Browsing by Author "Mercado-Garcia, Adriana"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Early Lead Exposure Associated with Molar Hypomineralization
    (American Academy of Pediatric Dentistry, 2023-09) Tagelsir, Ahmed A.; Hector, Emily C.; Urena-Cirett, Jose Luis; Mercado-Garcia, Adriana; Cantoral, Alejandra; Hu, Howard; Peterson, Karen E.; Tellez-Rojo, Martha M.; Martinez-Mier, Esperanza A.; Dental Public Health and Dental Informatics, School of Dentistry
    Purpose: The purpose of this study was to determine the association between prenatal and early life exposure to lead and the presence of molar hypomineralization (MH) in a group of Mexican children. Methods: A subset of participants of the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENTS) cohort study was examined for the presence of molar hypomineralization using European Academy of Pedi- atric Dentistry (EAPD) criteria. Prenatal lead exposure was assessed by K-ray fluorescence measurements of patella and tibia lead and by maternal blood lead levels by trimester and averaged over trimesters. Postnatal exposure was assessed by levels of maternal blood lead at delivery and child blood lead at 12 and 24 months. Results: A subset of 506 subjects from the ELEMENT cohorts (nine to 18 years old) were examined for MH; 87 subjects (17.2 percent) had MH. Maternal blood lead levels in the third trimester (odds ratio [OR] equals 1.08; 95 percent confidence interval [95% CI] equals 1.02 to 1.15) and averaged over three trimesters (OR equals 1.10; 95% CI equals 1.02 to 1.19) were significantly associated with MH status. None of the maternal bone lead or the child's blood lead parameters was significantly associated with the presence of MH (P>0.05). Conclusions: This study documents a significant association between prenatal lead exposure especially in late pregnancy and the odds of molar hypomineralization.
  • Thumbnail Image
    Item
    Urinary and Plasma Fluoride Levels in Pregnant Women from Mexico City
    (Elsevier, 2016-10) Thomas, Deena B.; Basu, Niladri; Martinez-Mier, E. Angeles; Sánchez, Brisa N.; Zhang, Zhenzhen; Liu, Yun; Parajuli, Rajendra; Peterson, Karen; Mercado-Garcia, Adriana; Bashash, Morteza; Hernández-Avila, Mauricio; Hu, Howard; Téllez-Rojo, Martha Maria; Department of Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    Background There is need to assess the developmental neurotoxicity of fluoride. Our knowledge of prenatal fluoride exposure is challenged as few population-based studies have been conducted and these generally date back several decades, provide incomplete data on sociodemographic variables, and have methodological limitations. Objective To measure urinary and plasma fluoride levels across three time points in pregnant mothers who were enrolled in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) birth cohort study. Methods Fluoride levels were characterized in archived urine and plasma from 872 pregnant mothers sampled from the ELEMENT cohort. Various statistical methods were used to analyze the fluoride data with particular consideration for changes across three stages of pregnancy and against sociodemographic variables. Results All samples had detectable levels of fluoride. The mean urinary and plasma fluoride levels were 0.91 and 0.0221 mg/L respectively, and these were not statistically different across three stages of pregnancy. Fluoride levels correlated across the stages of pregnancy studied, with stronger correlations between neighboring stages. Urinary fluoride changed as pregnancy progressed with levels increasing until ~23 weeks and then decreasing until the end of pregnancy. For plasma fluoride, there was a decreasing trend but this was not of statistical significance. Creatinine-adjusted urinary fluoride levels did not associate consistently with any of the sociodemographic variables studied. Conclusions This study provides the most extensive characterization to date of fluoride exposure throughout pregnancy. These results provide the foundation to explore exposure-related health outcomes in the ELEMENT cohort and other studies.