<p>Triclosan is an antimicrobial additive found in a number of personal care and household products. Widely detected in humans, the compound has been given increasing attention due to reports of its endocrine-disrupting potential. Recent evidence indicates that triclosan is mildly estrogenic. The carefully timed event of blastocyst implantation in mammals is modulated in part by estrogen and can be disrupted by above optimal elevations in estrogenic stimulation. Here, we examined the influences of triclosan administration in inseminated female mice. Doses of 18 and 27 mg/animal/day on gestation days (GD) 1–3 reduced implantation site numbers as observed on GD 6, relative to vehicle controls and females given lower doses. Single doses of 18 or 27 mg reduced implantations when given on GD 3, whereas only 27 mg did so when given on GD 2. Subsequently, we examined the impacts on early pregnancy of triclosan in combination with the xenoestrogen bisphenol-A, which has been previously found to disrupt implantation, at doses that were individually ineffective. A combination of 4 mg BPA and 9 mg triclosan/animal/day administered on GD 1–3 reduced the number of implantations observed on GD 6 and increased the length of gestation, relative to controls and those animals simply given one or the other compound. All of these effects mimicked stronger effects seen in positive controls given 17β-estradiol. These data are consistent with the notion that triclosan has mild estrogenic properties, and show that it can act together with a known xenoestrogen to disrupt implantation.</p> / Master of Science (MSc)

Today a lot of attention is focused on compounds called endocrine disrupters (EDs) among substances released to environment by humans. They are a group of substances which can disturb function of hormonal system of organisms including humans. Their poor removal at wastewater treatment plants (WwTP) were shown at various studies, thus they can reach the environment in water. A prospective way for the degradation of EDs at WwTP can be their removal by ligninolytic fungi. They are able to degrade lots of lignin-like aromatic substances because of their highly nonspecific enzymes. In this work growth and enzyme production capability of four ligninolytic fungal strains were monitored on three solid substrates (straw pellets, poplar sawdust mixed with straw pellets, oak sawdust with straw pellets), which may be suitable substrates for fungal growth in bioreactors for wastewater treatment. Ability of these enzymes to degrade EDs were tested in in-vitro degradation experiment. Trametes versicolor was found as best degrading strain with 20 μg/ml of bisphenol A, 17 α- ethynylestradiol and nonylphenol degraded below a quantification limit within 24 hours. Fungal strains degraded EDs well on all of the three substrates but wood sawdust seemed to be a better substrate for fungal growth because straw pellets...

Hormonaly active compounds in wastewaters represent nowdays a serious problem. Proceses currently used in watewater treatment plants (WWTP) are unefficient in removing these compounds from contaminated wastewaters. The compounds are supposed to sorb onto solid sludge elements and sediments. In this work seven endocrine disruptors were detected in the sludge samples from WWTPs. A new sensitive method for detection of seven selected endocrine disruptors (4-nonylphenol, bisphenol A, estriol, 17β-estradiol, estrone, 17α- ethynylestradiol, irgasan) was developed. The method is based on accelerated solvent extraction (ASE), gel permeation chromatography (GPC) and solid phased extraction. For final extract analysis, gas chromatography coupled with mass spectrometry (GC/MS) was used. The efficiency of this method was tested using artificially contaminated sludge and the method was used to analyse real samples from several WWTPs in Czech Republic. The effect of sludge age on detection of individual analytes was assessed as well. The concentrations of endocrine disruptors measured in the samples reached up to 1 µg/g. The results are comparable or higher then those reported in other works and they show the necessity of further research on endocrine disruptors in the environment.