Abstract
Aims: Dental personnel are exposed to mercury when using dental amalgam. This exposure constitutes a potential hazard to offspring of women working in dentistry. The present study examined increased mortality risk in offspring of mothers working in dentistry.
Methods: Mortality was compared between sons of dental personnel and sons of nondental health-care personnel. Hazard ratios were calculated for three decades (1960s–1980s), when the magnitude of mercury exposure in dentistry was likely to have varied.
Results: During the 1960s, there was a statistically significant increase in the risk of neonatal mortality for sons of dental nurses when compared with sons of assistant nurses: hazard ratio (HR) 1.82 (95% confidence interval, CI: 1.04–3.22). There was no increased risk in the subsequent decades, but a trend test demonstrated a consistent decrease in the risk over the three decades: HR for trend 0.63 (95% CI: 0.44–0.90). The raised mortality risk was limited to neonatal mortality. The comparison between dentists and physicians had insufficient statistical power.
Conclusions: There is no increased mortality risk among sons of female dentists after the 1960s. Although the results should be interpreted with caution, they suggest a modestly raised risk of neonatal mortality, during the 1960s, when exposure to mercury was thought to be highest.
Acknowledgements
This study was supported by grants from Karolinska Institutet, the National Board of Health and Welfare, and the Swedish Society of Medicine.
References
[1] Bjornberg KA, Vahter M, Berglund B, Niklasson B, Blennow M, Sandborgh-Englund G. Transport of methylmercury and inorganic mercury to the fetus and breast-fed infant. Environ Health Perspect. 2005;113:1381–5.10.1289/ehp.7856Search in Google Scholar
[2] Bodin L, Axelsson G, Ahlborg G, Jr. The association of shift work and nitrous oxide exposure in pregnancy with birth weight and gestational age. Epidemiol (Cambridge, Mass.). 1999;10:429–36.Search in Google Scholar
[3] Clarkson TW. The three modern faces of mercury. Environ Health Perspect. 2002;110:11–23.10.1289/ehp.02110s111Search in Google Scholar
[4] De Rosis F, Anastasio SP, Selvaggi L, Beltrame A, Moriani G. Female reproductive health in two lamp factories: effects of exposure to inorganic mercury vapour and stress factors. Br J Ind Med. 1985;42:488–94.10.1136/oem.42.7.488Search in Google Scholar
[5] Echeverria D, Heyer NJ, Martin MD, Naleway CA, Woods JS, Bittner AC, Jr. Behavioral effects of low-level exposure to elemental Hg among dentists. Neurotoxicol Teratol. 1994;17:161–8.10.1016/0892-0362(94)00049-JSearch in Google Scholar
[6] Echeverria D, Woods JS, Heyer NJ, Rohlman DS, Farin FM, Bittner AC, Jr., et al. Chronic low-level mercury exposure, BDNF polymorphism, and associations with cognitive and motor function. Neurotoxicol Teratol. 2005;27:781–96.10.1016/j.ntt.2005.08.001Search in Google Scholar PubMed
[7] Ekbom A. The Swedish multi-generation register. Methods Mol Biol. 2011;675:215–20.10.1007/978-1-59745-423-0_10Search in Google Scholar PubMed
[8] Ericson A, Kallen B. Pregnancy outcome in women working as dentists, dental assistants or dental technicians. Int Arch Occup Environ Health. 1989;61:329–33.10.1007/BF00409388Search in Google Scholar PubMed
[9] Hammerstrom K, Holte H, Dalsbo T, Vist G, Steiro A, Lidal I, et al. Kvikksølveksponering hos tannhelsepersonell [Mercury exposure in dental personnel]. Oslo: The Norwegian Knowledge Centre for the Health Services; 2011.Search in Google Scholar
[10] Heggland I, Irgens A, Tollanes M, Romundstad P, Syversen T, Svendsen K, et al. Pregnancy outcomes among female dental personnel –a registry-based retrospective cohort study. Scand J Work Environ Health. 2011;37:539–46.10.5271/sjweh.3175Search in Google Scholar PubMed
[11] Horsted-Bindslev P. Amalgam toxicity – environmental and occupational hazards. J Dent. 2004;32:359–65.10.1016/j.jdent.2004.02.002Search in Google Scholar PubMed
[12] Jokstad A. Mercury excretion and occupational exposure of dental personnel. Commun Dent Oral Epidemiol. 1990;18:143–8.10.1111/j.1600-0528.1990.tb00040.xSearch in Google Scholar PubMed
[13] Jones L, Bunnell J, Stillman J. A 30-year follow-up of residual effects on New Zealand School Dental Nurses, from occupational mercury exposure. Human Exp Toxicol. 2007;26:367–74.10.1177/0960327107076824Search in Google Scholar PubMed
[14] Joselow MM, Goldwater LJ, Alvarez A, Herndon J. Absorption and excretion of mercury in man. XV. Occupational exposure among dentists. Arch Environ Health. 1968;17:39–44.10.1080/00039896.1968.10665185Search in Google Scholar
[15] Larsson KS. The dissemination of false data through inadequate citation. J Intern Med. 1995;238:445–50.10.1111/j.1365-2796.1995.tb01222.xSearch in Google Scholar PubMed
[16] Lenvik K, Woldbæk T, Halgard K. Kvikksølveksponering blant tannhelsepersonell: en presentasjon av historiske måledata [Exposure to mercury among dental personnel: a presentation of historic measurement data; English summary]. Nors Tannlegeforenings Tid. 2006;116:350–6.Search in Google Scholar
[17] Lindbohm ML, Ylostalo P, Sallmen M, Henriks-Eckerman ML, Nurminen T, Forss H, et al. Occupational exposure in dentistry and miscarriage. Occup Environ Med. 2007;64:127–33.10.1136/oem.2005.026039Search in Google Scholar PubMed PubMed Central
