An assessment of occupational noise exposures in four construction trades

Three hundred thirty-eight noise exposure samples were collected from 133 construction workers employed in 4 construction trades: carpenters, laborers, ironworkers, and operating engineers. Four sites using a variety of construction techniques were sampled at least 12 times on a randomly chosen date over a 22-week period. Up to 10 volunteer workers were sampled for an entire work shift on each sampling day using datalogging noise dosimeters, which recorded both daily time-weighted averages (TWAs) and 1-min averages. Workers also completed a questionnaire throughout the workday detailing the tasks performed and tools used throughout the day. Regression models identified work characteristics associated with elevated exposure levels. Comparisons were made between exposures measured using the Occupational Safety and Health Administration (OSHA) exposure metric and the 1996 draft National Institute for Occupational Safety and Health/International Organization for Standardization (NIOSH/ISO) metric to examine the effects of differing exchange rates and instrument response times on construction noise exposures. The mean OSHA TWA for 338 samples was 82.8 dBA +/- 6.8 dBA, whereas the mean NIOSH/ISO TWA for 174 samples was 89.7 dBA +/- 6.0 dBA. Forty percent of OSHA TWAs exceeded 85 dBA, and 13% exceeded 90 dBA, the OSHA permissible exposure limit. The tasks and tools associated with the highest exposure levels were those involving pneumatically operated tools and heavy equipment. Trade was a poor predictor of noise exposure; construction method, stage of construction, and work tasks and tools used were found to be better exposure predictors. An internal validation substudy indicated excellent agreement between worker self-reporting and researcher observation. These data provide substantial documentation that construction workers in several key trades are frequently exposed to noise levels that have been associated with hearing loss, and demonstrate the need for targeted noise reduction efforts and comprehensive hearing conservation programs in the industry.

Incidental treatment of nipple discharge caused by benign intraductal papilloma through diagnostic Mammotome biopsy

OBJECTIVE

The purpose of this study was to evaluate imaging-guided vacuum-assisted mammotome biopsy as a minimally invasive method of obtaining a satisfactory diagnosis and eliminating the bothersome symptoms in patients presenting with nipple discharge.

MATERIALS AND METHODS

Forty-nine women who presented with nipple discharge and who had final pathologic diagnoses of papillary lesions were retrospectively identified. Fifty-six lesions were biopsied in this group. The examinations included mammography, ductography, sonography, and, if possible, percutaneous biopsy. All lesions were centrally located and most were superficial. Of this study group, four patients with five lesions proceeded to sonographically guided automated core biopsy, and 38 patients with 44 intraductal lesions identified by sonography advanced to sonographically guided biopsy with an 11-gauge mammotome probe. One patient underwent stereotactic 11-gauge mammotome biopsy. Patients not advancing to sonographically guided biopsy were those with masses either in the nipple or nipple-areolar complex (five patients), one patient with no identifiable lesion at sonography, and one directly referred for open surgical biopsy.

RESULTS

In all biopsied patients, satisfactory tissue for diagnosis was obtained. In patients biopsied with the mammotome probe, follow-up at a mean time of 13 months revealed resolution of the presenting problematic discharge in 97.2% of patients. Complications were mild and infrequent. Only one of 50 percutaneously biopsied lesions was not benign and required subsequent surgery.

CONCLUSION

Papilloma excision with percutaneous biopsy allows safe and accurate tissue analysis and a high probability of terminating the symptomatic nipple discharge.

Alteration of Baumann's angle by humeral position: implications for treatment of supracondylar humerus fractures

To determine the effects of limb positioning on Baumann's angle, we made a controlled radiographic study of a 6-year-old cadaver upper extremity specimen. Radiographic measurement of Baumann's angle was obtained at 10 degrees increments of humeral rotation from 40 degrees of internal rotation to 40 degrees of external rotation. These measurements were obtained with the humerus parallel to the x-ray cassette and with the humerus flexed 30 degrees from the cassette. Measurement of Baumann's angle with radiographs obtained with the humerus parallel to the x-ray cassette was associated with less variation in the measured angle (6 degrees of change for every 10 degrees of rotation). The relevance of these findings in management of supracondylar fractures is discussed.

