What are the problems with pesticides?
Around 31,000 tonnes of chemicals are used in farming in the UK each year to kill weeds, insects and other pests that attack crops. There is surprisingly little control over how these chemicals are used in the non-organic sector and in what quantities or combinations. What we do know is that 150 of the available 311 pesticides commonly used have been identified as potentially causing cancer and many of us would have been exposed to these pesticides before we were born.
Effects on health
Even food that we think is healthy, such as non-organic Cox's apples, can be sprayed 18 times. The most dangerous chemicals used in farming, such as organophosphates, have been linked with a range of problems including cancer, decreasing male fertility, foetal abnormalities, chronic fatigue syndrome in children and Parkinson's disease.
It has been widely reported that the hormones of wildlife can be affected by pesticides containing compounds that work in a similar way to oestrogen, known as hormone disrupting chemicals. There is evidence that humans are also affected. These chemicals have been linked to genital abnormalities in male babies' and a decline in semen quality over the last 50 years. In 2000 the European Commission produced a draft list of 34 pesticides that are, or could be, hormone disrupters.
The cocktail effect
Some crops are sprayed with more than one type of chemical and, consequently, food can contain residues of a number of different pesticides. While there is some scientific evidence about the effects of individual chemicals on our health, there is little research regarding how combinations of pesticides react: this is often referred to as the cocktail effect. The few studies that are available show worrying results. Mixtures of insecticides, herbicides and nitrates at low levels (which are permitted in groundwater) can affect the reproductive, immune and nervous systems in ways that individual chemicals do not.
Wildlife and environment
Some chemicals are so mobile and persistent that residues of them have been found in the Arctic. Washing produce with water may have little effect as residues are formulated to resist being washed off easily so that they can survive during rain showers and some chemicals are designed to work within the plant.