This chapter explains how racial residential segregation affects the health of Black Americans. Housing is highly racially segregated in most American cities. While this occurs to some extent because people want to live with other people similar to them, it is primarily due to governmental policies and private business practices that created widespread residential segregation by severely restricting where Black people could live. The neighborhoods to which Black Americans were relegated were typically in undesirable areas, physically separated from the larger community, and containing few resources. Once these neighborhoods were created, the practices of banks (e.g., refusing loans) and real estate firms (e.g., restrictive covenants) made it difficult for Black Americans to improve these areas or to leave them. Living in these neighborhoods makes poverty more likely, which, by itself, is associated with poorer health. These neighborhoods are also more likely to have high levels of environmental toxins (e.g., polluted air and water), limited availability of healthy food, unhealthy built environments (e.g., dangerous housing, absence of green spaces), and limited access to healthcare. In sum, residential segregation, which is the product of anti-Black racism, creates living conditions that threaten Black Americans’ health.

Polycystic ovary syndrome (PCOS) is now globally recognized as the most common endocrinopathy in women of reproductive age and has a prevalence of 5–21% depending on the criteria used (NIH, Rotterdam or Androgen Excess Society). What is special about the syndrome is its dual entity involving both the reproductive and the metabolic profile of the women affected. As a result, any intrinsic or extrinsic factors affecting both these components could lead to pathophysiological alterations that characterize PCOS. In fact, the heterogenicity of the syndrome suggests that, apart from the genetic background, the role of the environment and a person’s lifestyle are equally important. In particular, during the last twenty years, interest has been drawn to the impact of certain environmental toxins, referred to by the terms “endocrine disruptors” or “endocrine disruptive chemicals” (EDCs), which may modify both reproductive and metabolic pathways. Western civilization advancements in industrial products and food processing have led to increased daily exposure to plasticizers, such as bisphenol A (BPA) and phthalates, as well as dietary glycotoxins, such as advanced glycation end products (AGEs), which may exert adverse effects on reproduction and metabolism throughout the female lifespan.