Urban air pollution caused by fine particles, the increasing development of nanotechnology and the spread of contagious diseases, as well as bioterrorism, has raised concerns about aerosols and bioaerosols. This research aims to study the effect of various parameters on the diameter and uniformity of electrospun polyurethane/chitosan nanofibers and to evaluate their filtration performance and antimicrobial activity against nanoaerosols and Escherichia coli (E. coli) bacteria as a model bioorganism, respectively. Using response surface methodology, the main and interactive effects of four parameters including polyurethane/chitosan weight ratio, applied voltage, needle tip-to-collector distance and polymer flow rate were investigated on the mean diameter and uniformity of electrospun nanofibers. The nanoparticle filtration efficiency of the polyurethane/ chitosan electrospun nanofiber filter was determined after preparation under recommended optimum conditions using a standard filtration test rig. There was an increase in the mean diameter of nanofibers and decrease in the uniformity of them with increase in polyurethane polymer solution concentration. The mean diameter of nanofibers decreased significantly with increasing applied voltage and chitosan content in polyurethane/chitosan blended polymer solution. A significant, positive correlation was seen between needle tip-to-collector distance, polymer flow rate and the mean diameter of nanofibers. The prepared nanofiber filters showed an acceptable range of quality factor and pressure drop for using in filtration applications such as industrial filtration processes and personal respiratory protection equipment. The results of the performing bacterial disk diffusion method indicated that electrospun polyurethane/chitosan nanofibers have good antibacterial activity against E. coli bacteria as a model microorganism.

The aim of this study was to ascertain whether symptoms of respiratory disorders and lung functional impairments are associated with occupational inhalation exposure to carbon black (CB) in a group of rubber workers. Methods: The study population consisted of 72 male workers with a past history of and current exposure to CB and 69, randomly selected, healthy unexposed male office workers that served as the referent group. Subjects were interviewed and given standardized respiratory symptom questionnaires to answer. Furthermore, pulmonary function tests (PFTs) were performed before and after the work shift for exposed subjects and once during the work shift for referent subjects. Furthermore, to assess the extent to which workers were exposed to CB, using standard methods, inhalable and respirable dust fractions of CB were measured in different dusty worksites. Results: The levels of exposure to inhalable and respirable CB dust were estimated to be 6.2 ± 1.7 and 2.3 ± 0.29 mg/ m 3 respectively (mean ± SD). Respiratory symptom questionnaires revealed that regular cough, phlegm, wheezing and shortness of breath were significantly (p<0.05) more prevalent among exposed workers. Furthermore, significant decreases in some preshift and postshift parameters of pulmonary function of exposed workers with a spirometric pattern consistent with restrictive ventilatory disorder were found. Conclusion: The findings of this study provide circumstantial evidence to support the notion that exposure to CB exceeding its current TLV is associated with a significant increase in the prevalence of respiratory symptoms along with both acute, partially reversible and chronic irreversible significant decreases in some parameters of pulmonary function. (J Occup Health 2011; 53: 432-438)

Manual material handling (MMH) tasks can be found in most workplaces and they may constitute a risk factor for work-related musculoskeletal disorders (WMSDs

BACKGROUND: Shift-work, which is an ergonomics issue in workplaces, can negatively affect workers. The security personnel of medical centers in Iran have multiple responsibilities and consequently are exposed to such unwanted situations as observing patients, disputing with patient's attendants, unwanted shift schedules, and being away from family for long periods. OBJECTIVE: This study assessed health problems of Iranian hospital security personnel (shift-worker personnel) using the Survey of Shift-workers (SOS) questionnaire (Persian version). METHODS: This cross-sectional study was conducted in seven medical centers (4 hospitals and 3 clinics). A total of 416 workers were surveyed: shift-workers (exposed group) (n = 209) and non-shift-workers (unexposed group) (n = 207). RESULTS: The prevalence of adverse health effects was higher in shift-workers than day-workers. The level of education and mean Body Mass Index (BMI) in shift-workers were significantly higher compared with day-workers. The prevalence of gastrointestinal disorders, cardiovascular and psychological problems were also significantly higher in shift-workers compared with day-workers. CONCLUSIONS: Overall, the prevalence of health problems among the security personnel of medical centers was high. Hence, it is recommended that personnel be put under periodic monitoring and receive medical counseling and treatment if there is any disorder.

The aim of this study was to develop a new method for the determination of benzene, toluene, ethylbenzene and xylene isomers (BTEXs) in urine samples. In this method, MIL‐100(Fe)@Fe3O4@SiO2 metal–organic framework was synthesized, characterized and packed inside a needle trap device (NTD) as a sorbent for headspace extraction of unmetabolized BTEXs from urine samples followed by gas chromatography (GC) analysis. The GC device was equipped with a flame ionization detector (FID). The results showed that the optimal extraction time, extraction temperature and salt content were 60 min, 30°C and 5%, respectively. Also, the optimal desorption time and temperature were determined to be 1 min and 250°C, respectively. The limits of detection and quantification of the analytes of interest were in the ranges 0.0001–0.0005 and 0.0003–0.0014 μg ml−1, respectively. The intra‐ and inter‐day repeatability were <7.6%. The accuracy of the measurements in urine samples was in the range 7.1–11.4%. The results also demonstrated that the proposed NTD offered various advantages such as having high sensitivity and being inexpensive, reusable, user friendly, environmentally friendly and compatible for use with the GC device. Therefore, it can be efficiently used as a MIL–NTD for the extraction and analysis of unmetabolized BTEXs from urine samples.