The Daily Bork

July 05, 2005

Green science, aka voodoo

So the Green representative for bad science and voodoo has found a report that says that big power lines increase miscarriages...

The report, by De-Kun Li of Oakland’s Kaiser Foundation Research Institute, shows an 80 percent higher rate of miscarriage amongst women exposed to more than 1.6 micro-teslas of magnetic forces. It was presented at a weekend health forum in Hamilton organised by opponents of Transpower’s Waikato mega-lines.

The Earth's clean-green and all-natural magnetic field strength varies between about 30 and 60 micro-Tesla. So wandering across a field will probably expose you to more change of "teslas of magnetic force" than the 1.6 micro-Tesla from a power line. Presumably we are talking about non-static or not slowly varying fields here, but not specified.

Oh yeah. Tesla is not a measure of force, you green dingbat. But what do we expect from those who can't separate beta and gamma radiation. So long as you scare people it doesn't matter about your level of honesty or literacy. Likewise

It is crucial that we do this before any decision is made on whether to put these 400Kvh lines near residential dwellings.

That is kV. k is kilo, not capitalised. V as in Volt, derived from some bloke's name therefore capitalised. Oh yeah, Tesla was a person to, so it is micro-Tesla. Both dead white men I know, but the convention is well set. And what pray tell is a 400 kVh line? Perhaps you mean 400 kV, since kVh would be a unit of well, not much sensible really. Even kVH would be Volt-Henrys, which again is not much sensible.

Here is another dead giveaway for anyone from NZ...

Claims that there may even be a biological effect from exposure to electro-magnetic radiation at levels below the current standard, first made by New Zealander Dr Neil Cherry many years ago, should be looked at, Ms Kedgley says.

Neil Cherry, RIP, was a scientific fraud who played on every possible community fear (mostly to do with children) to make money and influence people.

The paper from which all this is taken is

Li DK, Odouli R, Wi S, Janevic T, Golditch I, Bracken D, Senior R, Rankin R. A population-based prospective cohort study of personal exposure to magnetic fields during pregnancy and the risk of spontaneous abortion. Epidemiology. 2002;13:9-20

Which can be found online. The conclusion states

Our findings provide for the first time strong prospective evidence that prenatal
MMF exposure above a certain level (possibly around 16 mG) may be associated with SAB risk.

Which is very vague. Indeed the whole paper is full of conditionals

Although 12 mG would have been a better cutoff from the view of the
threshold effect, 16 mG was the only available cutoff point between 10 and 20 mG, chosen
before the data collection, upon which many parameters for exposure dose (e.g., total sum of MF,
duration, and number of times above the cutoff point) were constructed.

So the 1.6 micro-Tesla figure is arbitrary, chosen for convenience between 10 and 20 milli-Gauss. What if the "true figure", assuming a real effect, was 100 micro-Tesla?

The exposed women (MMF≥ 16 mG) were more likely to
have been employed before conception, to have had fever during pregnancy, and to have drunk
tap water; but they were less likely to have had a history of subfertility defined as failure in
conceiving after having had regular intercourse without contraception for more than 12 months.

Errrr, that seems to be a bit of a hole right there. Fever and tap water? Surely someone ought to investigate that.

Overall, I wouldn't be crapping myself about it until a better controlled study is done, ruling out things like fever for starters.


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