(Hypertension. 2002;39:e21.)
© 2002 American Heart Association, Inc.
Letters to the Editor |
Electronic Sphygmomanometers: Are They a Source of Mercury in Hospitals?
New Farm, Queensland, Australia philjquitt@hotmail.com
To the Editor:
The letter by O’Brien1 on the article by Jones et al2 and the subsequent response by Jones et al1 continue to confine debate to areas already established by O’Brien,3 ie, finding a suitable replacement for the mercury (Hg) sphygmomanometer. However, 2 recent studies finding that aneroid gauges are accurate in US clinical settings4,5 suggest Hg abatement is set to accelerate in United States, rather than stall as the Jones et al Hg retention position indicates.2
Further, it should be noted that electronic devices and computers cycle Hg by collecting and vaporizing it,6 and hospitals are a ready source of spilt Hg from broken thermometers and leaking sphygmomanometers.7 Also, computers are themselves hazardous waste in that they contain Hg switches and relays.8 Recently, it was shown that Hg from thermometers broken in the domestic environment produces significant indoor pollution, decades after the original spillage.9 One should factor in by several times the domestic environmental exposure for hospital workers, based on high Hg hospital usage; spillage; and then translocation to the domestic environment. Human fatalities caused by one broken fever thermometer in the domestic environment have been reported.10
With the above in mind, all electronic equipment used in clinical and domestic settings should be properly labeled to show the Hg content at manufacture and, if not containing Hg, should be labeled as being Hg free. Purchasing arrangements should make this mandatory, and negative consequences in terms of funding should apply for those still purchasing Hg containing equipment.
References
1. O’Brien E. Response to the advisory statement from the Council of High Blood Pressure Research, American Heart Association, advocating retention of mercury sphygmomanometers. Hypertension. 2001; 38: e19–e20.[Medline] [Order article via Infotrieve]
2.
Jones DW, Frolich ED, Grim CM, Grim CE, Taubert KA. Mercury sphygmomanometers should not be abandoned: an advisory statement from the Council for high Blood Pressure Research, American Heart Association. Hypertension. 2001; 37: 185–186.
3.
O’Brien E. Replacing the mercury sphygmomanometer. BMJ. 2000; 320: 815–816.
4.
Canzanello VJ, Jensen PL, Schwartz GL. Are aneroid sphygmomanometers accurate in hospital and clinic settings? Arch Intern Med. 2001; 161: 729–731.
5. Yarows SA, Quian K. Accuracy of aneroid sphygmomanometers in clinical usage: University of Michigan experience. Blood Press Monit. 2001; 6: 101–106.[CrossRef][Medline] [Order article via Infotrieve]
6. Barry D. Patterns of Metallic Mercury Exposure. Agency for Toxic Substances and Disease Registry 1997. Available at: http://www.atsdr.cdc.gov/alerts/970626.html Accessed December 20, 2001.
7. Colquitt PJ. Will the millimetre of mercury be replaced by the kilopascal? J Hypertens. 1999; 17: 305–306.[Medline] [Order article via Infotrieve]
8. Lee CH, Chang SL, Wang KM, Wen LC. Management of scrap computer recycling in Taiwan. J Hazard Mater. 2000; 73: 209–220.[CrossRef][Medline] [Order article via Infotrieve]
9. Carpi A, Chen YE. Gaseous elemental mercury as an indoor pollutant. Environ Sci Technol. 2001; 35: 4170–4173.[Medline] [Order article via Infotrieve]
10. Jaeger A, Tempe JD, Haegy JM, Leroy M, Porte A, Mantz JM. Accidental acute mercury vapor poisoning. Vet Hum Toxicol. 1979; 21 (suppl): 62–63.[Medline] [Order article via Infotrieve]
University of Mississippi Medical Center, Jackson, Mississippi
Response
The focal issue of the advisory is accurate measurement of blood pressure, not the long- term retention of mercury products in hospitals. Sufficient standards of validation and good programs of calibration of blood pressure instruments are needed. If nonmercury instruments do prove to be accurate over a wide range of clinical circumstances and hospitals adopt rigid calibration programs, there will no longer be a need for discussion of mercury safety regarding blood pressure measurement.
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