Journal of Health and Safety at Work

Introduction: Electrospun nanofibers are suitable option to synthesize filtering mats for nanoparticles. This study was aimed to fabricate polyurethane nanofiber mats through electrospinning process and to investigate the effect of different parameters such as packing density, face velocity and particle type on the filtration efficiency and quality factor of electrospun polyurethane nanofiber mats.
 

Material and Method: The nanofiber mats were produced by electrospinning  process. Polyurethane granules were dissolved (15w/w%) in a solvent system consisting of dimethylformamide and tetrahydrofuran (3:2). Then, the filtration performance testing system was made at the Fluid Mechanics Department of Hanyang University of South Korea and the filtration efficiency and pressure drop of prepared nanofiber mats were studied.
 

Result: Findings showed that by increasing the duration of electrospinning, the basis weight, thickness, packing density, initial pressure drop and filtration efficiency of the mats increased, and the quality factor of the mats decreased due to the increase of the pressure drop. The increase in electrospinning duration from 15 to 45 minutes was led to the increase in pressure drop from 7 to 32 Pa and the average filtration efficiency was increased about 9-10% for KCl and DEHS test particles. The filtration efficiency and quality factor of the prepared polyurethane nanofiber mats were declined with the increase of filtration face velocity from 2 to 5 and 10 cm/s. The reduction in filtration efficiency was more obvious for particles smaller than 425 nm.
 

Conclusion: The results demonstrated that prepared polyurethan naofiber mats provide acceptable filtration performance. What is more, such nanofiber mats can have other potential benefits such as light basis weight, low thickness and simple production.

Introduction: Adverse effects of volatile organic compounds (VOCs) including general and specific effects like carcinogenic of benzene are well known. The aim of this study was to evaluate occupational exposure to BTEX compounds in the painting unit of an automotive industry and subsequently health risk assessment of exposure to these compounds.

Material and Method: This cross-sectional study was conducted in the paint unit of an automotive industry including painting cabin, pre-painting salon and painting salon sections. After analyzing samples, gathered from different sections, by GC-MS, BTEX compound were identified as the main contaminants. In the next step, NIOSH1501 and EPA methods were used to measure and analysis of BTEX and risk assessment, respectively.

Result: Findings showed that benzene concentration in painting cabin was higher than occupational exposure limits provided by the Environmental and Occupational Health Center of Iran. Life time cancer risk for benzene per 1000 has been reported10, 3.63 and 1.27in the painting cabin, pre-painting and salon sections, respectively. It was also for ethyl benzene 2.5m 1.8 and 38.0 in the mentioned sections, respectively. The non-cancer risk for benzene and xylene in the painting cabin and pre-painting sections were higher than recommended allowable level.

Conclusion: Regarding the high level of cancer risk values obtained for benzene and ethylbenzene in the studied units and also high values of non-cancer risk for benzene and xylene, it is recommended to conduct biological exposure assessmnet of the workers and improve existence control systems using modern engineering control systems.