Nurses experience psychosocial work stress that may negatively affect physical and mental health over time. In this cross-sectional study we investigated prevalence of job stress and oxidative stress in nurses, and determined if significant relationships exist between higher job stress scores and demographic factors and working conditions. Emergency department nurses (n = 42) were recruited from a University Hospital following Institutional Review Board approval. Job stress indicators, effort–reward ratio and overcommitment were evaluated from survey questionnaires using the effort–reward imbalance model, and associations with age, sex, body mass index, and working conditions were measured by logistic regression analysis. Oxidative stress biomarkers, 8-isoprostane, malondialdehyde, and antioxidant levels were measured from urine specimens. Job stress was prevalent with effort–reward ratio > 1 in 93% and overcommitment > 50 in 83% of the study participants. Age, body mass index, years of experience, weekend work, work hours per week, and shift work showed strong associations with effort–reward ratio and overcommitment scores. Malondialdehyde was higher in participants with high overcommitment. We report that psychosocial job stress is prevalent among nurses, as revealed by the high effort–reward and overcommitment scores. Job stress may be reduced through implementation of appropriate stress reduction interventions.

In the context of workplace safety, activated carbon in the fiber form (i.e., activated carbon fiber, ACF) represents an alternative adsorbent to granular activated carbon (GAC) for use in organic vapor respiratory protection devices. ACFs are high surface area carbonaceous materials that are often available in a self-supporting non-woven form. The physical form of ACF suggests the potential for a filtration medium that is capable of supporting both organic vapor adsorption and particulate filtration. To study the application of these materials in respiratory protection devices, ACFs (ACFF 1200 m²/g, ACFF 1800 m²/g, and ACFF 2000 m²/g) were challenged with representative organic vapors (toluene, hexane, and methyl ethyl ketone (MEK)) at an occupationally relevant concentration (200 ppm). Breakthrough curves were generated for at least three different bed weights of adsorbent. Pressure drop (i.e., the resistance across the filtration media) was also measured to determine maximum ACF bed depths for use in respiratory protection devices. Breakthrough experiments indicate that ACFF 2000 has the highest adsorption capacity for toluene (381 mg/g), followed by ACFF 1800 and ACFF 1200 (344 mg/g and 239 mg/g, respectively). A similar trend was observed for hexane: 221 mg/g, 196 mg/g, and 146 mg/g for ACFF 2000, ACFF 1800, and ACFF 1200, respectively. ACFF 1200 showed the highest adsorption capacity for the polar adsorbate MEK (168 mg/g), followed by ACFF 1800 and ACFF 2000 (166 mg/g and 147 mg/g, respectively). Based on the constraints of pressure drop, it seems unlikely the exclusive use of ACF in a filtering facepiece respirator can provide an adsorbent mass sufficient for full shift protection against organic vapor contaminants at or above the legally enforceable permissible exposure level (PEL). Nevertheless, the incorporation of ACF into a facepiece respirator appears promising for “nuisance odor” applications; i.e., the further reduction of organic vapor concentrations when workplace exposures are already below PEL concentrations. Implications: This research brings innovation to the field of occupational health and air pollution control technology by investigating the adsorption performance of activated carbon fiber (ACF) media in the context of worker respiratory protection. ACF properties such as high specific surface area (m²/g), high permeability to airflow, and rapid adsorption kinetics make it ideal for use in thin, N95-style respirators for organic vapors. Respiratory protection is an exciting and relevant application for ACF media. A lightweight adsorbent such as ACF, if incorporated into an N95-style respirator, could potentially provide nuisance-level VOC protection in a physical form that is accessible to workers and consistent with OSHA’s voluntary use provisions for facepiece respirators. The research presented in this manuscript represents one of several steps planned in the characterization of ACF media for this particular application.

