NFA: Videnskabelige artikler

Spreadning of chronic pain between body regions: prospective cohort study among health care workers [Epub ahead of print]

Mon, 14 May 2012 00:00:00 +0200

Objective: To estimate the prognostic value of pain in one body region onthe risk for developing chronic pain in other body regions.Methods: Prospective cohort study among 5052 Danish female healthcare workers responding to a baseline and follow-up questionnaire in 2005and 2006, respectively. Using adjusted logistic regression analysis, the riskfor developing chronic pain (>30 days last year) at follow-up in the lowback (among those without low back pain during the last year at baseline)when experiencing sub-chronic (1-30 days last year) or chronic pain inother body regions (i.e., the neck/shoulders and/or the knees at baseline)was modelled. Similar risks were modelled for developing chronic pain inthe neck/shoulders and knees.Results: Chronic pain in the neck/shoulders (OR 3.14; 95% CI1.74-5.70) or knees (OR 2.57; 95% CI 1.28-5.16) at baseline increased therisk for developing chronic pain in the low back at follow-up. Likewise,chronic pain in the neck/shoulders (OR 2.39; 95% CI 1.36-4.17) or lowback (OR 1.82 95%; CI 1.07-3.09) at baseline increased the risk fordeveloping chronic pain in the knees at follow-up. The risk for developingchronic neck/shoulder pain was not significantly increased when havingpain in the low back or knees at baseline.Conclusion: Among health care workers, chronic musculoskeletal painin one body region increases the risk for developing chronic pain in otherpain-free body regions. Prevention of musculoskeletal disorders amonghealth care workers should focus holistically on the musculoskeletalsystem.

Bullying or violence during training and the risk of dropout from the eldercare sector 2 years later [Epub ahead of print]

Mon, 14 May 2012 00:00:00 +0200

Background: The proportion of old people in need of care is growing rapidly in most western societies, and there is a rising demand for qualified eldercare workers in the years to come. Hence, solutions to high turnover in the eldercare sector are becoming increasingly important.Aim: To test whether bullying, violence and/or threats of violence (violence) among health care trainees are predictors of subsequent dropout from the eldercare sector 2 years after graduation from college.Methods: A questionnaire was given to all health care trainees in Denmark approximately 2 weeks before their graduation in 2004. Female respondents (N = 5000) were followed in national employment registers to see whether they had dropped out of the eldercare sector by the end of 2006. Logistic regression was used to model the outcome.Results: Among the respondents, 5.5% had been bullied during the training period, 9.1% had been subjected to violence. Hereof, 1% reported exposure to both bullying and violence. At follow-up, 37% had dropped out of the eldercare sector. The odds of dropout were significantly associated with bullying, OR = 1.39 (95% CI: 1.08-1.79), but not with violence, OR = 0.89 (95% CI: 0.72-1.09).Conclusion: Being bullied while in training as a health care worker is a predictor of subsequent dropout from the eldercare sector.

Nano-silver induces dose-response effects on the nematode Caenorhabditis elegans

Fri, 11 May 2012 00:00:00 +0200

Toxicity of nano-formulated silver to eukaryotes was assessed by exposing nematodes (Caenorhabditis elegans) to two types of silver nanoparticles (AgNPs): with average primary particle diameters of 1 nm (AgNP1) and 28 nm (AgNP28, PVP coated), respectively. Tests were performed with and without presence of Escherichia coli to evaluate how the presence of a food bacterium affects the AgNP toxicity. A pre-exposure experiment was also conducted with nematodes pre-exposed to 0 and 1 mg AgNP L-1, respectively, for 20 h prior to exposure at higher concentrations of AgNP. Both AgNP1 and AgNP28 showed adverse dose-response effects and mortality on C. elegans. LC50 for AgNP28 was lower than for AgNP1 and, hence, at the present test conditions the PVP-coated AgNP28 was more toxic than AgNP1. Including E. coli in the test medium as a food source increased AgNPs toxicity towards nematodes compared to when bacteria were not present. Pre-exposure to a low-level AgNP1 concentration made the nematodes slightly more sensitive to further exposure at higher concentrations compared to no pre-exposure, indicating that nematodes have no efficient physiological ability to counteract nano-silver toxicity by acclimation. The amount of dissolved Ag+ was 0.18 to 0.21 mg L-1 after 20 h at the highest AgNP1 (10 mg L-1) and AgNP28 (3 mg L-1) doses in the exposure medium, respectively. The upper limit of Ag+ solubility cannot immediately explain the dose-response-related toxic effects of the AgNP nor the difference between AgNP1 and AgNP28. Higher toxicity of AgNP28 than AgNP1 may be explained by a combination of effects of coating, Ag-solubility and higher uptake rates due to agglomeration into µm-size agglomerates in the exposure medium.

