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Association between Bone Lead Concentration and Aggression in Youth from a Sub-Cohort of the Birth to Twenty Cohort. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19042200. [PMID: 35206393 PMCID: PMC8871669 DOI: 10.3390/ijerph19042200] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 02/04/2023]
Abstract
BACKGROUND An association between blood-lead levels and aggression has been demonstrated in children and adolescent youth in South Africa. However, there are limited studies that have assessed aggression as an outcome for cumulative lead exposure using bone lead concentration. This study aims to assess the association between bone lead concentration and aggressive behaviour among a sample of youth in South Africa. METHODS Bone lead in 100 participants (53 males and 47 females) recruited and followed in the Birth to Twenty (BT20) Cohort were measured using 109 Cd-based, K-shell X-ray fluorescence (KXRF). The Buss-Perry Aggression questionnaire was used to measure aggressive behaviour. Linear regression models were fitted to determine the association between aggression score for physical, verbal, anger and hostility and bone lead, adjusting for known confounders. RESULTS A one-microgram-per-gram increase in bone lead was found to increase the score for all four scales of aggression, but significantly only for anger (β = 0.2 [95% CI 0.04-0.370]). Psychosocial factors such as a history of family violence and exposure to neighbourhood crime were significant predictors for aggression. CONCLUSIONS The study provides a preliminary overview of the relationship between cumulative lead exposure and behavioural problems such as aggression. A larger sample, across exposed communities, may prove more definitive in further investigating the association between these two important public health factors and to maximize generalizability.
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Kponee-Shovein KZ, Weisskopf MG, Grashow R, Rotem RS, Coull BA, Schnaas L, Hernández-Chávez MDC, Sanchez B, Peterson K, Hu H, Téllez-Rojo MM. Estimating the causal effect of prenatal lead exposure on prepulse inhibition deficits in children and adolescents. Neurotoxicology 2020; 78:116-126. [PMID: 32126243 DOI: 10.1016/j.neuro.2020.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 12/20/2022]
Abstract
During pregnancy, maternal lead from earlier exposures mobilizes and crosses placental barriers, placing the developing fetus at risk for lead exposure and neurodevelopmental deficits. Some neuronal circuits known to be affected in neurodevelopment disorders can be probed with simple physiological behavioral paradigms. One such neural biomarker is Pre-Pulse Inhibition (PPI), an indicator of adequate sensorimotor gating processing. In clinical studies, deficits in PPI have been associated with neurodevelopmental disorders in human subjects. To our knowledge, no studies have examined the use of PPI as a biomarker of toxicant effects on the brain in epidemiological studies. We aimed to estimate the causal effect of prenatal lead exposure, assessed by maternal cortical bone lead concentrations, on PPI in 279 children from Mexico City. in vivo maternal cortical bone lead measurements were taken at four weeks postpartum at the mid-tibia shaft using a K-Shell X-ray fluorescence instrument. PPI recording occurred in an isolated clinical setting and eye blink responses were measured using electromyography. We assessed if the conditions for causal inference held in our study and used the results of our assessment to estimate the causal effect of prenatal lead exposure on PPI using an ordinary least squares regression model, a marginal structural model, and the parametric g-formula. Results were consistent across the three modeling approaches. For the parametric g-formula, a one standard deviation (10.0 μg/g) increase in prenatal lead significantly reduced PPI by approximately 19.0 % (95 % CI: 5.4 %, 34.3 %). This decrease is similar in magnitude to clinical studies on schizophrenia, which have observed PPI impairments in patients with schizophrenia as compared to controls. Our results are consistent with findings from other studies establishing an association between lead exposure and neurodevelopmental disorders in children and suggest that PPI may be useful as an objective biomarker of toxicant effects on the brain.
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Affiliation(s)
- Kalé Z Kponee-Shovein
- Departments of Environmental Health and Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
| | - Marc G Weisskopf
- Departments of Environmental Health and Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Rachel Grashow
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Ran S Rotem
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Brent A Coull
- Departments of Biostatistics and Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Lourdes Schnaas
- Division of Research in Community Interventions, Instituto Nacional De Perinatología Isidro Espinosa De Los Reyes, Miguel Hidalgo, Mexico
| | - Maria Del Carmen Hernández-Chávez
- Division of Research in Community Interventions, Instituto Nacional De Perinatología Isidro Espinosa De Los Reyes, Miguel Hidalgo, Mexico
| | - Brisa Sanchez
- Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
| | - Karen Peterson
- Departments of Global Public Health and Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan, USA
| | - Howard Hu
- University of Washington School of Public Health, Seattle, Washington, USA
| | - Martha M Téllez-Rojo
- Center for Nutrition and Health Research, National Institute of Public Health, Mexico
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Wang X, Kim D, Tucker KL, Weisskopf MG, Sparrow D, Hu H, Park SK. Effect of Dietary Sodium and Potassium Intake on the Mobilization of Bone Lead among Middle-Aged and Older Men: The Veterans Affairs Normative Aging Study. Nutrients 2019; 11:nu11112750. [PMID: 31766133 PMCID: PMC6893449 DOI: 10.3390/nu11112750] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 10/31/2019] [Accepted: 11/07/2019] [Indexed: 01/25/2023] Open
Abstract
Bone is a major storage site as well as an endogenous source of lead in the human body. Dietary sodium and potassium intake may play a role in the mobilization of lead from bone to the circulation. We examined whether association between bone lead and urinary lead, a marker of mobilized lead in plasma, was modified by dietary intake of sodium and potassium among 318 men, aged 48–93 years, in the Veterans Affairs (VA) Normative Aging Study. Dietary sodium and potassium were assessed by flame photometry using 24-h urine samples, and a sodium-to-potassium ratio was calculated from the resulting measures. Patella and tibia bone lead concentrations were measured by K-shell-x-ray fluorescence. Urinary lead was measured by inductively coupled plasma mass spectroscopy in 24-h urine samples. Linear regression models were used to regress creatinine clearance-corrected urinary lead on bone lead, testing multiplicative interactions with tertiles of sodium, potassium, and sodium-to-potassium ratio, separately. After adjustment for age, body mass index, smoking, vitamin C intake, calcium, and total energy intake, participants in the highest tertile of sodium-to-potassium ratio showed 28.1% (95% CI: 12.5%, 45.9%) greater urinary lead per doubling increase in patella lead, whereas those in the second and lowest tertiles had 13.8% (95% CI: −1.7%, 31.7%) and 5.5% (95% CI: −8.0%, 21.0%) greater urinary lead, respectively (p-for-interaction = 0.04). No statistically significant effect modification by either sodium or potassium intake alone was observed. These findings suggest that relatively high intake of sodium relative to potassium may play an important role in the mobilization of lead from bone into the circulation.
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Affiliation(s)
- Xin Wang
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA; (X.W.); (D.K.)
| | - Douglas Kim
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA; (X.W.); (D.K.)
| | - Katherine L. Tucker
- Department of Clinical Laboratory and Nutritional Sciences, University of Massachusetts at Lowell, Lowell, MA 01854, USA;
| | - Marc G. Weisskopf
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA;
| | - David Sparrow
- Normative Aging Study, Veterans Affairs Boston Healthcare System, and Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA;
| | - Howard Hu
- School of Public Health, University of Washington, Seattle, WA 98195, USA;
| | - Sung Kyun Park
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA; (X.W.); (D.K.)
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI 48109, USA
- Correspondence: ; Tel.: +1-(734)-936-1719; Fax: +1-(734)-936-2084
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Liu Y, Téllez-Rojo MM, Sánchez BN, Zhang Z, Afeiche MC, Mercado-García A, Hu H, Meeker JD, Peterson KE. Early lead exposure and pubertal development in a Mexico City population. ENVIRONMENT INTERNATIONAL 2019; 125:445-451. [PMID: 30763831 PMCID: PMC6472946 DOI: 10.1016/j.envint.2019.02.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 01/14/2019] [Accepted: 02/06/2019] [Indexed: 05/14/2023]
Abstract
BACKGROUND Previous studies have examined the association between blood lead levels and pubertal timing in adolescent girls; however, the evidence is lacking on the role of lead exposure during sensitive developmental periods on sexual maturation. OBJECTIVES To examine the association of prenatal and early childhood lead exposure with pubertal stages among 264 boys and 283 girls aged 9.8-18.0 years in Mexico City. METHODS We measured maternal bone lead (a proxy for cumulative fetal exposure to lead from maternal bone stores mobilized during pregnancy) at 1 month postpartum. Blood lead was measured annually from 1 to 4 years. Pubertal stage was assessed by a pediatrician. We examined the association between lead and pubertal stages of breast, pubic hair and genitalia using ordinal regression. Age at menarche was evaluated using Cox proportional-hazard models. RESULTS Multivariate models showed that maternal patella lead and early childhood blood lead were inversely associated with breast growth (patella OR = 0.72, 95% CI: 0.51-1.00; blood OR = 0.70, 95% CI: 0.53-0.93) in girls. Girls with maternal patella lead in the 3rd tertile and child blood lead in the 2nd tertile had a later age at menarche compared with girls in the 1st tertile (patella HR = 0.60, 95% CI: 0.41-0.88; blood HR = 0.65, 95% CI 0.46-0.91). Additionally, early childhood blood lead was negatively associated with pubic hair growth (OR = 0.68, 95% CI: 0.51-0.90) in girls. No associations were found in boys. CONCLUSIONS These data suggest that higher prenatal and early childhood exposure to lead may be associated with delayed pubertal development in girls but not boys. Our findings are consistent with previous analyses and reinforce the reproductive effects of lead for girls.
