Neuropsychological studies on lead workers in Singapore.

Abstract

The neuropsychological performance of a group of 49 workers occupationally exposed to lead was compared with a matched control group of 36 non-exposed workers. The psychometric measurements were composed of tests covering a broad range of different neuropsychological functions, particular emphasis being given to perceptual motor ability and attention concentration functioning. A questionnaire to assess subjective symptoms in mood, sleep disturbance, poor concentration and forgetfulness, somatic complaints, and social passivity was also included in the battery of tests. Compared with the controls, the performance of the lead workers was found to be significantly poorer for digit symbol, Bourdon-Wiersma, trail making test (part A), Santa Ana test, flicker fusion, and simple reaction time. In terms of subjective symptoms the exposed group also reported significantly more complaints of anxiety and depressed mood, poor concentration and forgetfulness, and other somatic complaints. These differences were observed among lead workers with a mean blood lead value of 2-35 umol/l (SD 0-7).

Subclinical neurophysiological effects of lead: A review on peripheral, central, and autonomic nervous system effects in lead workers

“…Furthermore, the P300 latency was signi®cantly correlated with BPbs in the latter two studies. These ®ndings agree with the data from neurobehavioral studies, which indicated impairment of psychological performance and reduction in intelligence in lead workers [Baker et al, 1984;Mantere et al, 1984;Araki et al, 1986c;Jeyaratnam et al, 1986;Yokoyama et al, 1988;Stollery et al, 1991] and with the data on the event-related potential in children [Otto et al, 1981]. Thus, it appears that cognitive function is especially susceptible to lead in its low-level exposure.…”

Subclinical Cerebellar Anterior Lobe, Vestibulo-Cerebellar and Spinocerebellar Afferent Effects in Young Female Lead Workers in China: Computerized Posturography with Sway Frequency Analysis and Brainstem Auditory Evoked Potentials.

“…Subclinical effects of lead on the central and peripheral nervous systems have been widely documented through demonstration of prolongation of latencies in visual, auditory and somatosensory evoked potentials and in eventrelated potentials [1][2][3][4][5][6][7][8][9][10][11][12][13][14] , of impairment of psychological performance 2,4,5,[14][15][16][17][18] , and of slowing of nerve conduction velocities 1,[4][5][6][7][20][21][22][23][24][25][26][27][28][29][30] . Some groups of investigators reported that postural balance was adversely affected by lead using a computerized static posturography [31][32][33][34][35][36][37][38] .…”

Neurobehavioral Tests as a Medical Surveillance Procedure: Applying Evaluative Criteria

“…Exposure to lead was expressed in blood lead levels (Jeyaratnam et al, 1986;Mantere et al, 1984;Pasternak et al, 1989;Repko et al, 1975Repko et al, , 1978Stollery et al, 1989;Tola and Nordman, 1977), zinc protoporphyrin (Parkinson et al, 1986;Valciukas et al, 1978a,b), and deltaaminolevulinic acid (Tola and Nordman, 1977). A blood lead level between 40 and 60 g/dl was re- ported to be associated with neurobehavioral impairment (Baker et al, 1984;Campara et al, 1984;Jeyaratnam et al, 1986).…”