Mercury neurotoxicity in gold miners

Abstract

Chronic mercury poisoning is the oldest occupational disease, and mercury is currently among the top three chemicals of major public health concern. Moreover, all human beings are currently exposed to certain quantity of mercury. Artisanal and small-scale gold mining (ASGM) is the first contributor to mercury emissions from anthropogenic activities that contaminates the environment, directly or indirectly, with the three species of mercury (elemental, inorganic and organic). All these species are toxic for humans, and the central nervous system (CNS) arises as the most important target organ, with the most diverse consequences. In addition to the current context of human exposure and symptomatology, this chapter provides an overview of our present knowledge on cellular and molecular mechanisms elicited by the different species of mercury in neurons, astrocytes, microglia and oligodendrocytes. Classical mechanisms such as oxidative stress and other contemporary ones such as neuroimmune system modulation including selective inflammatory mediators release in the CNS and cell-cell interaction orchestrating beneficial responses are reviewed. Furthermore, cutting-edge knowledge such as the use of a mercury-induced amyotrophic lateral sclerosis model or alterations in extracellular vesicles can be found. Finally, current challenges on research about mercury neurotoxicity from epidemiological studies (e.g., multi-species exposure) to models (e.g., brain-periphery dialogue) are discussed to support the better development of our knowledge.