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. 2002 May;59(5):287–293. doi: 10.1136/oem.59.5.287

Health and neuropsychological functioning of dentists exposed to mercury

K Ritchie 1, W Gilmour 1, E Macdonald 1, F Burke 1, D McGowan 1, I Dale 1, R Hammersley 1, R Hamilton 1, V Binnie 1, D Collington 1
PMCID: PMC1740287  PMID: 11983843

Abstract

Objectives: A cross sectional survey of dentists in the west of Scotland and unmatched controls was conducted to find the effect of chronic exposure to mercury on health and cognitive functioning.

Methods: 180 dentists were asked to complete a questionnaire that included items on handling of amalgam, symptoms experienced, possible influences on psychomotor function, and the 12 item general health questionnaire. Dentists were asked to complete a dental chart of their own mouths and to give samples of urine, hair, and nails for mercury analysis. Environmental measurements of mercury in dentists' surgeries were made and participants undertook a package of computerised psychomotor tests. 180 control subjects underwent a similar procedure, completing a questionnaire, having their amalgam surfaces counted, giving urine, hair, and nail samples and undergoing the psychomotor test package.

Results: Dentists had, on average, urinary mercury concentrations over four times that of control subjects, but all but one dentist had urinary mercury below the Health and Safety Executive health guidance value. Dentists were significantly more likely than control subjects to have had disorders of the kidney and memory disturbance. These symptoms were not significantly associated with urinary mercury concentration. Differences were found between the psychomotor performance of dentists and controls after adjusting for age and sex, but there was no significant association between changes in psychomotor response and mercury concentrations in urine, hair, or nails.

Conclusions: Several differences in health and cognitive functioning between dentists and controls were found. These differences could not be directly attributed to their exposure to mercury. However, as similar health effects are known to be associated with mercury exposure, it would be appropriate to consider a system of health surveillance of dental staff with particular emphasis on symptoms associated with mercury toxicity where there is evidence of high levels of exposure to environmental mercury.

