Developmental Windows of Susceptibility to Inorganic Arsenic: A Survey of Current Toxicologic and Epidemiologic Data

Globally, millions of people are exposed to elevated levels of inorganic arsenic (iAs) via drinking water. Exposure to iAs is associated with a wide range of negative health outcomes, including cancers, skin lesions, neurological impairment, cardiovascular diseases, and an increased susceptibility to infection. Among those exposed to iAs, the developing fetus and young children represent particularly sensitive subpopulations. Specifically, it has been noted in animal models and human populations that prenatal and early life iAs exposures are associated with diseases occurring during childhood and later in life. Recent epidemiologic and toxicologic studies have also demonstrated that epigenetic alterations may play a key mechanistic role underlying many of the iAs-associated health outcomes, including the carcinogenic and immunologic effects of exposure. This review summarizes some of the key studies related to prenatal and early life iAs exposure and highlights the complexities in isolating the precise developmental windows of exposure associated with these health outcomes.