Cumulative lead exposure and neuropsychological function.
Morrow LA; Needleman H; Kirisci L; Sandstrom D
J Int Neuropsychol Soc 2002 Feb; :252
Lead continues to be a major occupational toxin. While blood lead levels (BLL) estimate recent exposure, they don't measure cumulative exposure or body burden. Bone lead concentration - measured with X-ray fluorescence (XRF) - is the best way to estimate cumulative lead exposure. The current study is a longitudinal follow-up of a group of workers with past and current occupational exposure to lead. (average years at lead battery plants = 27.0), and nonexposed controls. Subjects were initially tested 20 years ago and little difference was found between the groups. At that time, only BLL were taken. To date, we have reassessed 35 subjects on measures of neuropsychological function, and BLL, and additionally collected SRF. Preliminary results show significantly higher BLL (p < .001) and XRF (p < .05) in exposed workers, as well as poorer performance on most neuropsychological performance, controlling for age. Higher bone lead was associated with poorer performance on a number of measures - verbal learning, symbol-digit learning, digit symbol substitution, incidental recall, block design, visual memory, and delayed symbol-digit learning (vs ranged from -.42 to -.75). Correlations between BLL and neuropsychological test scores were less consistent but I the expected direction. These findings indicate that cumulative lead exposure, as indicated by higher concentrations of bone lead, is related to poorer neuropsychological function in occupationally exposed workers.
Blood-analysis; Blood-tests; Heavy-metals; Heavy-metal-poisoning; Lead-compounds; Battery-manufacturing-industry; Metal-compounds; Metals; Metal-poisoning; Demographic-characteristics; Statistical-analysis; Epidemiology; Psychological-effects; Age-factors
University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA 15231
Work Environment and Workforce: Special Populations
Journal of the International Neuropsychological Society
University of Pittsburgh, Pittsburgh, Pennsylvania