|
This is a piece from, The Ecologist
It covers the topic of pesticides etc on our
Non Organic Salads.
The pristine-looking salad leaves we have acquired an appetite for cannot achieve their cosmetic perfection without a little hi-tech help, particularly when they are grown outside their normal season. Intensive monoculture of salads with extended seasons of cropping allows the build-up of pests and diseases in the soil. There has been a correspondingly rapid increase in pesticide usage. Salad leaves are particularly likely to contain pesticide residues.
Most large producers in the UK are fairly coy about what pesticides they use. So, I spoke to an agricultural technical consultant who works with the agrochemical industry in Spain. He explained the system to me on the condition of anonymity.
‘Lettuces have a two-and-a-half- to three-month growing period in Spain. They are sprayed every week with a mixture of fungicide and insecticide, except for the last two weeks. There is a lot of pesticide resistance, so the products we used last year were completely different to the ones we were using five or six years ago. Some of them are very toxic. For example, we treat the lettuces with dithiocarbamates as a preventive – the English seem to use a lot of these. They are very hazardous.
‘This monoculture allows a lot of funguses and pests to flourish. It is devastating: you can lose half the crop. With the plastic hothouses it’s bad, too: they are all so close together; pests spread through those crops like wildfire. I also have to advise growers to use more pesticides than I would like, because if there is just one tiny aphid, their whole crop can be rejected by the supermarkets. If you want something so perfect that you can’t even see one tiny aphid on it, as though it came not from the soil but from a factory, of course you have to use much more pesticide.’
The government’s Central Science Laboratory records the overall usage of pesticides in this country. Its most up-to-date figures (from 1999) referred to outdoor salad crops receiving an average of four insecticide sprays, two fungicide applications and two herbicide doses; lettuces grown indoors were treated with even more fungicides. While there had been some decline in the amount of pesticides used between 1995 and 1999, the general usage of pesticides on these crops has increased dramatically since 1986 and is still several times greater than it was 20 years ago.
Government tests for residues in salads on sale in shops bear this out. One sample contained residues above the statutory maximum residue level of propamocarb, an insecticide that works on the nervous system in a similar way to organophosphates; and one contained residues of the endocrine disruptor vinclozolin, a substance not permitted for use in lettuces in the UK. Endocrine disruptors are chemicals that interfere with hormones, and are sometimes popularly called ‘gender-benders’.
The Pesticide Safety Directorate’s survey of UK lettuce for 2001/2002 shows that the problem is continuing. Nearly one in five lettuces exceeded maximum residue levels, and 6 per cent contained pesticides not approved for use. An organophosphate banned in the UK was found in several samples, and at 10 times the EU-permitted level in one of them.
The effect of pesticide residues on our health is disputed. The government advisory body the Pesticide Residues Committee says that most residues are present at such a low level that they do not ‘present a concern for consumer health’. Other experts are less sanguine. Dr Vyvyan Howard is a leading toxicopathologist at the University of Liverpool. He has studied the effects of pesticides on unborn children, and points out that the average Briton has between 300 and 500 chemicals in their body that were not present 50 years ago. ‘We have substantially changed the chemical environment of the womb,’ he says. ‘Pregnant women are now exposed to completely novel molecules that their grandmothers were not. Quite a number of these are capable of hormone disruption, and it takes only extremely low doses to cause effects.’ Dr Howard believes there is ample evidence that the pesticide cocktail effect is producing enormous change. Exposure to endocrine disruptors in the womb could be one of the reasons for the much-decreased age of puberty in girls. Early onset of puberty is linked to breast cancer later in life. In the 1960s women had a one in 20 chance of getting breast cancer; now the probability is one in nine. Dr Howard recommends minimising exposure to pesticides on a precautionary basis.
|
