Acute neurobehavioural effects of toluene.

Abstract

An acute inhalation chamber study of 42 college students was performed to investigate the relation between exposure to 0, 75, and 150 ppm of toluene and changes in central nervous system function and symptoms. Paid subjects were exposed for seven hours over three days. Verbal and visual short term memory (Steinberg, digit span, Benton, pattern memory); perception (pattern recognition); psychomotor skill (simple reaction time, continuous performance, digit symbol, handeye coordination, finger tapping, and critical tracking); manual dexterity (one hole); mood (profile of mood scales (POMS)); fatigue (fatigue checklist); and verbal ability were evaluated at 0800, 1200, and 1600 hours. Voluntary symptoms and observations of sleep were collected daily. An analysis of variance and test for trend was performed on the difference and score for each concentration reflecting an eight hour workday where each subject was their own control. A 3 x 3 Latin square study design evaluated toluene effects simultaneously, controlling for learning across the three days and the solvent order. Intersubject variation in solvent uptake was monitored in breath and urine. A 5-10% decrement in performance was considered significant ifit was consistent with a linear trend at p < 0 05. Adverse performance at 150 ppm toluene was found at 6-0% for digit span, 12-1% for pattern recognition (latency), 5-0% for pattern memory (number correct), 6-5% for one hole, and 3 0% for critical tracking. The number of headaches and eye irritation also increased in a dose response manner. The greatest effect was found for an increasing number of observations of sleep. Overall, no clear pattern of neurobehavioural effects was found consistent with the type 1 central nervous system as classified by the World Health Organisation. Subtle acute effects, however, were found just below and above the ACGIH TLV of 100 ppm toluene, supporting the position that the guideline be lowered since the biological threshold ofbehavioural effects may be comparable with the TLV.The acute behavioural effects of inhaling toluene after a single exposure are reversible,' but although reversible, they may also be an early sign of central nervous system (CNS) impairment leading to irreversible losses in performance with repeated exposures.23 Acute decrements may be large enough to decrease the safety margin of industrial tasks or to lower productivity. Evidence from solvent studies suggests that symptoms might occur before other measurable acute CNS effects are apparent."The effects of toluene were first studied under controlled eight hour exposures in 1942.4 Mild CNS symptoms and irritation were reported at 200 ppm, fatigue and muscular weakness were noted at 300 ppm, and headache, dizziness, and staggering were incapacitating at 600 ppm. Mild physiological effects have also been reported at 200 ppm.78Later studies emphasised detecting changes in The evidence suggests that inhaling toluene at 100 ppm over seven hours can cause slight impairments in vigilance, manual dexterity...

Richtwerte für Toluol und gesundheitliche Bewertung von C7-C8-Alkylbenzolen in der Innenraumluft

“…In Kurzzeitstudien traten Leistungseinbußen, trockene Schleimhäute, Kopfschmerzen und Müdigkeit ab 287 mg/m³ auf [47]. Von diesen akuten Effekten wird angenommen, dass sie nach Expositionsende reversibel sind.…”

“…Der europäische Wissenschaftliche Ausschuss für Expositionsbegrenzungen am Arbeitsplatz (SCOEL) sowie die Arbeitsstoff-Kommission der Deutschen Forschungsgemeinschaft empfahlen aufgrund von beobachteten Gedächt-nis-und Geschicklichkeitsdefiziten durch Kurzzeit exposition von 281 mg Toluol/m³ [47] und durch Langzeitexposition von 337 mg Toluol/m³ [52] eine maximale Arbeitsplatzkonzentration von 190 mg Toluol/m 3 (50 ml/m 3 ) [43,30]. Einbezogen wurden auch Studien, in denen keine neurologischen Effekte bei Konzentrationen von 237 mg Toluol/m³ mit Ko-Exposition von Lärm festgestellt wurden [117].…”

Bioremediation of Petroleum Hydrocarbon-Contaminated Soils, Comprehensive Report

“…However, the paucity of exposure information and identification of only a LOAEL is not sufficient to warrant a higher confidence than medium for this study. Other studies indicate that irritation may occur at around the same concentration, 100 ppm (Baelum et al, 1985;Echeverria et al, 1989). In regard to this effect, the NTP (1990) rat chronic inhalation study was well conducted, established the rat as the most sensitive species, examined an adequate number of animals, and performed histopathology on all major organs, including the brain and the respiratory tract.…”

Measurement of Toluene Concentrations in the Blood of Fetuses of Pregnant Rats Exposed to Low Concentration Toluene Using Headspace-Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry

“…One particular study clarified the lethal toxicity and acute effects on the central nervous system resulting from exposure to high concentration toluene. 1) Regarding chronic toxicity, effects on the nervous system were also reported. 2,3) Toluene is also suspected to enhance chemical sensitivity (CS) or multiple chemical sensitivity (MCS).…”