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A historical review of the effects of dental radiography on pregnant patients. J Am Dent Assoc 2022; 153:989-995. [PMID: 35985884 DOI: 10.1016/j.adaj.2022.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 05/18/2022] [Accepted: 06/09/2022] [Indexed: 02/02/2023]
Abstract
BACKGROUND The safety of dental radiography performed on pregnant patients has been a controversial topic since the 1960s. This review synthesizes and consolidates findings, from 1957 through 2021, of the effects dental ionizing radiation could have on a pregnant patient and in utero birth defects. TYPES OF STUDIES REVIEWED Using PubMed, the following key words were searched: pregnancy, radiology, radiograph, radiation dose, fetus, x-ray, and dental. Criteria evaluation was done on the basis of availability, completeness, quality, relevance, technicality (that is, dental radiography), topicality (that is, pregnant patients), and usability. These results were then filtered on the basis of quantitative and qualitative data as well as the period (decades within the historical framework). The final selection of relevant literature consisted of various studies including cohort studies, systematic reviews, meta-analyses, case reports, and other narrative reviews. RESULTS If properly performed, the amount of ionizing radiation produced during dental radiographic procedures is so low that it is unlikely to reach the teratogenic threshold. Thus, dental ionizing radiation is unlikely to cause in utero birth defects because it has been detected to have a deterministic (not stochastic) effect. With this information and historical context, this article shows that necessary dental radiography is safe at any stage during pregnancy, as long as proper safety equipment is appropriately used. CONCLUSIONS AND PRACTICAL IMPLICATIONS As technology advances, more research can further clarify ionizing radiation safety for pregnant patients and its potential effects on in utero birth defects, improving overall oral health care. The dental community must remain educated about current ionizing radiation safety guidelines to make better-informed decisions and successfully provide proper oral health care to pregnant patients.
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The benefits of fish intake: results concerning prenatal mercury exposure and child outcomes from the ALSPAC prebirth cohort. Neurotoxicology 2022; 91:22-30. [DOI: 10.1016/j.neuro.2022.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/14/2022] [Accepted: 04/26/2022] [Indexed: 11/22/2022]
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Sekovanić A, Piasek M, Orct T, Sulimanec Grgec A, Matek Sarić M, Stasenko S, Jurasović J. Mercury Exposure Assessment in Mother-Infant Pairs from Continental and Coastal Croatia. Biomolecules 2020; 10:biom10060821. [PMID: 32471193 PMCID: PMC7355586 DOI: 10.3390/biom10060821] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 12/31/2022] Open
Abstract
The main source of mercury (Hg) exposure in the general population is fish. Another possible source is dental amalgam. Here, we compare the levels of Hg and selenium (Se) in samples of maternal and fetal origin collected shortly after childbirth of healthy postpartum women in the coastal (n = 96) and continental (n = 185) areas of Croatia related to maternal seafood/fish consumption. We also evaluated Hg concentrations and maternal serum metallothionein (MT2) concentrations in relation to the number of dental amalgam fillings, and MT2A-5A/G (rs28366003) polymorphism. The levels of Hg and Se in maternal hair and blood/serum, placenta and cord blood/serum increased in relation to increasing fish consumption with the highest values in subjects from the coast. The concentrations of each element and between elements correlated across the matrices. Increasing amalgam number correlated linearly with increased Hg levels in maternal and cord serum and was not associated with serum MT2. No association of MT2A-5A/G polymorphism and Hg or Se levels were found. The results confirmed higher fish consumption in coastal vs. continental Croatia and increases of both Hg and Se related to fish consumption in all analyzed samples. Increased blood Hg reflected the predominant MeHg share from seafood, while increased serum Hg matched exposure from dental amalgams.
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Affiliation(s)
- Ankica Sekovanić
- Institute for Medical Research and Occupational Health, 10000 Zagreb, Croatia; (A.S.); (T.O.); (A.S.G.); (J.J.)
| | - Martina Piasek
- Institute for Medical Research and Occupational Health, 10000 Zagreb, Croatia; (A.S.); (T.O.); (A.S.G.); (J.J.)
- Correspondence:
| | - Tatjana Orct
- Institute for Medical Research and Occupational Health, 10000 Zagreb, Croatia; (A.S.); (T.O.); (A.S.G.); (J.J.)
| | - Antonija Sulimanec Grgec
- Institute for Medical Research and Occupational Health, 10000 Zagreb, Croatia; (A.S.); (T.O.); (A.S.G.); (J.J.)
| | | | - Sandra Stasenko
- Clinical Department of Obstetrics and Gynecology, Merkur University Hospital, 10000 Zagreb, Croatia;
| | - Jasna Jurasović
- Institute for Medical Research and Occupational Health, 10000 Zagreb, Croatia; (A.S.); (T.O.); (A.S.G.); (J.J.)
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Lygre GB, Aase H, Haug K, Lie SA, Björkman L. Prenatal exposure to dental amalgam and risk of symptoms of attention-deficit and hyperactivity disorder (ADHD). Community Dent Oral Epidemiol 2018; 46:472-481. [PMID: 30084494 DOI: 10.1111/cdoe.12409] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 07/05/2018] [Indexed: 01/06/2023]
Abstract
BACKGROUND ADHD is multifactorial, including both genetic and environmental factors. The safety of amalgam used in dental treatment has been discussed due to its content of mercury and potential risks for negative neurodevelopmental consequences in the offspring. The aim of the study was to investigate possible associations between symptoms related to ADHD in children of three and five years of age and prenatal exposure to mercury from mothers' amalgam fillings. METHODS Data from the Norwegian Mother and Child Cohort Study (MoBa) were used. Data were collected by questionnaires sent to participating women in week 17 (Q1) and 30 (Q3) of pregnancy and when the child was three (Q6) and five years of age (Q7). Information about exposure to amalgam during pregnancy was obtained from Q3. Information about symptoms related to ADHD was obtained from Q6 and Q7. Valid data were obtained for 42 163 children at three years of age and 23 392 children at five years of age. Logistic regression models, including mothers' age, education, body mass index, parity, smoking and alcohol consumption during pregnancy, were used to estimate the association between ADHD symptoms and prenatal exposure to amalgam fillings. RESULTS No significant associations between number of teeth with amalgam filling, amalgam fillings placed or removed during pregnancy, and symptoms related to ADHD in children of three and five years of age were found. CONCLUSIONS In a large, prospective cohort study, we found no indication of increased risk of ADHD-related symptoms in children prenatally exposed to mother's amalgam fillings.
