Nukes and Lib Dems: a response

Science is about testing assumptions; politics is generally about confirming them.

In his response to my column on the Liberal Democrats' policy on nuclear power, the party's environment spokesman, Simon Hughes, takes me to task for my "polemical" approach. I can only apologise if my writing style offends. I had supposed that putting things bluntly might be the best way to communicate with politicians who put populism ahead of good sense.

Hughes reiterates his assertion that nuclear power has detrimental effects on people's health. Unfortunately, the particular study he cites to justify this assertion supports my argument, not his. I will try to explain why below, using numbers where necessary and giving scientific references for other cited studies in the text.

Let's begin by looking in detail at the single German study Hughes bases his anti-nuclear argument on. Published in 2008 and generally referred to as the KiKK study, it appeared to show a relationship between a child's risk of contracting leukaemia and distance between the child's residence and the nearest nuclear power plant.

At first pass, this looks worrying, and campaigning groups quickly picked up on these results to trumpet a 120 per cent increase in childhood cancer rates (Hughes mentions "a doubling of the incidence of childhood leukaemia").

But let's look at the figures, rather than the propaganda. First, the numbers when expressed in percentage terms sound scary, but in absolute terms are rather small. (Yes, I realise that any child getting leukaemia is a terrible thing, but please let's refrain from emotive point-scoring.)

The study looked at children living within a five-kilometre radius of Germany's 16 nuclear installations over a 23-year period. It found 37 cases of leukaemia when statistically 17 would have been expected. That is about one extra case of leukaemia in the entire country each year -- hardly a major indictment of an entire industry, even if nuclear power were the cause of the increased incidence, which it almost certainly isn't.

Second, and more importantly, the study does not suggest any causal relationship between radiation emissions from the power plants and the increased cancers, a point that the authors explicitly acknowledge. Again, at first pass this seems odd. We know that exposure to environmental ionising radiation can cause leukaemia. We know that there seems to be an (admittedly tiny) increase in leukaemia around some nuclear power stations. It is safe to assume that nuclear power stations release some radiation. Case proven, right? Wrong.

Influence of a world-view

Here we go right to the heart of the matter. The assumption that living near a nuclear power station delivers a significant dose of radiation -- implicit in Hughes's response and most anti-nuclear discourse on the subject -- does not stand up to scrutiny.

As the German study itself points out, the annual natural radiation exposure is about 1.4 milliSieverts, and average exposure from medical procedures (X-rays and the like) is about 1.8 milliSieverts. A companion study gives precise figures for the additional doses of radiation for those living near German nuclear power plants: "cumulative exposure to atmospheric discharges" for a 50-year-old person in 1991 living five kilometres from one of the nuclear plants would range from 0.0000019 mSv at Obrigheim station to 0.00032 mSv at Gundremmingen station.

For anyone who is unhappy with numbers (including, I suspect, Simon Hughes), the original study makes very clear that additional "radiation exposure near German nuclear power plants is a factor of 1,000-100,000 less" than natural background levels. Given that these levels vary by more than a factor of ten between different regions for entirely natural reasons (such as differing geology), it is vanishingly unlikely that tiny amounts of additional radiation from nuclear power stations causes leukaemia among children.

So why, in that case, is there a statistical correlation, albeit a very minor one? There is no easy answer to this, another problem with basing one's world-view on science rather than prejudice. Looking at other studies may help, however.

As long ago as 1989 a paper published in the Lancet found that "excess mortality due to leukaemia and Hodgkin's disease in young people who lived near potential [nuclear] sites was similar to that in young people who lived near existing sites". In other words, cancer clusters appeared around sites at the planning stage, well before any radiation exposure might have occurred -- and persisted even if no nuclear facilities were ever built.

Studies have also found that cancer rates around nuclear facilities remained unchanged before and after start-up: in other words, where cancer "clusters" existed, they were already in evidence before any radiation was produced. Once again, this raises more questions than answers, but suggests that radiation exposure has nothing to do with it.

A further piece of evidence comes from the site of the world's worst nuclear accident, at Chernobyl. That children were exposed to major doses of radiation here is not in doubt: one study looking at childhood leukaemia in Belarus, Russia and Ukraine (published in the International Journal of Epidemiology) found that the median exposure to participants in the study was about 10 milliGray (the change in units is to do with biological doses received, but, for our purposes, Grays and Sieverts are roughly comparable) -- about ten times natural background levels. Even so, the authors concluded that their study "provides no convincing evidence of an increased risk of childhood leukaemia as a result of exposure to Chernobyl radiation".

Cause and effect

Why does this matter? Because if children near Chernobyl who were irradiated with doses 100,000 or more times that received by German children living near nuclear plants did not show statistically significant increases in leukaemia, then the conclusion is obvious: once again, it is incredibly unlikely that German nuclear power stations are causing leukaemia in kids. (I say "incredibly unlikely" advisedly: a relationship can never be ruled out with absolute certainty. Science is like that, Simon.)

