The major classes of pesticides are organochlorines (OCPs) or persistent organic pollutants (POPs), organophosphates, carbamates, phyrethroids, and triazines.
Associations have been found with: leukemia, lymphoma, brain, kidney, breast, prostate, pancreas, liver, lung, stomach, esophageal, and skin cancers.
[23] A mother's occupational exposure to pesticides during pregnancy is associated with an increases in her child's risk of leukemia, Wilms' tumor, and brain cancer.
Acute exposure to high levels of pesticides that affect the central nervous system can cause neurotoxicity, including cognitive and motor changes.
[27][3] In-utero and early-childhood exposure to organophosphates can cause neurodevelopmental impairment,[3][28][29] in particular because some pesticides and their metabolites cross the placenta and fetal blood-brain-barrier, which has not fully developed in a fetus.
[29] In addition, an accumulation of chronic exposure has been associated with an increased risk of developing neurodegenerative disease later in life.
As such, high levels of and/or long-term exposure to pesticides can impact reproductive health and is associated with decreased fertility, increased rates of miscarriage, and changes in pattern of maturity.
[35] The effects of endocrine disruption is dependent on the timing of pesticide exposure (for example, during embryogenesis in early pregnancy or in infancy) as windows of varying susceptibility dictate disease manifestation.
[33] Several studies suggest that higher levels of pesticides in the blood of the mother is associated with longer time to pregnancy and greater infertility rates.
Similarly, studies evaluating the short-term impact of occupational exposure to a variety of pesticides on reproductive health suggest that pesticides can have deleterious effects on sperm—pesticide exposure, associated with decreased sperm motility, defects in sperm morphology and semen volume.
[29] Because some pesticides and their resulting metabolites can cross the placenta and, therefore, the blood-brain-barrier, they can also impact development of the fetus; strong evidence links pre- and post-natal exposures to pesticides to congenital disorders, including physical and/or mental disabilities, fetal death and altered fetal growth.
[38] Maternal exposure to pesticides has also been linked to higher incidence of hypospadias in the newborn, which is the abnormal opening of the urethra in males.
[39] A significant association was found between exposure to pesticides and decreased lung function along with related airway symptoms.
Studies have suggested a correlation between inhibition of cholinesterase by pesticides like carbamate and organophosphate and reduction or impairment of lung function.
[40] Summaries of peer-reviewed research have examined the link between pesticide exposure and neurologic outcomes and cancer, perhaps the two most significant things resulting in organophosphate-exposed workers.
[3] The precautionary principle is thus frequently used in environmental law such that absolute proof is not required before efforts to decrease exposure to potential toxins are enacted.
[44] They came to this conclusion due to the fact that surveillance systems currently in place are inadequate to determine problems related to exposure.
[44] The utility of applicator certification and public notification programs are also of unknown value in their ability to prevent adverse outcomes.
[50] A study in North Carolina indicated that more than 30 percent of the quail tested were made sick by one aerial insecticide application.