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Affiliation(s)
- Gunvor B Lygre
- Dental Biomaterials Adverse Reaction Unit, Uni Research Health, Bergen, Norway
| | - Heidi Aase
- Norwegian Institute of Public Health, Oslo, Norway
| | - Kjell Haug
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Stein A Lie
- Department of Clinical Dentistry, University of Bergen, Bergen, Norway
| | - Lars Björkman
- Dental Biomaterials Adverse Reaction Unit, Uni Research Health, Bergen, Norway.,Department of Clinical Dentistry, University of Bergen, Bergen, Norway
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Pihlstrom BL. Selections From the Current Literature. J Am Dent Assoc 2017. [DOI: 10.1016/j.adaj.2016.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Murcia M, Ballester F, Enning AM, Iñiguez C, Valvi D, Basterrechea M, Rebagliato M, Vioque J, Maruri M, Tardon A, Riaño-Galán I, Vrijheid M, Llop S. Prenatal mercury exposure and birth outcomes. ENVIRONMENTAL RESEARCH 2016; 151:11-20. [PMID: 27448728 DOI: 10.1016/j.envres.2016.07.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 06/10/2016] [Accepted: 07/03/2016] [Indexed: 06/06/2023]
Abstract
BACKGROUND Results regarding the association between mercury exposure and anthropometry at birth, gestational length and placental weight are inconsistent, as is the role of seafood intake in these associations. OBJECTIVE We assessed whether prenatal mercury exposure is associated with anthropometry at birth, placental weight and gestational length in a population with a relatively high exposure to mercury from seafood consumption. METHODS Total mercury (T-Hg) was determined in cord blood from 1869 newborns with birth outcome measures, within the Spanish multicenter INMA cohort from 2004 to 2008. We adjusted cohort specific linear and Cox regression models to evaluate the association between T-Hg and birth anthropometry (weight, length, and head circumference), placental weight and gestational length. Non-spontaneous labor was taken to be censoring in the survival analysis. Final estimates were obtained using meta-analysis. RESULTS Geometric mean T-Hg was 8.2μg/L. A doubling of T-Hg was associated with a 7.7g decrease in placental weight (95% CI: -13.6, -1.8) and marginally with head circumference (beta: -0.052cm, 95% CI: -0.109, 0.005). T-Hg was also inversely related to weight and length, although with weaker estimates. Mercury exposure was not associated with the length of gestation. The inverse relation between T-Hg and growth was enhanced when the intake of different seafood groups was adjusted for in the models. CONCLUSIONS Prenatal mercury exposure may be associated with reduced placental and fetal growth. Confounding by fish intake should be considered when assessing these relationships.
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Affiliation(s)
- Mario Murcia
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain.
| | - Ferran Ballester
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Nursing Department, Universitat de València, Valencia, Spain
| | - Ashley Michel Enning
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Universitat Pompeu Fabra, Barcelona, Spain
| | - Carmen Iñiguez
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
| | - Damaskini Valvi
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Universitat Pompeu Fabra, Barcelona, Spain; Harvard T.H. Chan School of Public Health, Boston, USA
| | - Mikel Basterrechea
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Public Health Division of Gipuzkoa, San Sebastián, Spain; Health Research Institute (BIODONOSTIA), San Sebastián, Spain
| | - Marisa Rebagliato
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain; Medicine Department, Universitat Jaume I, Castelló de la Plana, Spain
| | - Jesús Vioque
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Universidad Miguel Hernández, San Juan de Alicante, Spain
| | - Maite Maruri
- OSI Goierri-Alto Urola, Centro de Salud de Azkoitia, Spain
| | - Adonina Tardon
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; IUOPA-Universidad de Oviedo, Spain
| | - Isolina Riaño-Galán
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Pediatric Unit, Hospital San Agustin, Aviles, Spain
| | - Martine Vrijheid
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain; Universitat Pompeu Fabra, Barcelona, Spain
| | - Sabrina Llop
- Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Spain; Epidemiology and Environmental Health Joint Research Unit, FISABIO-Universitat Jaume I-Universitat de València, Valencia, Spain
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Lygre GB, Haug K, Skjaerven R, Björkman L. Prenatal exposure to dental amalgam and pregnancy outcome. Community Dent Oral Epidemiol 2016; 44:442-9. [PMID: 27146796 DOI: 10.1111/cdoe.12233] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 03/23/2016] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Questions have been raised about potential risks of prenatal exposure to mercury from amalgam fillings during pregnancy. The aim of this study was to assess possible associations between exposure to amalgam fillings in pregnant women participating in a large cohort study and adverse pregnancy outcome. METHODS In the Norwegian Mother and Child Cohort Study (MoBa), a valid information about the number of teeth with amalgam fillings and dental treatment, including new amalgam fillings placed or removed during pregnancy, was available from 69 474 pregnancies. The information was obtained from two questionnaires sent to the women at 17 and 30 weeks of pregnancy, and the data were linked to the Medical Birth Registry of Norway. Logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (95% CI) as a measure of association between pregnancy outcome and prenatal exposure to amalgam fillings. RESULTS Logistic regression models, including mothers' age, education, BMI, parity, smoking during pregnancy, and alcohol consumption during pregnancy revealed no significant associations between the number of teeth with amalgam fillings and early preterm delivery, late preterm delivery, low birthweight, malformation or stillbirth. CONCLUSIONS We found no evidence for serious perinatal consequences of maternal exposure to amalgam fillings during pregnancy.