Phase II trial of pirfenidone in adults with neurofibromatosis type 1

We performed an open-label phase II trial of oral pirfenidone in 24 patients with neurofibromatosis type 1 (NF1). Tumors were monitored by three-dimensional MRI. At the end of treatment, four patients had a decrease in tumor volume by 15% or more, three had tumor progression, and 17 remained stable. Pirfenidone warrants further investigation in NF1, which has until now lacked an effective control therapy.

Improvement of lipid production in the marine strains Alexandrium minutum and Heterosigma akashiwo by utilizing abiotic parameters

Two different strains of microalgae, one raphidophyte and one dinoflagellate, were tested under different abiotic conditions with the goal of enhancing lipid production. Whereas aeration was crucial for biomass production, nitrogen deficiency and temperature were found to be the main abiotic parameters inducing the high-level cellular accumulation of neutral lipids. Net neutral lipid production and especially triacylglycerol (TAG) per cell were higher in microalgae (>200% in Alexandrium minutum, and 30% in Heterosigma akashiwo) under treatment conditions (25°C; 330 μM NaNO3) than under control conditions (20°C; 880 μM NaNO3). For both algal species, oil production (free fatty acids plus TAG fraction) was also higher under treatment conditions (57 mg L−1 in A. minutum and 323 mg L−1 in H. akashiwo). Despite the increased production and accumulation of lipids in microalgae, the different conditions did not significantly change the fatty acids profiles of the species analyzed. These profiles consisted of saturated fatty acids (SAFA) and polyunsaturated fatty acids (PUFA) in significant proportions. However, during the stationary phase, the concentrations per cell of some PUFAs, especially arachidonic acid (C20:4n6), were higher in treated than in control algae. These results suggest that the adjustment of abiotic parameters is a suitable and one of the cheapest alternatives to obtain sufficient quantities of microalgal biomass, with high oil content and minimal changes in the fatty acid profile of the strains under consideration.

Pain After Epithelial Removal by Ethanol-assisted Mechanical Versus Transepithelial Excimer Laser Debridement

PURPOSE

To compare subjective pain responses between two techniques of epithelial removal prior to photorefractive keratectomy (PRK) treatment: ethanol-soaked pledget with mechanical debridement of the epithelium versus excimer laser transepithelial ablation.

METHODS

Nine patients underwent bilateral PRK. Each had the epithelium in one eye debrided by placing a pledget soaked in 20% ethanol on the cornea for 2 minutes followed by gentle scraping with a blade. The epithelium in the other eye was removed by transepithelial phototherapeutic keratectomy (PTK) treatment. For each eye, PRK was initiated immediately after removal of the epithelium. On postoperative day one, each patient was asked to rate the level of pain suffered over the last 24 hours on a scale of 0 (minimal) to 10 (maximal). Data were analyzed in a masked fashion.

RESULTS

Postoperative day one average pain level in the ethanol-assisted mechanically debrided eyes was 3.0 +/- 2.5 and in the transepithelial PTK eyes was 6.8 +/- 1.8. The difference was statistically significant by Student's t-test (P < .01). All epithelial defects healed within 3 days with no clinically significant difference in healing time between the two techniques.

CONCLUSION

In preparation for PRK, ethanol-assisted mechanical debridement of the epithelium caused significantly less postoperative pain than epithelial removal using the excimer laser.

Exposures to wood dust in U.S. industries and occupations, 1979 to 1997

BACKGROUND

We analyzed 1,632 measurements of airborne wood dust reported to OSHA's Integrated Management Information System in the period 1979 to 1997.

METHODS

The relationships between wood dust concentrations and various factors documented in the OSHA database were examined in a multiple regression model.

RESULTS

Exposures ranged from less than 0.03 to 604 mg/m3, with an arithmetic mean of 7.93 and a geometric mean of 1.86. Reported exposure levels decreased substantially over time (e.g., unadjusted geometric mean in 1979 = 4.59 mg/m3; in 1997 = 0.14 mg/m3). High exposure jobs included sanders in the transportation equipment industry (unadjusted geometric mean = 17.5 mg/m3), press operators in the wood products industry (12.3 mg/m3), lathe operators in the furniture industry (7.46 mg/m3), and sanders in the wood cabinet industry (5.83 mg/m3).

