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. 1996 Apr;53(4):264–268. doi: 10.1136/oem.53.4.264

Cumulative concentrations of blood lead and postural stability.

S E Chia 1, H P Chia 1, C N Ong 1, J Jeyaratnam 1
PMCID: PMC1128461  PMID: 8664965

Abstract

OBJECTIVE: To study the association in a group of battery manufacturing workers between computerised postural sway parameters and present concentrations of blood lead (PPb), index of cumulative blood lead years (CBI), and cumulative blood lead at different years of exposure (CPbYs). METHODS: Postural stability was investigated with a computerised postural sway measurement system in 60 workers exposed to lead with exposure duration of 84 (range 3-366) months and in 60 control subjects. An index of CBIs in 55 workers (previous blood lead results of five workers were not available) and CPbYs were computed for each worker by calculating the area under the curve of concentrations of blood lead against time. RESULTS: The mean (SD) PPb was 36.0 (11.7) (range 6.4 to 64.5) micrograms/dl for the exposed workers and 6.3 (2.4) (range 3.1-10.9) micrograms/dl for the 14 randomly selected control subjects. Significant differences between groups for the postural sway parameters obtained when the eyes were closed were found for length of sway path (L); mean velocity of the centre of pressure along its path (Vel); area included within the path of the centre of pressure (Ao); 95% confidence elliptical area (Ae). The Romberg ratio (the relation between eyes closed and open) for the Vel, L, Ao, and Ae of the exposed group were also significantly different from those of the controls. The postural sway parameters (eyes closed) were not significantly correlated with PPb or CBI. However, the cumulative blood lead for the past two years before the postural sway assessment, CPbY2, was significantly correlated with all the postural sway parameters. CONCLUSION: The study showed that workers exposed to lead had significantly poorer postural stability than a control group. Lead may affect certain parts of the somatosensory system resulting in postural instability when the visual input is cut off. The CPbY2 was significantly positively correlated with most of the postural sway parameters. Effects of lead on postural stability may be related to recent increases in blood lead concentration among the exposed workers rather than to cumulative body burden.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Begbie G. H. The effects of alcohol and of varying amounts of visual information on a balancing test. Ergonomics. 1966 Jul;9(4):325–333. doi: 10.1080/00140136608964388. [DOI] [PubMed] [Google Scholar]
  2. Bhattacharya A., Shukla R., Bornschein R. L., Dietrich K. N., Keith R. Lead effects on postural balance of children. Environ Health Perspect. 1990 Nov;89:35–42. doi: 10.1289/ehp.908935. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Bhattacharya A., Shukla R., Bornschein R., Dietrich K., Kopke J. E. Postural disequilibrium quantification in children with chronic lead exposure: a pilot study. Neurotoxicology. 1988 Fall;9(3):327–340. [PubMed] [Google Scholar]
  4. Chia S. E., Chua L. H., Ng T. P., Foo S. C., Jeyaratnam J. Postural stability of workers exposed to lead. Occup Environ Med. 1994 Nov;51(11):768–771. doi: 10.1136/oem.51.11.768. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Hytönen M., Pyykkö I., Aalto H., Starck J. Postural control and age. Acta Otolaryngol. 1993 Mar;113(2):119–122. doi: 10.3109/00016489309135778. [DOI] [PubMed] [Google Scholar]
  6. Jeyaratnam J., Devathasan G., Ong C. N., Phoon W. O., Wong P. K. Neurophysiological studies on workers exposed to lead. Br J Ind Med. 1985 Mar;42(3):173–177. doi: 10.1136/oem.42.3.173. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Kantner R. M., Rubin A. M., Armstrong C. W., Cummings V. Stabilometry in balance assessment of dizzy and normal subjects. Am J Otolaryngol. 1991 Jul-Aug;12(4):196–204. doi: 10.1016/0196-0709(91)90120-5. [DOI] [PubMed] [Google Scholar]
  8. Landrigan P. J., Todd A. C. Direct measurement of lead in bone. A promising biomarker. JAMA. 1994 Jan 19;271(3):239–240. [PubMed] [Google Scholar]
  9. Ledin T., Odkvist L. M., Möller C. Posturography findings in workers exposed to industrial solvents. Acta Otolaryngol. 1989 May-Jun;107(5-6):357–361. doi: 10.3109/00016488909127521. [DOI] [PubMed] [Google Scholar]
  10. Linz D. H., Barrett E. T., Jr, Pflaumer J. E., Keith R. E. Neuropsychologic and postural sway improvement after Ca(++)-EDTA chelation for mild lead intoxication. J Occup Med. 1992 Jun;34(6):638–641. [PubMed] [Google Scholar]
  11. Phoon W. O., Ong C. N. Lead exposure patterns and parameters for monitoring lead absorption among workers in Singapore. Ann Acad Med Singapore. 1982 Oct;11(4):593–600. [PubMed] [Google Scholar]
  12. Seppäläinen A. M., Hernberg S., Vesanto R., Kock B. Early neurotoxic effects of occupational lead exposure: a prospective study. Neurotoxicology. 1983 Summer;4(2):181–192. [PubMed] [Google Scholar]

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