A group of researchers from the Research Center Hospital San Mateo in Pavia, Italy examined over 100 recent studies of toxic materials used as pesticides and solvents and found a high correlation with the risk of developing Parkinson’s disease by people who used them. These are often the people who work on farms or in landscape or horticultural industries..
Pesticides are types of toxic chemicals or biological agents usually identified by the type of pest they are designed to control. Herbicides are used to control unwanted plant materials in food crops, ornamental plants and lawns and meadows. Controls for specific types of insect or rodent pests are also included in pesticides. Some pesticides are applied as liquid, others as powders and still others are used a bait.
Specific chemicals or combinations of chemicals were not differentiated in this survey study, nor were the methods of application or strength of the agent reviewed. The main criteria examined was the length of time workers had been using the products. It was noted that the risk of developing Parkinson’s increased in a dose response manner as the length of exposure to the chemicals increased. People utilizing these chemicals had between 30 and 80 per cent increased risk.
Also included in the review materials was exposure to the chemical solvent used in the dry cleaning industry, trichloroethylene . Previous studies of this solvent have noted a 5 times greater risk of developing Parkinson’s.
The analysis of over 100 studies does show a causative role for pesticides and solvents in neurodegenerative disorders in people who work with them. However more studies are needed to understand how people who may be exposed to these chemicals in hobby gardening or in residential maintenance or people who wear clothing that has been dry cleaned may be affected by these agents. Of even more importance, is the diet of people who consume the fruits, vegetables and grains that are grown in fields treated with these chemicals.