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Affiliation(s)
| | - Kjell Haug
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Rolv Skjaerven
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.,Medical Birth Registry of Norway, Norwegian Institute of Public Health, Bergen, Norway
| | - Lars Björkman
- Dental Biomaterials Adverse Reaction Unit, Uni Research Health, Bergen, Norway.,Department of Clinical Dentistry, University of Bergen, Bergen, Norway
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Pihlstrom BL. Selections From the Current Literature. J Am Dent Assoc 2016. [DOI: 10.1016/j.adaj.2016.02.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Wells EM, Herbstman JB, Lin YH, Jarrett J, Verdon CP, Ward C, Caldwell KL, Hibbeln JR, Witter FR, Halden RU, Goldman LR. Cord Blood Methylmercury and Fetal Growth Outcomes in Baltimore Newborns: Potential Confounding and Effect Modification by Omega-3 Fatty Acids, Selenium, and Sex. ENVIRONMENTAL HEALTH PERSPECTIVES 2016; 124:373-9. [PMID: 26115160 PMCID: PMC4786979 DOI: 10.1289/ehp.1408596] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 06/24/2015] [Indexed: 05/22/2023]
Abstract
BACKGROUND Methylmercury (MeHg) may affect fetal growth; however, prior research often lacked assessment of mercury speciation, confounders, and interactions. OBJECTIVE Our objective was to assess the relationship between MeHg and fetal growth as well as the potential for confounding or interaction of this relationship from speciated mercury, fatty acids, selenium, and sex. METHODS This cross-sectional study includes 271 singletons born in Baltimore, Maryland, 2004-2005. Umbilical cord blood was analyzed for speciated mercury, serum omega-3 highly unsaturated fatty acids (n-3 HUFAs), and selenium. Multivariable linear regression models controlled for gestational age, birth weight, maternal age, parity, prepregnancy body mass index, smoking, hypertension, diabetes, selenium, n-3 HUFAs, and inorganic mercury (IHg). RESULTS Geometric mean cord blood MeHg was 0.94 μg/L (95% CI: 0.84, 1.07). In adjusted models for ponderal index, βln(MeHg) = -0.045 (g/cm(3)) × 100 (95% CI: -0.084, -0.005). There was no evidence of a MeHg × sex interaction with ponderal index. Contrastingly, there was evidence of a MeHg × n-3 HUFAs interaction with birth length [among low n-3 HUFAs, βln(MeHg) = 0.40 cm, 95% CI: -0.02, 0.81; among high n-3 HUFAs, βln(MeHg) = -0.15, 95% CI: -0.54, 0.25; p-interaction = 0.048] and head circumference [among low n-3 HUFAs, βln(MeHg) = 0.01 cm, 95% CI: -0.27, 0.29; among high n-3 HUFAs, βln(MeHg) = -0.37, 95% CI: -0.63, -0.10; p-interaction = 0.042]. The association of MeHg with birth weight and ponderal index was affected by n-3 HUFAs, selenium, and IHg. For birth weight, βln(MeHg) without these variables was -16.8 g (95% CI: -75.0, 41.3) versus -29.7 (95% CI: -93.9, 34.6) with all covariates. Corresponding values for ponderal index were -0.030 (g/cm(3)) × 100 (95% CI: -0.065, 0.005) and -0.045 (95% CI: -0.084, -0005). CONCLUSION We observed an association of increased MeHg with decreased ponderal index. There is evidence for interaction between MeHg and n-3 HUFAs; infants with higher MeHg and n-3 HUFAs had lower birth length and head circumference. These results should be verified with additional studies.
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Affiliation(s)
- Ellen M. Wells
- School of Health Sciences, Purdue University, West Lafayette, Indiana, USA
- Address correspondence to E.M. Wells, Purdue University, School of Health Sciences; Hampton Hall of Civil Engineering 1269; 550 Stadium Mall Dr.; West Lafayette, IN 47907 USA. Telephone: (765) 496-3535. E-mail:
| | - Julie B. Herbstman
- Columbia Center for Children’s Environmental Health, Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, New York, USA
| | - Yu Hong Lin
- Laboratory of Membrane Biochemistry and Biophysics, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland, USA
| | - Jeffery Jarrett
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Carl P. Verdon
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Cynthia Ward
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Kathleen L. Caldwell
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Joseph R. Hibbeln
- Laboratory of Membrane Biochemistry and Biophysics, National Institute of Alcohol Abuse and Alcoholism, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland, USA
| | - Frank R. Witter
- Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Rolf U. Halden
- Center for Environmental Security, Biodesign Institute, Global Security Initiative, Arizona State University, Tempe, Arizona, USA
| | - Lynn R. Goldman
- Department of Environmental and Occupational Health, Milken Institute School of Public Health, George Washington University, Washington, DC, USA
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Al-Saleh I, Nester M, Abduljabbar M, Al-Rouqi R, Eltabache C, Al-Rajudi T, Elkhatib R. Mercury (Hg) exposure and its effects on Saudi breastfed infant's neurodevelopment. Int J Hyg Environ Health 2016; 219:129-41. [DOI: 10.1016/j.ijheh.2015.10.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 10/18/2015] [Accepted: 10/19/2015] [Indexed: 10/22/2022]
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Golding J, Steer CD, Gregory S, Lowery T, Hibbeln JR, Taylor CM. Dental associations with blood mercury in pregnant women. Community Dent Oral Epidemiol 2015; 44:216-22. [PMID: 26688340 PMCID: PMC4840325 DOI: 10.1111/cdoe.12208] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 11/16/2015] [Indexed: 12/01/2022]
Abstract
Objectives There is curiosity concerning the source of mercury that is absorbed into the mother's blood and which may affect the developing fetus. This study therefore sets out to determine the extent to which dental amalgam (DA) may contribute to total blood mercury (TBHg) levels of pregnant women in the UK. Methods Whole blood samples and information on diet and socio‐demographic factors were collected from pregnant women (n = 4484) enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). The whole blood samples were assayed for total mercury levels using inductively coupled plasma dynamic reaction cell mass spectrometry (ICP‐DRC‐MS), and the women were retrospectively asked about features of their dental care during the pregnancy. Linear regression was used to estimate the relative contributions of DA to TBHg levels (log‐transformed) based on R2 values, compared to the results from dietary and socio‐demographic variables. Results The contribution to the variance of the mothers' TBHg levels by dental variables was 6.47%, a figure comparable to the 8.75% shown for seafood consumption in this population. Dietary and dental variables explained 20.16% of the variance, with socio‐demographic variables contributing only a further 3.40%. The number of amalgams in the mouth at the start of pregnancy accounted for most of the variance in dental variables. Conclusions Dental amalgam contributes a comparable amount of variance in TBHg to seafood consumption in this population. However, because the measures of DA exposure were imprecise, these findings are likely to be an underestimate. There is no evidence to date in the literature that fetal exposures to mercury from maternal DAs have adverse effects on the developing child, but long‐term studies are warranted.
