Impact of pesticide exposure in childhood.

Pesticides represent a wide variety of chemicals presented as different formulations and concentrations and used in different settings: agriculture, animal sanitary bath, domestic use, and vector control. Lack of awareness, poor agricultural practices, and inappropriate disposal of containers will increase the exposure and risk of health effects during childhood. The concern about children's exposure to pesticides is based on their toxic properties and the special vulnerability to the exposure, which may occur in different stages, from the prenatal period to infancy. Pesticide related diseases may manifest during the infancy, adolescence, or adulthood. Children may be exposed by multiple routes of exposure, in different scenarios. In domestic settings, insecticides and rodenticides are usually stored within the reach of children, or may be transferred to non-original containers, leading to acute non intentional ingestion. Exploratory behavior increases the risk for exposure to pesticides present on the ground. Gardens and playgrounds may have pesticides residues. Children may be in contact with domestic animals that have been treated with pesticides. In rural settings, children can be exposed to pesticide residues in areas where they have been applied, or by contamination of work equipment and parents clothing. Families dedicated to rural activity have higher levels of exposure, through ingesting contaminated fruits, vegetables, milk, eggs, and water. Several studies confirmed pesticide exposure in children by biomonitoring. Higher levels of organophosphate metabolites have been reported in children compared to adult populations. Toxic effects of pesticides depend on their intrinsic toxic properties as well as on the dose, duration, and life period of exposure. Acute poisonings are related to high doses exposure, while chronic, subtle and delayed effects are often related to low levels/doses exposure. Epidemiologic, animal, and clinical studies suggest an association between chronic, low-level exposures and alterations in growth and development (particularly impaired neurobehavioral development), cancer and increased susceptibility to infections. New research presents evidence that some pesticides are a risk factor of a wide range of acute and chronic diseases. Better practices and public health policies are needed to prevent and protect children from pesticides exposure.