CONCLUSIONS

In the multiple regression model, year, state, job, and industry were found to be predictors of exposure. Year and state were likely surrogates for other factors which directly influence exposure, but which were not included in the IMIS database, such as the use of engineering control measures.

Farmworker exposure to organophosphorus pesticide residues during apple thinning in central Washington State

The purpose of this study was to characterize worker exposure to azinphos-methyl (Guthion) over an entire 4-6 week apple-thinning season. Twenty workers from three work sites in the Chelan-Douglas County region of Washington state were recruited for the study. Exposure potential was estimated by dislodgeable foliar residue measurements, and individual exposures were estimated by biological monitoring through urinary metabolites. Measureable azinphos-methyl residues were found on apple foliage at all sites throughout the six-week sampling period, indicating continuous exposure potential (median residue level of 0.5 microgram/cm2). Measurable levels of the urinary dialkylphosphate metabolite, DMTP, were found in virtually all urine samples (limit of detection = 0.04 microgram/mL). Mean DMTP concentrations differed significantly across sites (0.53, 0.29, and 0.90 microgram/mL for Sites 1-3, respectively; analysis of variance, p < .002), and intraindividual variability was much greater than interindividual differences. Group mean DMTP concentrations at each site fluctuated according to foliar residue levels. Measurable DMTP concentrations were found in 9% of reference workers, ranging from 0.04-0.18 microgram/mL. Cholinesterase activity levels monitored with a field test kit were not considered reliable due to temperature changes of the instrument.

Noise exposure among construction electricians

Data-logging noise dosimetry was used to assess the exposure levels of electricians working for a major electrical subcontractor in Washington State at five sites using four types of construction methods. Subjects documented activities and work environment information throughout their work shift, resulting in an activity/exposure record for each of the 174 full-shift samples collected over the 4-month duration of the study. Over 24% of the TWA samples exceeded 85 dBA; 5.2% exceeded the federal Occupational Safety and Health Administration permissible exposure limit of 90 dBA. The National Institute for Occupational Safety and Health exposure metric, which specifies a 3-dB ER, was also utilized; using this metric, 67.8% of the samples exceeded 85 dBA and 27% exceeded 90 dBA. Subjects were directly observed for a subset of 4469 min during which more detailed activity and environmental information was recorded. Linear and logistic regression models using this subset were used to identify the determinants of average exposure, and exposure exceedences, respectively. These models demonstrated the importance of multiple variable modeling in interpreting exposure assessments, and the feasibility and utility of modeling exposure exceedences using logistic regression. The results further showed that presumably quiet trades such as electrician are at risk of exposure to potentially harmful noise exposures, and that other workers' activities and the general environment contribute substantially to that risk. These results indicate that noise control strategies will have to address the construction work environment as an integrated system.

Serum hepatic biochemical activity in two populations of workers exposed to styrene

OBJECTIVE

To determine whether hepatic biochemical changes, as measured by routinely available tests indicative of hepatocellular necrosis, cholestasis, or altered hepatic clearance of bilirubin, occur in association with low to moderate exposure to styrene commonly experienced in industrial production.

METHODS

Two independent cross sectional studies were performed comparing serum hepatic transaminases (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), cholestatic enzymes (alkaline phosphatase (AP) and gamma glutamyl transpeptidase (GGT)), and bilirubin in (a) 47 workers of fibreglass reinforced plastics who were exposed to styrene and (b) 21 boat and tank fabricators, with separate referent groups of unexposed workers. Exposure to styrene was assessed in air by dosimetry, and in venous blood by headspace analysis. Hepatic biochemical variables were assessed across strata of exposure to styrene defined as 25 ppm in air, or 0.275 mg/l in blood, adjusting for age, sex, body mass index, and ethanol consumption.

