Fluorosis Villages Research Articles

Gene-environment interaction: Does fluoride influence the reproductive hormones in male farmers modified by ERα gene polymorphisms?

The occurrence of endemic fluorosis is derived from high fluoride levels in drinking water and industrial fumes or dust. Reproductive disruption is also a major harm caused by fluoride exposure besides dental and skeletal lesions. However, few studies focus on the mechanism of fluoride exposure on male reproductive function, especially the possible interaction of fluoride exposure and gene polymorphism on male reproductive hormones. Therefore, we conducted a cross-sectional study in rural areas of Henan province in China to explore the interaction between the estrogen receptor alpha (ERα) gene and fluoride exposure on reproductive hormone levels in male farmers living in the endemic fluorosis villages. The results showed that fluoride exposure significantly increased the serum level of estradiol in the hypothalamic-pituitary-testicular (HPT) axis in male farmers. Moreover, the observations indicated that fluoride exposure and genetic markers had an interaction on serum concentration of follicle-stimulating hormone and estradiol, and the interaction among different loci of the ERα gene could impact the serum testosterone level. Findings in the present work suggest that chronic fluoride exposure in drinking water could modulate the levels of reproductive hormones in males living in endemic fluorosis areas, and the interaction between fluoride exposure and ERα polymorphisms might affect the serum levels of hormones in the HPT axis in male farmers.

Fluorine contents and its characteristics of groundwater in fluorosis area in Laizhou Bay, China

Fluorine concentration and other parameters in groundwater were assessed and attempts were made to clarify the relationship between fluorine (Fl) and seawater intrusion in coastal area of Laizhou Bay, China by comparing samples in fluorosis and non-fluorosis areas. The water from fluorosis villages reflects the influence of seawater intrusion and higher levels of conductivity (Ec), total dissolved solids (TDS), hardness (TH), Cl−, Br−, , Li+, Na+, Mg2+, and Sr2+. High Fl concentration was positive correlated with Ec, TDS, Cl−, Br−, Li+, Mg2+, Ca2+, Sr2+ and significantly with Na+, Na+/Ca2+, and sodium adsorption ratio. This investigation also observed that seawater intrusion and fluorosis show similar distribution and originating sources. Thus, the special process-seawater intrusion seems to be an important dynamic of Fl enrichment by changing chemical characters and enhancing Fl release ability. Moreover, the water treated by bone coal adsorption still maintains high risk of Ec, Na+, and TDS, even though Fl was within the safe limit. This study indicates that in Laizhou Bay, together with other coastal areas, seawater intrusion is a cause for concern when examining mechanism underlying fluorosis occurrence and developing integrated treatment technology.

A national cross-sectional study on effects of fluoride-safe water supply on the prevalence of fluorosis in China

ObjectiveTo assess the effects of provided fluoride-safe drinking-water for the prevention and control of endemic fluorosis in China.DesignA national cross-sectional study in China.SettingIn 1985, randomly selected villages in 27 provinces...

Endemic fluorosis in Huangyuan county Qinghai province in 2009: an analysis of surveillance results

