Category Archives: Endocrine Disruptors

Evidence of Fluoride as an Endocrine Disruptor in Women

Zhao MX, Zhou GY, Zhu JY, Gong B, Hou JX, Zhou T, Duan LJ, Ding Z, Cui LX, Ba Y. Fluoride Exposure, Follicle Stimulating Hormone Receptor Gene Polymorphism and Hypothalamus-pituitary-ovarian Axis Hormones in Chinese Women. Biomedical and Environmental Sciences:BES. 2015 Sep;28(9):696-700. doi: 10.3967/bes2015.099.

The effects of fluoride exposure on the functions of reproductive and endocrine systems have attracted widespread attention in academic circle nowadays. However, it is unclear whether the gene-environment interaction may modify the secretion and activity of hypothalamus-pituitary- ovarian (HPO) axis hormones. Thus, the aim of this study was to explore the influence of fluoride exposure and follicle stimulating hormone receptor (FSHR) gene polymorphism on reproductive hormones in Chinese women. A cross sectional study was conducted in seven villages of Henan Province, China during 2010-2011. A total of 679 women aged 18-48 years were recruited through cluster sampling and divided into three groups, i.e. endemic fluorosis group (EFG), defluoridation project group (DFPG), and control group (CG) based on the local fluoride concentration in drinking water. The serum levels of gonadotropin releasing hormone (GnRH), follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) were determined respectively and the FSHR polymorphism was detected by real time PCR assay. The results provided the preliminary evidence indicating the gene-environment interaction on HPO axis hormones in women.

Dietary Exposure to Endocrine Disrupting Chemicals; China

Dongliang He, Xiaolei Ye, Yonghua Xiao, Nana Zhao, Jia Long, Piwei Zhang, Ying Fan, Shibin Ding, Xin Jin, Chong Tian, Shunqing Xu, Chenjiang Ying. Dietary exposure to endocrine disrupting chemicals in metropolitan population from China: A risk assessment based on probabilistic approach. Chemosphere Volume 139, November 2015, Pages 2–8

The intake of contaminated foods is an important exposure pathway for endocrine disrupting chemicals (EDCs). However, data on the occurrence of EDCs in foodstuffs are sporadic and the resultant risk of co-exposure is rarely concerned. In this study, 450 food samples representing 7 food categories (mainly raw and fresh food), collected from three geographic cities in China, were analyzed for eight EDCs using high performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS). Besides estrone (E1), other EDCs including diethylstilbestrol (DES), nonylphenol (NP), bisphenol A (BPA), octylphenol (OP), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), and estriol (E3) were ubiquitous in food. Dose-dependent relationships were found between NP and EE2 (r = 0.196, p < 0.05), BPA (r = 0.391, p < 0.05). Moreover, there existed a correspondence between EDCs congener and food category. Based on the obtained database of EDCs concentration combined with local food consumption, dietary EDCs exposure was estimated using the Monte Carlo Risk Assessment (MCRA) system. The 50th and 95th percentile exposure of any EDCs isomer were far below the tolerable daily intake (TDI) value identically. However, the sum of 17β-estradiol equivalents (∑EEQs) exposure in population was considerably larger than the value of exposure to E2, which implied the underlying resultant risk of multiple EDCs in food should be concern. In conclusion, co-exposure via food consumption should be considered rather than individual EDCs during health risk evaluation.

 

Endocrine Disrupting Compounds in a Water Supply System, Portugal

Carvalho AR, Cardoso VV, Rodrigues A, Ferreira E, Benoliel MJ, Duarte EA. Occurrence and analysis of endocrine-disrupting compounds in a water supply system. Environmental Monitoring and Assessment. 2015 Mar;187(3):4374. doi: 10.1007/s10661-015-4374-0.

This paper presents the study of the occurrence of 10 endocrine-disrupting compounds (EDCs) in 60 water samples using a method for simultaneous quantification and confirmation of the presence of these emerging compounds, using ultra-performance liquid chromatography with electrospray ionization and tandem mass spectrometry (UPLC-ESI-MS/MS). All samples were previously extracted by solid-phase extraction (SPE). Several natural and synthetic hormones (17-β-estradiol, ethinylestradiol, estriol, estrone, progesterone, mestranol, and diethylstilbestrol) and some industrial products (4-n-nonylphenol, 4-tert-octylphenol, and bisphenol A) were chosen for this survey. The analytical limits were calculated for each compound and were used in the identification and quantification of these target compounds in EPAL’s water supply system. In this study, several samples were taken from the main intakes of water (surface and groundwater) used for production of water for human consumption and from different sampling points of the drinking water distribution system (piping, nets, and reservoirs). Some target compounds, such as estriol, 4-tert-octylphenol, mestranol, and nonylphenol, were found in trace amounts in several water samples. However, the studied endocrine-disrupting appeared in very low concentrations when compared with the assessed analytical limits.

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Shi et al 2011: Occurrence of Thyroid Hormone Activities in Drinking Water from Eastern China: Contributions of Phthalate Esters

W. Shi, X. Hu, F. Zhang, G. Hu, Y. Hao, X. Zhang, H. Liu, S. Wei, X. Wang, J.P. Giesy, and H. Yu. 2011. Occurrence of Thyroid Hormone Activities in Drinking Water from Eastern China: Contributions of Phthalate Esters. Environ Sci Technol. Dec 15.