[18] Ludvigsson JF, Otterblad-Olausson P, Pettersson BU, Ekbom A. The Swedish personal identity number: possibilities and pitfalls in healthcare and medical research. Eur J Epidemiol. 2009;24:659–67.10.1007/s10654-009-9350-ySearch in Google Scholar PubMed PubMed Central
[19] Meyer-Baron M, Schaeper M, Seeber A. A meta-analysis for neurobehavioural results due to occupational mercury exposure. Arch Toxicol. 2002;76:127–36.10.1007/s00204-002-0327-9Search in Google Scholar PubMed
[20] Naimi-Akbar A, Sandborgh Englund G, Ekbom A, Ekstrand J, Montgomery S. Cognitive function among sons of women who worked in dentistry. Scand J Work Environ Health. 2012;38:546–52.10.5271/sjweh.3279Search in Google Scholar PubMed
[21] Nilsson B. Mercury in dental practice. II. Urinary mercury excretion in dental personnel. Swed Dent J. 1986;10:221–32.Search in Google Scholar
[22] Ritchie KA, Burke FJ, Gilmour WH, Macdonald EB, Dale IM, Hamilton RM, et al. Mercury vapour levels in dental practices and body mercury levels of dentists and controls. Br Dent J. 2004;197:625–32; discussion 1.10.1038/sj.bdj.4811831Search in Google Scholar PubMed
[23] Ritchie KA, Gilmour WH, Macdonald EB, Burke FJ, McGowan DA, Dale IM, et al. Health and neuropsychological functioning of dentists exposed to mercury. Occup Environ Med. 2002;59:287–93.10.1136/oem.59.5.287Search in Google Scholar PubMed PubMed Central
[24] Roeleveld N, Zielhuis GA, Gabreels F. Mental retardation and parental occupation: a study on the applicability of job exposure matrices. Br J Ind Med. 1993;50:945–54.10.1136/oem.50.10.945Search in Google Scholar PubMed PubMed Central
[25] Rowland AS, Baird DD, Shore DL, Weinberg CR, Savitz DA, Wilcox AJ. Nitrous oxide and spontaneous abortion in female dental assistants. Am J Epidemiol. 1995;141:531–8.10.1093/oxfordjournals.aje.a117468Search in Google Scholar
[26] Rowland AS, Baird DD, Weinberg CR, Shore DL, Shy CM, Wilcox AJ. The effect of occupational exposure to mercury vapour on the fertility of female dental assistants. Occup Environ Med. 1994;51:28–34.10.1136/oem.51.1.28Search in Google Scholar
[27] Sandborgh-Englund G, Ask K, Belfrage E, Ekstrand J. Mercury exposure in utero and during infancy. J Toxicol Environ Health. 2001;63:317–20.10.1080/15287390152103634Search in Google Scholar
[28] Seidler A, Raum E, Arabin B, Hellenbrand W, Walter U, Schwartz FW. Maternal occupational exposure to chemical substances and the risk of infants small-for-gestational-age. Am J Ind Med. 1999;36:213–22.10.1002/(SICI)1097-0274(199907)36:1<213::AID-AJIM30>3.0.CO;2-ASearch in Google Scholar
[29] Sikorski R, Juszkiewicz T, Paszkowski T, Szprengier-Juszkiewicz T. Women in dental surgeries: reproductive hazards in occupational exposure to metallic mercury. Int Arch Occup Environ Health. 1987;59:551–7.10.1007/BF00377918Search in Google Scholar
[30] Stone ME, Cohen ME, Debban BA. Mercury vapor levels in exhaust air from dental vacuum systems. Dent Mater. 2007;23:527–32.10.1016/j.dental.2006.03.011Search in Google Scholar
[31] Svendsen K, Syversen T, Melo I, Hilt B. Historical exposure to mercury among Norwegian dental personnel. Scand J Work Environ Health. 2010;36:231–41.10.5271/sjweh.2878Search in Google Scholar
[32] WHO. Concise international chemical assessment document 50. Elemental mercury and inorganic compounds: Human health aspects. Geneva: WHO; 2003.Search in Google Scholar
The authors stated that there are no conflicts of interest regarding the publication of this article.
©2014 by De Gruyter
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Articles in the same Issue
- Frontmatter
- Editorial
- The CROWN Initiative: journal editors invite researchers to develop core outcomes in women’s health
- Academy’s Corner
- Invasive or non-invasive prenatal genetic diagnosis?
- Original articles - Obstetrics
- Effect of depth on shear-wave elastography estimated in the internal and external cervical os during pregnancy
- Analysis of measurement process of placental volume in early pregnancy: an interobserver reliability study
- Acute pancreatitis in pregnancy: a comparison of associated conditions, treatments and complications
- Cesarean section and placental disorders in subsequent pregnancies – a meta-analysis
- Effect of magnesium sulfate and nifedipine on the risk of developing pulmonary edema in preterm births
- Prediction of preeclampsia by placental protein 13 and background risk factors and its prevention by aspirin
- Maternal and neonatal outcome of labour induction at term comparing two regimens of misoprostol
- Comparison of placental alpha microglobulin-1 in vaginal fluid with intra-amniotic injection of indigo carmine for the diagnosis of rupture of membranes
- Clinical differences between early- and late-onset severe preeclampsia and analysis of predictors for perinatal outcome
- Maternal serum placental growth factor and fetal SGA in pregnancy complicated by type 1 diabetes mellitus
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- Imaging of fetal thymus in pregnant women with rheumatic diseases
- Original articles – Newborn
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- Absence of antibodies against Bordetella pertussis in pregnant women and newborns in the state of Nuevo Leon
- Mortality among sons of female dental personnel – a national cohort study
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