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Affiliation(s)
- Jean Golding
- Centre for Child and Adolescent Health, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Colin D Steer
- Centre for Child and Adolescent Health, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Steven Gregory
- Centre for Child and Adolescent Health, School of Social & Community Medicine, University of Bristol, Bristol, UK
| | - Tony Lowery
- National Seafood Inspection Laboratory, National Marine Fisheries Service, National Oceanic & Atmospheric Administration, Pascagoula, MS, USA
| | - Joseph R Hibbeln
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD, USA
| | - Caroline M Taylor
- Centre for Child and Adolescent Health, School of Social & Community Medicine, University of Bristol, Bristol, UK
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Al-Saleh I, Abduljabbar M, Al-Rouqi R, Eltabache C, Al-Rajudi T, Elkhatib R, Nester M. The extent of mercury (Hg) exposure among Saudi mothers and their respective infants. ENVIRONMENTAL MONITORING AND ASSESSMENT 2015; 187:678. [PMID: 26450688 DOI: 10.1007/s10661-015-4858-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 09/09/2015] [Indexed: 06/05/2023]
Abstract
A total of 1016 healthy Saudi mothers and their respective infants (aged 3-12 months) were recruited from 57 Primary Health Care Centers (PHCCs) in Riyadh, Saudi Arabia, to evaluate the extent of mercury (Hg) exposure and predict its sources in the healthy Saudi population. Total Hg levels were measured in maternal urine, breast milk, blood, and hair and in the infants' urine and hair. Only 1.9% of the mothers had urinary Hg (UHg)>10 μg/l, the limit for asymptomatic adults recommended by the World Health Organization, but the median (0.99 μg/l) was higher than in other countries. Also, 49.3% of the mothers had UHg>1 μg/l, the German reference value for adults. Median infant UHg was 0.729 μg/l, and 77 and 93 % of the infants had levels higher than 0.4 and 0.1 μg/l, the reference values of the Centers for Disease Control and Prevention and for Germany, respectively. The median Hg level in breast milk was 0.884 μg/l. Even though 43.2% of the milk samples were above the background level for Hg in human milk (1 μg/l), our results were lower than those reported from other countries. Median maternal total Hg in blood was 0.637 μg/l, and only 0.4 and 6.9% of samples were higher than the Hg reference levels of 5.8 μg/l of the Environmental Protection Agency (EPA) and of 2 μg/l for Germany, respectively. Total Hg levels in hair (HHg) varied widely among mothers and infants, but only 3.9% of the mothers and 2.8% of the infants had HHg>1 μg/g (the EPA reference level). Median HHg values were 0.117 μg/g dry weight in mothers and 0.1 μg/g dry weight in infants; both were lower than in other countries. The Hg levels in mothers and their respective infants were relatively low, but our results were consistent with other studies indicating that dental amalgam fillings and fish consumption were the main predictors of maternal Hg exposure. Among the several biomarkers of Hg exposure, Hg levels in maternal hair and urine were the strongest predictors of infant exposure. The lack of an association between Hg in breast milk and Hg in infant urine and hair suggested that the infants were exposed to Hg predominately during pregnancy rather than during breastfeeding. We expect that our data can serve as a baseline for further biomonitoring and follow-up studies, particularly of the long-term impact of Hg on childhood neurodevelopment.
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Affiliation(s)
- Iman Al-Saleh
- Environmental Health Section, King Faisal Specialist Hospital and Research Centre, PO Box: 3354, Riyadh, 11211, Saudi Arabia.
