鈥淪UMMER is icumen in鈥� as the old song goes 鈥� so the pollen will soon be flying, and the vexed question of how far genetically modified crops can spread will assume a new significance. Last year, Canadian scientists reported that stray pollen and seed from genetically modified oilseed rape, or canola, is now so widespread in Canada that it is difficult to grow conventional strains there without them being contaminated (快猫短视频, 24 November 2001, p 14).
When I raised the significance of this finding for Britain with environment minister Michael Meacher, he replied that the important question is what the consequences of cross-pollination are. The first GM crop varieties for possible commercial use in Britain are being grown in the Farm-Scale Evaluation programme.
The government鈥檚 Advisory Committee on Releases to the Environment reckons that these crops, which have been modified to be tolerant of herbicides, don鈥檛 pose any greater risk to human health or the environment than their non-GM counterparts. Meacher said he deduced from this that cross-pollination will not be a safety issue. He admitted though that GM cross-pollination raises questions of agronomic management and the coexistence of GM and non-GM production.
Advertisement
Meacher said the Canadian research focused on the impact of GM 鈥渧olunteers鈥�, the plants from spilt seed that grow as weeds in a succeeding crop. Because the Canadian farmers are growing more than one type of GM herbicide-tolerant rape, cross-pollination between them could lead to volunteers that are tolerant to more than one herbicide. This causes concern, as volunteers may become difficult to eradicate and lead to agronomic or environmental problems. Meacher said he is advised that, for oilseed rape, a separation distance of 800 metres would not result in significantly less cross-pollination than a distance of 200 metres, although it would be far harder to achieve in practice.
At present, the European Union鈥檚 labelling rules on GM food only require it to be marked as such if it contains more than 1 per cent of GM material. Lots of people I meet would like the GM threshold to be lower. The government is discussing this thorny subject before any final decision is made on actual commercial GM plantings in Britain. Good, say I.
LATE last year, when fears of bioterrorism abounded, claims were made that ageing emergency stocks of smallpox vaccine could prove ineffective if called upon to meet a spread of this deadly disease (快猫短视频, 3 November 2001, p 6). Health minister John Hutton now tells me that this is unlikely. He said that the Lister Institute in Elstree, near London, produced Britain鈥檚 smallpox vaccine until the mid-1970s, when manufacture ceased because it seemed the disease had been eradicated worldwide. In 1979, the institute closed and its residual stocks of the vaccine were transferred to the Department of Health.
Because vaccines are live, biological material, it is possible for their potency to decrease with time. However a recent American study has shown that a smallpox vaccine manufactured before 1982 still has substantial potency, even when the vaccine is diluted 1 in 10, said the minister.
So be it, but I think the government is right to contract PowderJect Pharmaceuticals, the British partner for Bavarian Nordic of Denmark, with a view to boosting Britain鈥檚 stocks of smallpox vaccine. Covering a potential emergency is, in my opinion, more important than avoiding political criticism.