scholarly journals Hydrogeogenic fluoride in groundwater and dental fluorosis in Thai agrarian communities: a prevalence survey and case–control study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chanapong Rojanaworarit ◽  
Luz Claudio ◽  
Nopporn Howteerakul ◽  
Auamduan Siramahamongkol ◽  
Pattraravith Ngernthong ◽  
...  
Keyword(s):  
Drinking Water ◽  
Case Control Study ◽  
Dental Fluorosis ◽  
Irrigation System ◽  
Case Control ◽  
Public Health Issue ◽  
Drinking Water Source ◽  
Agrarian Communities ◽  
Endemic Areas ◽  
Control Study

Abstract Background Dental fluorosis can be a disease of social inequity in access to safe drinking water. This dental public health issue becomes prominent in socially disadvantaged agrarian communities in fluoride endemic areas where the standard irrigation system is unavailable and groundwater containing natural fluoride is the major drinking water source. This study aimed to determine the prevalence and severity of dental fluorosis in children and to evaluate its association with fluoride in groundwater in the aforementioned setting in Thailand. Methods A cross-sectional survey of 289 children in Nakhon Pathom Province was conducted in 2015. Children with very mild to severe fluorosis were regarded as ‘cases’ while their counterparts were ‘controls’ for a subsequent case–control study. Records of fluoride concentrations in groundwater used for household supply corresponding to resident and number of years by age of each child during 2008–2015 were retrieved. Other exposure variables were measured using a questionnaire. Prevalence ratio (PR), a measure indicating the relative effect of different levels of fluoride on dental fluorosis, was obtained from Poisson regression with robust standard error. Result There were 157 children with very mild to moderate dental fluorosis (54.3% prevalence). The univariable analysis revealed that the prevalence of dental fluorosis among children with fluoride concentrations in water sources of 0.7–1.49 (index category 1) and ≥ 1.5 ppm (index category 2) was 1.62 (95% CI; 0.78, 3.34) and 2.75 (95% CI; 1.42, 5.31) times the prevalence among those with fluoride < 0.7 ppm (referent category). After adjusting for all covariates, the adjusted prevalence ratios in both index categories were 1.64 (95% CI; 0.24, 11.24) and 2.85 (95% CI; 0.44, 18.52) which were close to their corresponding crude estimates. Since the magnitude of confounding, measured by (PRcrude–PRadjusted)/PRadjusted, were less than 10% for both index categories; this indicated the limited confounding effect of all covariates. Conclusions In fluoride endemic areas, groundwater containing natural fluoride utilized for household consumption resulted in high dental fluorosis prevalence, particularly in the groundwater with fluoride concentrations of ≥ 1.5 ppm.

scholarly journals Hydrogeogenic fluoride in groundwater and dental fluorosis occurrence in agrarian communities: a prevalence survey and case-control study

2021 ◽  
Author(s):  
CHANAPONG ROJANAWORARIT
Keyword(s):  
Drinking Water ◽  
Case Control Study ◽  
Dental Fluorosis ◽  
Irrigation System ◽  
Case Control ◽  
Public Health Issue ◽  
Drinking Water Source ◽  
Agrarian Communities ◽  
Endemic Areas ◽  
Control Study

Abstract Background: Dental fluorosis can be a disease of social inequity in access to safe drinking water. This dental public health issue becomes prominent in the socially disadvantaged agrarian communities in fluoride endemic areas where the standard irrigation system is unavailable and groundwater containing natural fluoride is the major drinking water source. This study aimed to determine prevalence and severity of dental fluorosis in children and to evaluate its association with fluoride in groundwater in the aforementioned setting in Thailand.Methods: A cross-sectional survey of 289 children in Nakhon Pathom Province was conducted in 2015. Children with very mild to severe fluorosis were regarded as ‘cases’ while their counterparts were ‘controls’ for a subsequent case-control study. Records of fluoride concentrations in groundwater used for household supply corresponding to resident and number of years by age of each child during 2008 to 2015 were retrieved. Other exposure variables were measured using a questionnaire. Poisson regression with robust standard error was employed to estimate the dental fluorosis prevalence ratio (PR) comparing different levels of fluoride exposure.Result: There were 157 children with very mild to moderate dental fluorosis (54.3% prevalence). The univariable analysis revealed that the prevalence of dental fluorosis among children with fluoride concentrations in water sources of 0.7-1.49 (index category 1) and ≥ 1.5 ppm (index category 2) was 1.62 (95% CI; 0.78, 3.34) and 2.75 (95% CI; 1.42, 5.31) times the prevalence among those with fluoride < 0.7 ppm (referent category). After adjusting for all covariates, the adjusted prevalence ratios in both index categories were 1.64 (95% CI; 0.24, 11.24) and 2.85 (95% CI; 0.44, 18.52) which were close to their corresponding crude estimates. Since the magnitude of confounding, measured by (PRcrude – PRadjusted)/PRadjusted, were less than 10% for both index categories; this indicated the limited confounding effect of all covariates.Conclusions: In fluoride endemic areas, groundwater containing natural fluoride utilized for household consumption resulted in high dental fluorosis prevalence, particularly in the groundwater with fluoride concentrations of ≥ 1.5 ppm.