| | - Mai Abduljabbar
- Environmental Health Section, King Faisal Specialist Hospital and Research Centre, PO Box: 3354, Riyadh, 11211, Saudi Arabia
| | - Reem Al-Rouqi
- Environmental Health Section, King Faisal Specialist Hospital and Research Centre, PO Box: 3354, Riyadh, 11211, Saudi Arabia
| | - Chafica Eltabache
- Environmental Health Section, King Faisal Specialist Hospital and Research Centre, PO Box: 3354, Riyadh, 11211, Saudi Arabia
| | - Tahreer Al-Rajudi
- Environmental Health Section, King Faisal Specialist Hospital and Research Centre, PO Box: 3354, Riyadh, 11211, Saudi Arabia
| | - Rola Elkhatib
- Environmental Health Section, King Faisal Specialist Hospital and Research Centre, PO Box: 3354, Riyadh, 11211, Saudi Arabia
| | - Michael Nester
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, PO Box: 3354, Riyadh, 11211, Saudi Arabia
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Thomas S, Arbuckle TE, Fisher M, Fraser WD, Ettinger A, King W. Metals exposure and risk of small-for-gestational age birth in a Canadian birth cohort: The MIREC study. ENVIRONMENTAL RESEARCH 2015; 140:430-9. [PMID: 25967284 DOI: 10.1016/j.envres.2015.04.018] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 04/23/2015] [Accepted: 04/28/2015] [Indexed: 05/20/2023]
Abstract
BACKGROUND Lead, mercury, cadmium and arsenic are some of the most common toxic metals to which Canadians are exposed. The effect of exposure to current low levels of toxic metals on fetal growth restriction is unknown. OBJECTIVE The aim of this study was to examine relationships between exposure to lead, mercury, cadmium and arsenic during pregnancy, and risk of small for gestational age (SGA) birth. METHODS Lead, mercury, cadmium and arsenic levels were measured in blood samples from the first and third trimesters in 1835 pregnant women from across Canada. Arsenic species in first trimester urine were also assessed. Relative risks and 95% confidence intervals were estimated using log binomial multivariate regression. Important covariates including maternal age, parity, pre-pregnancy BMI, and smoking, were considered in the analysis. An exploratory analysis was performed to examine potential effect modification of these relationships by single nucleotide polymorphisms (SNPs) in GSTP1 and GSTO1 genes. RESULTS No association was found between blood lead, cadmium or arsenic and risk for SGA. We observed an increased risk for SGA for the highest compared to the lowest tertile of exposure for mercury (>1.6 µg/L, RR=1.56.; 95% CI=1.04-2.58) and arsenobetaine (>2.25 µg/L, RR=1.65; 95% CI=1.10-2.47) after adjustment for the effects of parity and smoking. A statistically significant interaction was observed in the relationship between dimethylarsinic acid (DMA) levels in urinary arsenic and SGA between strata of GSTO1 A104A (p for interaction=0.02). A marginally significant interaction was observed in the relationship between blood lead and SGA between strata of GSTP1 A114V (p for interaction=0.06). CONCLUSIONS These results suggest a small increase in risk for SGA in infants born to women exposed to mercury and arsenic. Given the conflicting evidence in the literature this warrants further investigation in other pregnant populations.
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Affiliation(s)
- Shari Thomas
- Department of Public Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Tye E Arbuckle
- Population Studies Division, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Canada.
| | - Mandy Fisher
- Population Studies Division, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Canada
| | - William D Fraser
- Sainte Justine University Hospital Research Center, University of Montreal, Montreal, Canada
| | - Adrienne Ettinger
- Center for Perinatal, Pediatric & Environmental Epidemiology, Yale School of Public Health, New Haven, CT, USA
| | - Will King
- Department of Public Health Sciences, Queen's University, Kingston, Ontario, Canada
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Ou L, Chen C, Chen L, Wang H, Yang T, Xie H, Tong Y, Hu D, Zhang W, Wang X. Low-level prenatal mercury exposure in north China: an exploratory study of anthropometric effects. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:6899-908. [PMID: 25936461 DOI: 10.1021/es5055868] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
In order to investigate anthropometric effects of mercury (Hg) exposure, we examined the status of human prenatal exposure to Hg species, including total mercury (THg), methylmercury (MeHg) and inorganic mercury (IHg), in North China, as well as their potential effects on fetal and infant growth. Hg concentrations in various bioindicators were measured from 50 Chinese women and newborns in 2011. The participants were followed for 12 months to collect anthropometric information. Linear and two-level regression analyses were performed to determine the associations between Hg levels and body growth. The geometric mean levels of THg in the placenta, cord blood, fetal hair, and maternal blood, hair, and urine were 25.88 μg/kg dry wt, 2.73 μg/L, 572.98 μg/kg, 2.29 μg/L, 576.54 μg/kg, and 0.58 μg/g creatinine, respectively. Nearly 100% of Hg presented as IHg in urine, and the percentage of IHg in other bioindicators was 14.86-48.73%. We observed significantly negative associations between Hg levels in some matrixes and anthropometry of neonates (weight and height) and infants (height) (p < 0.05). THg levels in maternal hair were also negatively associated with infant growth rate of weight during 12 months after delivery (p = 0.017). This study suggests that low-level prenatal Hg exposure could play a role in attenuating fetal and infant growth, and the effects of MeHg and IHg are different.
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Affiliation(s)
- Langbo Ou
- †Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Cen Chen
- †Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Long Chen
- †Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Huanhuan Wang
- †Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Tianjun Yang
- †Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Han Xie
- †Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Yindong Tong
- †Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Dan Hu
- †Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Wei Zhang
- ‡School of Environment and Natural Resources, Renmin University of China, Beijing, 100872, China
| | - Xuejun Wang
- †Ministry of Education Laboratory of Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
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15
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Bashore CJ, Geer LA, He X, Puett R, Parsons PJ, Palmer CD, Steuerwald AJ, Abulafia O, Dalloul M, Sapkota A. Maternal mercury exposure, season of conception and adverse birth outcomes in an urban immigrant community in Brooklyn, New York, U.S.A. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2014; 11:8414-42. [PMID: 25153469 PMCID: PMC4143869 DOI: 10.3390/ijerph110808414] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 07/23/2014] [Accepted: 08/04/2014] [Indexed: 02/01/2023]
Abstract
Adverse birth outcomes including preterm birth (PTB: <37 weeks gestation) and low birth weight (LBW: <2500 g) can result in severe infant morbidity and mortality. In the United States, there are racial and ethnic differences in the prevalence of PTB and LBW. We investigated the association between PTB and LBW with prenatal mercury (Hg) exposure and season of conception in an urban immigrant community in Brooklyn, New York. We recruited 191 pregnant women aged 18-45 in a Brooklyn Prenatal Clinic and followed them until delivery. Urine specimens were collected from the participants during the 6th to 9th month of pregnancy. Cord blood specimens and neonate anthropometric data were collected at birth. We used multivariate logistic regression models to investigate the odds of LBW or PTB with either maternal urinary mercury or neonate cord blood mercury. We used linear regression models to investigate the association between continuous anthropometric outcomes and maternal urinary mercury or neonate cord blood mercury. We also examined the association between LBW and PTB and the season that pregnancy began. Results showed higher rates of PTB and LBW in this cohort of women compared to other studies. Pregnancies beginning in winter (December, January, February) were at increased odds of LBW births compared with births from pregnancies that began in all other months (OR7.52 [95% CI 1.65, 34.29]). We observed no association between maternal exposure to Hg, and either LBW or PTB. The apparent lack of association is consistent with other studies. Further examination of seasonal association with LBW is warranted.
