Mandelic acid (MA) is a major metabolite of ethylbenzene and styrene. For the first time, a selective, fast, and easy-to-use procedure was developed for the determination of MA in urine samples. The new procedure is based on MIMEPS, the combination of a molecularly imprinted polymer (MIP) and microextraction by packed sorbent (MEPS). High-performance liquid chromatography with ultraviolet detection (HPLC-UV) was used for the separation and determination of MA. The bulk polymerization method was used to synthesize the MIP, and the MIP and non-imprinted polymer (NIP) were characterized by Fourier transform infrared spectroscopy. The selectivity of the MIP was investigated in the presence of interferents. In addition, we investigated the various parameters that affect the performance of the MEPS, including the pH of the sample, the number of extraction cycles, sample volume, and the types and volumes of the washing and elution solvents. A six-point calibration curve was obtained in the range of 0.2-20 µg/mL (R = 0.9994). The extraction recovery was more than 88.8%. The limit of detection and the limit of quantitation were 0.06 and 0.2 µg/mL, respectively. The intra- and inter-day precisions were in the range of 3.6-4.7% and 3.8-5.1%, respectively. The accuracy was -8.4 to -11.1%. The optimized procedure was selective, sensitive, and rapid, and it was both user friendly and environmentally friendly. The sample preparation process took only about 5 min, so the MIMEPS-HPLC-UV procedure is recommended as an alternative for the biomonitoring of workers exposed to ethylbenzene and/or styrene.

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Sciences, Iran-Background and Objectives: Exposure to n-hexane, a neurotoxic solvent, has been associated with sensorimotor polyneuropathy, both in occupationally exposed workers and in glue-sniffing addicts. The present study was carried out to ascertain whether exposure to sub-TLV levels of n-hexane was associated with electrophysiological abnormalities and to determine if these possible abnormalities have any correlations with parameters such as the biological exposure index (BEI) of this neurotoxic chemical, workers' TWA exposure to n-hexane and/or duration of employment. Materials and Methods: Twenty-seven asymptomatic male workers from 6 shoemaking workshops were studied and compared with a group of 20 age-and sexmatched normal controls with no history of exposure to any neurotoxic agent. They underwent physical examinations as well as conventional needle electromyographic examinations and sensory and motor nerve conduction studies of upper and lower extremities. The TWA exposure to n-hexane and urinary concentration of free 2,5-hexanedione were also determined. Data were analyzed using version 16.0 of the SPSS/PC statistical package. Results: The TWA exposure to n-hexane was estimated to be 83.2 mg/m 3 . Electrophysiological studies showed that the amplitudes of sensory nerve action potential (SAP) for median and sural nerves were significantly lower in exposed subjects than in unexposed normal controls. Additionally, a significant correlation was found between these

BackgroundConstruction industry is among the most hazardous industries, and needs a comprehensive and simple-to-administer tool to continuously assess and promote its health and safety performance.MethodsThrough the study of various standard systems (mainly Health, Safety, and Environment Management System; Occupational Health and Safety Assessment Series 180001; and British Standard, occupational health and safety management systems-Guide 8800), seven main elements were determined for the desired framework, and then, by reviewing literature, factors affecting these main elements were determined. The relative importance of each element and its related factors was calculated at organizational and project levels. The provided framework was then implemented in three construction companies, and results were compared together.ResultsThe results of the study show that the relative importance of the main elements and their related factors differ between organizational and project levels: leadership and commitment are the most important elements at the organization level, whereas risk assessment and management are most important at the project level.ConclusionThe present study demonstrated that the framework is easy to administer, and by interpreting the results, the main factors leading to the present condition of companies can be determined.

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Benzene, toluene, ethylbenzene, and xylene (BTEX) are a group of volatile organic compounds that human exposure to them may result in the development of some diseases, including cancer. Biological monitoring plays an important role in exposure assessment of workers occupationally exposed to chemicals. Several metabolites have been proposed for biological monitoring of individuals who are exposed to BTEX. There are a variety of extraction methods and analytical techniques for the determination of unmetabolized BTEX in exhaled air and their urinary metabolites. The present study aimed to summarize and review the toxicokinetics of BTEX and sample preparation and analytical methods for their measurement. Metabolites of BTEX are discussed to find out reliable ones for biological monitoring of workers exposed to these chemicals. In addition, analytical methods for unmetabolized BTEX in exhaled air and their metabolites were reviewed in order to obtain a comparison between them in term of selectivity, sensitivity, simplicity, time, environmental-friendly and cost. Given the recent trends in sample preparation, including miniaturization, automation, high-throughput performance, and on-line coupling with analytical instrument, it seems that microextraction techniques, especially microextraction by packed sorbents are the methods of choice for the determination of the BTEX metabolites.

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