. Study population included office workers of different departments as well as central organization and library. We use descriptive statistic, t test and chi-square test for data analysis. Results: The mean and standard deviation of participants' age was 35.4 ± 6.7 years and their work experience was 9.7 ± 6.65 years, respectively. Most signs (51%) were in back region, which forced 18.9% of individuals to withdraw from daily activities. Statistical analysis also showed 36.7% neck disorders in office workers, which demonstrated significant association with age and work experience (P < 0.001). Conclusions: Significant association of work experience and age with musculoskeletal disorders shows that individual's education and knowledge improvements with regard to ergonomics risk factors and correction of work postures are very important and ought to follow management and technical practices in the organization.

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Keywords air sampling, antibacterial, indoor air quality, metal ion, nano filter, nano zeolite Y. Correspondence AbstractAims: Fibre membranes containing metals have attracted great attention because of their high antibacterial efficiency. However, comparison of antibacterial activity of fibres with multi-metals in air samples has remained understudied. Methods and Results: Different ion exchanged nano-zeolite Y (IE-NZY) of Ag, Zn and Cu was studied. Polyvinylpyrrolidine/polyvinylidene fluoride nanofibres containing various IE-NZY were synthesized according to electrospinning technique. The presence of metal ions was confirmed using XRF. The morphological properties of nanofibres were characterized by SEM. Zone of inhibition was seen between 10Á1 and 12 mm against Staphylococcus aureus and 11Á5-14Á57 for Escherichia coli. IE-NZY containing Ag, Zn and Cu had the highest antibacterial efficiency. In the air samples, there were any colonies on the media under the Ag/Cu-NZY and Zn/Cu/Ag-NZY nanofibres. Conclusions: The bacterial inhibition for nanofibres containing a three metal nano-zeolite Y (TM-NZY) is higher than bimetals (BM-NZY) types while for monometals nano-zeolite Y (MM-NZY), it was lower compared to the others. Significance and Impact of the Study: The results indicate significant antibacterial activity of ion-exchanged NZY in air sampling.

The possible emission of sulfuric acid mists from a laboratory scale, counter-current packed bed tower operated with a caustic scrubbing solution was studied. Acid mists were applied through a local exhaust hood. The emissions from the packed bed tower were monitored in three different categories of gas flow rate as well as three liquid flow rates, while other influencing parameters were kept almost constant. Air sampling and sulfuric acid measurement were carried out iso-kinetically using USEPA method 8. The acid mists were measured by the barium-thorin titration method. According to the results when the gas flow rate increased from 10 L/s to 30 L/s, the average removal efficiency increased significantly (p < 0.001) from 76.8 ± 1.8% to 85.7 ± 1.2%. Analysis of covariance method followed by Tukey post-hoc test of 92 tests did not show a significant change in removal efficiency between liquid flow rates of 1.5, 2.5 and 3.5 L/min (p = 0.811). On the other hand, with fixed pressure loss across the tower, by increasing the liquid/gas (L/G) mass ratio, the average removal efficiency decreased significantly (p = 0.001) from 89.9% at L/G of <2 to 83.1% at L/G of 2–3 and further to 80.2% at L/G of >3, respectively. L/G of 2–3 was recommended for designing purposes of a packed tower for sulfuric acid mists and vapors removal from contaminated air stream.

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