Exposure to Mercury Vapor and Impact on Health in the Dental Profession in Sweden

Abstract

Possible adverse effects of mercury exposure in dentistry have been discussed in several studies. The objective of the present study was to carry out detailed measurements of mercury exposure in the dental profession in Sweden, and to search for adverse health effects from such exposure. We examined 22 dentists and 22 dental nurses, working in teams, at six Swedish dental clinics. Measurements of air mercury, performed with personal, active air samplers, showed a median air Hg of 1.8 micrograms/m3 for the dentists, and 2.1 micrograms/m3 for the dental nurses. Spot measurements with a direct reading instrument displayed temporarily elevated air Hg, especially during the preparation and application of amalgam. The average concentration of mercury in whole blood (B-Hg) was 18 nmol/L, in plasma (P-Hg) 5.1 nmol/L, and in urine (U-Hg) 3.0 nmol/mmol creatinine. Possible effects on the central nervous system (CNS) were registered with three questionnaires: Q16, Eysenck Personality Inventory (EPI), and the Profile of Mood Scales (POMS). In the Q16, the number of symptoms was statistically significantly higher in the dentistry group compared with an age- and gender-matched control group (n = 44). The urinary excretion of albumin and urinary activity of the tubular enzyme N-acetyl-beta-glucose-aminidase (NAG) did not differ between the two groups. The results confirm that exposure to mercury in the dental profession in Sweden is low. The air Hg levels were mainly influenced by the method of amalgam preparation and inserting, and by the method of air evacuation during drilling and polishing.

Exposure to Mercury Vapors in Dental Workers in Poland

“…In Sweden, the exposure to Hg vapor in the dental profession was much lower in 1986 and in 1997 comparable to the American data. The mean values for Hg-U in the dental [10,13]. In some countries, the mean and range of Hg-U concentrations in the dental staff are still rather high.…”

“…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].…”

Blood mercury levels of dental students and dentists at a dental school

“…The way in which amalgam is prepared, cleaning habits, and types of floor coverings have been pointed out to be important factors. 24 In this study the blood results were obtained by considering the plasma and erythrocyte ratio (2/3). 19 The study demonstrated that the increase of total mercury in plasma and blood was significant in groups IV, V, and particularly in the teaching staff (Group VI) who worked with amalgam.…”

Toxic effects of mercury, lead and gadolinium on vascular reactivity

“…Human toxicological data about methylmercury poisoning show that symptoms of toxic effects appear at a concentration of mercury in blood of 0.1 µg/mL and death occurs at concentrations above 3 µg/mL (9). It has also been reported that professional exposure to mercury vapor and the release of mercury from or during the removal of amalgam dental fillings increases the blood and plasma concentration of the metal (18)(19)(20). After exposure to mercury vapor, blood concentrations attain 18 nM (20) and, after exposure to dental amalgam fillings and their removal, plasma concentration attains 5 nM (19).…”

“…It has also been reported that professional exposure to mercury vapor and the release of mercury from or during the removal of amalgam dental fillings increases the blood and plasma concentration of the metal (18)(19)(20). After exposure to mercury vapor, blood concentrations attain 18 nM (20) and, after exposure to dental amalgam fillings and their removal, plasma concentration attains 5 nM (19). Another important mechanism of exposure is fish consumption.…”