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Affiliation(s)
- Cynthia J Bashore
- Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Room 2234F, College Park, MD 20742-2611, USA.
| | - Laura A Geer
- Department of Environmental and Occupational Health Sciences, Downstate School of Public Health, State University of New York, Box 43,450 Clarkson Ave., Brooklyn, NY 11203-2533, USA.
| | - Xin He
- Department of Epidemiology and Biostatistics, University of Maryland College Park School of Public Health, 2234H SPH Building, College Park, MD 20742-2611, USA.
| | - Robin Puett
- Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Room 2234F, College Park, MD 20742-2611, USA.
| | - Patrick J Parsons
- Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, Department of Health, New York State University, Albany, NY 12201-0509, USA.
| | - Christopher D Palmer
- Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, Department of Health, New York State University, Albany, NY 12201-0509, USA.
| | - Amy J Steuerwald
- Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, Department of Health, New York State University, Albany, NY 12201-0509, USA.
| | - Ovadia Abulafia
- Department of Obstetrics and Gynecology, State University of New York Downstate Medical Center, 445 Lenox Road, Brooklyn, NY 11203, USA.
| | - Mudar Dalloul
- Department of Obstetrics and Gynecology, State University of New York Downstate Medical Center, 445 Lenox Road, Brooklyn, NY 11203, USA.
| | - Amir Sapkota
- Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, Room 2234F, College Park, MD 20742-2611, USA.
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16
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Marques RC, Bernardi JVE, Dórea JG, de Fatima R Moreira M, Malm O. Perinatal multiple exposure to neurotoxic (lead, methylmercury, ethylmercury, and aluminum) substances and neurodevelopment at six and 24 months of age. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 187:130-135. [PMID: 24486466 DOI: 10.1016/j.envpol.2014.01.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/03/2014] [Accepted: 01/04/2014] [Indexed: 06/03/2023]
Abstract
We studied neurodevelopment in infants from two communities. Children living in the vicinity of tin-ore kilns and smelters - TOKS; n = 51) were compared to children from a fishing village (Itapuã; n = 45). Mean hair-Hg (HHg) concentrations were significantly higher in Itapuã children which received significantly (p = 0.0000001) less mean ethylmercury (88.6 μg) from Thimerosal-containing vaccines (TCV) than the TOKS children (120 μg). Breast-milk Pb concentrations were significantly higher in the TOKS mothers (p = 0.000017; 10.04 vs. 3.9 μg L(-1)). Bayley mental development index (MDI) and psychomotor development index (PDI) were statistically significant (respectively p < 0.0000001, p = 0.000007) lower for the TOKS children only at 24 months of age. Multivariate regression analysis showed that MDI was negatively affected by breast-milk Pb and by HHg. PDI was positively affected by breastfeeding and negatively affected by ethylmercury. Milestone achievements were negatively affected by breast-milk Pb (age of walking) and by HHg (age of talking).
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Affiliation(s)
- Rejane C Marques
- Federal University of Rio de Janeiro, Campus Macaé, CEP 27930-560 RJ, Brazil
| | | | - José G Dórea
- University of Brasília, Brasília, 70919-970 DF, Brasil.
| | | | - Olaf Malm
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, CEP 21941-902 RJ, Brazil
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17
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Dórea JG, Marques RC, Abreu L. Milestone achievement and neurodevelopment of rural Amazonian toddlers (12 to 24 months) with different methylmercury and ethylmercury exposure. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2014; 77:1-13. [PMID: 24555642 DOI: 10.1080/15287394.2014.861335] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Neurological outcomes (Gesell development schedules [GDS]), age of walking, and age of talking were studied in 299 toddlers (12 to 24 mo) in relation to environmental (fish consumption and tin mining) exposure. Exposure to fish methylmercury (MeHg) consumption and iatrogenic ethylmercury (EtHg) in Thimerosal-containing vaccines (TCV) was quantified in toddlers from two rural villages (n = 91, Itapuã; n = 218, Bom Futuro) respectively populated by fishers and cassiterite miners. Median total hair Hg (HHg) concentrations of infants from Itapuã (3.5 μg/g) were significantly higher than those of infants from Bom Futuro (2.2 μg/g). Median EtHg exposure from TCV was also significantly higher in toddlers from Itapuã (137.5 μg) than in those from Bom Futuro (112.5 μg). There were no significant differences between groups for any of the Gesell schedules; however, there were proportionally more compromised toddlers (GDS < 70) in Itapuã than Bom Futuro. Median age of talking was not statistically different but median age of walking was significantly higher in Bom Futuro. In toddlers from both villages, of fishers and miners, HHg concentrations were significantly correlated with family fish consumption. A logistic regression model was applied to all infants after classification into two groups: above or below the median Gesell schedules. Overall, there was no distinctive pattern of neurodevelopment associated with either HHg or EtHg exposure; however, nutritional status was significantly associated with GDS. In conclusion, milestone achievement was delayed in toddlers from tin-ore mining communities. Despite significantly higher exposure to both forms of organic Hg (MeHg from maternal fish consumption, and EtHg from TCV) in toddlers from the fishing village, significant differences were seen only among the proportions of most severely affected toddlers (GDS < 70).
