Environmental Toxicology and Pharmacology 19 (2005) 645–650 Neurobehavioral performance in workers exposed to toluene Seong-Kyu Kang a, ∗ , Diane S. Rohlman b , Mi-Young Lee a , Hye-Sil Lee a , Soo-Young Chung a , W. Kent Anger b a Center for Occupational Diseases Research, Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency (KOSHA), 34-6 Gusan-dong Bupyong-gu, Incheon 403-711, Republic of Korea b Center for Research on Occupational and Environmental Toxicology (CROET), Oregon Health Science University, Portland, OR, USA Abstract Toluene is widely used in adhesive, printing, painting and petroleum industries in many countries. This study was conducted to examine the effect of chronic exposure to toluene below 100 ppm on neurobehavioral performance using a computerized neurobehavioral test battery that emphasizes simple instructions and practice prior to testing. The Behavioral Assessment and Research System (BARS) with Korean language instructions was administered to 54 workers from three different industries: oil refinery, gravure printing, and rubber boat manufacturing. The battery consisted of the following tests: Digit Span (DS), Simple Reaction Time (SRT), Selective Attention (SAT), Finger Tapping (FT), and Symbol Digit (SD). Urine was collected at the end-of-shift to analyze urinary hippuric acid to assess exposure level to toluene. Based on the previous air toluene level, workers were divided into three groups: Low (21 workers, less than 10 ppm), Moderate (13 workers, 20–30 ppm) and High (20 workers, 70–80ppm) exposure status. Analysis of Covariance (ANCOVA) adjusting for age, education and work duration as covariates, was performed to examine the relationship between the neurobehavioral performance and the exposure groups. Poorer performance of the High exposure group was found on FT-preferred (F = 7.034, p = 0.002) and SAT latency (F = 11.710, p = 0.000). Age showed a significant correlation with SD (r = 0.417, p =0.002) and SAT number correct (r = -0.460, p =0.000). Years of education and work duration were not significantly correlated with any items. This study supports that toluene exposure below 100 ppm is associated with neurobehavioral changes and that high-level toluene exposure could cause not only attention and concentration, but also motor performance deficits. © 2005 Elsevier B.V. All rights reserved. Keywords: Toluene; Neurobehavioral changes; BARS; TLV 1. Introduction and objective Toluene is widely used in adhesive, printing, painting and petroleum industries in many countries. Glues contain- ing toluene have also been used for recreational drug use in adolescents. People exposed chronically to toluene, both occupationally and through recreational glue sniffing, have demonstrated anatomical changes in the brain, as well as neu- robehavioral impairment (Boor and Hurtig, 1977; Rosenberg et al., 1988; Kang et al., 1992; Feldman et al., 1999). Workers exposed chronically to toluene show neurological and psychological deficits reported as neurologic damage or ∗ Corresponding author. Tel.: +82 32 510 0915; fax: +82 52 5180862. E-mail addresses: skk@kosha.net, skk2@unitel.co.kr (S.-K. Kang). chronic toxic encephalopathy (Benignus, 1981a; Benignus, 1981b). Toluene can cause damages in the central and pe- ripheral nervous system (Boor and Hurtig, 1977; Gallassi et al., 1980, Kang et al., 1992). Advanced neuroimaging tech- niques have revealed anatomical or pathological changes in the brain resulting from high level toluene exposure. A glue sniffer showed severe neurologic damage (Boor and Hurtig, 1977). A diffuse white matter involvement can be found in chronic toluene abusers (Rosenberg et al., 1988). A spray painter exposed to a high level of organic solvents, mainly toluene, developed a demyelinating lesion in the white mat- ter after repeated high-concentration exposure (Kang et al., 1992). A worker exposed to various organic solvents for over 30 years showed impaired short-term memory and global vol- ume loss in brain, especially the white matter (Feldman et al., 1382-6689/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.etap.2004.12.049