Pesticides and Cancer – Recent Results from Epidemiological Studies

Pesticides are used to prevent and destroy pests in agriculture and forestry but also in homes, private and public gardens, and on domestic animals. Although pesticides have benefits such as increasing yield by protecting crops from weeds and insects, and preventing transmission of diseases such as malaria by killing mosquitoes, some pesticides have been linked to adverse health outcomes, including cancer. Most epidemiological studies on pesticides in relation to cancer have been carried out on farmers and agricultural workers, and are almost exclusively conducted in high income countries. The IARC monographs have evaluated the evidence and classified a large number of pesticides in terms of their carcinogenic potential. In 2015 eight pesticides were evaluated, in which the insecticide lindane was classified as carcinogenic to humans (Group 1). More pesticides may be classified as carcinogenic to humans in the future; i.e. when the on-going large studies taking place in different parts of the world, with improved exposure assessment and longer follow-up, will provide further results and better evidence together with experimental data, and more epidemiological studies from low and middle income countries become available. Well-designed exposure assessment studies are a prerequisite to study the link between use of pesticides and morbidity. For informed decisions on cancer control and prevention, reliable data on exposure of workers and the general population are needed, in particular in Africa where agricultural activities expand