Many people are, in my opinion, rightly concerned about pesticides. 31,000 tons of pesticides are sprayed on UK land each year. Farm workers may have direct, intense contact with pesticides, but the general population are also exposed to pesticides via residues in and on food, pesticides in the air, as a result of spraying in fields, pesticides applied to road sides to control weeds, and even pesticide contamination of drinking water. As well as the active ingredients there are also likely to be chemicals used to help the stickiness and consistency of the pesticide.
PAN UK (formerly the Pesticide Trust) cites studies that have shown:
93% of non-organic oranges analysed contained pesticide residues
78% of apples analysed contained pesticide residues
43% of all fruit and vegetables analysed had detectable levels of pesticides
50% of lettuce contained residues from 7 or more chemical
71% of cereal bars with residues
83% of oily fish showed pesticide residues
Looking at the health risks of pesticides is difficult because many of the risks may be long term and these can be difficult to establish. There is also the problem of pesticide interaction, and the interaction of pesticides with other chemicals encountered in the environment. We just do not know enough to be certain that these chemicals are safe for us, but harmful to pests.
There are two basic types of pesticides:
Organochlorides kill pests by attacking their central nervous systems. Linked to cancer, birth defects and genetic changes in animals. They are fat-soluble and stored in body fat. They are far more persistent than organophosphates.
Organophosphates interfere with nerve conduction in pests. They are the most common pesticide used today. They are water-soluble and break down rapidly.
Governments control the use of pesticides through legislation, and there are various lists of banned and restricted pesticides. Since 1993 the EU has been implementing a programme to establish harmonised Maximum Residue Levels (MRLs) for pesticide residues in foodstuffs sold in the EU. Once the level is agreed for a pesticide, EU member states are obliged to incorporate these MRLs into their national legislation within 12 months.
How effective is pesticide policing?
Investigations continually show that illegal and dangerous pesticides are appearing in food. This appears to be from two sources: illegal use of pesticides in a country, and also the use of pesticides that are legal (or unpoliced) in the country where the food is grown. In 1996 a UK investigation by the Ministry of Agriculture, Fisheries and Food showed that over 4% of the milk supply contained amounts of lindane above the maximum recommended levels, and in 2 samples DDT was detected even though it has been banned for over 10 years. [The Food Magazine, Issue 34, 1996]
There are likely to be commonly used pesticides that will prove eventually to be harmful. This has happened repeatedly with problems only being scientifically pinpointed after many years of use. There is no reason to feel confident that governments have identified and banned all harmful pesticides. Surely it is better to ere on the side of safety and buy properly certified organic products?