Assessment of estrogenicity in tap and bottled waters and its relation with the presence of endocrine disrupting compounds

Several natural and synthetic compounds may affect the endocrine system of organisms due to their chemical structure. These compounds have been labeled as "Endocrine Disrupting Compounds (EDCs)". Some materials which are included in water and waste water are called as Endocrine Disrupting Compounds (EDCs) due to their oestrogenic activities. Water is a fundamental basic compound that organisms need for living. The pollutants in the water is a significant research topic due to they may be cause the serious problems to living organisms. EDCs are some of the these type of pollutants and they mix in the water sources from domestic waste water and industrial waste water as a point source pollutant so they constitute oestrogenic activities in water resources. Beside the aquatic organisms, also humankind is exposed to estrogenic activities due to unsuccesful treatment of these chemical materials in waste water treatment plants or the plastic pipes which are used in dwellings and drinking water distribution network systems. Thus, the chemical materials with oestrogenic activities pose risks in both environment and people. Furthermore, the public is exposed to waters which have oestrogenic activity potential due to the drinking waters are packaged by polycarbonate or polyethylene terephthalate based bottles to be sold to the people because the tap water is not trustworthy for the public to drink and also the packaging by the plastic based materials is one of the practical methods. It is clearly known that EDCs cause permanent damage in the living organisms. The potential effects of the EDCs on the gamogeneses, cancer, metabolic functions, immune system, growing functions and some disorders such as behaviour, growing and memory give researchers worry though the sexual differentiation is one of the main topics of the toxicological assessment of EDCs (Dorival-Garcia et all., 2012; Plotan ve diğ., 2013). EDCs may possibly have an interference in wildlife and the endocrine system of humans by: i) mimicing natural hormones ii) disrupting action, pathways and synthesis of natural hormones iii) antagonizing the effect of natural hormones or iv) disrupting the synthesis of specific hormone receptors. Natural (estron and 17β-estradiol) and synthetic (17α-ethinylestradiol) hormones are the top of the EDCs and they mix in the water resources and cause problems for various organisms due to they are used in hormonal theraphy and birth control. In addition to the hormones also some organic pesticides such as DDT and atrazine may be categorised as in EDCs. Moreover, some materials such as alkylphenols and bisphenol A which are used in the production processes of fire resistant materials, surface active agents, pesticides, polycorbonates and epoxy resin are in the EDCs category. Bisphenol A is basically used in the production process of epoxy resin and polycorbonate (Crain et all.,2007; Wright-Walters et all., 2011). Therefore, caution is warranted for the bisphenol A based polycorbonate bottled waters due to the drinking waters are sold in polycorbonate bottles. The main reason the mixing of the EDCs to the water cycles by discharging of the EDCs from the treatment plants to water resources. Nevertheless, beside the point source pollution sources, also distributed pollution sources may be reason to mixing of the EDCs into the surface and groundwater resources due to EDCs include various pesticides. Nowadays, in case of the unsuccesful treatment of EDCs from the water resources, there is a possibility to mix of EDCs to the drinking water due to surface water resources are used in many drinking water production plants (Zhang et all., 2013). Both tap waters and bottled waters are subjected to chlorination and ozonization processes before entering the network system or packaging process. These methods may decrease the concentration of the EDCs thanks to oxidation of the EDCs. However, in addition to EDCs in the water resources, it is a possibility to mixing of the EDCs to network water system because of the contact with the plastic pipes which are used in water network systems or dwelling distribution systems. Also it is another possible to mixing of the EDCs to water systems because of the plastic water storage tanks. Similarly, it is a possibility the forming of the oestrogenic activities based on the tha packaging material and storage conditions of the bottles. It is especially indicated that the high pH increases the transfer rate of bisphenol A from the polycorbonate bottles to the water. Besides, it is known that sunshine duration and temperature are another two crucial parameters for this transfer. Health Canada proposed classification of BPA as toxic to human health and the environment in April, 2008. In 2011, EC established a specific migration limit for BPA from food plastic of 600 ng/g and a tolerable daily intake (TDI) of 0.05 mg/kg body weight has been set by the European Food Safety Authority (2006). The United States Environmental Protection Agency (USEPA) has established 50 μg/kg per day based on the lowest observable adverse effect level of BPA. In 2011, Sweden announced the ban of BPA in cans containing food for children under the age of three. Turkey banned the usage of BPA in baby bottles and other PC items which are produced for babies on 10 June 2011. Because of the harmful effects of the degradation of products containing nonylphenol ethoxylates in the environment, the use and production of these compounds have been banned in EU countries and strictly monitored in many other countries including Canada and Japan. In this study, existance of the EDCs in the water network system of Istanbul and various purchased bottled drinking waters was investigated by using yeast based oestrogenic activity bioexperiments. Istanbul has five main water treatment plants to distribute the tap water to all the city borders and tap water samples were collected from these five different region in order to demonstrate the situation of the end user. In each region, the tap water was bottled from at least two different dwellings. Moreover, in order to indicate the season effects, samples were collected in each seaoson respectively. The experiments were performed to investigate the effects of temperature, pH and photolysis in bottled tap waters due to effect of the storage condition on the estrogenic activity and plactic materials. In addition to bioexperiments, measurements of the bisphenol A and bisphenol S were performed due to high existence probability of these materials in the network and drinking waters. By this way, the relationship between concentration of these materials and oestrogenic activity was investigated. Oestrogenity measurements were carried out by YES method due to its effect on the human in high hazard group so it is the first time this experiment have been performed in Turkey. However, measurement of the bisphenol A and bisphenol S were performed by using LC-MS/MS in order to perform the measurements in low concentrations. The total estrogenic activities in tap waters were found <2,71 ng/L equivalent of E2 for all seasons due to most water treatment plants that provide drinking water to Istanbul use ozonation helps to remove pollutants that can cause estrogenic activity. BPA concentrations in most samples were <1 ng/L under the limit of detection. Other BPA concentrations measured 1.2±0.3 ng/L and 18.3±3.8 ng/L range. BPS concentrations in most samples were <10 ng/L under the limit of detection. BPS was found in two samples with concentrations of 60,2±4,6 ng/L and 13,2±2,1 ng/L. pH , hardness and TOC analysis are performed and showed as a result of medium hardness and pH of the samples was measured at around 7. The total estrogenic activities in bottled waters were found between 3±0,3 ng/L and 118±14 ng/L. BPA concentrations measured between 1,5±0,2 ng/L and 6600±725 ng/L range. BPS was found in only one sample with concentration of 49,5±6,6 ng/L'dir.