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Affiliation(s)
- José G Dórea
- a Department of Nutrition , Universidade de Brasília , Brasília , Brazil
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18
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Karagas MR, Choi AL, Oken E, Horvat M, Schoeny R, Kamai E, Cowell W, Grandjean P, Korrick S. Evidence on the human health effects of low-level methylmercury exposure. ENVIRONMENTAL HEALTH PERSPECTIVES 2012; 120:799-806. [PMID: 22275730 PMCID: PMC3385440 DOI: 10.1289/ehp.1104494] [Citation(s) in RCA: 448] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 01/24/2012] [Indexed: 05/17/2023]
Abstract
BACKGROUND Methylmercury (MeHg) is a known neuro-toxicant. Emerging evidence indicates it may have adverse effects on the neuro-logic and other body systems at common low levels of exposure. Impacts of MeHg exposure could vary by individual susceptibility or be confounded by beneficial nutrients in fish containing MeHg. Despite its global relevance, synthesis of the available literature on low-level MeHg exposure has been limited. OBJECTIVES We undertook a synthesis of the current knowledge on the human health effects of low-level MeHg exposure to provide a basis for future research efforts, risk assessment, and exposure remediation policies worldwide. DATA SOURCES AND EXTRACTION We reviewed the published literature for original human epidemiologic research articles that reported a direct biomarker of mercury exposure. To focus on high-quality studies and those specifically on low mercury exposure, we excluded case series, as well as studies of populations with unusually high fish consumption (e.g., the Seychelles), marine mammal consumption (e.g., the Faroe Islands, circumpolar, and other indigenous populations), or consumption of highly contaminated fish (e.g., gold-mining regions in the Amazon). DATA SYNTHESIS Recent evidence raises the possibility of effects of low-level MeHg exposure on fetal growth among susceptible subgroups and on infant growth in the first 2 years of life. Low-level effects of MeHg on neuro-logic outcomes may differ by age, sex, and timing of exposure. No clear pattern has been observed for cardio-vascular disease (CVD) risk across populations or for specific CVD end points. For the few studies evaluating immunologic effects associated with MeHg, results have been inconsistent. CONCLUSIONS Studies targeted at identifying potential mechanisms of low-level MeHg effects and characterizing individual susceptibility, sexual dimorphism, and non-linearity in dose response would help guide future prevention, policy, and regulatory efforts surrounding MeHg exposure.
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Affiliation(s)
- Margaret R Karagas
- Section of Biostatistics and Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
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19
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Abstract
Amalgam has been used in dentistry since about 150 years and is still being used due to its low cost, ease of application, strength, durability, and bacteriostatic effect. When aesthetics is not a concern it can be used in individuals of all ages, in stress bearing areas, foundation for cast-metal and ceramic restorations and poor oral hygiene conditions. Besides all, it has other advantages like if placed under ideal conditions, it is more durable and long lasting and least technique sensitive of all restorative materials, but, concern has been raised that amalgam causes mercury toxicity. Mercury is found in the earth's crust and is ubiquitous in the environment, so even without amalgam restorations everyone is exposed to small but measurable amount of mercury in blood and urine. Dental amalgam restorations may raise these levels slightly, but this has no practical or clinical significance. The main exposure to mercury from dental amalgam occurs during placement or removal of restoration in the tooth. Once the reaction is complete less amount of mercury is released, and that is far below the current health standard. Though amalgam is capable of producing delayed hypersensitivity reactions in some individuals, if the recommended mercury hygiene procedures are followed the risks of adverse health effects could be minimized. For this review the electronic databases and PubMed were used as data sources and have been evaluated to produce the facts regarding amalgam's safety and toxicity.
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Affiliation(s)
- Monika Rathore
- Department of Pedodontics, BBD College of Dental Sciences, Lucknow, Uttar Pradesh, India
| | - Archana Singh
- Department of Periodontics, BBD College of Dental Sciences, Lucknow, Uttar Pradesh, India
| | - Vandana A. Pant
- Department of Periodontics, BBD College of Dental Sciences, Lucknow, Uttar Pradesh, India
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20
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Lygre GB, Björkman L, Haug K, Skjaerven R, Helland V. Exposure to dental amalgam restorations in pregnant women. Community Dent Oral Epidemiol 2011; 38:460-9. [PMID: 20406270 DOI: 10.1111/j.1600-0528.2010.00544.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The Norwegian Mother and Child Cohort Study (MoBa) started in 1999 to identify environmental factors that could be involved in mechanisms leading to disease. Questions have been raised about potential risks to the fetus from prenatal exposure to mercury from amalgam fillings in pregnant women. The aim of the present study was to identify factors potentially associated with amalgam fillings in pregnant women participating in the Norwegian Mother and Child Cohort Study (MoBa). An additional aim was to obtain information about dental treatment in the cohort. METHODS Total of 67,355 pregnancies from the MoBa study were included in the present study. Information regarding age, education, smoking habits, alcohol consumption, weight, and height for the women was obtained from a questionnaire that was filled in at the 17th week of pregnancy. In another questionnaire, which was sent to all participants in the 30th week of pregnancy, the women reported types of dental treatment during pregnancy, total number of teeth, and number of teeth with amalgam fillings. The self-assessed number of teeth and number of teeth with amalgam fillings were validated in an external sample of 97 women of childbearing age. RESULTS Odds ratio for having more than 12 teeth with amalgam fillings increased considerably with age. Other significant risk factors for having high exposure to amalgam were low education, high body mass index (BMI), and smoking during pregnancy. Women with the lowest levels of education had a twofold increased odds ratio of having more than 12 teeth filled with amalgam compared with women who had more than 4 years of university studies. According to the results from the validation of self-assessed number of teeth with amalgam fillings, the information obtained was reliable. CONCLUSION Age, education, smoking habits, and BMI were associated with amalgam exposure.
