Corian(R), a solid-surface composite (SSC), is composed of alumina trihydrate and acrylic polymer. The aim of the present study was to examine the pulmonary toxicity attributed to exposure to SSC sawing dust. Male mice were exposed to either phosphate buffer saline (PBS, control), 62.5, 125, 250, 500, or 1000 microg of SSC dust, or 1000 microg silica (positive control) via oropharyngeal aspiration. Body weights were measured for the duration of the study. Bronchoalveolar lavage fluid (BALF) and tissues were collected for analysis at 1 and 14 days post-exposure. Enhanced-darkfield and histopathologic analysis was performed to assess particle distribution and inflammatory responses. BALF cells and inflammatory cytokines were measured. The geometric mean diameter of SSC sawing dust following suspension in PBS was 1.25 microm. BALF analysis indicated that lactate dehydrogenase (LDH) activity, inflammatory cells, and pro-inflammatory cytokines were significantly elevated in the 500 and 1000 microg SSC exposure groups at days 1 and 14, suggesting that exposure to these concentrations of SSC induced inflammatory responses, in some cases to a greater degree than the silica positive control. Histopathology indicated the presence of acute alveolitis at all doses at day 1, which was largely resolved by day 14. Alveolar particle deposition and granulomatous mass formation were observed in all exposure groups at day 14. The SSC particles were poorly cleared, with 81% remaining at the end of the observation period. These findings demonstrate that SSC sawing dust exposure induces pulmonary inflammation and damage that warrants further investigation. Abbreviations: ANOVA: Analysis of Variance; ATH: Alumina Trihydrate; BALF: Bronchoalveolar Lavage Fluid; Dpg: Geometric Mean Diameter; FE-SEM: Field Emission Scanning Electron Microscopy; IACUC: Institutional Animal Care and Use Committee; IFN-gamma: Interferon Gamma; IL-1 Beta: Interleukin-1 Beta; IL-10: Interleukin-10; IL-12: Interleukin-12; IL-2: Interleukin-2; IL-4: Interleukin-4; IL-5: Interleukin-5; IL-6: Interleukin-6; KC/GRO: Neutrophil-Activating Protein 3; MMAD: Mass Median Aerodynamic Diameter; PBS: Phosphate-Buffered Saline; PEL: Permissible Exposure Limit; PM: Polymorphonuclear Leukocytes; PNOR: Particles Not Otherwise Regulated; SEM/EDX: Scanning Electron Microscope/Energy-Dispersive X-Ray; SSA: Specific Surface Area; SSC: Solid Surface Composite; TNFalpha: Tumor Necrosis Factor-Alpha; VOC: Volatile Organic Compounds; sigmag: Geometric Standard Deviation.

OBJECTIVES: Laser Doppler blood flow measurements have been used for diagnosis or detection of peripheral vascular dysfunction. This study used a rat tail model of vibration-induced vascular injury to determine how laser Doppler measurements were affected by acute and repeated exposures to vibration, and to identify changes in the Doppler signal that were associated with the exposure. METHODS: Blood flow was measured immediately after a single exposure to vibration, or before vibration exposure on days 1, 5, 10, 15, and 20 of a 20 days exposure. RESULTS: After a single exposure to vibration, average tail blood flow was reduced. With 20 days of exposure, there was a reduction in the amplitude of the arterial pulse on days 10 to 20 in vibrated rats and days 15 to 20 in control rats. CONCLUSIONS: More detailed statistical analyses of laser Doppler data may be needed to identify early changes in peripheral circulation after exposure to vibration.

