Mercury poisoning of generations of Grassy Narrows and Whitedog native people  in Ontario, Canada who were exposed to high levels of mercury by consuming mercury-contaminated fish when Dryden Chemical Company discharged over 9,000 kilograms (20,000 lb) of mercury directly into the Wabigoon–English River system and continued with mercury air pollution until 1975. Widespread mercury poisoning occurred in rural Iraq in 1971–1972, when grain treated with a methylmercury-based fungicide that was intended for planting only was used by the rural population to make bread, causing at least 6530 cases of mercury poisoning and at least 459 deaths (see Basra poison grain disaster). On August 14, 1996, Karen Wetterhahn, a chemistry professor working at Dartmouth College, spilled a small amount of dimethylmercury on her latex glove. She began experiencing the symptoms of mercury poisoning five months later and, despite aggressive chelation therapy, died a few months later from a mercury induced neurodegenerative disease
In April 2000, Alan Chmurny attempted to kill a former employee, Marta Bradley, by pouring mercury into the ventilation system of her car. On March 19, 2008, Tony Winnett, 55, inhaled mercury vapors while trying to extract gold from computer parts (by using liquid mercury to separate gold from the rest of the alloy), and died ten days later. His Oklahoma residence became so contaminated that it had to be gutted. In December 2008, actor Jeremy Piven was diagnosed with mercury poisoning possibly resulting from eating sushi twice a day for twenty years or from taking herbal remedies.
Organic brain syndrome, also known as organic brain disease, organic brain disorder, organic mental syndrome, or organic mental disorder, refers to any syndrome or disorder of mental function whose cause is alleged to be known as organic (physiologic) rather than purely of the mind. These names are older and nearly obsolete general terms from psychiatry, referring to many physical disorders that cause impaired mental function. They are meant to exclude psychiatric disorders (mental disorders). Originally, the term was created to distinguish physical (termed "organic") causes of mental impairment from psychiatric (termed "functional") disorders, but during the era when this distinction was drawn, not enough was known about brain science (including neuroscience, cognitive science, neuropsychology, and mind-brain correlation) for this cause-based classification to be more than educated guesswork labeled with misplaced certainty, which is why it has been deemphasized in current medicine. While mental or behavioural abnormalities related to the dysfunction can be permanent, treating the disease early may prevent permanent damage in addition to fully restoring mental functions. An organic cause to brain dysfunction is suspected when there is no indication of a clearly defined psychiatric or "inorganic" cause, such as a mood disorder. Types
Organic brain syndrome can be divided into 2 major subgroups: acute (delirium or acute confusional state) and chronic (dementia). A third entity, encephalopathy (amnestic), denotes a gray zone between delirium and dementia.