تاثیر عوامل فنی، عملیاتی و محیطی بر میزان مواجهه کار گران  با BTEX در فرایند رنگ  یک صنعت خودرو سازی

Background and Aim: Considering the acute and chronic effects of organic solvents to which vehicle painters are exposed for long periods of time, their evaluation and control is crucial for protection of health of the employees. This study aimed to find the most influential factors on exposure to, and spreading pollution with, benzene, toluene, xylem, and etylebenzene (BTEX) in order to be able to choose the best control measures. Materials and Methods: In a motor-vehicle company the vehicle painting process was studied in detail and the solvents used in paints and in spreading organic solvent stations were identified. Based on the types and concentrations of the variables being studied, using the NIOSH method a total of 240 air samples were collected (5 samples for each variable and the respective controls) and analyzed. The SPSS version 11.5 was used for data analysis, the statistical tests being multi-regression and analysis of variance. Results: Exposure to benzene in all occupational tasks, as well as to toluene in top coating and undercoating stations exceeded, while exposure to etylebenzene and xylene did not reach, the respective permitted exposure limits (p<0.05). The most effective factors on exposure to all the four solvents were, in order of effectiveness, occupational task, gun type, and the type of paint sued (p<0.05). Conclusion: The effects of the variables studies – occupational task, gun and paint types – on exposure to BTEX relate to differences in occupational task work load, the type of gun used, and the paint organic solvent formulation. The reason for the potentially high exposure to benzene is its presence as an impurity in the paint solvents. Thus, it is highly recommended that in the process of control and evaluation special attention be paid to these factors.