RESULTS

A consistent and significant linear trend for increasing direct bilirubin and direct/total bilirubin ratio was found in association with increasing exposure to styrene, by both air and blood monitoring, in both studies. Mean direct bilirubin concentrations increased from 0.05-0.08 mg% in referents to 0.12-0.19 in workers exposed above 25 ppm, with a significant exposure-response trend (p<0.005). Significantly increased direct/total bilirubin ratios, ranging from 0.22 to 0.35 were associated with exposure to styrene (p<0.001), indicating diminished hepatic clearance of conjugated bilirubin. Also, a significant linear association between the hepatic transaminases ALT and AST and exposure to styrene was found in pooled regression analyses, with an increase in AP of about 10 IU/ml in workers exposed above 25 ppm air or 0.275 mg/l blood styrene in pooled analyses from both studies.

CONCLUSIONS

The consistent finding of increased direct bilirubin and AP concentrations in these two independent studies provides evidence for diminished hepatic clearance of conjugated bilirubin with associated cholestasis in workers exposed to styrene. The finding of a significant linear association between hepatic transaminase concentrations and exposure to styrene in pooled analyses is consistent with mild hepatic injury and associated metabolic dysfunction.

Comparison of calibrated and uncalibrated bone mineral density by CT to DEXA in menopausal women

OBJECTIVES

Coronary artery disease and osteoporosis increase in women after menopause. Computed tomography (CT) scans of the heart used to evaluate coronary arterial calcification include images of the thoracic vertebrae. The utility of using these images to assess bone health in women remains to be defined. Analyses of thoracic spine volumetric bone mineral density (vBMD) from CT scans of the heart were performed to determine how specific calibration affects the ability to assess vBMD in recently menopausal women and to evaluate how vBMD relates to areal bone mineral density (aBMD) using dual-energy X-ray absorptiometry (DEXA).

METHODS

Women (n = 111) enrolled in the Kronos Early Estrogen Prevention Study (KEEPS) at Mayo Clinic underwent a CT scan of the heart that included calibration phantoms and a DEXA of the lumbar spine. The Spine Cancer Assessment program was used to determine vBMD of thoracic vertebrae with and without the calibration correction.

RESULTS

Trabecular bone vBMD at T8 averaged 163.57±28.58 and 157.94±27.55 mg/cc (mean±standard deviation, SD) for calibrated and uncalibrated values, respectively. The relationship between calibrated and uncalibrated measures approached unity (R = 0.98). Lumbar spine (L2-4) aBMD was 1.19±0.16 g/cm(2) (mean±SD). Both calibrated and uncalibrated thoracic vBMD correlated positively and significantly with lumbar aBMD, but the relationship was less than unity (R = 0.63).

CONCLUSION

Uncalibrated measures of thoracic spine vBMD obtained from CT scans of the heart may provide clinically relevant information about bone health and osteoporosis/osteopenia risk in recently menopausal women.

Biomass and lipid production of dinoflagellates and raphidophytes in indoor and outdoor photobioreactors

The principal fatty acids from the lipid profiles of two autochthonous dinoflagellates (Alexandrium minutum and Karlodinium veneficum) and one raphidophyte (Heterosigma akashiwo) maintained in bubble column photobioreactors under outdoor culture conditions are described for the first time. The biomass production, lipid content and lipid productivity of these three species were determined and the results compared to those obtained when the strains were cultured indoors. Under the latter condition, the biotic values did not significantly differ among species, whereas under outdoor conditions, differences in both duplication time and fatty acids content were observed. Specifically, A. minutum had higher biomass productivity (0.35 g·L⁻¹ day⁻¹), lipid productivity (80.7 mg lipid·L⁻¹ day⁻¹) and lipid concentration (252 mg lipid·L⁻¹) at harvest time (stationary phase) in outdoor conditions. In all three strains, the growth rate and physiological response to the light and temperature fluctuations of outdoor conditions greatly impacted the production parameters. Nonetheless, the species could be successfully grown in an outdoor photobioreactor and were of sufficient robustness to enable the establishment of long-term cultures yielding consistent biomass and lipid production.