Objective To investigate the prevalence change of drinking water type of endemic fluorosis and the effect of control measures implemented in Huangyuan county of Qinghai province. Methods In 2009, all the endemic fluorosis villages in Huangyuan county were divided into two degrees, light and medium, according to the water fluorosis content before implementing the improving water project, 1 to 2 villages were selected from each degree village, respectively,as monitoring sites, and a total of 3 villages were selected. Source water and tap water samples were collected from each village and water fluoride concentration was determined. Dental fluorosis of all children aged 8 to 12 of monitoring villages was examined, and urine samples were collected by age group of children for determination of urinary fluoride. skeletal fluorosis of adults over 16 years of age was examined, and 20 copies of adults urine samples were collected to determine urinary fluoride. One village was selected in the 3 villages monitored to conduct X-rays examination of skeletal fluorosis. fluoride was tested in accordance with the Non-metallic Targets Test Methods for Drinking Water (GB/T 5750.6-2006); urinary fluoride was tested by fluoride ion-selective electrode method (WS/T 89-1996); dental fluorosis was diagnosed using Dean method;adult skeletal fluorosis was diagnosed by Clinical Diagnostic Criteria for Endemic Skeletal Fluorosis(WS 192-2008). Results Twelve water samples were assayed, water fluoride was (0.35 ± 0.43) mg/L. The detectable rate of dental fluorosis of 122 children aged 8-12 was 34.43%(42/122) and the geometric mean urinary fluoride was 0.89 mg/L of the 96 children. Of the 834 adults aged 16 and over, clinical detection of skeletal fluorosis was 47.72% (398/836) and geometric mean urinary fluoride was 1.10 mg/L of the 65 cases of adult urine samples assayed, detection rate of X-rays was 31.4% (11/35) in Gangou village of the 35 adults examined.Conclusions In Huangyuan county, water fluoride of the 3 surveyed villages are normal but the endemic fluorosis is still serious. It should strengthen monitoring and analyze the causes and improve prevention measures. Key words: Fluorosis; Drinking; Data collection; Osteofluorosis

Association of Dental Fluorosis with Polymorphisms of Estrogen Receptor Gene in Chinese Children

Dental fluorosis (DF) is one of the important performances of endemic fluorosis. Some studies indicated that estrogen receptor (ESR) gene polymorphisms were associated with bone metabolism-related diseases. Therefore, it is possible that the variation in ESR genotypes will be associated with DF status. A case-control study was conducted among children aged 8-12 years with (n = 75) or without (n = 165) DF in China to investigate the relationship between ESR gene polymorphisms and DF. Gene polymorphisms were genotyped using the PCR-RFLP procedure. Children carrying R allele of ER RsaI had significantly increased risk of DF (Odds ratio (OR) = 1.821; 95% confidence interval (CI), 1.013-3.274) compared to children carrying r allele of ER RsaI in endemic fluorosis villages. For children with high-loaded fluoride status, carrying X allele of ESRα XbaI had a significantly decreased risk of DF (OR = 0.542; 95% CI, 0.314-0.936) compared to carrying x allele. This study provides the first evidence of an association between polymorphisms in the ESR gene with DF in high-fluoride-exposed populations. Further studies are needed to confirm the association.

Outcome analysis on drinking-water type endemic fluorosis in Qinghai in 2008

Objective To observe the state of endemic flurosis in Qinghai province in 2008 and to provide scientific basis for endemic flurosis control and prevention. Methods All the endemic fluorosis villages in Qinghai province was divided into slight,medium and heavy degree according to the water fluoride content before improving water,and 2,4,4 villages were collected from each degree,respectively. Water samples were collected from each direction of east,west,south,north and centre,and fluoride concentration were determined from each surveyed villages with unimproved-water. At the same time,3 copies of the peripheral water samples and a sample of source water were collected to determine fluoride concentration. In all the village children aged 8 to 12 were tested for dental fluorosis by Dean method. Six copies of the urinary fluoride were randomly sampled in different age groups. The fluorine content in urine was determined with F-ion selective electrode. The situation of clinical skeletal fluorosis of adults over 16 years of age was examined,and 20 adults in the villages of medium and heavy levels were filmed for skeletal fluorosis. Results The detectable rate of dental fluorosis of children aged 8-12 years old was 43.59% (245/562),that of skeletal flurosis of adults aged above 16 years was 50.32% (1582/3144) and detectable rate of X-ray was 29.45% (48/163). Fluoride content in urine was 1.52 mg/L. Conclusions Endemic fluorosis is still very serious in Qiaghai province in a rising trend,so the control measures need to be strengthen. Key words: Fluoride poisoning; Data collection ; Fluorosis,dental; Osteofluorosis

COL1A2 gene polymorphisms (Pvu II and Rsa I), serum calciotropic hormone levels, and dental fluorosis