Background: Police officers’ stress perception, frequency of stressful events (stressors), and police work characteristics may contribute to poor sleep quality through different mechanisms. Methods: We investigated associations of stress severity (measured by stress rating score) and frequency of stressors with sleep quality and examined the influence of police work characteristics including workload, police rank, prior military experience, and shift work on the associations. Participants were 356 police officers (256 men and 100 women) enrolled in the Buffalo Cardio-Metabolic Occupational Police Stress Study from 2004 to 2009. A mean stress rating score and mean frequency of stressors occurring in the past month were computed for each participant from the Spielberger Police Stress Survey data. Sleep quality was assessed using the global score derived from the Pittsburgh Sleep Quality Index survey. Linear associations of the stress rating score and frequency of stressors with sleep quality (Pittsburgh Sleep Quality Index global score) were tested. Age, sex, race/ethnicity, and smoking status were selected as potential confounders. Results: The stress rating score was positively and independently associated with poor sleep quality (beta = 0.17, p = 0.002). Only workload significantly modified this association (beta = 0.23, p = 0.001 for high workload group; p-interaction = 0.109). The frequency of stressors was positively and independently associated with poor sleep quality (beta = 0.13, p = 0.025). Only police rank significantly modified the association (beta = 0.007, p = 0.004 for detectives/other executives; p-interaction = 0.076). Conclusion: Both police officers’ perception of stress severity and the frequency of stressors are associated with poor sleep quality. Stress coping or sleep promotion regimens may be more beneficial among police officers reporting high workloads.

AIM: In this study, we evaluated whether peritraumatic dissociation (PD) was associated with symptoms of depression and posttraumatic stress disorder (PTSD), and whether this association was modified by trauma prior to police work. METHOD: Symptoms of depression, PTSD, peritraumatic dissociative experience (PDE), and trauma prior to police work were measured using the Center for Epidemiologic Studies Depression scale, PTSD Checklist-Civilian, PDE questionnaire, and the Brief Trauma questionnaire, respectively, in 328 police officers. Separate regression models were used to assess if either symptoms of depression or PTSD were associated with PD stratified by prior trauma. Means were adjusted for race, number of drinks per week, and smoking. RESULTS: PD was associated with symptoms of PTSD and depression (β = 0.65, p < .001 and β = 0.27, p < .001, respectively). PD was positively associated with symptoms of PTSD regardless of prior trauma (β = 0.61, p < .001(without prior trauma), 0.75, p < .001 (with prior trauma). In contrast to PTSD, depression symptoms were significantly associated with PD scores in individuals with prior trauma (β = 0.47, p < .001), but not in individuals without prior trauma (β = 0.13, p = .165). LIMITATIONS: This is a cross-sectional study. Outcomes were obtained via self-report and were not clinically diagnosed. Aspects of both the trauma event as well as the symptoms and severity of PD may have introduced recall bias. CONCLUSION: These results add to the literature indicating that PD plays a role in symptoms of PTSD and depression and how prior trauma may modify this relationship. (PsycINFO Database Record

Police officers often continue to face numerous threats and stressors in the aftermath of a disaster. To date, posttraumatic growth (PTG) has been studied primarily in the context of significant trauma; thus, it is not known whether stressful life events are associated with PTG. This study investigated the development of PTG among 113 police officers working in the New Orleans area following Hurricane Katrina. Hierarchical regression was used to evaluate if gratitude, social support, and satisfaction with life moderated the relationship between stressful life events (as measured by the total life stress score) and PTG, after adjustment for age, sex, race, level of involvement in Hurricane Katrina, and alcohol intake. Results indicate that stressful life events are independently associated with PTG. Gratitude, satisfaction with life, and social support were seen to moderate this relationship; as stressful life events increased so too did PTG-particularly among officers with higher levels of gratitude (B = 0.002, p ≤ .05), satisfaction with life (B = 0.002, p ≤ .05), and social support (B = 0.001, p ≤ .05). These findings suggest that promoting satisfaction with life, interpersonal support, and gratitude may be beneficial to those who are regularly at risk of trauma exposure.

