A number of chemical agents, and their degradation products, have been recognized as having estrogenic activity on animals. On fish they interfere with endogenous estrogen and in many cases mimic its activity, thus increase estrogenic reponse, with elevated levels of vitellogenin. Hence they are called Endocrine Disrupting Chemicals, EDCs. Vitellogenin levels is often used as a biomarker of exposure to estrogenic pollutants. Wastewater from sewage treatment works contains chemicals known as EDCs, and there are evidence of roach (Rutilus rutilus) living in recipients of such wastewater having traits of both gender, i.e. oocytes in male gonads (Intersex) on histological examination. This study was done on roach living in Lake Funbosjön Uppland, Sweden.

Over the past thirty years, the living conditions of Intersex people have received attention both in Sweden and internationally. A particularly intense debate has emerged from a human rights perspective, focusing on medical interventions and treatments performed on children with Intersex variations. These procedures are often carried out at an early age without the child?s consent. Several UN committees have highlighted that such interventions risk violating fundamental human rights, including the right to consent, protection against torture and inhuman treatment, as well as Article 3 of the Convention on the Rights of the Child: the principle of the best interests of the child.