Cancer of the Pancreas and Drinking Water: A Population-based Case-Control Study in Washington County, Maryland

1992 ◽  
Vol 136 (7) ◽  
pp. 836-842 ◽  
Author(s):  
C. B. IJsselmuiden ◽  
C. Gaydos ◽  
B. Feighner ◽  
W. L. Novakoski ◽  
D. Serwadda ◽  
...  
Keyword(s):  
Drinking Water ◽  
Case Control Study ◽  
Population Based ◽  
Case Control ◽  
Washington County ◽  
Cancer Of The Pancreas ◽  
Control Study

scholarly journals The association of tryptophan and phenylalanine are associated with arsenic-induced skin lesions in a Chinese population chronically exposed to arsenic via drinking water: a case–control study

BMJ Open ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. e025336 ◽  
Author(s):  
Yaping Wei ◽  
Chaonan Jia ◽  
Yuan Lan ◽  
Xiangqing Hou ◽  
Jingjing Zuo ◽  
...  
Keyword(s):  
Drinking Water ◽  
High Performance ◽  
Case Control Study ◽  
Conditional Logistic Regression ◽  
Characteristic Curve ◽  
Skin Lesions ◽  
Case Control ◽  
Conditional Logistic Regression Model ◽  
Hetao Plain ◽  
Control Study

ObjectivesWe investigated the association of specific serum amino acids (AAs) with the odds of arsenic-induced skin lesions (AISL) and their ability to distinguish patients with AISL from people chronically exposed to arsenic.DesignCase–control study.SettingThree arsenic-exposed villages in Wuyuan County, Hetao Plain, Inner Mongolia, China were evaluated.ParticipantsAmong the 450 residents aged 18–79 years, who were chronically exposed to arsenic via drinking water, 56 were diagnosed as having AISL (defined as cases). Another 56 participants without AISL, matched by gender and age (±1 year) from the same population, were examined as controls.Main outcome measures and methodsAA levels were determined by ultra-high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry-based metabolomics analysis. Potential confounding variables were identified via a standardised questionnaire and clinical examination. Multivariable conditional logistic regression model and receiver operating characteristic curve analyses were performed to investigate the relationship between specific AAs and AISL.ResultsTryptophan and phenylalanine levels were negatively associated with AISL (p<0.05). Compared with that in the first quartile, the adjusted OR of AISL in the second, third and fourth quartiles were decreased by 44%, 88% and 79% for tryptophan and 30%, 80% and 80% for phenylalanine, respectively. The combination of these two higher-level AAs showed the lowest OR for AISL (OR=0.08; 95% CI 0.02 to 0.25; p<0.001). Furthermore, both AAs showed a moderate ability to distinguish patients with AISL from the control, with the area under the curve (AUC; 95% CI) as 0.67 (0.57 to 0.77) for tryptophan and 0.70 (0.60 to 0.80) for phenylalanine (p<0.05). The combined pattern with AUC (95% CI) was 0.72 (0.62 to 0.81), showing a sensitivity of 76.79% and specificity of 58.93% (p<0.001).ConclusionsSpecific AAs may be linked to AISL and play important roles in early AISL identification.Trial Registration numberNCT02235948.

Sign in / Sign up

Export Citation Format

Share Document