Autonomic and central nervous system effects of lead in female glass workers in china

Abstract

To clarify the effects of lead on autonomic and central nervous system functions, electrocardiographic R-R interval variability (CVRR) as well as visual and brainstem auditory evoked potentials (VEP and BAEP) were measured in 36 female workers exposed to lead (exposed group) and in 15 female textile workers (unexposed group). The C-CVLF, C-CVHF (two component CVs of the CVRR reflecting sympathetic and parasympathetic activities, respectively), and LF/HF ratio (indicator of sympatho-vagal balance) were also computed from component spectral powers by means of autoregressive spectral and component analyses. The exposed group had engaged in glass work for 2-17 (mean 7.8) years. Blood lead (BPb) concentrations were 25.8-79.3 (mean 55.6) micrograms/dl in the exposed group and 4.7-8.6 (mean 6.3) micrograms/dl in the unexposed group. The CVRR, C-CVLF, C-CVHF, and LF/HF ratio in the exposed group were significantly lower than those in the unexposed group. Also, the exposed group had more complaints of subjective symptoms and signs than did the unexposed group. On the other hand, no significant differences in either VEP or BAEP latencies were found between the two groups. It is suggested that autonomic nervous function is more susceptible to lead than visual and auditory nervous functions; lead affects sympathetic activity more strongly than parasympathetic activity.

Cardiac autonomic activity in methylmercury neurotoxicity: 14-year follow-up of a Faroese birth cohort

“…30 In a study of lead-exposed workers, electrophysiological parameters showed a significant exposure-associated HRV depression, although not the anticipated delayed latencies of BAEP peaks. 24 This finding may suggest that changes in HRV could be an earlier effect than increased BAEP latencies. Another study of occupational lead exposure reported an association between lead-induced changes in HRV and peripheral nerve conduction.…”

“…The paucity of information is perhaps not surprising, given the substantial age-dependency of the HRV parameters that might complicate interpretation of cross-sectional studies. Studies of adults with occupational exposure to neurotoxicants [21][22][23][24][25][26][27][28] clearly show that HRV may be affected by chemical exposures that damage the nervous system. However, effects on children would be difficult to predict from studies conducted in adults.…”

“…[17][18][19][20] Abnormalities have also been documented after exposure to neurotoxic agents, such as MeHg, mercury vapor, other metals, certain solvents, and nerve gases. [21][22][23][24][25][26][27][28] In most cases, the CVRR was apparently affected mainly through a relative depression of parasympathetic activity. 21 In particular, a decreased HRV in adult patients that had been born with congenital MeHg poisoning appeared to be mainly due to parasympathetic hypofunction.…”

Lead Toxicity: Does the Critical Level of Lead Resulting in Adverse Effects Differ between Adults and Children?

“…Then, the paired data of the BPb level and outcome variable in each subject were scored using Paint software (Microsoft Co., U.S.A.) after scanning the figure. Finally, four more studies were selected [24][25][26][27] , and therefore publication bias cannot be avoided in this case.…”

Effects of Pesticides on the Peripheral and Central Nervous System in Tobacco Farmers in Malaysia: Studies on Peripheral Nerve Conduction, Brain-Evoked Potentials and Computerized Posturography

“…These methods include nerve conduction velocities (NCVs) [5][6][7][8][9][10][11][12][13][14] , visual-, auditory-and somatosensory-evoked potentials (VEP, AEP, SSEP) [10][11][12][14][15][16][17][18] , event-related potential (ERP) 7,8,10,11,14,17) and computer-based posturography 6,7,10,11,[18][19][20][21][22][23][24] . For example, neorophysiological tests have been employed to detect and document subclinical changes before lead-exposed individuals develop overt symptoms and signs, thereby preventing acute and/or persistent neurological illness among populations exposed to lead 18) .…”