Do sleep interventions change sleep duration in children aged 0-5 years? A systematic review and meta-analysis of randomised controlled trials

This review investigated whether randomised controlled trials attempting to improve sleep or prevent sleep problems in 0-5 year olds influenced nocturnal sleep duration, day-time naps, or 24-h sleep. Medline (Ovid), EMBASE, and CINAHL were searched from inception until 9 July 2020 and supplemented with hand searching. Search results were screened, eligible data were extracted, and risk of bias was assessed by at least two reviewers. Of 8571 publications considered, 32 trials which used a variety of subjective and objective sleep measurements were included in generic inverse variance random effects meta-analysis of nocturnal (n = 24), day-time (n = 14), and 24-h (n = 13) sleep duration. Overall, sleep interventions increased nocturnal sleep duration by a mean of 9 min (95% CI 4.1 to 13.8, I²28%) per night when compared with no sleep intervention. Increases were predominantly seen in sleep-only, rather than multi-component interventions. Total 24-h sleep duration tended to increase by a similar amount (8.6 min (95% CI -2.7 to 19.8, I² = 59%)), but this was mainly only seen in studies that assessed sleep using diaries. There was no evidence that interventions changed day-time sleep duration. Future studies should involve sleep-only rather than multi-component interventions, and use objective sleep measures (reviewregistry857).

Comparison of inpatient and outpatient traction in developmental dislocation of the hip

We studied 83 hips in 72 children being treated for developmental hip dislocation to assess the influence of home traction upon the incidence and severity of avascular necrosis (AVN). We compared two types of traction prior to closed or open reduction: inpatient Bryant's skin traction (40 hips), and outpatient (home) Bryant's skin traction (43 hips). No routine in-traction radiographs were taken in either group. After traction, a stable closed reduction was achieved in 55 hips (66%). Open reduction was performed on 28 hips (34%). The rate of severe AVN involving growth disturbance and resultant deformity (Bucholz types II, III, and IV) was low in both traction groups (inpatient, three out of 40, outpatient, one out of 43). These results demonstrate that an outpatient traction program without attention to radiographic hip station is as safe as identically instituted inpatient programs, as well as those that emphasize achievement of a traction reduction or a predetermined hip station.

Trial of a negative ion generator device in remediating problems related to indoor air quality

It has been suggested that supplementation of indoor air with negative ions can improve air quality. This study examined the effects of a "negative ion-generator" device on air contaminants and symptom reporting in two office buildings. Separate sets of functional and nonfunctional negative ion generators were monitored using a double blind, crossover design involving two 5-week exposure periods. There were no detectable direct or residual effects of negative ion generator use on air ion levels, airborn particulates, carbon dioxide levels, or symptom reporting. Symptom reporting declined at both sites initially and appeared to be consistent with placebo effect. Job dissatisfaction was an apparent contributor to symptom reporting, with a magnitude comparable to presumed effects of air quality. Further testing of such devices is needed before they should be considered for office air quality problems.

Erotomania after aneurysmal subarachnoid hemorrhage: case report and literature review

A woman developed the delusional syndrome of erotomania 4 years after subarachnoid hemorrhage from a ruptured basilar artery aneurysm. The authors review the literature on erotomania in association with neurologic and medical conditions. Although no cause-and-effect relationship can be established between the neurologic event and erotomania in this patient, the possible neuropsychiatric correlates of this syndrome highlight the need for careful attention to neurologic and medical factors in future cases. Available information suggests that diffuse brain dysfunction may contribute to erotomania, perhaps by interfering with the operations of cerebral regions subserving complex emotional function.

Coronary arterial calcification and thoracic spine mineral density in early menopause

OBJECTIVES

Cardiovascular disease and osteoporosis increase in women after menopause. While aortic calcification is associated with bone loss in women, a similar relationship for coronary arterial calcification (CAC), a risk factor for coronary artery disease in women, is less clear. This study was designed to examine the relationship between CAC and volumetric bone mineral density (vBMD) in women (n=137) who were within a median of 18 months past their last menses at screening for the Kronos Early Estrogen Prevention Study (KEEPS).

METHODS

CAC was measured using 64-slice computed tomography; vBMD was measured from these images using the Spine Cancer Assessment program. Concentrations of osteocalcin, bone alkaline phosphatase, tartrate-resident acid phosphatase-5b and osteopontin as bone matrix protein in serum and plasma were evaluated by ELISA.