Thyroid hormone is essential for the development of humans. However, some synthetic chemicals with thyroid disrupting potentials are detectable in drinking water. The study investigated the presence of thyroid active chemicals and their toxicity potential in drinking water from five cities in eastern China by use of an in vitro CV-1 cell-based reporter gene assay. Waters were examined from several phases of drinking water processing, including source water, finished water from waterworks, tap water and boiled tap water. To identify the responsible compounds, concentrations and toxic equivalents of a list of phthalate esters were quantitatively determined. None of the extracts exhibited thyroid receptor (TR) agonist activity. Most of the water samples exhibited TR antagonistic activities. None of the boiled water displayed the TR antagonistic activity. Dibutyl phthalate accounted for 84.0% to 98.1% of the antagonist equivalents in water sources, while diisobutyl phthalate, di-n-octyl phthalate and di-2-ethylhexyl phthalate also contributed. Approximately 90 % of phthalate esters and TR antagonistic activities were removable by waterworks treatment processes, including filtration, coagulation, aerobic biodegradation, chlorination and ozonation. Boiling water effectively removed phthalate esters from tap water. Thus, this process was recommended to local residents to reduce certain potential thyroid related risk through water drinking.

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Cragin et al 2011: Menstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water

This study, despite the typical limitations, has received some press (click here).

L.A. Cragin, J.S. Kesner, A.M. Bachand, D.B. Barr, J.W. Meadows, E.F. Krieg, and J.S. Reif Menstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water. Environmental Research 2011 Nov;111(8):1293-301.

Abstract: Atrazine is the most commonly used herbicide in the U.S. and a wide-spread groundwater contaminant. Epidemiologic and laboratory evidence exists that atrazine disrupts reproductive health and hormone secretion. We examined the relationship between exposure to atrazine in drinking water and menstrual cycle function including reproductive hormone levels. Women 18-40 years old residing in agricultural communities where atrazine is used extensively (Illinois) and sparingly (Vermont) answered a questionnaire (n=102), maintained menstrual cycle diaries (n=67), and provided daily urine samples for analyses of luteinizing hormone (LH), and estradiol and progesterone metabolites (n=35). Markers of exposures included state of residence, atrazine and chlorotriazine concentrations in tap water, municipal water and urine, and estimated dose from water consumption. Women who lived in Illinois were more likely to report menstrual cycle length irregularity (odds ratio (OR)=4.69; 95% confidence interval (CI): 1.58-13.95) and more than 6 weeks between periods (OR=6.16; 95% CI: 1.29-29.38) than those who lived in Vermont. Consumption of >2 cups of unfiltered Illinois water daily was associated with increased risk of irregular periods (OR=5.73; 95% CI: 1.58-20.77). Estimated “dose” of atrazine and chlorotriazine from tap water was inversely related to mean mid-luteal estradiol metabolite. Atrazine “dose” from municipal concentrations was directly related to follicular phase length and inversely related to mean mid-luteal progesterone metabolite levels. We present preliminary evidence that atrazine exposure, at levels below the US EPA MCL, is associated with increased menstrual cycle irregularity, longer follicular phases, and decreased levels of menstrual cycle endocrine biomarkers of infertile ovulatory cycles.

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Jeffries et al 2011: No Endocrine Effects of Argichemicals

This study monitored the Bow Creek watershed, Nebraska, to determine the occurrence and endocrine effects of agrichemicals. This watershed is dominated by beef cattle and row crops. Steroid hormones were not found at four sites. Pesticides were detected. Evidence of defeminization was observed in caged fathead minnows, however these effects could not be attributed to any of the pesticides detected.

Jeffries, M.K., K.I. Abbott, T. Cowman, and A.S. Kolok 2011. The occurrence and endocrine effects of agrichemicals in a small Nebraska, USA watershed. Environmental Toxicology and Chemistry, Jul 5. doi: 10.1002/etc.615.

Agricultural and Occupational Health, University of Nebraska – Medical Center, Omaha, Nebraska, USA.

Click here for the abstract (free) and to obtain the full paper (fee). 

Abstract (National Library of Medicine):

The Bow Creek watershed, Nebraska, USA is dominated by the production of beef cattle and row crops; therefore, surface waters are likely to receive runoff containing steroid hormones and pesticides. The goal of the current study was to determine the occurrence and endocrine effects of agrichemicals in this watershed. To accomplish this, four sites within the watershed – Pearl, Bow, and East Bow Creeks and a site at the confluence with the Missouri River – were selected. In June of 2008, polar organic chemical integrative samplers (POCIS) were deployed at each site, whereas in June of 2009, water and sediment samples were collected. Caged fathead minnows (Pimephales promelas) were deployed at all of the selected sites in both years. Analysis of these samples revealed that steroid hormones were not present; however, pesticides were present in POCIS extracts and water samples. In general, the amount of pesticides was higher in POCIS retrieved from Pearl and Bow Creeks than in POCIS from East Bow Creek and the Confluence. This variation between sites appeared to be related to row crop density, as row crop land cover surrounding the Pearl and Bow Creek sites was higher than that surrounding the East Bow and Confluence sites. In order to determine the endocrine effects of agrichemicals within this watershed, the hepatic mRNA expression of vitellogenin and estrogen receptor α (ERα), as well as the gonadal expression of P450 aromatase A, was determined for the caged minnows. Females deployed at East Bow Creek and the Confluence experienced decreases in the expression of ERα suggesting that these females had been defeminized; however, this defeminization could not be attributed to any of the pesticides detected at these sites.

H.R. 553 Endocrine Disruptor Screening Enhancement Act

H.R.553
Latest Title: Endocrine Disruptor Screening Enhancement Act of 2011
Sponsor: Rep Markey, Edward J. [MA-7] (introduced 2/8/2011)      Cosponsors (6)
Latest Major Action: 2/15/2011 Referred to House subcommittee. Status: Referred to the Subcommittee on Environment and the Economy.
Click here for full text of the bill.