To investigate the relationship between dental fluorosis, polymorphisms in the COL1A2 gene, and serum calciotropic hormone levels. We conducted a case-control study among children between 8 and 12 years of age with (n = 75) and without (n = 165) dental fluorosis in two counties in Henan Province, China. The PvuII and RsaI polymorphisms in the COL1A2 gene were genotyped using the PCR-RFLP procedure. Calcitonin and osteocalcin levels in the serum were measured using radioimmunassays. Children carrying the homozygous genotype PP of COL1A2 PvuII had a significantly increased risk of dental fluorosis (OR =4.85, 95% CI: 1.22-19.32) compared to children carrying the homozygous genotype pp in an endemic fluorosis village (EFV). However, the risk (OR = 1.07, 95% CI: 0.45-2.52) was not elevated when the control population was recruited from a non-endemic fluorosis village. Additionally, fluoride levels in urine and osteocalcin levels in serum were found to be significantly lower in controls from non-endemic villages compared to cases. However, the differences in fluoride and osteocalcin levels were not observed when cases were compared to a control population from endemic fluorosis villages. This study provides the first evidence of an association between polymorphisms in the COL1A2 gene with dental fluorosis in high fluoride exposed populations. Future studies are needed to confirm the association.

Investigation on water fluoride content and water-improving defluoridation projects in endemic fluorosis areas in Jining City, Shandong Province in 2005

Objective To investigate water fluoride content and the current status of water-improving project in Jining,Shandong Province in 2005.Methods Water fluoride content and the status of water-lmprovlng project were havestigated in Bencheng Ditrict,Liangshan and Jiaxiang Couties of Jining City.The fluoride content in drinking warer was assessed by F-ion selective electrode.Results Water fluoride contents of 671 fluorosis villages were determined.One hundred and seventy villages had water fluoride content less than or equal to 1.00 mg/L(accounting for 25.34%)and 501 villages water fluoride content higher that 1.00 mg/L(accounting for 74.66%),with the highest being 11.33 mg/L.Four hundred and ninty.seven projects were surveyed,in which 161 Projects were discarded (accounting for 32.39%),334 projeets worked well(accounting for 67.20%),and 2 pmjects worked fitfully(accounting 0.40%).Two hundreds and eighty-one projects had water fluoride content≤1.00 ms/L and 55 projects had water fluofide cantent>1.00 mg/L(aceounting for 26.82%),with the highest being 4.28 ms/L.Conclusions The situation of endemic fluorosis control is still serious in Jining City.Countermeasures for endemic fluorosis must be carried out as sppm as possible and surveillance of water-improving and defluoridation projects must be strevIsthend. Key words: Dringking water; Fluoride poisoning; Engineering; Epidemiologic studies

Epidemiological investigation of endemic fluorosis along the Yellow River basin of Shandong Province

Objective To investigate the current prevailing status of endemic fluorosis in the Yellow River basin of Shandong Province and to provide the scientific evidence for making strategies in prevention and control.Methods Nine counties were chosen to carry out the epidemiological investigation.The content of fluoride in drinking water was determined by F-ion selective electrode and dental fluorosis of children aged 8～12 years old was diagnosed by Deans method.Results Water fluoride content was determined in 1761 fluorosis villages,among which 606 villages had water fluoride content≤1.00 mg/L,accounting for 34.41%(606/1761);1155 villages had water fluoride content＞1.00 mg/L,which accounted for 65.59%(1155/1761).The highest water fluoride content was 11.33 mg/L.Water fluoride content of 618 water-improving and defluoridation projects had been determined,among which 449 projects had water fluoride content≤1.00 mg/L and accounted for 72.65%(449/618),169 projects had water fluoride content＞1.00 mg/L and accounted for 27.35%(169/618),the highest water fluoride content was 5.85 mg/L.The total rate of dental fluorosis of children aged 8～12 years old was 45.03%(25 579/56 804) and the index of dental fluorosis was 0.80. Conclusions In the Yellow River basin in Shandong Province,up to 50.00%in the villages the water fluoride content exceeds the county standard(≤1.00 mg/L).The prevalence of endemic fluorosis in the basin hasn't been effectively controlled.So the counterrneasures for endemic fluorosis should be carried out as soon as possible. Key words: Endemic diseases; Fluoride poisoning; Drinking water; Epidemiology