Pesticides of one sort or another are used to produce 95 per cent of the produce grown in the UK and are promoted by the companies that make them as being the only way to ensure that yields remain high, prices remain low, and that growers can make a living. However, this is far from the truth, and many studies show that it is possible to maintain yields and profitability with reduced pesticide inputs by working with nature rather than against it.
The problem is that reliance on agrochemicals, and pesticides in particular, is hardwired into our current agricultural system. Factors such as the demands of supermarkets for perfect produce, the limited range of varieties available to farmers, monocrop systems and crop rotations that create ideal conditions for pests to develop all place pressure on farmers to use more and more pesticides with devastating consequences for the environment and human health.
From field to fork the use of pesticides ensures that people and the environment are exposed to potentially harmful risks from these toxic chemicals that are designed to kill. In the UK over 20 000 tonnes of pesticides are sprayed on farmland annually to grow the food that we eat.
A great number of these chemicals are potentially toxic to humans, pollute waterways and have harmful effects on our biodiversity as has been seen by the recent loss of bees and other pollinators here in the UK and elsewhere.
We know that the impacts of pesticides are incredibly serious. In 2008, a European parliament commissioned study concluded that the families of farm workers are far more susceptible to childhood leukaemia’s than the general population. It is also estimated that 25 million agricultural workers suffer at least one incident of pesticide poisoning annually. And you can add to this all the unreported poisonings of bystanders and residents that occur throughout the pesticide spraying season.
All along the production trail people – whether it is the grower, the picker, the packager, local residents and bystanders or the end consumer – are exposed to pesticides.
Pesticides are used from the very earliest stage of production – and can be applied to the very seeds themselves. Dressing seeds with pesticides prior to planting is touted as a ‘safe’ way of applying pesticides that will reduce human exposure. Under this approach, the insecticides are taken up into the structure of the plant as it grows making the plant itself poisonous to its pests. What this also means is that the pesticide remains in the plant even after harvesting and no amount of washing or cooking will eradicate it.
But farmers and farmworkers are also exposed through handling the seeds. Many do not realise that the seeds are toxic and they – and neighbouring residents – can be contaminated by the pesticides covered dust that is kicked up and dispersed.
Other fungicides, herbicides and insecticides are applied throughout the growth cycle of the plant to opening up yet further potential routes of exposure. The pesticide applicator, while at greatest risk, is usually required to wear protective equipment to reduce exposure. But others are not so lucky.
One particular group, that has been neglected by successive UK governments, is rural residents. People who live in the countryside can be exposed to pesticides during and after spraying in fields close to their homes. This exposure can go on for years and increases the risk of chronic illnesses including some cancers and neurological diseases like Parkinson’s.
Workers in the fields are also open to exposure as they walk amongst the crops and particularly if they are put in the fields soon after the crops are sprayed.
In particular, labourers employed to harvest the crops can be exposed to pesticides that remain on the crops whilst they pick them. Even after leaving the field, exposure is still possible on clothes that have been contaminated with pesticides taken home for washing or often used again the next day.
The problems can be exacerbated by the fact that many of the labourers used to harvest and pack produce in the UK do not have English as their first language and so cannot understand warnings about what they need to do to minimise or avoid the risk of pesticide contamination. Their status also often limits their ability to report any incidents of pesticide poisoning that might occur and so these incidents go largely unreported in the UK.
And finally, the end consumer will come into contact with pesticides as residues on the food that they eat. The DEFRA Expert Committee on Pesticide Residues in Food (PRiF) samples a range of produce each year. This sampling shows that 30-40 per cent of the food purchased in the UK has pesticide residues present on it - and often multiple residues are present.
Multiple pesticide residues are particularly concerning because some pesticides can interact with one another and increase their toxicity – the so-called cocktail effect. If we take lettuce as an example there are 122 registered professional pesticides that can be used for growing lettuces in the UK of those:
• 20 are fungicides
• 45 are herbicides
• 57 are insecticides
Amongst them are some particularly unpleasant actives:
Mancozeb, a fungicide that is also classified as a carcinogen, a developmental or reproductive toxin, a suspected endocrine disruptor and a potential groundwater contaminant. Pirimicarb, an insecticide and also classified as a carcinogen and a cholinesterase inhibitor. Lambda-cyhalothrin, an insecticide and suspected endocrine disruptor. Cypermethrin, an insecticide and classified as a possible carcinogen and suspected endocrine disruptor.
Fungicides are applied to the soil even before sowing. If the lettuce is grown under cover, it is possible that two to three applications of fungicides could be used as well as an insecticide.
The Pesticide Action Network UK has analysed the figures made available by PRiF between the years 2000 and 2006 and found that of 826 non-organic lettuces tested, 36.7 per cent contained pesticide residues with 19.5 per cent containing a cocktail of residues.
Because lettuces along with many other crops such as soft fruits are considered to be high value crops, farmers will often use pesticides prophylactically in a bid to head off pest damage rather than to treat an existing pest problem. Unnecessary applications result in higher usage and on the whole don’t ensure that the crop will actually be any better protected.
Significant reductions in pesticide use are easily achievable simply by changing crop rotations, or using resistant varieties can dramatically. But this requires a fundamental shift in the approach away from pesticides first to pesticides last. This means that pesticides would only be used when all other methods have failed and then they would be used in a targeted manner ensuring that what is used is the least toxic option available. It requires working with, rather than against, nature and if we do so, we will all benefit.
This article was first published in The Ecologist on 1st September 2011