Three sets of soil samples were collected by the National Institute for Occupational Safety and Health and one set by South Dakota School of Mines & Technology from in and around the Slim Buttes Land Unit of the Sioux Ranger District of the Custer–Gallatin National Forest in the northwest of South Dakota. The rocks forming the Slim Buttes are sedimentary clays, sands and gravels including re-worked volcanic ash-falls in which the zeolite mineral erionite has crystallized during diagenesis in a fibrous form or morphology similar to that of asbestos. The samples were prepared using the fluidized bed asbestos segregator (FBAS) and analyzed by phase contrast microscopy (PCM) or transmission electron microscopy to detect the presence of mineral fibers. FBAS–PCM results compared to semi-quantitative polarized light microscopy (PLM) and X-ray diffraction analysis indicated a recovery of approximately 1% and a linear relationship that likely can be extrapolated to concentrations well below the 1% detection limit of PLM. There were small variations between a PCM count of 10 fibers to a count of 100 fibers (or a maximum of 200 microscopic fields of view), which indicates the possibility of rapid turnaround of results. Although the four sets of samples examined in this work were collected by slightly different techniques, some tentative conclusions can be drawn about the distribution of erionite in soils. Erionite was detected in almost every soil sample, even those taken several miles from the outcrop, but without any distribution indicating recent transportation from the current volcaniclastic sediment outcrops. Removal of more extensive volcaniclastic sediments through erosion may have resulted in remnant material in soils, including erionite crystals, but this possibility requires further study. Although we have demonstrated that erionite in soils can be detected through FBAS–PCM, we have not attempted to correlate those results with human inhalation exposure through activity-based sampling, and thus, any risk inherent in working these soils is unknown.

The problem of recovering the ruin probability in the classical risk model based on the scaled Laplace transform inversion is studied. It is shown how to overcome the problem of evaluating the ruin probability at large values of an initial surplus process. Comparisons of proposed approximations with the ones based on the Laplace transform inversions using a fixed Talbot algorithm as well as on the ones using the Trefethen–Weideman–Schmelzer and maximum entropy methods are presented via a simulation study.

Anti-vibration gloves have been used to block the transmission of vibration from powered hand tools to the user, and to protect users from the negative health consequences associated with exposure to vibration. However, there are conflicting reports as to the efficacy of gloves in protecting workers. The goal of this study was to use a characterized animal model of vibration-induced peripheral vascular and nerve injury to determine whether antivibration materials reduced or inhibited the effects of vibration on these physiological symptoms. Rats were exposed to 4 h of tail vibration at 125 Hz with an acceleration 49 m/s(2). The platform was either bare or covered with antivibrating glove material. Rats were tested for tactile sensitivity to applied pressure before and after vibration exposure. One day following the exposure, ventral tail arteries were assessed for sensitivity to vasodilating and vasoconstricting factors and nerves were examined histologically for early indicators of edema and inflammation. Ventral tail artery responses to an alpha2C-adrenoreceptor agonist were enhanced in arteries from vibration-exposed rats compared to controls, regardless of whether antivibration materials were used or not. Rats exposed to vibration were also less sensitive to pressure after exposure. These findings are consistent with experimental findings in humans suggesting that antivibration gloves may not provide protection against the adverse health consequences of vibration exposure in all conditions. Additional studies need to be done examining newer antivibration materials.

The ability to disinfect and reuse disposable N95 filtering facepiece respirators (FFRs) may be needed during a pandemic of an infectious respiratory disease such as influenza. Ultraviolet germicidal irradiation (UVGI) is one possible method for respirator disinfection. However, UV radiation degrades polymers, which presents the possibility that UVGI exposure could degrade the ability of a disposable respirator to protect the worker. To study this, we exposed both sides of material coupons and respirator straps from four models of N95 FFRs to UVGI doses from 120 to 950 J/cm2. We then tested the particle penetration, flow resistance and the bursting strengths of the individual respirator coupon layers, and the breaking strength of the respirator straps. We found that UVGI exposure led to a small increase in particle penetration (up to 1.25%) and had little effect on the flow resistance. UVGI exposure had a more pronounced effect on the strengths of the respirator materials. At the higher UVGI doses, the strength of the layers of respirator material was substantially reduced (in some cases, by >90%). The changes in the strengths of the respirator materials varied considerably among the different models of respirators. UVGI had less of an effect on the respirator straps; a dose of 2360 J/cm2 reduced the breaking strength of the straps by 20% to 51%. Our results suggest that UVGI could be used to effectively disinfect disposable respirators for reuse, but the maximum number of disinfection cycles will be limited by the respirator model and the UVGI dose required to inactivate the pathogen.

