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For human risk assessment of toxic chemicals, especially volatile organic compounds (VOCs), the Ministry of the Environment, Government of Japan, has called for the interconversion of inhalation-dose and oral-dose data, two common exposure routes. To address this issue, the present study investigated the time-course changes of ethylbenzene (EB) concentrations in the blood of rats during and after 6-hr inhalation exposure to EB (25, 50, 100, and 200 ppm) and after oral administration of EB by a single oral gavage (25, 50, 100, and 200 mg/kg) of EB. The Area Under the blood concentration-time Curve (AUC) at each blood collection time point (0, 30, 60, 120, 180, 360, 420, 540, and 1440 min, after starting exposure) was determined. The inhalation dose of 25 ppm corresponded closely to the oral administration of 25 mg/kg・bw (r value of 0.859), and the inhalation dose of 200 ppm correlated with the oral administration of 100 mg/kg・bw (r value of 0.948). These results suggest that this comparison using the AUC data at each blood collection time point is valuable for understanding the route- and dose-effects of EB. This study will improve risk assessment of human exposure to EB and other VOCs. [ABSTRACT FROM AUTHOR]

Abstract We investigated the personal exposure of gas station employees to benzene, toluene, ethylbenzene, xylene, formaldehyde, and acetaldehyde at three full-service gas stations in Okayama, Japan. We also assessed both the indoor (offices) and ambient background concentrations. The personal exposure, indoor, and ambient concentrations of benzene were 57.3, 6.11, and 1.31 μg/m3, respectively, in spring and 17.0, 2.04, and 0.603 μg/m3, respectively, in winter. Those for toluene were 196, 25.8, and 2.66 μg/m3, respectively, in spring and 30.6, 5.31, and 1.23 μg/m3, respectively, in winter. The personal exposure concentrations of benzene, toluene, ethylbenzene, and xylene for a gas station employee were significantly higher than those for indoors and the ambient air. However, the personal exposure, indoor, and ambient concentrations of formaldehyde were 5.08, 10.1, and 4.29 μg/m3, respectively, in spring and 11.6, 24.1, and 6.04 μg/m3, respectively, in winter. The indoor concentrations of formaldehyde were significantly higher than both the personal exposure concentrations for gas station employees and the ambient concentrations. The excess lifetime cancer risk from benzene exposure was estimated to be 2.22 × 10−5, 2.43 × 10−6, and 2.56 × 10−7 for full-service gas station employees, self-service gas station employees, and self-service gas station users who are assumed to use the station once a week, respectively. Assuming the occupational exposure to toluene, ethylbenzene, and xylene at the gas station were comparable to the maximum 2-h average exposure levels in the present study, the total hazard quotient for non-carcinogenic risk was calculated to be much lower than 1 (2.72–5.56 × 10−3) based on the TLV-TWA (8-h). Highlights • Gas station employee's VOC exposure levels were higher than indoor and ambient air. • Indoor formaldehyde was higher than gas station employee's exposure and ambient air. • Exposure levels to TVOC in gas station showed sharp increase during refueling. • Excess lifetime cancer risk was estimated to be 2.2 × 10−5 for refueling employees. • Non-cancer risk of refueling employees were much lower than TLV-TWA (8-h). [ABSTRACT FROM AUTHOR]

The European Center for Ecotoxicology and Toxicology of Chemicals (ECETOC) Targeted Risk Assessment (TRA) that is positioned as a Tier 1 model for screening assessment in Europe can contribute to improvement of the independent work environment of workers if utilized in Japanese workplaces. In this study, estimated values of ethylbenzene obtained using ECETOC TRA were compared to measured values, and applicability of ECETOC TRA to the Japanese workplace was studied. Measured values and the work content collected from exposure field surveys conducted by the Japanese government in FY 2009 and FY 2010 were utilized for this study. The 137 tasks in 17 companies evaluated were related to manufacturing and painting. The process categories (PROCs) related to ECETOC TRA were selected for manufacturing (PROC 2, 3, 4, 5, 8a, 8b, 9, 13, 14 or 15) and painting (PROC 7 or 10). The results showed that most of the estimated values of manufacturing work were above the measured values, and just 3 of 52 tasks were below the measured values. On the other hand, the estimated values of painting work below the measured values were observed in 27 of 85 tasks. In particular, it was observed that the estimated values were below the measured values in 22 of 38 tasks for roller painting work (PROC 10). The 24 tasks for which 20 ppm was exceeded were related to painting work, and 4 of 10 tasks for PROC 7 and 13 of 14 tasks for PROC 10 were below the estimated values. All of the work for which the estimated values were below the measured values consisted of the hull block painting in ship building work. Though the painting work performed at indoor workplaces in Japan was subject to regulations for ethylbenzene in 2013 and reduction measures are being developed, independent risk assessment and management by workers is required continuously at workplaces engaged in the production of ethylbenzene. ECETOC TRA can be adequately utilized as a Tier 1 model for screening assessment to perform independent risk assessment at Japanese workplaces engaged in the production of ethylbenzene. [ABSTRACT FROM AUTHOR]

The article presents a study on the use ethyl benzoates in the growth of silkworm in Japan. The compound was tested for its ability to stimulate early development of the worm's larvae which accelerates the insect's growth hormones. In the study, the metamorphosis brought by the ester compound can also be suppressed by activity of 6-methyl-3-pyridyl analog through its antagonistic reaction to the hormone.