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Affiliation(s)
- Yun Liu
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Martha M Téllez-Rojo
- Centro de Investigacion en Salud Poblacional, Instituto Nacional de Salud Publica, Cuernavaca, Morelos, Mexico.
| | - Brisa N Sánchez
- Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Zhenzhen Zhang
- Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Myriam C Afeiche
- Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA
| | - Adrianna Mercado-García
- Centro de Investigacion en Salud Poblacional, Instituto Nacional de Salud Publica, Cuernavaca, Morelos, Mexico
| | - Howard Hu
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA; Occupational and Environmental Health, Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
| | - John D Meeker
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Karen E Peterson
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
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Wang X, Ding N, Tucker KL, Weisskopf MG, Sparrow D, Hu H, Park SK. A Western Diet Pattern Is Associated with Higher Concentrations of Blood and Bone Lead among Middle-Aged and Elderly Men. J Nutr 2017; 147:1374-1383. [PMID: 28592514 PMCID: PMC5483966 DOI: 10.3945/jn.117.249060] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/13/2017] [Accepted: 05/08/2017] [Indexed: 12/15/2022] Open
Abstract
Background: Little is known about the effects of overall dietary pattern on lead concentration.Objective: We examined the association of overall dietary patterns, derived from a semiquantitative food frequency questionnaire, with bone and blood lead concentrations.Methods: These longitudinal analyses included mostly non-Hispanic white, middle-aged-to-elderly men from the Veterans Affairs Normative Aging Study. Long-term lead exposures were measured as tibia and patella lead concentrations by using K-shell-X-ray fluorescence. Short-term lead exposures were measured as blood lead concentrations by using graphite furnace atomic absorption spectroscopy. Dietary pattern scores were derived by using factor analysis. Linear mixed-effects models were utilized to predict blood lead concentrations among 983 men, aged 44-92 y at baseline, with a total of 3273 observations (during 1987-2008). We constructed linear regression models to determine the relations between dietary patterns and bone lead concentrations among 649 participants with an age range of 49-93 y.Results: Two major dietary patterns were identified: a prudent dietary pattern, characterized by high intakes of fruit, legumes, vegetables, whole grains, poultry, and seafood; and a Western dietary pattern, characterized by high intakes of processed meat, red meat, refined grains, high-fat dairy products, French fries, butter, and eggs. After adjusting for age, smoking status, body mass index, total energy intake, education, occupation, neighborhood-based education and income level, men in the highest tertile of the Western pattern score (compared with the lowest) had 0.91 μg/dL (95% CI: 0.41, 1.42 μg/dL) higher blood lead, 5.96 μg/g (95% CI: 1.76, 10.16 μg/g) higher patella lead, and 3.83 μg/g (95% CI: 0.97, 6.70 μg/g) higher tibia lead. No significant association was detected with the prudent dietary pattern in the adjusted model.Conclusions: These findings suggest that the Western diet is associated with a greater lead body burden among the middle-aged-to-elderly men. More studies are needed to examine the underlying mechanisms by which dietary patterns are associated with lead concentrations.
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Affiliation(s)
| | | | - Katherine L Tucker
- Department of Clinical Laboratory and Nutritional Sciences, University of Massachusetts at Lowell, Lowell, MA
| | - Marc G Weisskopf
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA
| | - David Sparrow
- Normative Aging Study, Veterans Affairs Boston Healthcare System, Boston, MA
- Department of Medicine, Boston University School of Medicine, Boston, MA; and
| | - Howard Hu
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON
| | - Sung Kyun Park
- Departments of Epidemiology and
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI
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Ding N, Wang X, Weisskopf MG, Sparrow D, Schwartz J, Hu H, Park SK. Lead-Related Genetic Loci, Cumulative Lead Exposure and Incident Coronary Heart Disease: The Normative Aging Study. PLoS One 2016; 11:e0161472. [PMID: 27584680 PMCID: PMC5008632 DOI: 10.1371/journal.pone.0161472] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 08/06/2016] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Cumulative exposure to lead is associated with cardiovascular outcomes. Polymorphisms in the δ-aminolevulinic acid dehydratase (ALAD), hemochromatosis (HFE), heme oxygenase-1 (HMOX1), vitamin D receptor (VDR), glutathione S-transferase (GST) supergene family (GSTP1, GSTT1, GSTM1), apolipoprotein E (APOE),angiotensin II receptor-1 (AGTR1) and angiotensinogen (AGT) genes, are believed to alter toxicokinetics and/or toxicodynamics of lead. OBJECTIVES We assessed possible effect modification by genetic polymorphisms in ALAD, HFE, HMOX1, VDR, GSTP1, GSTT1, GSTM1, APOE, AGTR1 and AGT individually and as the genetic risk score (GRS) on the association between cumulative lead exposure and incident coronary heart disease (CHD) events. METHODS We used K-shell-X-ray fluorescence to measure bone lead levels. GRS was calculated on the basis of 22 lead-related loci. We constructed Cox proportional hazard models to compute adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CHD. We applied inverse probability weighting to account for potential selection bias due to recruitment into the bone lead sub-study. RESULTS Significant effect modification was found by VDR, HMOX1, GSTP1, APOE, and AGT genetic polymorphisms when evaluated individually. Further, the bone lead-CHD associations became larger as GRS increases. After adjusting for potential confounders, a HR of CHD was 2.27 (95%CI: 1.50-3.42) with 2-fold increase in patella lead levels, among participants in the top tertile of GRS. We also detected an increasing trend in HRs across tertiles of GRS (p-trend = 0.0063). CONCLUSIONS Our findings suggest that lead-related loci as a whole may play an important role in susceptibility to lead-related CHD risk. These findings need to be validated in a separate cohort containing bone lead, lead-related genetic loci and incident CHD data.
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Affiliation(s)
- Ning Ding
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Xin Wang
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Marc G. Weisskopf
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - David Sparrow
- Veterans Affairs Normative Aging Study, Veterans Affairs Boston Healthcare System, Boston, Massachusetts, United States of America
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Joel Schwartz
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Howard Hu
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sung Kyun Park
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States of America
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Goodrich JM, Dolinoy DC, Sánchez BN, Zhang Z, Meeker JD, Mercado-Garcia A, Solano-González M, Hu H, Téllez-Rojo MM, Peterson KE. Adolescent epigenetic profiles and environmental exposures from early life through peri-adolescence. ENVIRONMENTAL EPIGENETICS 2016; 2:dvw018. [PMID: 29492298 PMCID: PMC5804533 DOI: 10.1093/eep/dvw018] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 07/18/2016] [Indexed: 05/07/2023]
Abstract
Epigenetic perturbations induced by environmental exposures at susceptible lifestages contribute to disease development. Even so, the influence of early life and ongoing exposures on the adolescent epigenome is rarely examined. We examined the association of exposure biomarkers for lead (Pb), bisphenol A (BPA), and nine phthalates metabolites with blood leukocyte DNA methylation at LINE-1 repetitive elements and environmentally responsive genes ( IGF2 , H19 , and HSD11B2 ) in peri-adolescents. Participants ( n = 247) from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) birth cohorts were followed-up once between the ages of 8 and 14 years, and concurrent exposures were measured in biospecimen collected at that time (blood Pb, urinary BPA, and phthalate metabolites). Prenatal and childhood exposures to Pb were previously approximated using maternal and child samples. BPA and phthalate metabolites were measured in third trimester maternal urine samples. Significant associations ( P < 0.05) were observed between DNA methylation and exposure biomarkers that were gene and biomarker specific. For example, Pb was only associated with LINE-1 hypomethylation during pregnancy ( P = 0.04), while early childhood Pb was instead associated with H19 hypermethylation ( P = 0.04). Concurrent urinary mono (2-ethylhexyl) phthalate (MEHP) was associated with HSD11B2 hypermethylation ( P = 0.005). Sex-specific associations, particularly among males, were also observed. In addition to single exposure models, principal component analysis was employed to examine exposure mixtures. This method largely corroborated the findings of the single exposure models. This study along with others in the field suggests that environment-epigenetic relationships vary by chemical, exposure timing, and sex.
