Exposure to neurotoxic factors and Sense

If only evaluation of senses become a part of both initial and follow-up occupational health examinations, could the real effects of chronic solvent exposures on senses be determined. Chronic exposure to neurotoxic agents leads to various disturbances in senses. Sometimes workers with even complete loss of a sense, especially taste and smell, might not benefit from legal rights.  Neurotoxic agents might cause loss of olfaction or hypersensitivity to odors. Solvents have been shown to cause olfactory nerve dysfunction and exposure to cadmium reduces olfactory acuity. Lead poisoning leads to metallic taste, while selenium exposure causes garlich like taste. Pesticide exposure has been associated with persistent bitter or metallic taste, unspecified dysgeusia and with taste loss. Taste disturbances have occurred after exposure to certain metals and metallic compounds.   The detrimental effects of neurotoxicants on hearing might be either due to impacts on central or peripheral nervous systems or to the probable presence of noise in working areas. Some chemicals directly harm auditory nerves. Carbon disulfide, toluene, trichloroethylene and styrene have been shown to impair hearing.  The importance of testing visual functions is not only to assess the direct burdens of chemicals, but also the possible confounding effect of impaired vision during testing of higher cognitive functions. Organic solvents may affect color vision and contrast sensitivity, while styrene impairs color discrimination. Lead exposure leads to impairment of critical flicker fusion, while chronic exposure to neurotoxicants causes reduction in contrast sensitivity.  Although the effects of some neurotoxic chemicals on senses are well-known, it appears that for many chemicals the influences of chronic low dose exposures and the results of interactions with age, genetics, sex and environmental factors needs further delineation. Considering that such longitudinal studies would need tremendous effort and expenses, including the evaluation of five senses into routine follow-ups seems more preferential.