Chronic neurobehavioural effects of mercury poisoning on a group of Zulu chemical workers

Primary objective: To assess the nature and severity of reported neurobehav ioural symptoms of mercury poisoning, in a group of Zulu chemical workers ( n = 16), employed by a mercury processing plant, exposed to neurotoxic leve ls of mercury, 5 years after exposure. Research design: A group-control design was adopted, where the exposed grou p was matched for age, sex, race, occupational and educational background. Method/procedures: Both groups were administered a specially selected batte ry of psychometric tests to measure neuropsychological functioning. Outcome and results: The exposed group had significantly impaired short ter m verbal and spatial memory, impaired sustained and divided attention, and impaired motor speed. They also suffered from elevated clinical levels of p sychiatric symptomatology, including anxiety, depression and phobic avoidan ce, and neurological symptoms of tremor, weakness in the limbs, and excessi ve sweating. Conclusions: The exposed group suffered from varying degrees of permanent n europsychological disability, which adversely affects their ability to work and be financially independent. Psychometric measures for monitoring cogni tive symptoms are discussed.