Organophosphates, carbamates and pyrethroids are classes more commonly involved in child pesticide poisonings in the US. Exposure to high levels of certain pesticides can result in acute poisoning, with symptoms including rash, nausea, vomiting, diarrhea, lethargy, and flu-like symptoms, abnormal muscular reflexes, seizures, coma, and death. Low dose exposures are far more common than acute poisonings and increasingly linked to chronic impairment and disease. Long-term exposures to some pesticides during preconception, pregnancy, and in childhood may be associated neurocognitive and neurobehavioral deficits (including reduced IQ, inattention/ADHD, and autism), increased risk of metabolic syndrome, and childhood cancer (brain, leukemia). Pesticide exposures during pregnancy have additionally been associated with adverse birth outcomes such as reduced fetal growth, fetal death, preterm birth, and congenital anomalies.