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Affiliation(s)
- Jaclyn M. Goodrich
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Dana C. Dolinoy
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
- Center for Human Growth and Development, University of Michigan, Ann Arbor, MI, USA
| | - Brisa N. Sánchez
- Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Zhenzhen Zhang
- Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - John D. Meeker
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Adriana Mercado-Garcia
- Center for Research on Nutrition and Health, National Institute of Public Health, Cuernavaca, Morelos, México
| | - Maritsa Solano-González
- Center for Research on Nutrition and Health, National Institute of Public Health, Cuernavaca, Morelos, México
| | - Howard Hu
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Martha M. Téllez-Rojo
- Center for Research on Nutrition and Health, National Institute of Public Health, Cuernavaca, Morelos, México
| | - Karen E. Peterson
- Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI, USA
- Center for Human Growth and Development, University of Michigan, Ann Arbor, MI, USA
- Department of Nutrition, Harvard School of Public Health, Boston, MA, USA
- *Correspondence address: 1415 Washington Heights, Ann Arbor, MI 48109-2029, USA. Tel: +1 734 647 1923; Fax: +1 734 936 7283; E-mail:
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Taylor CM, Humphriss R, Hall A, Golding J, Emond AM. Balance ability in 7- and 10-year-old children: associations with prenatal lead and cadmium exposure and with blood lead levels in childhood in a prospective birth cohort study. BMJ Open 2015; 5:e009635. [PMID: 26719320 PMCID: PMC4710813 DOI: 10.1136/bmjopen-2015-009635] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVES Most studies reporting evidence of adverse effects of lead and cadmium on the ability to balance have been conducted in high-exposure groups or have included adults. The effects of prenatal exposure have not been well studied, nor have the effects in children been directly studied. The aim of the study was to identify the associations of lead (in utero and in childhood) and cadmium (in utero) exposure with the ability to balance in children aged 7 and 10 years. DESIGN Prospective birth cohort study. PARTICIPANTS Maternal blood lead (n=4285) and cadmium (n=4286) levels were measured by inductively coupled plasma mass spectrometry in women enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC) during pregnancy. Child lead levels were measured in a subsample of 582 of ALSPAC children at age 30 months. MAIN OUTCOME MEASURES Children completed a heel-to-toe walking test at 7 years. At 10 years, the children underwent clinical tests of static and dynamic balance. Statistical analysis using SPSS V.19 included logistic regression modelling, comparing categories of ≥ 5 vs <5 µg/dL for lead, and ≥ 1 vs <1 µg/L for cadmium. RESULTS Balance at age 7 years was not associated with elevated in utero lead or cadmium exposure (adjusted OR for balance dysfunction: Pb 1.01 (95% CI 0.95 to 1.01), n=1732; Cd 0.95 (0.77 to 1.20), n=1734), or with elevated child blood lead level at age 30 months (adjusted OR 0.98 (0.92 to 1.05), n=354). Similarly, neither measures of static nor dynamic balance at age 10 years were associated with in utero lead or cadmium exposure, or child lead level. CONCLUSIONS These findings do not provide any evidence of an association of prenatal exposure to lead or cadmium, or lead levels in childhood, on balance ability in children. Confirmation in other cohorts is needed.
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Affiliation(s)
- Caroline M Taylor
- Centre for Child and Adolescent Health, School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Rachel Humphriss
- School of Social and Community Medicine, University of Bristol, Bristol, UK
- Children's Hearing Centre, University Bristol NHS Foundation Trust, Bristol, UK
| | - Amanda Hall
- School of Social and Community Medicine, University of Bristol, Bristol, UK
- Children's Hearing Centre, University Bristol NHS Foundation Trust, Bristol, UK
| | - Jean Golding
- Centre for Child and Adolescent Health, School of Social and Community Medicine, University of Bristol, Bristol, UK
| | - Alan M Emond
- Centre for Child and Adolescent Health, School of Social and Community Medicine, University of Bristol, Bristol, UK
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9
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King JC, Brown KH, Gibson RS, Krebs NF, Lowe NM, Siekmann JH, Raiten DJ. Biomarkers of Nutrition for Development (BOND)-Zinc Review. J Nutr 2015; 146:858S-885S. [PMID: 26962190 PMCID: PMC4807640 DOI: 10.3945/jn.115.220079] [Citation(s) in RCA: 287] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 07/29/2015] [Accepted: 12/29/2015] [Indexed: 12/17/2022] Open
Abstract
Zinc is required for multiple metabolic processes as a structural, regulatory, or catalytic ion. Cellular, tissue, and whole-body zinc homeostasis is tightly controlled to sustain metabolic functions over a wide range of zinc intakes, making it difficult to assess zinc insufficiency or excess. The BOND (Biomarkers of Nutrition for Development) Zinc Expert Panel recommends 3 measurements for estimating zinc status: dietary zinc intake, plasma zinc concentration (PZC), and height-for-age of growing infants and children. The amount of dietary zinc potentially available for absorption, which requires an estimate of dietary zinc and phytate, can be used to identify individuals and populations at risk of zinc deficiency. PZCs respond to severe dietary zinc restriction and to zinc supplementation; they also change with shifts in whole-body zinc balance and clinical signs of zinc deficiency. PZC cutoffs are available to identify individuals and populations at risk of zinc deficiency. However, there are limitations in using the PZC to assess zinc status. PZCs respond less to additional zinc provided in food than to a supplement administered between meals, there is considerable interindividual variability in PZCs with changes in dietary zinc, and PZCs are influenced by recent meal consumption, the time of day, inflammation, and certain drugs and hormones. Insufficient data are available on hair, urinary, nail, and blood cell zinc responses to changes in dietary zinc to recommend these biomarkers for assessing zinc status. Of the potential functional indicators of zinc, growth is the only one that is recommended. Because pharmacologic zinc doses are unlikely to enhance growth, a growth response to supplemental zinc is interpreted as indicating pre-existing zinc deficiency. Other functional indicators reviewed but not recommended for assessing zinc nutrition in clinical or field settings because of insufficient information are the activity or amounts of zinc-dependent enzymes and proteins and biomarkers of oxidative stress, inflammation, or DNA damage.
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Affiliation(s)
- Janet C King
- Children’s Hospital Oakland Research Institute, Oakland, CA
- University of California, Davis, Davis, CA
| | - Kenneth H Brown
- University of California, Davis, Davis, CA
- Bill & Melinda Gates Foundation, Seattle, WA
| | | | - Nancy F Krebs
- University of Colorado School of Medicine, Aurora, CO
| | - Nicola M Lowe
- University of Central Lancashire, Preston, United Kingdom; and
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Goodrich JM, Sánchez BN, Dolinoy DC, Zhang Z, Hernández-Ávila M, Hu H, Peterson KE, Téllez-Rojo MM. Quality control and statistical modeling for environmental epigenetics: a study on in utero lead exposure and DNA methylation at birth. Epigenetics 2015; 10:19-30. [PMID: 25580720 DOI: 10.4161/15592294.2014.989077] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
DNA methylation data assayed using pyrosequencing techniques are increasingly being used in human cohort studies to investigate associations between epigenetic modifications at candidate genes and exposures to environmental toxicants and to examine environmentally-induced epigenetic alterations as a mechanism underlying observed toxicant-health outcome associations. For instance, in utero lead (Pb) exposure is a neurodevelopmental toxicant of global concern that has also been linked to altered growth in human epidemiological cohorts; a potential mechanism of this association is through alteration of DNA methylation (e.g., at growth-related genes). However, because the associations between toxicants and DNA methylation might be weak, using appropriate quality control and statistical methods is important to increase reliability and power of such studies. Using a simulation study, we compared potential approaches to estimate toxicant-DNA methylation associations that varied by how methylation data were analyzed (repeated measures vs. averaging all CpG sites) and by method to adjust for batch effects (batch controls vs. random effects). We demonstrate that correcting for batch effects using plate controls yields unbiased associations, and that explicitly modeling the CpG site-specific variances and correlations among CpG sites increases statistical power. Using the recommended approaches, we examined the association between DNA methylation (in LINE-1 and growth related genes IGF2, H19 and HSD11B2) and 3 biomarkers of Pb exposure (Pb concentrations in umbilical cord blood, maternal tibia, and maternal patella), among mother-infant pairs of the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort (n = 247). Those with 10 μg/g higher patella Pb had, on average, 0.61% higher IGF2 methylation (P = 0.05). Sex-specific trends between Pb and DNA methylation (P < 0.1) were observed among girls including a 0.23% increase in HSD11B2 methylation with 10 μg/g higher patella Pb.
