31/03/2004 - UK NRPB adopt ICNIRP Guidance levels

UK NRPB adopt ICNIRP Guidance levels

Today the UK NRPB announced that they are adopting the ICNIRP non-ionising guidance levels. They describe this as "precautionary", but it is difficult to see why or how it is. In the past they have resolutely stuck to the ICNIRP occupational exposure levels also for the general public and have not applied the further precautionary factor of typically 5, because they correctly stated that this extra factor was not justified by the science. The NRPB adopted the ICNIRP levels for the mobile phone bands in 2000 after the UK IEGMP (a.k.a. "Stewart") Report suggested that they did so, but they did not adopt them for other frequencies.

However, in the introductory "Board Statement" they do admit for the first time that power-frequency magnetic fields have been associated with an increased risk of childhood leukaemia and that the need for further precautionary measures should be considered by government. This is an excellent improvement on previous Board Statements and is likely, in part, to be due to the more pro-actively precautionary attitute of the new NRPB Board Chairman, Sir William Stewart. The Board advice is played down by terms such as "intense" (0.4 microtesla is "intense" ?? - but they set their new guidance level at 100 microtesla!) and "small" (is a doubling "small?") and "reasons that uncertain", but in the body of the document the increased risk is more genuinely defined. This is discussed below.

Both ICNIRP and the old NRPB levels are based on old, well established, science and proven gross effects such as electrocution and tissue heating. They generally agree on the levels for occupational exposure. This is set approximately 10 times below the level of gross, acute, harm. ICNIRP then adopt a further small factor for protection of the general public.

Neither the ICNIRP nor the old NRPB levels were based on possible long-term effects such as cancer, depression, suicide, miscarriage, etc - i.e. the guidance was not even intended to protect against these effects at all. So by adopting ICNIRP for the general public exposure guidance the NRPB have not really moved forward in any practical way from their previous guidance.

For example, at the 50 Hz mains electricity power frequency the guidance level comes down from 1600 microtesla to 100 microtesla. This sounds a big decrease - and it is - but not a practical one. Even under the largest, highest power overhead pylon power-line the 50 Hz magnetic field rarely exceeds 25 microtesla, and never exceeds 50 microtesla in places with public access. Typical highest fields are in the range 0.5 to 15 microtesla. UK household levels away from powerlines and underground cables are typically 0.03 to 0.05 microtesla.

Even the NRPB, in this new Guidance, Docs NRPB 15-2, describes 0.4 microtesla as an "intense magnetic field", so it is difficult to see how they think a limit of 100 microtesla will protect the public in any meaningful way. Countries such as Italy and Switzerland that have precautionary guidance have set levels between 0.2 and 1 microtesla as the maximum public exposure from new installations or in new houses and schools.

The NRPB do admit that a doubling of childhood leukaemia has been found in magnetic field levels of 0.4 microtesla and above. They, slightly misleadingly, say this increases the risk from 1 in 20000 to 1 in 10000 per year. They fail to point out that this is over 15 years of childhood, so the risk to any one child during their childhood increases from 1 in 1330 to 1 in 670. CHILDREN with LEUKAEMIA are holding a 5-day scientific conference in Westminster, London, in September 2004, to examine all the possible causes of childhood leukaemia with the specific aim of trying to find ways of stopping the increasing incidence of childhood leukaemia which has become the UK's biggest childhood killer disease.

They try to dismiss the importance of the electricity-childhood leukaemia association by saying that it only increases the annual 500 UK childhood leukaemia cases by 2. However the latest molecular genetics shows conclusively that the initial genetic damage is done in utero (i.e. in the womb) and so if the power-frequency magnetic fields (EMF) link is real (as we believe it is) then much of the genetic damage may be due to EMF exposure of the mother before the child is born. This has never been investigated. This is more likely because two recent studies linked miscarriage with maternal EMF expsoure over 1.6 microtesla - over 60 times lower that the new, so called precautionary, NRPB advice. Now, miscarriage may occur when the damage is too great for the foetus to stay viable, but lesser damage may result in the leukaemia genetic marker damage. Much more scientific and medical work needs to be done on this, but the indications are that for advice to be precautionary the maximum exposure guidance level for the general public would need to be around 0.2 microstesla.

We will add more comments here on this site on the NRPB advice during today (Wednesday 31st March).

Watch and listen to Jon Kay.

P5/04 31st March 2004 on the NRPB website is their Press Release which inlcudes links to download the documents.