Title: neurotoxin | Definition, Examples, & Effects | Britannica
Headings: Neurotoxin
Neurotoxin
biology
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Characteristics
Physiological effects
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Content: In elderly individuals, a decline in neural function associated with aging can limit the ability to cope with the effects of neurotoxins, particularly for those with compromised liver metabolism or impaired renal function, which are the primary routes of toxin clearance from the body. Prenatal, postnatal, and early childhood exposure to certain chemicals can result in permanent damage to the developing brain, causing functional deficits that become apparent immediately or that emerge later in life. Studies have shown that the placenta cannot prevent many toxins from passing from mother to fetus; moreover, chemicals can be transferred through breast milk. Certain chemicals found in the environment and in common household items have been linked to behavioral and cognitive problems in children. In the early 2000s, increased exposure to some of those chemicals during fetal and early childhood development—as result of overall increases in the use of chemicals in food production and in consumer products—was blamed for the sharp rise in disorders such as autism and attention-deficit/hyperactivity disorder (ADHD) in children. Although genetic factors play a role, neurotoxins such as arsenic, chlorpyrifos, DDT (dichlorodiphenyltrichloroethane), ethyl alcohol, fluoride, lead, polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), manganese, mercury, and toluene are major contributors to the prevalence of neurobehavioral disorders. The impact of some neurotoxins, such as lead and ethyl alcohol, are well-documented. Fetal alcohol syndrome, characterized by brain damage and developmental delays in children, has been known since the 1970s to occur in children born to alcoholic mothers. Concern about lead contamination dates to ancient Rome, where the malleable metal was used to line aqueducts.