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Key Words
- ANOVA, analysis of variance
- DMR, differentially methylated region
- DNA methylation
- ELEMENT, early life exposures in Mexico to environmental toxicants
- GEE, generalized estimating equation
- GLM, general linear model
- H19, H19, imprinted maternally expressed transcript (non-protein coding)
- HSD11B2, hydroxysteroid (11-β) dehydrogenase 2
- IGF2, insulin-like growth factor 2
- K-XRF, K X-ray fluorescence
- LINE-1, long interspersed element-1
- OLS, ordinary linear regression
- PCR, polymerase chain reaction
- Pb, lead
- environmental exposure
- lead
- pyrosequencing
- quality control
- statistical methods
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Affiliation(s)
- Jaclyn M Goodrich
- a Department of Environmental Health Sciences ; University of Michigan School of Public Health ; Ann Arbor , MI USA
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Li T, Dai YH, Xie XH, Tan ZW, Zhang SM, Zhu ZH. Surveillance of childhood blood lead levels in 11 cities of China. World J Pediatr 2014; 10:29-37. [PMID: 24464661 DOI: 10.1007/s12519-014-0452-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 09/09/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND Exposure to lead can be deleterious to children's health. Surveillance for blood lead levels (BLLs) is reported every year in the USA and some other countries. However, such reports are lacking in China which has the world's largest population of children. In this study, we provided the latest nationally representative data on BLLs among Chinese children living in cities, described the change in BLLs since 2004, and explored the risk factors for elevated BLLs (EBLLs) among children. METHODS We studied 12 693 children aged 0-6 years in 2004 and 11 255 children aged 0-6 years in 2010. We evaluated the average BLLs and the prevalence of EBLLs, and a multivariate logistic regression model was used to estimate predictors of EBLLs. RESULTS The geometric mean BLLs of children aged 0-6 years dropped by 16% (from 46.38 ± 2.10 μg/L in 2004 to 38.95 ± 1.83 μg/L in 2010), while the prevalence of EBLLs dropped by 87% (from 9.78% in 2004 to 1.32% in 2010). In a multivariate analysis, the following factors were associated with EBLLs: (1) children being cared for at home or at a boarding nursery (compared to children being cared for in a day nursery), (2) children having fathers with a lower education level, and (3) children often eating popcorn and chewing fingernails or sucking fingers were associated with EBLLs. CONCLUSIONS The results of this study demonstrated a substantial decline in BLLs from 2004 to 2010 among Chinese children 0-6 years living in cities. However, these levels were higher than levels in countries, such as the USA, Canada, Japan and Sweden. These data demonstrate that Chinese children's lead exposure remains a public health problem that requires additional effort and resources.
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Affiliation(s)
- Tao Li
- Department of Integrated Early Childhood Development, Beijing, China
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12
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Bakulski KM, Rozek LS, Dolinoy DC, Paulson HL, Hu H. Alzheimer's disease and environmental exposure to lead: the epidemiologic evidence and potential role of epigenetics. Curr Alzheimer Res 2012; 9:563-73. [PMID: 22272628 PMCID: PMC3567843 DOI: 10.2174/156720512800617991] [Citation(s) in RCA: 130] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 10/20/2011] [Accepted: 01/20/2012] [Indexed: 11/22/2022]
Abstract
Several lines of evidence indicate that the etiology of late-onset Alzheimer's disease (LOAD) is complex, with significant contributions from both genes and environmental factors. Recent research suggests the importance of epigenetic mechanisms in defining the relationship between environmental exposures and LOAD. In epidemiologic studies of adults, cumulative lifetime lead (Pb) exposure has been associated with accelerated declines in cognition. In addition, research in animal models suggests a causal association between Pb exposure during early life, epigenetics, and LOAD. There are multiple challenges to human epidemiologic research evaluating the relationship between epigenetics, LOAD, and Pb exposure. Epidemiologic studies are not well-suited to accommodate the long latency period between exposures during early life and onset of Alzheimer's disease. There is also a lack of validated circulating epigenetics biomarkers and retrospective biomarkers of Pb exposure. Members of our research group have shown bone Pb is an accurate measurement of historical Pb exposure in adults, offering an avenue for future epidemiologic studies. However, this would not address the risk of LOAD attributable to early-life Pb exposures. Future studies that use a cohort design to measure both Pb exposure and validated epigenetic biomarkers of LOAD will be useful to clarify this important relationship.
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Affiliation(s)
- Kelly M. Bakulski
- University of Michigan, School of Public Health, Department of Environmental Health Sciences
| | - Laura S. Rozek
- University of Michigan, School of Public Health, Department of Environmental Health Sciences
- University of Michigan, Medical School, Department of Otolaryngology
| | - Dana C. Dolinoy
- University of Michigan, School of Public Health, Department of Environmental Health Sciences
| | | | - Howard Hu
- University of Michigan, School of Public Health, Department of Environmental Health Sciences
- University of Michigan, Department of Epidemiology
- University of Michigan, Medical School, Department of Internal Medicine
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Afeiche M, Peterson KE, Sánchez BN, Schnaas L, Cantonwine D, Ettinger AS, Solano-González M, Hernández-Avila M, Hu H, Téllez-Rojo MM. Windows of lead exposure sensitivity, attained height, and body mass index at 48 months. J Pediatr 2012; 160:1044-9. [PMID: 22284921 PMCID: PMC3360798 DOI: 10.1016/j.jpeds.2011.12.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 11/07/2011] [Accepted: 12/12/2011] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To examine longitudinal associations of prenatal, infancy, and early childhood lead exposure during sensitive periods with height and body mass index (BMI). STUDY DESIGN A total of 773 participants were recruited between 1994 and 2005 in Mexico City. Lead exposure history categories were constructed for the prenatal period (maternal patellar lead concentration) and for infancy and childhood (mean child blood lead concentration at birth to 24 months and 30-48 months, respectively). Linear regression models were used to study lead exposure history with height and BMI at 48 months. RESULTS Mean height at age 48 months was significantly lower in children with a blood lead level exceeding the median during infancy (-0.84 cm; 95% CI, -1.42 to -0.25) than in children with a level below the median. Prenatal lead exposure was not associated with height at 48 months. Results for attained BMI generally trended in the same direction as for height. CONCLUSION Our findings suggest an effect of lead exposure early in life on height attainment at 48 months, with the exposure window of greatest sensitivity in infancy.
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Affiliation(s)
- Myriam Afeiche
- Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts
| | - Karen E Peterson
- Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts,Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan
| | - Brisa N Sánchez
- Department of Biostatistics, University of Michigan School of Public Health, Ann Arbor, Michigan
| | - Lourdes Schnaas
- Division of Research on Public Health, National Institute of Perinatology, Mexico City, México
| | - David Cantonwine
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan
| | - Adrienne S Ettinger
- Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, Connecticut,Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts,Channing Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Maritsa Solano-González
- Division of Statistics, Center for Surveys and Evaluation Research, National Institute of Public Health, Cuernavaca, Morelos, México
| | | | - Howard Hu
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, Michigan
| | - Martha M Téllez-Rojo
- Division of Statistics, Center for Surveys and Evaluation Research, National Institute of Public Health, Cuernavaca, Morelos, México
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14
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Afeiche M, Peterson KE, Sánchez BN, Cantonwine D, Lamadrid-Figueroa H, Schnaas L, Ettinger AS, Hernández-Avila M, Hu H, Téllez-Rojo MM. Prenatal lead exposure and weight of 0- to 5-year-old children in Mexico city. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:1436-41. [PMID: 21715242 PMCID: PMC3230436 DOI: 10.1289/ehp.1003184] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 06/29/2011] [Indexed: 05/18/2023]
Abstract
BACKGROUND Cumulative prenatal lead exposure, as measured by maternal bone lead burden, has been associated with smaller weight of offspring at birth and 1 month of age, but no study has examined whether this effect persists into early childhood. OBJECTIVE We investigated the association of perinatal maternal bone lead, a biomarker of cumulative prenatal lead exposure, with children's attained weight over time from birth to 5 years of age. METHODS Children were weighed at birth and at several intervals up until 60 months. Maternal tibia and patella lead were measured at 1 month postpartum using in vivo K-shell X-ray fluorescence. We used varying coefficient models with random effects to assess the association of maternal bone lead with weight trajectories of 522 boys and 477 girls born between 1994 and 2005 in Mexico City. RESULTS After controlling for breast-feeding duration, maternal anthropometry, and sociodemographic characteristics, a 1-SD increase in maternal patella lead (micrograms per gram) was associated with a 130.9-g decrease in weight [95% confidence interval (CI), -227.4 to -34.4 g] among females and a 13.0-g nonsignificant increase in weight among males (95% CI, -73.7 to 99.9 g) at 5 years of age. These associations were similar after controlling for concurrent blood lead levels between birth and 5 years. CONCLUSIONS Maternal bone lead was associated with lower weight over time among female but not male children up to 5 years of age. Given that the association was evident for patellar but not tibial lead levels, and was limited to females, results need to be confirmed in other studies.
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Affiliation(s)
- Myriam Afeiche
- Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts, USA
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15
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Nie LH, Wright RO, Bellinger DC, Hussain J, Amarasiriwardena C, Chettle DR, Pejović-Milić A, Woolf A, Shannon M. Blood lead levels and cumulative blood lead index (CBLI) as predictors of late neurodevelopment in lead poisoned children. Biomarkers 2011; 16:517-24. [PMID: 21827276 DOI: 10.3109/1354750x.2011.604133] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To find the best lead exposure assessment marker for children. METHODS We recruited 11 children, calculated a cumulative blood lead index (CBLI) for the children, measured their concurrent BLL, assessed their development, and measured their bone lead level. RESULTS Nine of 11 children had clinically significant neurodevelopment problems. CBLI and current blood lead level, but not the peak lead level, were significantly or marginally negatively associated with the full-scale IQ score. CONCLUSION Lead exposure at younger age significantly impacts a child's later neurodevelopment. CBLI may be a better predictor of neurodevelopment than are current or peak blood lead levels.
