Rational Agriculture

Readers of much of the UK press will have found environmental journalists getting somewhat over-excited this week. Headlines included the Guardian's Weed discovery brings calls for GM ban (but then the Guardian is always calling for this), the Scotsman's Green body's fury at 'superweed' in field of GM crops (with the constant state of fury and outrage that many environmentalists find themselves in, I worry about their blood pressure) and, from the Daily Mail The GM superweed - Gene trial spawns a wild plant that won't be killed off (which makes me even more concerned about the health of the average Mail reader, unless they're so used to scare headlines that they've lost their power to shock). Even the Sun was driven to print a story under the headline Superweed - Scientists find mutant GM pest in British countryside (which, at risk of causing offence, I might suggest to be a bit indigestible for the average reader of this illustrious organ).

And the reason for this almost universal shock and horror? Scientists at the Centre for Ecology and Hydrology published a report on a study to look for gene flow from GM herbicide-tolerant oilseed rape (grown on a trial basis during the recent government-sponsored Farm Scale Evaluations) to neighbouring plants. In the study, they collected over 95,000 seeds from plants related to rape, germinated them in greenhouses and looked for herbicide tolerance. They found just two (that's right, two) turnip rape plants (a closely-related species) tolerant to the weedkiller in question (glufosinate).

But the observation which sparked the "outrage" was the discovery of one plant (charlock - a common weed, but not closely related to rape) resistant to glufosinate in a field margin. On looking again next year, nothing was found. And, on such flimsy foundations, those people who just know that genetic modification is wrong, who having been looking unsuccessfully for so long for scientific confirmation, have built a story which is essentially a house of cards, ready to be demolished by the first breathe of rationality.

Fortunately, more balanced comments have appeared. Pride of place must go to Professor Joyce Tait in the Scotsman (We need to move past scare stories in the GM debate). Also notable were comments from Brian Johnson of English Nature. Brian has concerns about the potential environmental impact of some GM crops, but he also makes judgements based on the evidence. He was originally heavily mis-quoted by the Guardian, but his letter corrects this. To quote it in full:

"As the scientist quoted in your article (GM crops created superweed, say scientists, July 25), can I clarify that I specifically said the plants found during the research were not, in my view, "superweeds" because one of them appeared to have non-viable seed? I neither said nor implied that the plants found by the researchers would multiply rapidly or have a "huge selective advantage" - quite the opposite.

I did not say "there is every reason to suppose that the GM trait could be in the plant's pollen", but that it was just possible that the GM trait could be carried in the pollen, and the research did not analyse the pollen so we could not know if the trait was there, and, in any case, pollen from hybrids might not be viable.

Dr Brian Johnson, English Nature"

A case of irresponsible journalists clutching at (super)straws?

Michael Meacher, freed from his responsibilites as a government Minister, continues to make mischief and act as the willing mouthpiece of the environmentalist lobby. In today's Grauniad, in a piece entitled Indecent Exposure, he tries to scare us all about the (unsubstantiated) links between pesticides and ill-health.

According to him "Government figures just released reveal startling evidence of the continued increase in the use of pesticides, despite their known toxic damage to the environment and probably to human health. In the past decade, the area of crops sprayed with pesticides in the UK has increased by a further million hectares. The use of pesticides has increased by more than 30% in the same period, even though the area of land under cultivation has decreased."

What he ignores, of course, is fact that crude figures tell you nothing: it's the environmental impact which is important. Increasingly, farmers are turning to the principles of Integrated Crop Management and, via schemes such as LEAF (Linking Environment and Farming), obtaining high yields of good quality crops while using crop protection products when needed rather than on a precautionary basis. As for "toxic damage to the environment" we know that all farming methods, including organic, have a massive impact on the farmed environment. Nitrogen run-off can have the same effect on water courses whether the nitrogen has been chemically fixed or added to the soil as animal or green manure. The deep ploughing needed to control weeds in organic systems results in greater carbon loss and increased soil erosion.

But the most egregious phrase is "toxic damage...and probably to human health". The impression is that pesticides harm health, but the "probably" has to be included because there's no evidence to support the statement. The article goes on to raise more fears of the "linked to" and "associated with" type, in the absence of hard data.

Where the article does quote figures, it gets them wrong in its eagerness to target Man-made chemicals. According to Meacher "The recent findings, which suggest that farmers who have been exposed to pesticides are 43 times more likely to develop Parkinson's disease, confirm suspicions that date back years." In fact, the reference is to a recent University of Aberdeen study which found that farmers had a 43% (note to Michael, that's not the same as 43 times) greater likelihood of developing Parkinson's disease. In fact, this study just looked at self-reported exposure to pesticides, in data collated from interviews in several countries (see link to original New Scientist story). This evidence is, at best, circumstantial, and the researchers themselves say that there are other more significant risk factors. It also has to be seen in light of the fact that these same farmers, exposed to these same chemicals, have a lower incidence of cancer than the general population. A clear warning that you need to take the broader picture rather than just pick out facts which apparently support your favourite case.

The most indecent thing this article exposes is Meacher's belief in the insinuations and half-truths put out by those who believe that use of synthetic pesticides is an offence against nature.

The UK Pesticide Residues Committee has published its latest findings on its monitoring work. This is summarised in Is there a risk to health from eating pesticide residues in food? And the answer is a resounding NO.

Unfortunately, the good news really doesn't get reported, presumably because it doesn't lead to scare headlines. It was reported by the BBC on-line service on 29th June (Pesticide levels "pose no threat"), but the article isn't listed under the Health or Science/Nature sections and can only be found by searching (or clicking on the link I've helpfully supplied: all part of the service).

Of course, this doesn't satisfy those people who think that farmers are conspiring to poison them: facts apparently don't interest them. So, from the BBC story, we have:

But Pesticide Action Network spokeswoman Alison Craig told BBC News the MRL was "completely irrelevant to human health".

The report failed to take into account the "cocktail effect" of combining different pesticides or the "lifetime of exposure to pesticides that starts in the womb", she said.

"Pesticides are poisons, and consumers are entitled to no contamination at all."

So, that's clear then: ignore the evidence and the advice of experts and stick to your beliefs.

But, to put real and imagined risks in perspective, look at the next quote:

An FSA spokesman told BBC News "long-term use" had been factored into the committee's findings.

But he warned consumers to continue to wash and peel fresh fruit and vegetables - not to remove traces of pesticides, but to ensure food was free from bacteria.

Whose view do you support?