Friday, 6 March 2009

ICNIRP and guidelines

The RRT EMF conference in September 2008 brought together a number of the leading scientists in the EMF world on both the "there is insufficient risk to be concerned" group and the "there is sufficient risk for serious preventative action" group.

With both Mike Repacholi (ex head of the WHO international EMF project and current chairman emeritus of ICNIRP) and Paolo Vecchia (current actual chairperson of ICNIRP) talking candidly about the assessment of science used to formulate guidelines, it became very clear that there was a serious gap in addressing areas of scientific uncertainty. For example, Paolo Vecchia explained that ICNIRP guidelines were set to provide protection against scientifically "established" effects, and established effects only. Associations between EMFs and health effects such as cancers are discussed in ICNIRP documentation, but until the association is considered causal no attempt will be made to adjust the guidelines to cater for them.

To reach the status of an established effect, he explained that the supporting research must be:

  • peer-reviewed,
  • replicated by separate research groups,
  • consistently find the same effects at approximately the same magnitude, and
  • show a clear mechanistic cause and effect.
All four criteria must be fully met before an association can meet the subjectively defined criteria. Mike Repacholi explained that, for the purposes of defining causal mechanism, there are four separate scientific stages, in hierarchical order:
  1. physics (atomic and molecular interactions with forces),
  2. chemical (intracellular interactions between atomic and molecular entities with each other),
  3. biological (intercellular interactions, such as nerve signalling pathways, bystander effects etc), and then finally
  4. how these interactions then manifest themselves as health effects.
He explained that unless all (or at least most) of these stages can be identified, a causal relationship cannot be accepted. Without this, it is not possible to view the association as an established effect.

Neither of these two speakers denied that there was evidence of health effects far below these guidelines, but made it very clear that until the evidence was sufficiently strong to be considered causal it was a) not appropriate to use the evidence in the context of setting guidance levels, and b) not appropriate to present the evidence to public policy makers whilst uncertainty that remains. The idea of presenting more than one possibility and possible preventative measures with associated estimated levels of certainty was considered to be outside of their remit. This view was supported by Anders Ahlbom, and Mike Dolan made a statement to suggest that "policy makers expect one clear outlook that they can perceive as the "truth" that they can act on, and would not accept a document with multiple potential outcomes".

This of course is quite an assertion. The differentiation between research, risk assessment, and risk management is quite widely accepted. Research investigates theories and then publishes results. Risk assessors collate these results and calculate their likely impact. Risk managers read the risk assessments and decide on an appropriate proportional response. In his presentation at the conference, Anders Ahlbom was adamant that scientists should be responsible for the research, and the risk assessment, but policy decisions and risk management practises were in the realms of policy makers instead. To make this claim implies that there is a clear divide, without overlap, which cannot be the case: Risk management is tied implicitly into risk assessment. To decide what sort of interpretation of the results is reasonable (including the possibility of multiple interpretations and all of their potential impacts) is a fundamentally risk management decision, as the criteria used will be based on an evaluation of social and political priorities. Indeed, the EU's acceptance of the Precautionary Principle requires that public risk managers are made aware of reasonable concerns where harm may occur but where there is still considerable scientific uncertainty - this is only possible with a consideration of multiple outcomes with different weightings based on impact and levels of certainty.

By this criteria, it is clear for both ICNIRP and WHO that, to accept and publish an association between EMFs and a number of health effects, the certainty that the association is causal must be extremely high, in the region of 95 to 98% chance. It is worth bearing in mind that risk factors for smoking, asbestos, thalidomide, lead in petrol etc. would not have been identified using these criteria. This does not mean that they are an invalid approach per se, as it is very important to have assessment criteria for establishing effects that are beyond reasonable doubt, but it is next to useless for policy makers who are attempting to pre-empt large scale health catastrophes by making risk management judgements in areas of scientific uncertainty. Whilst proportionality is a crucial factor, it is not for risk assessors to decide to withhold significant information from public risk managers because of lack of "full scientific certainty".