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Affiliation(s)
- Linda H Nie
- Purdue University, School of Health Sciences, West Lafayette, IN, USA.
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16
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Lamadrid-Figueroa H, Téllez-Rojo MM, Angeles G, Hernández-Ávila M, Hu H. Bias correction by use of errors-in-variables regression models in studies with K-X-ray fluorescence bone lead measurements. ENVIRONMENTAL RESEARCH 2011; 111:17-20. [PMID: 21092947 PMCID: PMC3026095 DOI: 10.1016/j.envres.2010.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 10/21/2010] [Accepted: 10/30/2010] [Indexed: 05/23/2023]
Abstract
In-vivo measurement of bone lead by means of K-X-ray fluorescence (KXRF) is the preferred biological marker of chronic exposure to lead. Unfortunately, considerable measurement error associated with KXRF estimations can introduce bias in estimates of the effect of bone lead when this variable is included as the exposure in a regression model. Estimates of uncertainty reported by the KXRF instrument reflect the variance of the measurement error and, although they can be used to correct the measurement error bias, they are seldom used in epidemiological statistical analyzes. Errors-in-variables regression (EIV) allows for correction of bias caused by measurement error in predictor variables, based on the knowledge of the reliability of such variables. The authors propose a way to obtain reliability coefficients for bone lead measurements from uncertainty data reported by the KXRF instrument and compare, by the use of Monte Carlo simulations, results obtained using EIV regression models vs. those obtained by the standard procedures. Results of the simulations show that Ordinary Least Square (OLS) regression models provide severely biased estimates of effect, and that EIV provides nearly unbiased estimates. Although EIV effect estimates are more imprecise, their mean squared error is much smaller than that of OLS estimates. In conclusion, EIV is a better alternative than OLS to estimate the effect of bone lead when measured by KXRF.
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Affiliation(s)
- Héctor Lamadrid-Figueroa
- Division of Statistics, Center for Evaluation Research and Surveys, National Institute of Public Health, Av. Universidad 655, Cuernavaca, Morelos 62440, Mexico.
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17
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Amaya MA, Jolly KW, Pingitore NE. Blood lead in the 21st Century: The sub-microgram challenge. J Blood Med 2010; 1:71-8. [PMID: 22282686 PMCID: PMC3262323 DOI: 10.2147/jbm.s7765] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Indexed: 11/23/2022] Open
Abstract
In the US the dominant sources of lead through much of the 20th Century (eg, vehicular emissions, plumbing, household paint) have been significantly diminished. The reductions in adult and pediatric average blood lead levels in the US have been extraordinary. Progress continues: the US Environmental Protection Agency recently developed a new air standard for lead. In the 21st Century, the average blood lead level in a society may be seen as a marker of the status of their public's health. However, the threat of lead exposure remains a significant public health problem among subpopulation groups in the US and in many less developed countries. This paper examines some of the specific issues involved in the reduction of blood lead in a post-industrial era. These involve the control of the remaining exogenous primary sources, both general (eg, industrial emissions) and specific (eg, at-risk occupations), exogenous secondary sources (eg, contaminated urban soils, legacy lead-based paints), an endogenous source (ie, cumulative body lead burden) and emergent sources.
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Affiliation(s)
- Maria A Amaya
- School of Nursing, The University of Texas at El Paso, El Paso, TX, USA
| | - Kevin W Jolly
- Department of Psychology, The University of Texas at El Paso, El Paso, Texas, USA
| | - Nicholas E Pingitore
- School of Nursing, The University of Texas at El Paso, El Paso, TX, USA
- Department of Geological Sciences, The University of Texas at El Paso, El Paso, TX, USA
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18
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de Souza Guerra C, Fernanda Gerlach R, Graciele Villela Pinto N, Coutinho Cardoso S, Moreira S, Pereira de Almeida A, Teixeira Alves Peixoto I, Henrique Meloni C, Lemos Mota C, Fernando de Oliveira L, Braz D, Cely Barroso R. X-ray fluorescence with synchrotron radiation to elemental analysis of lead and calcium content of primary teeth. Appl Radiat Isot 2010; 68:71-5. [DOI: 10.1016/j.apradiso.2009.08.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2009] [Revised: 08/05/2009] [Accepted: 08/07/2009] [Indexed: 10/20/2022]
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19
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Hsieh TJ, Chuang HY, Chen YC, Wang CL, Lan SH, Liu GC, Ho CK, Lin WC. Subclinical white matter integrity in subjects with cumulative lead exposure. Radiology 2009; 252:509-17. [PMID: 19546424 DOI: 10.1148/radiol.2522080653] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE To evaluate microstructural changes in the white matter of patients who were exposed to lead and to compare differences in fractional anisotropy (FA) between these patients and control subjects. MATERIALS AND METHODS Institutional review board approval and subject informed consent were obtained for this HIPAA-compliant study. Nineteen factory workers who had been exposed to lead and 18 healthy volunteers who had not were enrolled. FA values and T2-weighted fluid-attenuation inversion-recovery magnetic resonance images were obtained at several regions of interest (the bilateral parietal, frontal, occipital, and temporal white matter and the genu and splenium of the corpus callosum). Lead levels were measured in the blood, midtibia, and patella. The Student t test was used to compare the difference in continuous variables between the two groups. Pearson correlation coefficients were used to assess the association between two variables. RESULTS There were no significant differences in sex, age, body mass index, smoking history, betel nut consumption, or alcohol consumption between the factory workers and the volunteers. The number of milk drinkers among factory workers was significantly higher than that among volunteers (P < .001). The factory workers had significantly higher blood (P < .001), patella (P < .001), and midtibia (P = .005) lead levels than did the volunteers. Mean FA in the factory workers was lower than that in the volunteers at the same anatomic location; significant differences between the groups were noted bilaterally in the parietal, frontal, occipital, and temporal white matter. There was no significant difference in mean diffusivity values and mean T2 ratios between the factory workers and the volunteers. CONCLUSION Decreased FA was associated with exposure to lead. Negative correlations between FA and blood, midtibia, and patella lead levels suggest that FA may be a useful index of early white matter damage. SUPPLEMENTAL MATERIAL http://radiology.rsnajnls.org/cgi/content/full/2522080653/DC1.
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Affiliation(s)
- Tsyh-Jyi Hsieh
- Department of Medical Imaging, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
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20
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Hsieh TJ, Chen YC, Li CW, Liu GC, Chiu YW, Chuang HY. A proton magnetic resonance spectroscopy study of the chronic lead effect on the Basal ganglion and frontal and occipital lobes in middle-age adults. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:941-945. [PMID: 19590687 PMCID: PMC2702410 DOI: 10.1289/ehp.0800187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2008] [Accepted: 02/09/2009] [Indexed: 05/28/2023]
Abstract
BACKGROUND Lead is known to be a health hazard to the human brain and nervous system based on data from epidemiologic studies. However, few studies have examined the mechanism or biochemical changes caused by lead in the human brain, although recently some have used magnetic resonance spectroscopy (MRS) to test brain metabolism in vivo. OBJECTIVES In this study, we used 3-T MRS to investigate brain metabolism in workers chronically exposed to lead and matched nonexposed controls. METHODS Twenty-two workers at a lead paint factory served as chronically exposed subjects of this study. These workers did not have any clinical syndromes. Eighteen age- and sex-matched nonexposed healthy volunteers served as controls. We measured blood and bone lead and used a 3-T MRS to measure their levels of brain N-acetyl aspartate (NAA), choline (Cho), and total creatine (tCr). A structural questionnaire was used to collect demographic, work, and health histories and information about their life habits. RESULTS All the MRS measures were lower in the lead-exposed group. Increased blood and bone lead levels correlated with declines in Cho:tCr ratios, especially in the occipital lobe, where changes in all gray, subcortical, and white matter were significant. Increases in blood and patella lead in every layer of the frontal lobe correlated with significant decreases in NAA:tCr ratios. One of the strongest regression coefficients was -0.023 (SE = 0.005, p < 0.001), which was found in the NAA:tCr ratio of frontal gray matter. DISCUSSION We conclude that chronic exposure to lead might upset brain metabolism, especially NAA:tCr and Cho:tCr ratios. Brain NAA and Cho are negatively correlated to blood and bone lead levels, suggesting that lead induces neuronal and axonal damage or loss. The most significant changes occurred in frontal and occipital lobes, areas in which previous neurobehavioral studies have shown memory and visual performance to be adversely affected by lead toxicity.