The current measurement method for occupational exposure to wood dust is by gravimetric analysis and is thus non-specific. In this work, diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) for the analysis of only the wood component of dust was further evaluated by analysis of the same samples between two laboratories. Field samples were collected from six wood product factories using 25-mm glass fiber filters with the Button aerosol sampler. Gravimetric mass was determined in one laboratory by weighing the filters before and after aerosol collection. Diffuse reflection mid-infrared spectra were obtained from the wood dust on the filter which is placed on a motorized stage inside the spectrometer. The metric used for the DRIFTS analysis was the intensity of the carbonyl band in cellulose and hemicellulose at ~1735cm-1. Calibration curves were constructed separately in both laboratories using the same sets of prepared filters from the inhalable sampling fraction of red oak, southern yellow pine, and western red cedar in the range of 0.125-4mg of wood dust. Using the same procedure in both laboratories to build the calibration curve and analyze the field samples, 62.3% of the samples measured within 25% of the average result with a mean difference between the laboratories of 18.5%. Some observations are included as to how the calibration and analysis can be improved. In particular, determining the wood type on each sample to allow matching to the most appropriate calibration increases the apparent proportion of wood dust in the sample and this likely provides more realistic DRIFTS results.

OBJECTIVES: Police officers have a high prevalence of cardiovascular disease (CVD). Reduced heart rate variability (HRV) is known to increase CVD risk. Leptin and adiponectin may be related to CVD health. Therefore, our objective was to investigate the relationship between these variables and HRV. METHODS: Leptin and adiponectin levels were measured in 388 officers from the Buffalo Cardio-Metabolic Occupational Police Stress study. HRV was assessed according to methods published by the Task Force of the European Society of Cardiology and the North American Society of Pacing Electrophysiology for measurement and analysis of HRV. Mean values of high-frequency (HF) and low-frequency (LF) HRV were compared across tertiles of leptin and adiponectin using analysis of variance and analysis of covariance; trends were assessed using linear regression models. RESULTS: Leptin, but not adiponectin, was significantly and inversely associated with HRV. Body mass index (BMI) and percent body fat significantly modified the association between leptin and LF (but not HF) HRV. Among officers with BMI < 25 kg/m2 , leptin was not significantly associated with HRV. However, among officers with BMI ≥ 25 kg/m2 , leptin was inversely associated with HRV, after adjustment for age, gender, and race/ethnicity; HF HRV, P = 0.019 and LF HRV, P < 0.0001. Similarly, among officers with percent body fat ≥ 25.5%, leptin and LF HRV showed significant, inverse associations (adjusted P = 0.001). CONCLUSIONS: Leptin levels were inversely associated with LF HRV, especially among officers with increased adiposity. Increased leptin levels may be associated with CVD-related health problems.

