Main and Interaction Effects of Metallic Pollutants on Cognitive Functioning

The present study investigated possible relationships of metal levels and metal combinations with children's cognitive functioning. Hair-metal concentrations of lead, arsenic, mercury, cadmium, and aluminum were determined in 69 randomly selected elementary age children. They were also administered the Wide Range Achievement Test reading and spelling tests and the Bender Visual-Motor Gestalt Test. Parents of subjects were interviewed to control for confounding variables that may affect cognitive development. Regression data indicated that increases in arsenic and the interaction of arsenic with lead were significantly related to decreased reading and spelling achievement, and increases in aluminum and the interaction of aluminum with lead were significantly related to decreased visual-motor performance. A continuing reexamination of metal poisoning concentrations is needed, because metal levels and metal combinations previously thought harmless may be associated with cognitive deficits.