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Affiliation(s)
| | - Yi-Chun Chen
- Department of Community Medicine, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Chun-Wei Li
- Department of Medical Imaging and Radiation Technology, College of Health Sciences and
| | - Gin-Chang Liu
- Department of Medical Imaging and
- Department of Radiology, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
| | - Yu-Wen Chiu
- Department of Community Medicine, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Hung-Yi Chuang
- Department of Community Medicine, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
- Department of Public Health, College of Health Sciences, and Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
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Muntner P, Menke A, Batuman V, Rabito FA, He J, Todd AC. Association of tibia lead and blood lead with end-stage renal disease: a pilot study of African-Americans. ENVIRONMENTAL RESEARCH 2007; 104:396-401. [PMID: 17511982 DOI: 10.1016/j.envres.2007.04.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2006] [Revised: 03/19/2007] [Accepted: 04/04/2007] [Indexed: 05/07/2023]
Abstract
The association between body lead burden and kidney disease remains controversial. Fifty-five African-American end-stage renal disease (ESRD) cases and 53 age- and sex-matched African-American controls without known renal disease were recruited from Tulane University-affiliated dialysis clinics and out-patient clinics, respectively. Blood lead was measured via atomic absorption spectrophotometry and tibia lead (a measure of body lead) was measured via (109)Cd-based K shell X-ray fluorescence. Median blood lead levels were significantly higher among ESRD cases (6 microg/dL) compared to their control counterparts (3 microg/dL; P<0.001). Although no participants had overt lead poisoning (blood lead > or = 25 microg/dL), seven cases but no controls had blood lead levels above 10 microg/dL (P=0.006). The median tibia lead level was 17 micrograms of lead per gram of bone mineral (microg/g) and 13 microg/g among ESRD cases and their control counterparts, respectively (P=0.134). Four ESRD cases (7%), but no controls, had a tibia lead level above 40 microg/g (P=0.115) while a similar proportion of cases and controls had tibia lead between 20 and 39 microg/g (33% and 32%, respectively; P=0.726). After adjustment for potential confounders, the odds ratios of ESRD associated with a tibia lead > or = 20 microg/g and each four-fold higher tibia lead (e.g., 5-20 microg/g) were 1.55 (95% CI: 0.55, 4.41) and 1.88 (95% CI: 0.53, 6.68), respectively. These findings support the need for prospective cohort studies of body lead burden and renal disease progression.
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Affiliation(s)
- Paul Muntner
- Department of Epidemiology, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA 70112, USA.
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Kondrashov V, McQuirter JL, Miller M, Rothenberg SJ. Assessment of lead exposure risk in locksmiths. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2006; 2:164-9. [PMID: 16705814 PMCID: PMC3814711 DOI: 10.3390/ijerph2005010164] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Exposure to lead has been well recognized in a number of work environments, but little is known about lead exposure associated with machining brass keys containing lead. The brass that is widely used for key manufacturing usually contains 1.5% – 2.5 % of lead. Six (6) licensed locksmiths and 6 case-matched controls successfully completed the pilot study to assess the prevalence of increased body lead burden of professional locksmiths. We measured both Blood Lead (atomic absorption spectrometry), bone-lead (KXRF) and had each subject complete a health and lead exposure risk questionnaire. One locksmith had not cut keys during the past two years, therefore this subject and case-matched control was excluded from the blood lead analysis only. The average blood-lead concentration (±SEM) for the 5 paired subjects was 3.1 (± 0.4) μg/dL and 2.2 (± 0.3) μg /dL for controls. Bone measurements, including all 6 paired subjects, showed tibia lead concentration (±SEM) for locksmiths and controls was 27.8 (± 2.3) μg /g and 13.7 (± 3.3) μg /g, respectively; average calcaneus lead concentration for locksmiths and controls was 31.9 (± 3.7) μg /g and 22.6 (± 4.1) μg /g, respectively: The t-test shows a significantly higher tibia lead (p<0.05) and blood lead (p<0.05) for locksmiths than for their matched controls, but no significant difference for calcaneus lead (p>0.10). Given that the mean tibia bone lead concentration was 13.1μg/g higher in locksmiths than in their matched controls, this average difference in the two groups would translate to an OR of increased hypertension in locksmiths of between 1.1 and 2.3, based on the published literature. Even with the very small number of subjects participating in this pilot study, we were able to demonstrate that locksmiths had significantly higher current exposure to lead (blood lead concentration) and significantly higher past exposure to lead (tibia lead concentration) than their age, sex and ethnically matched controls. Additional research is needed to fully identify the prevalence and associated risk factors for occupational exposure of lead in this previously understudied profession.
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Affiliation(s)
- Vladislav Kondrashov
- Departments of Oral and Maxillofacial Surgery (J.L.M.), and Anaesthesiology (S.J.R. V.K.), Clinical Research Center (MM), Charles R. Drew University of Medicine and Sciences, Los Angeles, California, USA
| | - Joseph L. McQuirter
- Departments of Oral and Maxillofacial Surgery (J.L.M.), and Anaesthesiology (S.J.R. V.K.), Clinical Research Center (MM), Charles R. Drew University of Medicine and Sciences, Los Angeles, California, USA
| | - Melba Miller
- Departments of Oral and Maxillofacial Surgery (J.L.M.), and Anaesthesiology (S.J.R. V.K.), Clinical Research Center (MM), Charles R. Drew University of Medicine and Sciences, Los Angeles, California, USA
| | - Stephen J. Rothenberg
- Departments of Oral and Maxillofacial Surgery (J.L.M.), and Anaesthesiology (S.J.R. V.K.), Clinical Research Center (MM), Charles R. Drew University of Medicine and Sciences, Los Angeles, California, USA
- The Center for Research in Population Health, National Institute of Public Health, Cuernavaca, Morelos, Mexico
- Correspondence to Dr. Stephen Rothenberg,
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23
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Engin AB, Tuzun D, Sahin G. Evaluation of pteridine metabolism in battery workers chronically exposed to lead. Hum Exp Toxicol 2006; 25:353-9. [PMID: 16898163 DOI: 10.1191/0960327106ht634oa] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Occupationally-exposed lead affects the neuromuscular junction and might cause disturbances in the locomotor activity. This study was undertaken to evaluate pteridine metabolism, in which neurotransmitters are synthesized in battery workers. Urinary neopterin, biopterin and creatinine were measured using high performance liquid chromatography. Serum neopterin concentrations were detected by enzyme-linked immunoassay. Blood dihydropteridine reductase (DHPR) activities and deltaaminolevulinic acid (delta-ALA) were measured spectrophotometrically. Blood and urinary lead were detected by atomic absorption spectroscopy. Significantly increased blood and urinary lead levels, urinary neopterin, biopterin and delta-ALA were found in workers, while DHPR activities were indifferent compared to control group. Urinary creatinine decreased. This is the first study to demonstrate that increased activity of the pteridine pathway results in the accumulation of the neurotransmitters that may be responsible for the neurological disorders.
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Affiliation(s)
- A B Engin
- Department of Pharmaceutical Toxicology, Faculty of Pharmacy, University of Hacettepe, Sihhiye, Ankara, Turkey
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24
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Juárez-Pérez CA, Aguilar-Madrid G, Smith DR, Lacasaña-Navarro M, Téllez-Rojo MM, Piacitteli G, Hu H, Hernández-Avila M. Predictors of plasma lead among lithographic print shop workers in Mexico City. Am J Ind Med 2004; 46:245-52. [PMID: 15307123 DOI: 10.1002/ajim.20035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Plasma lead is considered a biological marker that reflects the fraction of lead in blood that is toxicologically available. We examined the relationship between plasma lead and other biomarkers of lead exposure in 69 lithographic print shop workers. METHODS Lead was measured in plasma and whole blood (by inductively coupled plasma-magnetic sector mass spectrometry), in bone (by 109Cd X-ray fluorescence), and in hand wipes and occupational air samples. Personal hygiene habits at work were surveyed. RESULTS Mean age was 47 years and 86% (n=59) were men. Mean lead levels were 0.3 microg/L in plasma, 11.9 microg/dL in blood, 46.7 microg/g in patella, and 27.6 microg/g in tibia. Taken together, two multivariate linear models explained 57% of variability in plasma lead levels. Predictors for the first model were lead in patella (beta = 0.006), blood (beta = 0.008), and hygiene index (beta = -0.11). Predictors for the second model were lead in tibia (beta = 0.008), blood (beta = 0.008), and hygiene index (beta = -0.13). CONCLUSIONS This study demonstrates that accumulated bone stores and hygiene habits are both significant independent predictors of plasma lead levels in active workers at this print shop.