Analysis of Proficiency Analytical Testing (PAT) results between 2003 and 2013 suggest that the variation in respirable crystalline silica analysis is much smaller today than it was in the period 1990-1998, partly because of a change in sample production procedure and because the colorimetric method has been phased out, although quality improvements in the x-ray diffraction (XRD) or infrared (IR) methods may have also played a role. There is no practical difference between laboratories using XRD or IR methods or between laboratories which are accredited or those which are not. Reference laboratory means (assigned values) are not different from the means of all participants across the current range of mass loading, although there is a small difference in variance in the ratios of all participants to reference laboratory means based on method because the reference laboratories are much more likely to use XRD than are the others. Matrix interference does not lead to biases or substantially larger variances for either XRD or IR methods. Data from proficiency test sample analyses that include results from poorly performing laboratories should not be used to determine the validity of a method. PAT samples are not produced below 40 mug and variance may increase with lower masses, although this is not particularly predictable. PAT data from lower mass loadings will be required to evaluate analytical performance if exposure limits are lowered without change in sampling method. Task-specific exposure measurements for periods shorter than a full shift typically result in lower mass loadings and the quality of these analyses would also be better assured from being within the range of PAT mass loadings. High flow rate cyclones, whose performance has been validated, can be used to obtain higher mass loadings in environments of lower concentrations or where shorter sampling times are desired.

OBJECTIVE: Low heart rate variability (HRV) has been linked to cardiovascular disease. Our objective was to examine the cross-sectional association between insulin and HRV. METHODS: Insulin levels were measured in 355 nondiabetic officers from the BCOPS study, following a 12 h fast. HRV was performed according to methods published by the task force of the European Society of Cardiology and the North American Society of Pacing Electrophysiology for measurement and analysis of HRV. Mean values of high (HF) and low frequency (LF) HRV were compared across tertiles of insulin using ANOVA and ANCOVA; p-values were obtained from linear regression models. RESULTS: Higher mean levels of insulin were significantly associated with lower (i.e., worse) mean levels of HRV before and after risk-factor adjustment. The results for HF HRV (ms2 ) were as follows: 1st insulin (microU/ml) tertile (156.3; 95% confidence interval (CI) = 128.6-189.9); 2nd tertile (154.3; 95% CI = 124.3-191.5); 3rd tertile (127.9; 95% CI = 105.0-155.8), p for trend = 0.017. Results with LF HRV were similar to HF HRV. Insulin was also inversely and significantly associated with HRV among officers with BMI ≥25 kg/m2 , with ≥25.5% body fat, and among those who reported low (<median) physical activity scores. CONCLUSIONS: In this cohort, insulin levels were inversely and significantly associated with both HF and LF HRV, especially among those with higher levels of obesity and lower levels of physical activity, suggesting associations with autonomic nervous system function. Prospective studies of this association in other populations are warranted. Am. J. Hum. Biol., 2013. (c) 2013 Wiley Periodicals, Inc.

The problem of recovering a cumulative distribution function of a positive random variable via the scaled Laplace transform inversion is studied. The uniform upper bound of proposed approximation is derived. The approximation of a compound Poisson distribution as well as the estimation of a distribution function of the summands given the sample from a compound Poisson distribution are investigated. Applying the simulation study, the question of selecting the optimal scaling parameter of the proposed Laplace transform inversion is considered. The behavior of the approximants are demonstrated via plots and table.

OBJECTIVE: To investigate the associations between long work hours and adiposity measures in police officers. METHODS: Participants included 408 officers from the Buffalo Cardio-Metabolic Occupational Police Stress study who were examined between 2004 and 2009. Total work hours were abstracted from payroll records and questionnaires. Analysis of variance and covariance models were used. RESULTS: Among male officers who worked the midnight shift, mean values of waist circumference and body mass index increased with longer work hours after adjustment for age, physical activity, energy intake, sleep duration, smoking status, police rank, activities after work (eg, child/family care, sports), and household income. Adiposity measures were not associated with work hours among women on any shift. CONCLUSION: Working longer hours was significantly associated with larger waist circumferences and higher body mass index among male police officers working the midnight shift.

In this article a new nonparametric density estimator based on the sequence of asymmetric kernels is proposed. This method is natural when estimating an unknown density function of a positive random variable. The rates of Mean Squared Error, Mean Integrated Squared Error, and the L 1 -consistency are investigated. Simulation studies are conducted to compare a new estimator and its modified version with traditional kernel density construction.