## 1 Introduction  
Bisphenols (Figure 1) consist of a group of compounds used mainly in polyester plastics, including polycarbonates, fast-drying epoxy resin adhesives and anticorrosion coatings [1, 2, 3, 4, 5]. They are also used in odontology for implant fixation, as well as in cosmetical and pharmaceutical formulation packages. These compounds are used mostly in polycondensation polymers, which degrade while heated [6; 7; 8; 9; 10]. This degradation splits the polymer molecules into monomers, which may penetrate the food or water stored in the polyester ducts or vessels. The main toxic action of bisphenols, principally A, F and S, consists of endocrine disruptions, mainly xenoestrogenic disruptions; bisphenols act as agonists or antagonists through endocrine receptor-dependent signalling pathways, therefore leading to several endocrine diseases, such as male and female infertility, precocious puberty, various metabolic disorders and hormone-dependent tumours. They also have an active effect on the neuroendocrine system by interfering with neuronal differentiation, the growth and formation of synapses and the affected individual's subsequent behaviour. The most frequent produced compound among the class of bisphenols is bisphenol A (BPA), which is currently one of the most produced compounds worldwide [10; 11; 12]. It is often found in food and cosmetic packages and active forms, dental materials, eyeglass lenses, health equipment and thermal paper. It is also considered a food contact material  
Figure 1: Most commonly used bisphenols. (FCM), which means that it is used in the manufacture of materials that come into direct contact with food, such as plastic packaging, kitchenware, inner coatings of cans and jar caps [13; 14; 15]. Although it partially degrades, it accumulates in the environment, becoming extremely toxic to aquatic organisms [16; 17; 18]. A recent European Food Safety Authority (EFSA) investigation, dated 2023 and supported by the European Commission, has shown high levels of bisphenol A intoxication in tested people in some EU member countries, including Portugal [10]. Bisphenol A contamination and human intoxication generally occur from exposure to contaminated air (inhalation of contaminated dust, for example), water, effluents and dust, or through the consumption of contaminated food due to leakage of BPA from its containers [19; 20; 21]. Infants, young children and pregnant or lactating women represent the highest-risk groups with regard to BPA exposure [22; 23]. Several inconsistent findings can be found in the literature for this compound, including controversial data concerning a safe level of human exposure to BPA [24; 25]. In 2002, the Scientific Committee on Toxicity, Ecotoxicity and the Environment (CSTEE) concluded that BPA presented a low potential for bioaccumulation, was not corrosive, was not mutagenic nor genotoxic, was not carcinogenic and was a non-inducer of oxidative or membrane damage [26; 27]. However, during its last re-evaluation, the EFSA reduced the tolerable daily dose (TDI) from 50 \(\upmu\)g/kg of body weight/day to 4 \(\upmu\)g/kg of body weight/day [10]. Even though a lot of studies have been conducted to evaluate the toxic effects of BPA in several model organism species (both vertebrate and invertebrate), there is still a lack of studies that consider the possible transgenerational effects of endocrine disruptors such as bisphenol A. With this in mind, for this study, we decided to perform a transgenerational analysis of the toxicity of this compound in _Drosophila melanogaster_. This species has become one of the most popular model organisms used in studies of most biological phenomena, including population studies, since it allows the study of several generations in a short period. Its high prolificacy also makes statistical analysis easy and reliable [28; 29; 30; 31; 32]. Invertebrate endocrine systems are composed primarily of neuroendocrine components, with true endocrine glands working in a similar way to vertebrate glands [33; 34; 35].