risks and benefits arising in the same manner as a Regulatory Impact Assessment.”
full response

The stakeholder discussions referred to are now known as SAGE – stakeholder advisory group on ELF EMFs. The SAGE First Interim Assessment contains detailed analyses of possible precautionary measures. More here.

What is the World Health Organization policy on precaution and EMFs?

WHO issued a Monograph and factsheet in 2007 which contain recommendations on precaution:

"When constructing new facilities and designing new equipment, including appliances, low-cost ways of reducing exposures may be explored. Appropriate exposure reduction measures will vary from one country to another. However, policies based on the adoption of arbitrary low exposure limits are not warranted."

More on the WHO recommendations on precaution.

The latest draft Framework was released in October 2004. The key conclusions are:

“Under the WHO Precautionary Framework, [childhood leukaemia] warrants a thorough consideration of precautionary measures including detailed cost-benefit or cost-effectiveness analyses”

and

“…even after fully allowing for the legitimate desire by society to err on the safe side, it seems likely that only very low-cost measures will be justified.”

more on this WHO Framework

The draft Framework is no longer available on the WHO web site but much of its thinking has been incorporated in the Environmental Health Criteria.

Other applications of the precautionary principle

Two publications give interesting and contrasting case studies of other issues where there has been scientific uncertainty.

The European Environment Agency report is called ”Late lessons from Early Warnings” and gives examples where it suggests early action could have prevented health or environmental problems.

By contrast, the American Council on Science and Health publish “Facts Versus Fears”, which gives examples where it suggests claims of health risks turned out to be unfounded or exagerated.

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