Chronic solvent exposure (Toluene and n-hexane) and Neuropathy

Nowadays, organic solvents are widely used in working life as parallel with industrial development. Organic solvents is a common designetaion for a large group of more than 200 lipophilic chemical compounds capable of dissolving fats, oils, waxes, resins, rubber, asphalt, cellulose filaments and plastic materials.There are mainly taken up via the lungs but some may penetrate the skin as well. They are distributed to organs rich in fat due to their lipophilicity. Although the mechanism of toxicity is not yet known, some possible mechanisms have been determinated such as blocing important enzymes in the metabolic breakdown of glucose, reducing energy formation in mitochondria, changing neuronal membrans, leading to impariment of ion channel function and slowing of axonal flow. Toluen and N-hexane, which are among organic solvent, are widely used in many different industries. N-hexane is commonly used in leather and shoue industry, graphic industry, painter, laboratories (sources of exposure: gluing, printing, plastic coating, painting, extraction). Toluene is commonly used in graphic and electronic industry (source of exposure: printing, cleaning, degreasing, electroplating, painting, spray painting). Neuropathy is the term used for diseases of the peripheral nervous system and it may present with varying combinations of weakness, autonomic and sensory symptoms. Chronic exposure to toluen and N-hexane has significant toxic effects on peripheral nerve system. These effects are associated with dose, exposure duration and usage. In n-hexane toxicity sensory motor polyneuropathy is the most seen clinical sign and sensory loss occur before motor loss. Cranial neuropathy is also reported. Electrophysiological studies indicate primary axonal polyneuropathy with secondary demyelinization. Distal muscles are effected more than proximal muscles. Effects of chronic exposure to toluene are low in peripheral nervous system.