Format

Send to

Choose Destination
Environ Health Perspect. 2018 Oct;126(10):107001. doi: 10.1289/EHP3546.

Community Water Fluoridation and Urinary Fluoride Concentrations in a National Sample of Pregnant Women in Canada.

Author information

1
Faculty of Health, York University, Toronto, Ontario, Canada.
2
Pediatrics and Environmental Health, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.
3
School of Dentistry, Indiana University, Indianapolis, Indiana, USA.
4
Department of Social and Preventive Medicine, Laval University, Quebec, Quebec, Canada.
5
Centre de Recherche du CHU de Québec, Université Laval, Quebec, Quebec, Canada.
6
School of Psychology, Laval University, Quebec, Quebec, Canada.
7
Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada.
8
Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.

Abstract

BACKGROUND:

Fluoride exposures have not been established for pregnant women who live in regions with and without community water fluoridation.

OBJECTIVE:

Our aim was to measure urinary fluoride levels during pregnancy. We also assessed the contribution of drinking-water and tea consumption habits to maternal urinary fluoride (MUF) concentrations and evaluated the impact of various dilution correction standards, including adjustment for urinary creatinine and specific gravity (SG).

METHODS:

We measured MUF concentrations in spot samples collected in each trimester of pregnancy from 1,566 pregnant women in the Maternal-Infant Research on Environmental Chemicals cohort. We calculated intraclass correlation coefficients (ICCs) to assess variability in MUF concentrations across pregnancy. We used regression analyses to estimate associations between MUF levels, tea consumption, and water fluoride concentrations as measured by water treatment plants.

RESULTS:

Creatinine-adjusted MUF values ([Formula: see text]; milligrams per liter) were almost two times higher for pregnant women living in fluoridated regions ([Formula: see text]) compared with nonfluoridated regions ([Formula: see text]; [Formula: see text]). MUF values tended to increase over the course of pregnancy using both unadjusted values and adjusted values. Reproducibility of the unadjusted and adjusted MUF values was modest ([Formula: see text]). The municipal water fluoride level was positively associated with creatinine-adjusted MUF ([Formula: see text], 95% CI: 0.46, 0.57), accounting for 24% of the variance after controlling for covariates. Higher MUF concentrations correlated with numbers of cups of black ([Formula: see text] but not green tea ([Formula: see text]). Urinary creatinine and SG correction methods were highly correlated ([Formula: see text]) and were interchangeable in models examining predictors of MUF.

CONCLUSION:

Community water fluoridation is a major source of fluoride exposure for pregnant women living in Canada. Urinary dilution correction with creatinine and SG were shown to be interchangeable for our sample of pregnant women. https://doi.org/10.1289/EHP3546.

PMID:
30392399
PMCID:
PMC6371693
DOI:
10.1289/EHP3546
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Atypon Icon for PubMed Central
Loading ...
Support Center