Lead Exposure - psychology notes

The Environment and the developing brain --- pending…….psychology notes…. Cont….from Lead (PB) Exposure . main routes of exposure through air and soil pollution; . Main focus of concern - moderate exposure levels - early childhood exposure . Currently accepted “safe” level: 10-15 /100 ml . Lead poisoning (plumbism) >50 - 80 /100 ml Common Environmental Sources - paint (especially in older buildings) - electrical battery casings - automobile emissions - lead plumbing - pottery and cooking utensils (eg. Old pewter, some paints and glazes). - Leaded crystal Effects of Lead . Blocks absorption of Iron, zinc and calcium (critical to nervous system and bones). . Accumulates in body tissues and selectively in certain brain regions: Hippocampus Amygdala Neocortex Behavioral Impairments (primate and rat studies) Results are very mixed. There are more studies of monkeys than others. . Delayed alternation (animals in maze goes one way and another, another way). . Delayed matching to sample. (visual stimulus). . Spatial and non-spatial reversal learning. Reversal learning is a measure of cognitive flexibility. Simply put, the basic idea is that simple learning is not impaired but when it becomes more complicated there seems to be impairment. Human Behavioral Studies . umbilical at fetus and teeth in children for lead exposure . Prospective studies - mixed results on IQ measures . School achievement - Some evidence for delays and lower achievement in children with moderate exposure to lead.