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Selected References

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  1. Barregård L. Biological monitoring of exposure to mercury vapor. Scand J Work Environ Health. 1993;19 (Suppl 1):45–49. [PubMed] [Google Scholar]
  2. Echeverria D., Heyer N. J., Martin M. D., Naleway C. A., Woods J. S., Bittner A. C., Jr Behavioral effects of low-level exposure to elemental Hg among dentists. Neurotoxicol Teratol. 1995 Mar-Apr;17(2):161–168. doi: 10.1016/0892-0362(94)00049-j. [DOI] [PubMed] [Google Scholar]
  3. Eggleston D. W. Effect of dental amalgam and nickel alloys on T-lymphocytes: preliminary report. J Prosthet Dent. 1984 May;51(5):617–623. doi: 10.1016/0022-3913(84)90404-9. [DOI] [PubMed] [Google Scholar]
  4. Eley B. M. The future of dental amalgam: a review of the literature. Part 2: Mercury exposure in dental practice. Br Dent J. 1997 Apr 26;182(8):293–297. doi: 10.1038/sj.bdj.4809370. [DOI] [PubMed] [Google Scholar]
  5. Fung Y. K., Molvar M. P. Toxicity of mercury from dental environment and from amalgam restorations. J Toxicol Clin Toxicol. 1992;30(1):49–61. doi: 10.3109/15563659208994445. [DOI] [PubMed] [Google Scholar]
  6. Herber R. F., de Gee A. J., Wibowo A. A. Exposure of dentists and assistants to mercury: mercury levels in urine and hair related to conditions of practice. Community Dent Oral Epidemiol. 1988 Jun;16(3):153–158. doi: 10.1111/j.1600-0528.1988.tb00564.x. [DOI] [PubMed] [Google Scholar]
  7. Langworth S., Almkvist O., Söderman E., Wikström B. O. Effects of occupational exposure to mercury vapour on the central nervous system. Br J Ind Med. 1992 Aug;49(8):545–555. doi: 10.1136/oem.49.8.545. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Langworth S., Sällsten G., Barregård L., Cynkier I., Lind M. L., Söderman E. Exposure to mercury vapor and impact on health in the dental profession in Sweden. J Dent Res. 1997 Jul;76(7):1397–1404. doi: 10.1177/00220345970760071001. [DOI] [PubMed] [Google Scholar]
  9. McComb D. Occupational exposure to mercury in dentistry and dentist mortality. J Can Dent Assoc. 1997 May;63(5):372–376. [PubMed] [Google Scholar]
  10. Naleway C., Sakaguchi R., Mitchell E., Muller T., Ayer W. A., Hefferren J. J. Urinary mercury levels in US dentists, 1975-1983: review of Health Assessment Program. J Am Dent Assoc. 1985 Jul;111(1):37–42. doi: 10.14219/jada.archive.1985.0069. [DOI] [PubMed] [Google Scholar]
  11. Ngim C. H., Foo S. C., Boey K. W., Jeyaratnam J. Chronic neurobehavioural effects of elemental mercury in dentists. Br J Ind Med. 1992 Nov;49(11):782–790. doi: 10.1136/oem.49.11.782. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Piikivi L., Hänninen H., Martelin T., Mantere P. Psychological performance and long-term exposure to mercury vapors. Scand J Work Environ Health. 1984 Feb;10(1):35–41. doi: 10.5271/sjweh.2365. [DOI] [PubMed] [Google Scholar]
  13. Pleva J. Dental mercury--a public health hazard. Rev Environ Health. 1994 Jan-Mar;10(1):1–27. doi: 10.1515/reveh.1994.10.1.1. [DOI] [PubMed] [Google Scholar]
  14. Pohl L., Bergman M. The dentist's exposure to elemental mercury vapor during clinical work with amalgam. Acta Odontol Scand. 1995 Feb;53(1):44–48. doi: 10.3109/00016359509005944. [DOI] [PubMed] [Google Scholar]
  15. Ritchie K. A., Macdonald E. B., Hammersley R., O'Neil J. M., McGowan D. A., Dale I. M., Wesnes K. A pilot study of the effect of low level exposure to mercury on the health of dental surgeons. Occup Environ Med. 1995 Dec;52(12):813–817. doi: 10.1136/oem.52.12.813. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Roels H., Gennart J. P., Lauwerys R., Buchet J. P., Malchaire J., Bernard A. Surveillance of workers exposed to mercury vapour:validation of a previously proposed biological threshold limit value for mercury concentration in urine. Am J Ind Med. 1985;7(1):45–71. doi: 10.1002/ajim.4700070106. [DOI] [PubMed] [Google Scholar]
  17. Roels H., Lauwerys R., Buchet J. P., Bernard A., Barthels A., Oversteyns M., Gaussin J. Comparison of renal function and psychomotor performance in workers exposed to elemental mercury. Int Arch Occup Environ Health. 1982;50(1):77–93. doi: 10.1007/BF00432495. [DOI] [PubMed] [Google Scholar]
  18. Schuurs A. H. Reproductive toxicity of occupational mercury. A review of the literature. J Dent. 1999 May;27(4):249–256. doi: 10.1016/s0300-5712(97)00039-0. [DOI] [PubMed] [Google Scholar]
  19. Uzzell B. P., Oler J. Chronic low-level mercury exposure and neuropsychological functioning. J Clin Exp Neuropsychol. 1986 Oct;8(5):581–593. doi: 10.1080/01688638608405177. [DOI] [PubMed] [Google Scholar]
  20. Verschoor M. A., Herber R. F., Zielhuis R. L. Urinary mercury levels and early changes in kidney function in dentists and dental assistants. Community Dent Oral Epidemiol. 1988 Jun;16(3):148–152. doi: 10.1111/j.1600-0528.1988.tb00563.x. [DOI] [PubMed] [Google Scholar]

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