Arsenic neurological effects

After initial contradictory reports it is now established that arsenic can cross the blood-brain barrier and produces alternations in whole rat brain biogenic amines levels in animals chronically exposed to arsenite (Tripathi et al, 1997). The neurological effects are many and varied. Usually, peripheral neuropathy, sensory neuropathy (Hafeman et al, 2005), and encephalopathy are the initial complaints associated with acute arsenic poisoning. Acute exposure to arsenic in humans has been shown to result in problems of memory, difficulties in concentration, mental confusion, and anxiety (Hall, 2002 Rodriguez et al, 2003). Other neurological symptoms arising due to arsenic are primarily those of a peripheral sensory neuritis, predominantly numbness, severe paresthesia of the distal portion of the extremities, diminished sense of touch, pain, heat and cold, and symmetrically reduced muscle power (Menkes, 1997). 

De Burbure, C., Buchet, J.-P., Leroyer, A., Nisse, C., Haguenoer, J.-M., Mutti, A., et al., 2006. Renal and neurologic effects of cadmium, lead, mercury, and arsenic in children Evidence of early effects and multiple interactions at environmental exposure levels. Environ. Health Perspect. 114, 584—590. 

It is important to take into account the fact that, besides the above examples, the number of environmental chemicals that might affect the neurological development of children is increasing. Recently, cognitive effects have been shown for ETS (Yolton et al., 2005), arsenic (Calderon et al., 2001 Wasserman et al., 2004), manganese (Wasserman et al., 2006), and some mixtures of arsenic and manganese (Wright et al., 2006). 

The objective of this chapter is to put into perspective some of the current knowledge with respect to trace metals and their health implications. Potential adverse health effects of occupational exposures to trace metals are dis cussed cancer (arsenic, beryllium chromium nickel, and perhaps cadmium) chronic lung disease (beryllium and cadmium) neurologic and reproductive disorders (lead and mercury) and kidney disorders (lead and cadmium). Also discussed are the National Institute for Occupational Safety and Health (NIOSH) recommended standards for occupational exposure to several trace metals, the difficulty of establishing safe levels of exposure (particularly for carcinogens), and problems involved in identifying toxic components of trade name products. Special attention is given to the role of chemists to help protect the public health. 

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