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25
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Affiliation(s)
- Anne Krantz
- Section of Clinical Toxicology, John H. Stroger, Jr. Hospital of Cook County, University of Illinois at Chicago School of Public Health, USA
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26
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Garrido Latorre F, Hernández-Avila M, Tamayo Orozco J, Albores Medina CA, Aro A, Palazuelos E, Hu H. Relationship of blood and bone lead to menopause and bone mineral density among middle-age women in Mexico City. ENVIRONMENTAL HEALTH PERSPECTIVES 2003; 111:631-6. [PMID: 12676627 PMCID: PMC1241456 DOI: 10.1289/ehp.111-1241456] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
To describe the relationship of blood lead levels to menopause and bone lead levels, we conducted a cross-sectional study on 232 pre- or perimenopausal (PreM) and postmenopausal (PosM) women who participated in an osteoporosis-screening program in Mexico City during the first quarter of 1995. Information regarding reproductive characteristics and known risk factors for blood lead was obtained using a standard questionnaire by direct interview. The mean age of the population was 54.7 years (SD = 9.8), with a mean blood lead level of 9.2 microg/dL (SD = 4.7/dL) and a range from 2.1 to 32.1 microg/dL. After adjusting for age and bone lead levels, the mean blood lead level was 1.98 microg/dL higher in PosM women than in PreM women (p = 0.024). The increase in mean blood lead levels peaked during the second year of amenorrhea with a level (10.35 microg/dL) that was 3.51 microg/dL higher than that of PreM women. Other important predictors of blood lead levels were use of lead-glazed ceramics, schooling, trabecular bone lead, body mass index, time of living in Mexico City, and use of hormone replacement therapy. Bone density was not associated with blood lead levels. These results support the hypothesis that release of bone lead stores increases during menopause and constitutes an internal source of exposure possibly associated with health effects in women in menopause transition.
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27
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Garrido Latorre F, Hernández-Avila M, Tamayo Orozco J, Albores Medina CA, Aro A, Palazuelos E, Hu H. Relationship of blood and bone lead to menopause and bone mineral density among middle-age women in Mexico City. ENVIRONMENTAL HEALTH PERSPECTIVES 2003. [PMID: 12676627 DOI: 10.1289/ehp.5149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
To describe the relationship of blood lead levels to menopause and bone lead levels, we conducted a cross-sectional study on 232 pre- or perimenopausal (PreM) and postmenopausal (PosM) women who participated in an osteoporosis-screening program in Mexico City during the first quarter of 1995. Information regarding reproductive characteristics and known risk factors for blood lead was obtained using a standard questionnaire by direct interview. The mean age of the population was 54.7 years (SD = 9.8), with a mean blood lead level of 9.2 microg/dL (SD = 4.7/dL) and a range from 2.1 to 32.1 microg/dL. After adjusting for age and bone lead levels, the mean blood lead level was 1.98 microg/dL higher in PosM women than in PreM women (p = 0.024). The increase in mean blood lead levels peaked during the second year of amenorrhea with a level (10.35 microg/dL) that was 3.51 microg/dL higher than that of PreM women. Other important predictors of blood lead levels were use of lead-glazed ceramics, schooling, trabecular bone lead, body mass index, time of living in Mexico City, and use of hormone replacement therapy. Bone density was not associated with blood lead levels. These results support the hypothesis that release of bone lead stores increases during menopause and constitutes an internal source of exposure possibly associated with health effects in women in menopause transition.
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28
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Frumkin H, Manning CC, Williams PL, Sanders A, Taylor BB, Pierce M, Elon L, Hertzberg VS. Diagnostic chelation challenge with DMSA: a biomarker of long-term mercury exposure? ENVIRONMENTAL HEALTH PERSPECTIVES 2001; 109:167-171. [PMID: 11266328 PMCID: PMC1240638 DOI: 10.1289/ehp.01109167] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Chelation challenge testing has been used to assess the body burden of various metals. The best-known example is EDTA challenge in lead-exposed individuals. This study assessed diagnostic chelation challenge with dimercaptosuccinic acid (DMSA) as a measure of mercury body burden among mercury-exposed workers. Former employees at a chloralkali plant, for whom detailed exposure histories were available (n = 119), and unexposed controls (n = 101) completed 24-hr urine collections before and after the administration of two doses of DMSA, 10 mg/kg. The urinary response to DMSA was measured as both the absolute change and the relative change in mercury excretion. The average 24-hr mercury excretion was 4.3 microg/24 hr before chelation, and 7.8 microg/24 hr after chelation. There was no association between past occupational mercury exposure and the urinary excretion of mercury either before or after DMSA administration. There was also no association between urinary mercury excretion and the number of dental amalgam surfaces, in contrast to recent published results. We believe the most likely reason that DMSA chelation challenge failed to reflect past mercury exposure was the elapsed time (several years) since the exposure had ended. These results provide normative values for urinary mercury excretion both before and after DMSA challenge, and suggest that DMSA chelation challenge is not useful as a biomarker of past mercury exposure.
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Affiliation(s)
- H Frumkin
- Department of Environmental and Occupational Health, Emory University, Atlanta, Georgia, USA.
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29
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Markowitz ME, Shen XM. Assessment of bone lead during pregnancy: a pilot study. ENVIRONMENTAL RESEARCH 2001; 85:83-89. [PMID: 11161658 DOI: 10.1006/enrs.2000.4117] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
More than 85% of American children raised in the 1970s had blood lead (BPb) levels >/=10 microg/dL, the level that currently defines childhood Pb poisoning. With exposure and absorption Pb accumulates in bone. Bone Pb release back to blood also occurs, particularly when kinetic rates of bone turnover are elevated. We examined a group of childbearing age, urban African American and Hispanic women to determine whether they had measurable bone Pb and whether bone Pb levels changed during pregnancy. Tibial bone Pb content was assessed sequentially 3 times over 4 months by L-line X-ray fluorescence (LXRF); for pregnant enrollees this occurred during the second and third trimesters and 1-2 months postpartum. LXRF is a noninvasive, low-dose radiation technique that measures superficial cortical bone Pb. Other measures included age, years living in New York City, BPb and a home Pb assessment employing KXRF methodology. Of 53 women evaluated 34 were pregnant. Of these 34, 2 had blood Pb levels >/=10 microg/dL; 2 had bone Pb levels above the minimum detection limit of the instrumentation at the time of enrollment. A case report is presented in which a declining bone Pb level was accompanied by an increase in BPb concentration. We surmise that the prevalence of elevated bone Pb levels will be low in Bronx women despite long-term exposure to leaded paint. However, fetuses of those with elevated bone Pb are at risk of excessive in-utero Pb exposure.
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Affiliation(s)
- M E Markowitz
- Pediatric Environmental Sciences Clinics, The Children's Hospital at Montefiore, 111 E. 210th Street, Bronx, New York 10467, USA
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30
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Mushak P. Uses and limits of empirical data in measuring and modeling human lead exposure. ENVIRONMENTAL HEALTH PERSPECTIVES 1998; 106 Suppl 6:1467-84. [PMID: 9860906 PMCID: PMC1533425 DOI: 10.1289/ehp.98106s61467] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This paper examines the uses and limits of empirical data in evaluating measurement and modeling approaches to human lead exposure. Empirical data from experiment or observation or both have been used in studies of lead exposure. For example, experimental studies have elucidated and quantified physiologic or biokinetic parameters of lead exposure under controlled conditions. Observation, i.e., epidemiology, has been widely applied to study population exposures to lead. There is growing interest in the use of lead exposure prediction models and their evaluation before use in risk assessment. Empirical studies of lead exposure must be fully understood, especially their limits, before they are applied as "standards" or reference information for evaluation of exposure models, especially the U.S. Environmental Protection Agency's lead biokinetic model that is a focus of this article. Empirical and modeled datasets for lead exposure may not agree due to a) problems with the observational data or b) problems with the model; caution should be exercised before either a model or observational data are rejected. There are at least three sources of discordance in cases where there is lack of agreement: a) empirical data are accurate but the model is flawed; b) the model is valid but reference empirical data are inaccurate; or c) neither empirical data nor model is accurate, and each is inaccurate in different ways. This paper evaluates some of the critical empirical input to biokinetic models, especially lead bioavailability.
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Affiliation(s)
- P Mushak
- PB Associates, Durham, North Carolina 27705, USA.
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31
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Farias P. Determinants of bone and blood lead levels among teenagers living in urban areas with high lead exposure. ENVIRONMENTAL HEALTH PERSPECTIVES 1998; 106:733-737. [PMID: 9799189 PMCID: PMC1533491 DOI: 10.1289/ehp.106-1533491] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Although lead has been extensively studied in children, its sources and effects remain unclear in adolescents. This study examined the relation of blood and tibia bone lead levels to lead determinants. One hundred adolescents living in Mexico City and surrounding suburbs were studied. Blood lead was measured by atomic absorption spectroscopy, and tibia lead was measured by a K X-ray Fluorescence (KXRF) instrument. Blood lead ranged from 1.8 to 29.2 microgram/dl, with a mean of 7.4 microgram/dl. Bone lead ranged from <1 to 44.82 microgram Pb/g bone mineral, with a mean of 4.8 microgram Pb/g. Predictors of bone lead included higher traffic density near the home, mother's smoking history, and time spent outdoors. Predictors of log-transformed blood lead included bone lead levels, male sex, use of lead-glazed ceramics, and living in Mexico City. Bone lead remained a significant predictor of blood lead after adjusting for covariates in a final multivariate regression model. In our final model, a rise in bone lead from the middle of the lowest quintile to the middle of the highest quintile (a difference of 21.6 microgram Pb/g) was associated with an increase in blood lead of 1.2 microgram/dl. Our data suggest that in addition to current sources of environmental lead exposure, bone lead accumulated over time constitutes a moderate source of circulating lead during adolescence and may account for some of the adverse health effects documented in recent studies.