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21
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Dórea JG. Making sense of epidemiological studies of young children exposed to thimerosal in vaccines. Clin Chim Acta 2010; 411:1580-6. [DOI: 10.1016/j.cca.2010.07.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 07/08/2010] [Accepted: 07/10/2010] [Indexed: 12/16/2022]
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22
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Lee BE, Hong YC, Park H, Ha M, Koo BS, Chang N, Roh YM, Kim BN, Kim YJ, Kim BM, Jo SJ, Ha EH. Interaction between GSTM1/GSTT1 polymorphism and blood mercury on birth weight. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:437-43. [PMID: 20194072 PMCID: PMC2854776 DOI: 10.1289/ehp.0900731] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Accepted: 10/23/2009] [Indexed: 05/19/2023]
Abstract
BACKGROUND Mercury (Hg) is toxic to both the reproductive and nervous systems. In addition, glutathione S-transferases (GSTs), which conjugate glutathione to a variety of electrophilic compounds, are involved in the detoxification of Hg. OBJECTIVE In this study we examined the association between prenatal exposure to Hg and birth weight as well as the influence of GST polymorphisms. METHODS The total Hg concentration in maternal and cord blood was measured from 417 Korean women and newborns in the Mothers and Children's Environmental Health study from 2006 to 2008. Information on birth weight was collected from the patients' medical records. The genotyping of glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) polymorphisms was carried out using polymerase chain reaction. Regression analysis was performed to determine the association between the blood Hg concentration and birth weight in mothers with GSTM1 and GSTT1 polymorphisms. RESULTS The geometric mean levels of Hg in the maternal blood during late pregnancy and in cord blood were 3.30 microg/L and 5.53 microg/L, respectively. For mothers with the GSTT1 null genotype, elevated Hg levels in maternal blood during late pregnancy were associated with an increased risk of lower birth weight. For mothers with both GSTM1 and GSTT1 null genotype, both maternal and cord blood Hg levels were associated with lower birth weight. CONCLUSIONS This study suggests that the interactions of Hg with GSTM1 and GSTT1 polymorphisms play a role in reducing birth weight.
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Affiliation(s)
- Bo-Eun Lee
- Department of Preventive Medicine, School of Medicine, Ewha Woman’s University, Seoul, Korea
| | - Yun-Chul Hong
- Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Hyesook Park
- Department of Preventive Medicine, School of Medicine, Ewha Woman’s University, Seoul, Korea
| | - Mina Ha
- Department of Preventive Medicine, Dankook University College of Medicine, Cheonan, Korea
| | - Bon Sang Koo
- Department of Obstetrics and Gynecology, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea
| | - Namsoo Chang
- Department of Nutritional Science and Food Management, Ewha Woman’s University, Seoul, Korea
| | - Young-Man Roh
- Institute of Environmental and Industrial Medicine, Hanyang University, Seoul, Korea
| | - Boong-Nyun Kim
- Division of Child and Adolescent Psychiatry, Department of Psychiatry and Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Young-Ju Kim
- Department of Obstetrics Medicine, School of Medicine, Ewha Woman’s University
| | - Byung-Mi Kim
- Department of Preventive Medicine, School of Medicine, Ewha Woman’s University, Seoul, Korea
| | - Seong-Joon Jo
- Ministry of Environment, Division of Environmental Health Policy, Gwacheon, Korea
| | - Eun-Hee Ha
- Department of Preventive Medicine, School of Medicine, Ewha Woman’s University, Seoul, Korea
- Address correspondence to E. Ha, 911-1 Mok-6-dong, Yangcheon-ku, Seoul, Korea. Telephone: 82-2-2650-5757. Fax: 82-2-2653-1086. E-mail:
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Golding J. Nesting sub-studies and randomised controlled trials within birth cohort studies. Paediatr Perinat Epidemiol 2009; 23 Suppl 1:63-72. [PMID: 19490446 DOI: 10.1111/j.1365-3016.2008.00994.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Although birth cohort studies can stand on their own, there are a number of different types of sub-studies that can add value to the overall project. These can be summarised within four main categories: (A) more detailed observations of relatively small subgroups aimed at describing mechanisms and processes; (B) nested case-control studies; (C) use of detailed observations to validate data collection by questionnaire or interview; (D) randomised controlled trials. For each category we give examples of ways in which they have been employed in current pregnancy birth cohort studies.
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Affiliation(s)
- Jean Golding
- Centre for Child and Adolescent Health, Department of Community Based Medicine, University of Bristol, Bristol, UK.
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24
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Wrzosek T, Einarson A. Dental care during pregnancy. CANADIAN FAMILY PHYSICIAN MEDECIN DE FAMILLE CANADIEN 2009; 55:598-599. [PMID: 19509200 PMCID: PMC2694079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
QUESTION Many of my patients have asked me if they should defer dental treatment until after they have given birth. Is there any risk associated with performing dental treatments during pregnancy? ANSWER Appropriate and timely dental care can lead to improved pregnancy outcomes as well as greater comfort for the woman. The treatment of periodontitis, as well as the use of local anesthetics, amalgams, and x-ray scans, does not pose an increased risk to the developing fetus and is, in fact, important in contributing to maintaining optimal health for mother and baby.
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Abstract
PURPOSE OF REVIEW To summarize recent evidence regarding associations of early life exposure to mercury from maternal fish consumption during pregnancy, thimerosal in vaccines and dental amalgam with child neurodevelopment. RECENT FINDINGS Recent publications have built upon previous evidence demonstrating mild detrimental neurocognitive effects from prenatal methylmercury exposure from maternal fish consumption during pregnancy. New studies examining the effects of prenatal fish consumption as well as methylmercury suggest there are benefits from prenatal fish consumption, but also that consumption of fish high in mercury should be avoided. Future studies incorporating information on both the methylmercury and the docosahexaenoic acid contained within fish will help to refine recommendations to optimize outcomes for mothers and children. Additional recent studies have supported the safety of vaccines containing thimerosal and of dental amalgam for repair of dental caries in children. SUMMARY Exposure to mercury may harm child development. Interventions intended to reduce exposure to low levels of mercury in early life must, however, be carefully evaluated in consideration of the potential attendant harm from resultant behavior changes, such as reduced docosahexaenoic acid exposure from lower seafood intake, reduced uptake of childhood vaccinations and suboptimal dental care.
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Affiliation(s)
- Emily Oken
- Department of Ambulatory Care and Prevention, Harvard Medical School and Harvard Pilgrim Healthcare, Boston, Massachusetts 02215, USA.
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