So what explains the German leukaemia clusters? No one knows. One theory is that population mixing in rural areas, which already show higher-than-average rates of leukaemia, is somehow to blame. A possible infectious agent has been suggested as a transmission pathway for leukaemia; yet none has been identified.

Statistical accidents may also explain much of the mystery. Most of the leukaemia clusters involve tiny numbers of people (another cluster around the Krummel nuclear plant in Germany involved five individuals, while the much-discussed Sellafield cluster involved 12 cases over 40 years), making any statistically significant conclusions incredibly difficult.

Leukaemia clusters have been found in villages in Scotland and Germany which are miles from the nearest nuclear plant, and where no causative agent is suggested. Studies of nuclear sites in other countries, including Canada, France, Israel, Japan, Spain, Sweden and the US, have found no cancer clusters of any sort.

In the interests of brevity, I will skip the rest of Hughes's accusations -- even though I note that they sound a little, er, polemical to me. I only wish to note that, in identifying me as a Conservative supporter, Hughes must also be a convert to telepathy as well as mind control: I have never written anything suggesting that I will vote Conservative; indeed, I have not yet decided which way to turn on 6 May.

I'll leave this with one observation. Science is about testing assumptions; politics is generally about confirming them. I wish it were different, but Simon Hughes will need to demonstrate more open-mindedness in future if he is to provide evidence to the contrary.


Mark Lynas has is an environmental activist and a climate change specialist. His books on the subject include High Tide: News from a warming world and Six Degree: Our future on a hotter planet.
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The tale of Battersea power station shows how affordable housing is lost

Initially, the developers promised 636 affordable homes. Now, they have reduced the number to 386. 

It’s the most predictable trick in the big book of property development. A developer signs an agreement with a local council promising to provide a barely acceptable level of barely affordable housing, then slashes these commitments at the first, second and third signs of trouble. It’s happened all over the country, from Hastings to Cumbria. But it happens most often in London, and most recently of all at Battersea power station, the Thames landmark and long-time London ruin which I wrote about in my 2016 book, Up In Smoke: The Failed Dreams of Battersea Power Station. For decades, the power station was one of London’s most popular buildings but now it represents some of the most depressing aspects of the capital’s attempts at regeneration. Almost in shame, the building itself has started to disappear from view behind a curtain of ugly gold-and-glass apartments aimed squarely at the international rich. The Battersea power station development is costing around £9bn. There will be around 4,200 flats, an office for Apple and a new Tube station. But only 386 of the new flats will be considered affordable

What makes the Battersea power station development worse is the developer’s argument for why there are so few affordable homes, which runs something like this. The bottom is falling out of the luxury homes market because too many are being built, which means developers can no longer afford to build the sort of homes that people actually want. It’s yet another sign of the failure of the housing market to provide what is most needed. But it also highlights the delusion of politicians who still seem to believe that property developers are going to provide the answers to one of the most pressing problems in politics.

A Malaysian consortium acquired the power station in 2012 and initially promised to build 517 affordable units, which then rose to 636. This was pretty meagre, but with four developers having already failed to develop the site, it was enough to satisfy Wandsworth council. By the time I wrote Up In Smoke, this had been reduced back to 565 units – around 15 per cent of the total number of new flats. Now the developers want to build only 386 affordable homes – around 9 per cent of the final residential offering, which includes expensive flats bought by the likes of Sting and Bear Grylls. 

The developers say this is because of escalating costs and the technical challenges of restoring the power station – but it’s also the case that the entire Nine Elms area between Battersea and Vauxhall is experiencing a glut of similar property, which is driving down prices. They want to focus instead on paying for the new Northern Line extension that joins the power station to Kennington. The slashing of affordable housing can be done without need for a new planning application or public consultation by using a “deed of variation”. It also means Mayor Sadiq Khan can’t do much more than write to Wandsworth urging the council to reject the new scheme. There’s little chance of that. Conservative Wandsworth has been committed to a developer-led solution to the power station for three decades and in that time has perfected the art of rolling over, despite several excruciating, and occasionally hilarious, disappointments.

The Battersea power station situation also highlights the sophistry developers will use to excuse any decision. When I interviewed Rob Tincknell, the developer’s chief executive, in 2014, he boasted it was the developer’s commitment to paying for the Northern Line extension (NLE) that was allowing the already limited amount of affordable housing to be built in the first place. Without the NLE, he insisted, they would never be able to build this number of affordable units. “The important point to note is that the NLE project allows the development density in the district of Nine Elms to nearly double,” he said. “Therefore, without the NLE the density at Battersea would be about half and even if there was a higher level of affordable, say 30 per cent, it would be a percentage of a lower figure and therefore the city wouldn’t get any more affordable than they do now.”

Now the argument is reversed. Because the developer has to pay for the transport infrastructure, they can’t afford to build as much affordable housing. Smart hey?

It’s not entirely hopeless. Wandsworth may yet reject the plan, while the developers say they hope to restore the missing 250 units at the end of the build.

But I wouldn’t hold your breath.

This is a version of a blog post which originally appeared here.

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