This study provides a comparison of different types of commercially available activated carbon fibres (ACFs). Thus, ACFs in cloth (ACFC) and felt forms (ACFF) with three different surface areas were each analyzed for their pore volumes, pore sizes and pore-size distributions. The fibre morphology and organization was visualized using scanning electron microscopy (SEM). The microporosity of the ACF materials based on nitrogen isotherms, the percentage of micropores by area and volume, the average pore size and the pore-size distribution were also determined. An increase in the surface areas of the ACFC types led to an increase in the total pore volume, micropore volume, micropore area and pore width, but led to a decrease in the percentage of micropores by area and volume. The nitrogen isotherms demonstrated that the surface area dictated the amount of adsorption onto the ACF regardless of the form of the latter. The difference in the volume of smaller micropores between the ACFC and ACFF types may be attributed to the difference in the adsorbent density and the accessibility of the fibre surface to the activating gas during the activation process. An understanding of the pore structure of ACFs by form and surface area is crucial in determining the appropriate specific applications of such adsorbents.

Volatile organic compounds (VOCs) pose an occupational exposure risk due to their commonplace usage across industrial and vocational sectors. With millions of workers annually exposed, monitoring personal VOC exposures becomes an important task. As such, there is a need to improve current monitoring techniques by increasing sensitivity and reducing analysis costs. Recently, our lab developed a novel, preanalytical technique known as photothermal desorption (PTD). PTD uses pulses of high-energy, visible light to thermally desorb analytes from carbonaceous sorbents, with single-walled carbon nanotube buckypapers (BPs) having the best overall performance. To apply this new technology most effectively for chemical analysis, a better understanding of the theoretical framework of the thermal phenomena behind PTD must be gained. The objectives of the present work were 3-fold: measure the thermal response of BPs during irradiation with light; determine the best method for conducting such measurements; and determine the thermal conductivity of BPs. BPs were exposed to four energy densities, produced by light pulses, ranging from 0.28 to 1.33 J/cm², produced by a xenon flash lamp. The resulting temperature measurements were obtained via fast response thermocouple (T/C) mounted to BPs by three techniques (pressing, adhering, and embedding). Temperature increase measured by T/C using the adhering and pressing techniques resulted in similar values, 29.2 ± 0.8 to 56 ± 3 °C and 29.1 ± 0.9 to 50 ± 5 °C, respectively, while temperature increase measured by embedding the T/C into the BP showed statistically larger increases ranging from 35.2 ± 0.9 to 76 ± 4 °C. Peak BP temperatures for each mounting technique were also compared with the temperatures generated by the light source, which resulted in embedded BPs demonstrating the most temperature conversion among the techniques (74–86%). Based on these results, embedding T/Cs into the BP was concluded to be the best way to measure BP thermal response during PTD. Additionally, the present work modeled BP thermal conductivity using a steady-state comparative technique and found the material’s conductivity to be 10.6 ± 0.6 W/m². The present work’s findings will help pave the way for future developments of the PTD method by allowing calculation of the energy density necessary to attain a desired sorbent temperature and providing a means for comparing BP fabrication techniques and evaluating BP suitability for PTD before conducting PTD trials with analytes of interest. Sorbents with greater thermal conductivity are expected to desorb more evenly and withstand higher energy density exposures.

Single-walled carbon nanotubes (SWNTs) have been investigated as a promising sorbent for volatile organic compound (VOC) sampling. We also successfully demonstrated that pre-analysis desorption can be achieved by irradiating the sorbent with high intensity visible light pulses. This technique, photothermal desorption (PTD), can improve sensitivity and shorten current analytical procedure. Different fabrication methods of a buckypaper (BP), a self-supporting form of carbon nanotubes (CNTs), were explored; three methods using arc discharge (AD) SWNTs included non-cleaned, acetone-cleaned, and methanol-cleaned and one method using high-pressure carbon monoxide (HiPco) SWNTs. Adsorption efficiencies of the fabricated BPs were compared in terms of Brunauer, Emmett, and Teller (BET) surface area, pore size, and toluene adsorption capacity. All materials were found to have high BET surface area (211 to 649 m² g⁻¹) and toluene adsorption capacity (25 to 106 mg g⁻¹) but HiPco BP exhibited the highest BET surface area (649 ± 3 m² g⁻¹) with the smallest mean pore size (7.7 ± 0.3 nm) and the greatest toluene adsorption capacity (106 mg g⁻¹). Additionally, HiPco BP had the simplest fabrication process which taken as a whole is a clear indication that further investigations using the PTD technique should be explored with this material.