RESULTS

CAC scores ranged from 0 to 327.6 Agatston Units (AU); 113 women had a score of 0 AU, 20 had a CAC score between 0 and 50 AU, and four had a CAC score>50 AU. Although not statistically significant, there was a trend toward decreasing central density of thoracic T9 with increasing CAC. On average, levels of markers of bone turnover were within the normal range but did not correlate with age or with months past menopause.

CONCLUSIONS

Clinically significant CAC and spine vBMD are quantifiable from the same scans within the first 3 years of menopause. Additional work is needed to determine how these measurements change with increasing age or with estrogenic treatments.

Gender- and Sexuality-Minoritised Adolescents in DBT: A Reflexive Thematic Analysis of Minority-Specific Treatment Targets and Experience

Gender- and sexuality-minoritised (GSM) adolescents are at increased risk of self-harm and suicidal behaviours compared to their cisgender and heterosexual peers. This increased risk is thought to be explained in part by exposure to stigma and societal oppression. Dialectical Behaviour Therapy (DBT) is an evidence-based intervention for self-harm and suicidal behaviour that may have advantages for supporting GSM young people in distress. No study has yet sought to understand what GSM-associated difficulties may be important to consider in DBT for adolescents, or the experiences of GSM young people in a standard DBT programme. Therefore, this study aimed to understand the experiences of GSM young people in DBT and what difficulties and dilemmas associated with their gender and sexuality diversity were thought by them to be important to target in DBT. Qualitative interviews were conducted with 14 GSM young people in a comprehensive DBT programme and were analysed using Reflexive Thematic Analysis. The analysis was supported by two further GSM young people who had finished DBT. The findings were split into three overarching themes (Identity, Impact of Others, and Space for Sexual and Gender Identity in DBT), each with themes within. The identity-based theme included "identity confusion and acceptance"; the relationship-based themes included "cis-Heterosexism" and "community connectedness"; and the space within DBT themes included "negotiating focus and targeting in DBT" and "creating safety in DBT". Findings are discussed in relation to implications and recommendations for therapists working with GSM young people within and outside of DBT.

Peripheral markers of neurochemical function among workers exposed to styrene

A cross sectional study of biological markers of neurochemical function in peripheral blood cells, and self reported nervous system symptoms, was conducted among 60 workers exposed to styrene in three reinforced plastics plants and 18 reference workers not exposed to styrene or other solvents. Concentrations of styrene in the air at the plants ranged from less than 1 to 160 ppm. Biomarkers of neurochemical function measured were: sigma receptor binding in lymphocytes, monoamine oxidase type B (MAO-B) activity in platelets, and serotonin uptake by platelets. Blood styrene concentration was used as the exposure index to take account of the use of protective equipment and dermal uptake. Four blood styrene exposure groups were defined as: non-exposed (reference) and exposed to less than 0.05, 0.05-0.19, and greater than or equal to 0.20 micrograms/ml. The prevalences of headache, dizziness, light headedness, fatigue, irritability, memory loss, and feeling "drunk" at work increased with increasing blood styrene concentration. No effect on sigma receptor binding was seen. A slight positive correlation was found for uptake of serotonin, which has been used as an exposure related effect indicator in previous studies of workers exposed to solvents. The MAO-B activity decreased with increasing blood styrene concentration; the mean (SE) MAO-B values for the four groups were 34.2 (3.0), 28.1 (5.3), 20.1 (4.8), and 16.9 (7.7) pmol/10(7) cells/min. The MAO-B activity also correlated negatively with the number of reported nervous system symptoms, whereas no associations were seen between prevalence of symptoms and either serotonin uptake or sigma receptor binding. The findings for MAO-B activity are consistent with previously reported experimental data, and suggest that MAO-B may be a useful marker of styrene neurotoxicity.

Determination and optimization of mode matching into optical cavities by heterodyne detection

We report on a novel high-sensitivity method to characterize and improve mode matching into optical cavities. This method is based on heterodyne detection of cylindrical transverse cavity modes. A specially designed annular-segmented photodiode is used to measure the amplitude of nonresonant modes reflected by the cavity. Our measurements allow us to optimize cavity mode matching to nearly 99.98% and will play an important diagnostic role in gravitational-wave detectors.