are polychlorinated dibenzo-dioxins (PCDDs) and -furans (PCDFs), polycyclic aromatic hydrocarbons (PAHs), phenol derivatives and a number of pesticides (most prominent being organochlorine insecticides like endosulfan, kepone (chlordecone) and DDT and its derivatives, the herbicide atrazine, and the fungicide vinclozolin), the contraceptive 17-alpha ethinylestradiol, as well as naturally occurring phytoestrogens such as genistein and mycoestrogens such as zearalenone. The molting in crustaceans is an endocrine-controlled process. In the marine penaeid shrimp Litopenaeus vannamei, exposure to endosulfan resulted increased susceptibility to acute toxicity and increased mortalities in the postmolt stage of the shrimp. Many sunscreens contain oxybenzone, a chemical blocker that provides broad-spectrum UV coverage, yet is subject to a lot of controversy due its potential estrogenic effect in humans. Tributyltin (TBT) are organotin compounds. For 40 years TBT was used as a biocide in anti-fouling paint, commonly known as bottom paint. TBT has been shown to impact invertebrate and vertebrate development, disrupting the endocrine system, resulting in masculinization, lower survival rates, as well as many health problems in mammals. Temporal trends of body burden Since being banned, the average human body burdens of DDT and PCB have been declining. Since their ban in 1972, the PCB body burden in 2009 is one-hundredth of what it was in the early 1980s. On the other hand, monitoring programs of European breast milk samples have shown that PBDE levels are increasing. An analysis of PBDE content in breast milk samples from Europe, Canada, and the US shows that levels are 40 times higher for North American women than for Swedish women, and that levels in North America are doubling every two to six years. It has been discussed that the long-term slow decline in average body temperature observed since the beginning of the industrial revolution may result from disrupted thyroid hormone signalling. Animal models Because endocrine disruptors affect complex metabolic, reproductive, and neuroendocrine systems, they cannot be modeled in in vitro cell based assay. Consequently, animal models are important for access the risk of endocrine disrupting chemicals. Mice There are multiple lines of genetically engineered mice used for lab studies, in this case the lines can be used as population-based genetic foundations. For instance, there is a population that is named Multi-parent and can be a Collaborative Cross (CC) or Diversity Outbred (DO). These mice while both from the same eight founder strains, have distinct differences. The eight founder strains, combine strains that are