Mercury excretion and occupational exposure of dental personnel

Abstract

At the annual congresses of the Norwegian Dental Association in 1986 and 1987 surveys were conducted to assess the significance of potential sources of mercury exposure. Morning urine samples and questionnaires were collected from 672 participants in 1986 and 273 participants in 1987. The mean values of the urinary mercury excretion were 39 nmol/L (SD = 29) in 1986, and 43 nmol/L (SD = 36) in 1987. The excretion values were correlated to the answers on questionnaires supplied from each participant. The data was analyzed using ANOVA, multiple classification analyses, and Pearson correlation. The correlations between environment and practice characteristics and the mercury excretion values reconfirm in general results from previous investigations. In addition, the data indicate that urinary mercury excretion may be gender dependent and that the restorative status of the participants contribute to the daily mercury exposure. Moreover, the excretion correlates not only to the number of placed restorations per week, but also to the number of polished and replaced amalgam restorations per week. Participants working in environments with wooden floors had significantly higher mean mercury values than other dental personnel. Elevated mercury values were also observed for participants working in clinics with installed amalgam separators or other filtering devices. The possibility that the storage of collected scrap amalgam and mercury from the filtering devices increases the mercury vapor in the work environment warrants further investigation.

Thirty-five year review of a mercury monitoring service for Scottish dental practices

“…Failure to detect statistical significance for pubic hair, fingernail, and toenail mercury concentrations may be related to the relatively low numbers of samples collected (100 to 200). This gender difference has been documented in previous surveys, 11,12 in which urine samples were predominantly monitored. A gender-based variation in the renal handling of mercury was proposed as a possible explanation, however, the samples collected in the present survey were of hair and nail making this explanation unlikely.…”

Exposure to Mercury Vapors in Dental Workers in Poland

“…A lower or no exposure in this group of practitioners may result from more modern standards of dental practice. Naleway C et al [9] Nilsson B et al [10] Langan DC et al [6] Herber RFM et al [11] Jokstad A [12] Martin MD et al [4] Langworth S et al [13] Rojas M et al [14] Millán MAP et al [15] Ritchie KA et al [16] IJOMEH 2007;20(2)…”

“…To assess low-level occupational mercury exposure of dental staff, urine mercury (Hg-U) concentration was used as an exposure index [4,[6][7][8][9][10][11][12][13][14][15][16]. The recent literature data confi rm that Hg-U remains the most practical and sensitive marker of monitoring low-level occupational exposure to inorganic mercury [7].…”

Historical exposure to mercury among Norwegian dental personnel

“…Important factors that may influence exposure and, thus, also the levels of mercury in urine include: (i) the use of a textile rag to squeeze out excess mercury, (ii) the number of years a clinic has used the same premises, (iii) the number of amalgam treatments per week, (iv) whether a mercury spill has occurred in the clinic, and (v) whether Dentomat or capsules were used (4,5,10,11,13,25).…”

“…One of the main challenges has been to assess the amount of mercury to which dental personnel have been exposed, preferably on an individual level. Studies of exposure levels in dental clinics have shown mostly low levels of mercury exposure, as indicated both by measured levels in the air at dental clinics and the urine of employees (8)(9)(10)(11). Such results have, however, been linked neither to short-nor long-term health effects.…”