Otoneurological findings in workers exposed to styrene.

Abstract

MOLLER C, ODKVIST L, LARSBY B, THAM R, LEDIN T, BERGHOLTZ L. Otoneurological findings in workers exposed to styrene. Scand J Work Environ Health 1990;16:189-94. An otoneurological test battery was adm inistered to 18 workers with long-term exposure (6-15 years) to styrene at levels well below the current Swedish limit (110 mg/m'). The results were compared with those of a reference gro up. Disturbances were found in the centr al auditory path ways of seven wor kers. Tests reflecting central pr ocessing of impu lses from different sensory equilib rium organs were abnormal for 16 workers. Th e most relevant tests seemed to be static posturography and the rotatory visual suppression test. In the posturograph y the styrene gro up had a significantl y larger sway area than the reference group. In the visual suppression test , the styrene workers displayed a significantly poorer abilit y to suppress vestibular nystagmus than the reference group. It was concluded that styrene exposur e in industrial environments at moderate or low levels causes central nervous system disturbances which ar e not always diagnosable with psychometric tests but can be apparent in special otoneurological tests.

Effects of Mixed Organic Solvents on Neuromotor Functions among Workers in Buddhist Altar Manufacturing Factories

“…However, concentrations may have been considerably higher in the past, because some new local exhaust and general ventilation systems have been set up at the factories, and one of those factories, in fact, was recommended to install such ventilation systems by the local labor inspector 15 yr ago. These findings agree with previous reports on workers exposed to a different mixture of organic solvents, e.g., industrial solvents (mainly, styrene) 1,2) , jet fuel (benzene, toluene and xylene) 3) , and n-hexane, xylene and toluene 4) . In addition, Yokoyama et al have postulated vestibulo-cerebellar effects of n-hexane, based on significantly increased sagittal sway at 2-4 Hz and transversal sway with eyes open in the solvent workers 4,20) .…”

“…Then, they were instructed to look at a picture placed at 200 cm in front of them, or to keep their eyes closed. Sway parameters calculated included: transversal sway (mm), sagittal sway (mm) and sway area (mm 2 ) with eyes open and eyes closed. Romberg quotients were also calculated for transversal and sagittal sways and sway area.…”

“…Little information has been developed regarding hand tremor in workers exposed to organic solvents, although styrene, n-hexane, and benzene have been reported to increase postural sway [1][2][3][4] . Since a toluene-induced tremor has been demonstrated in a 48-yr-old worker occupationally exposed to the substance 5) and in a 22-yrold man with a 7-yr history of chronic toluene misuse 6) , such tremors may be objectively detected even in workers exposed to subclinical levels of organic solvents if a specific test exists.…”

Chemical exposure and hearing loss

“…47 Toluene is a major component of adhesives, paints, lacquers, varnishes, printing inks, degreasers, fuel additives, glues and thinners, whereas styrene is present when manufacturing plastics, rubber articles, and glass fibers. 48 Chronic exposure to these aromatic solvents can affect the central nervous system 49,50,11 and also the inner ear. 51,52 The cochleotoxic effects of aromatic solvents such as toluene, styrene, ethylbenzene, p-xylene, various methylstyrenes, allylbenzene, and n-propylbenzene have been repeatedly demonstrated in animal experiments.…”

Auditory neuropathy in a patient exposed to xylene: case report

“…3 -5,7 There is also evidence that solvent exposure may result in retrocochlear rather than peripheral cochlear lesions in humans. For example, impaired speech recognition scores consistent with a retrocochlear pattern and/or abnormal cortical responses and/or abnormal reflex decay have been reported in populations working with toluene, 5 jet fuels, 8 styrene 9 and mixtures of solvents. 8,10 -12 It is now documented that solvents should be considered as individual substances with different specific toxicities, 12 and that solvents may act on transmitters specific for certain neural structures and pathways.…”