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Affiliation(s)
- P Farias
- Centro de Investigaciones en Salud Poblacional/INSP, Cuernavaca, Mexico
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32
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Hu H. Bone lead as a new biologic marker of lead dose: recent findings and implications for public health. ENVIRONMENTAL HEALTH PERSPECTIVES 1998; 106 Suppl 4:961-7. [PMID: 9703479 PMCID: PMC1533327 DOI: 10.1289/ehp.98106s4961] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Measurements of lead in bone have recently become the focus of research because a) bone lead levels serve as a cumulative dosimeter of lead exposure over many years (because of lead's long residence time in bone), and cumulative exposure may be more predictive of chronic toxicity than recent exposure, which is what blood lead levels mostly reflect; b) there is suspicion that heightened bone turnover (e.g. during pregnancy, lactation, and aging) may liberate enough stored lead to pose a significant threat of delayed toxicity; and c) although lead exposure has largely declined in the United States over the past 10 to 15 years, decades of heavy environmental pollution have resulted in significant accumulation of lead in bone among most members of the general U.S. population. Epidemiologic research on the impact of lead stored in bone is now possible with the development of 109Cd K-X-ray fluorescence (KXRF) instruments for the in vivo measurement of lead in bone. In this paper, the KXRF method will be briefly reviewed, followed by a summary of several Superfund-supported studies (and others) of blood lead and KXRF-measured bone lead in which these measures are compared as biologic markers of lead dose. Measurement of bone lead in epidemiologic studies has proved useful in exposure assessment studies, i.e., in identifying factors that contribute most to retained body lead burden, and in investigating cumulative lead exposure as a risk factor for poor health outcomes such as hypertension, kidney impairment, cognitive impairment, behavioral disturbances, and adverse reproductive outcomes.
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Affiliation(s)
- H Hu
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA.
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33
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Payton M, Riggs KM, Spiro A, Weiss ST, Hu H. Relations of bone and blood lead to cognitive function: the VA Normative Aging Study. Neurotoxicol Teratol 1998; 20:19-27. [PMID: 9511166 DOI: 10.1016/s0892-0362(97)00075-5] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The relationship between performance on cognitive tasks and circulating levels of lead in blood and accumulated levels of lead in bone was examined in 141 middle-aged and elderly men from a longitudinal study of aging. The mean (SD) blood lead level was low [5.5 (3.5) micrograms/dl], and mean patella and tibia lead levels were 31.7 (19.2) and 22.5 (12.2) micrograms/g bone mineral, respectively. Cognitive tests measured attention, perceptual speed, memory, language, and spatial copying. Regression models, adjusted for age and education, demonstrated that men with higher levels of blood lead recalled and defined fewer words, identified fewer line-drawn objects, and required more time to attain the same level of accuracy on a perceptual comparison test as men with the lowest level of blood lead. Men with higher levels of blood and bone (tibia) lead copied spatial figures less accurately; men with higher levels of bone (tibia) lead had slower responses for pattern memory. These findings suggest that low levels of lead contribute to impairments in cognitive function among elderly men.
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Affiliation(s)
- M Payton
- Department of Medicine, Brigham and Women's Hospital, Channing Laboratory, Harvard Medical School, Boston, MA 02115, USA.
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34
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Hernandez-Avila M, Gonzalez-Cossio T, Palazuelos E, Romieu I, Aro A, Fishbein E, Peterson KE, Hu H. Dietary and environmental determinants of blood and bone lead levels in lactating postpartum women living in Mexico City. ENVIRONMENTAL HEALTH PERSPECTIVES 1996; 104:1076-82. [PMID: 8930549 PMCID: PMC1469486 DOI: 10.1289/ehp.961041076] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Despite the recent declines in environmental lead exposure in the United States and Mexico, the potential for delayed toxicity from bone lead stores remains a significant public health concern. Some evidence indicates that mobilization of lead from bone may be markedly enhanced during the increased bone turnover of pregnancy and lactation, resulting in lead exposure to the fetus and the breast-fed infant. We conducted a cross-sectional investigation of the interrelationships between environmental, dietary, and lifestyle histories, blood lead levels, and bone lead levels among 98 recently postpartum women living in Mexico City. Lead levels in the patella (representing trabecular bone) and tibia (representing cortical bone) were measured by K X-ray fluorescence (KXRF). Multivariate linear regression models showed that significant predictors of higher blood lead included a history of preparing or storing food in lead-glazed ceramic ware, lower milk consumption, and higher levels of lead in patella bone. A 34 micrograms/g increase in patella lead (from the medians of the lowest to the highest quartiles) was associated with an increase in blood lead of 2.4 micrograms/dl. Given the measurement error associated with KXRF and the extrapolation of lead burden from a single bone site, this contribution probably represents an underestimate of the influence of trabecular bone on blood lead. Significant predictors of bone lead in multivariate models included years living in Mexico City, lower consumption of high calcium content foods, and nonuse of calcium supplements for the patella and years living in Mexico City, older age, and lower calcium intake for tibia bone. Low consumption of milk and cheese, as compared to the highest consumption category (every day), was associated with an increase in tibia bone lead of 9.7 micrograms Pb/g bone mineral. The findings of this cross-sectional study suggest that patella bone is a significant contributor to blood lead during lactation and that consumption of high calcium content foods may protect against the accumulation of lead in bone.
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Affiliation(s)
- M Hernandez-Avila
- Centro de Investigaciones en Salud Poblacional, Instituto Nacional de Salud Publica, Cuernavaca, Mexico
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35
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Kim R, Hu H, Rotnitzky A, Bellinger D, Needleman H. A longitudinal study of chronic lead exposure and physical growth in Boston children. ENVIRONMENTAL HEALTH PERSPECTIVES 1995; 103:952-7. [PMID: 8529592 PMCID: PMC1519152 DOI: 10.1289/ehp.95103952] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We investigated the cross-sectional and longitudinal relationships between chronic exposure to lead and physical growth among a cohort of children reassessed 13 years after initial examination. We measured weight, height, and dentin lead levels of 270 children in 1975-78. In 1989-1990 we reexamined 79 of these children for measurement of weight, height, and bone lead levels by means of in vivo K X-ray fluorescence. To avoid potential confounding by race and chelation history, analysis was restricted to white subjects without a history of lead chelation therapy. A total of 236 subjects provided complete information for the study of cross-sectional relationship between dentin lead levels and changes in physical growth: 58 subjects for the study of longitudinal relationship between dentin lead levels and changes in physical growth and 54 subjects for the study of longitudinal relationship between bone lead levels and changes in physical growth. Dentin lead levels averaged 14.9 micrograms/g; tibia and patella lead levels averaged 1.2 and 5.0 micrograms/g, respectively. With control for potential confounders including age, sex, baseline body size, and mother's socioeconomic status, log10 dentin lead level was positively associated with body mass index as of 1975-1978 (beta = 1.02, p = 0.03) and increase in body mass index between 1975-78 and 1989-90 (beta = 2.65, p = 0.03). Bone lead levels were not significantly associated with physical growth. This is the first study relating chronic lead exposure to body mass index. The results suggest that chronic lead exposure in childhood may result in obesity that persists into adulthood.
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Affiliation(s)
- R Kim
- Department of Environmental Health, Harvard School of Public Health, Boston, MA 02115, USA
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36
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Kim R, Aro A, Rotnitzky A, Amarasiriwardena C, Hu H. K x-ray fluorescence measurements of bone lead concentration: the analysis of low-level data. Phys Med Biol 1995; 40:1475-85. [PMID: 8532760 DOI: 10.1088/0031-9155/40/9/007] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
K line x-ray fluorescence (KXRF) measurements of bone lead have emerged as a promising new biological marker of internal lead dose in epidemiological studies. Some disagreements exist, however, over the analysis of data at low levels of bone lead concentration. In this study, we performed 30 serial measurements on each of three phantoms containing spiked amounts of lead. Chemical analysis of these phantoms using an inductively coupled plasma mass spectrometer (ICPMS) indicated that the lead concentrations were 0.30, 5.77, and 11.57 micrograms g-1. Analysis of the data was performed using several definitions of a minimum detectable limit (MDL) to recode data below the MDL, and using all of the continuous point estimates of lead concentration in the phantom (including negative estimates). The results demonstrate that the use of MDLs to recode low-level observations reduces the efficiency of the analysis and the ability to distinguish between the phantoms. Retaining all point estimates of KXRF-measured bone lead concentration provides less bias and greater efficiency in comparing the mean or median levels of bone lead of different populations.
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Affiliation(s)
- R Kim
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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