Effects of airflow and changing humidity on the aerosolization of respirable fungal fragments and conidia of botrytis cinerea

Fri, 11 May 2012 00:00:00 +0200

The purpose of this study was to investigate the aerosolization of particles (micro- and macroconidia and fragments) from Botrytis cinerea cultures in relation to potential human inhalation in indoor environments. The influence of the following factors on the aerosolization of B. cinerea particles was studied: exposure to airflow, relative humidity (rh), changing rh, and plant or building materials. The aerodynamic diameter (da) and the respirable fraction of the aerosolized particles were determined. Conidia and fragments of B. cinerea were not aerosolized as a response to a decrease in the rh. In contrast, both micro- and macroconidia and fungal fragments were aerosolized when exposed to an airflow of 1.5 m s-1 or 0.5 m s-1. Significantly more particles of microconidial size and fragment size were aerosolized at a low rh (18 to 40% rh) than at a higher rh (60 to 80% rh) when cultures were exposed to airflow. The size of the respirable fraction of the aerosolized particles was dependent on the rh but not on the growth material. At high rh, about 30% of the aerosolized particles were of respirable size, while at low rh, about 70% were of respirable size. During low rh, more fungal (1?3)-ß-d-glucan and chitinase were aerosolized than during high rh. In conclusion, exposure to external physical forces such as airflow is necessary for the aerosolization of particles from B. cinerea. The amount and size distribution are highly affected by the rh, and more particles of respirable sizes were aerosolized at low rh than at high rh.

Exposure to negative acts at work, psychological stress reactions and physiological stress response [Epub ahead of print]

Thu, 10 May 2012 00:00:00 +0200

Objectives: The overall aim of the study was to test the association between exposure to negative acts at work, psychological stress-reactions and cortisol secretion and whether some negative acts are more detrimental to health than others.Methods: A questionnaire study included 1010 respondents from 55 workplaces. Three saliva samples collected from the participants at awakening, 30 min later and at 20:00 during a workday were analysed for cortisol concentrations. Negative acts were measured using a modified version of the revised Negative Acts Questionnaire (to measure bullying behaviour). Factor analyses identified four subscales: social isolation, direct harassment, intimidating behaviour and work related acts. Psychological stress-reactions were measured by the Impact of Event Scale (IES) measuring traumatic stress-reactions.Results: Having controlled for gender, age, other traumatic incidents and physical violence, multiple regression analyses showed significant linear associations between social isolation and the three IES scales: hyper-arousal, intrusive thoughts, and avoidance behaviour. Work-related negative acts were significantly associated with all three outcome scales though to a lesser degree, whereas direct harassment was only associated with avoidance behaviour. Intimidating acts were significantly associated with hyper-arousal. We found significantly reduced levels of cortisol concentration for exposure to direct harassment and intimidating behaviour.Conclusion: The results show that some negative acts such as direct harassment and intimidating behaviour are associated with psychological stress-reactions and a negative physiological stress response. Extending previous research this indicates that some negative acts are more detrimental than others in so far as exposure to these acts affects both psychological and physiological health.

Organic dust toxic syndrome at a grass seed plant caused by exposure to high concentrations of bioaerosols [Epub ahead of print]

Thu, 10 May 2012 00:00:00 +0200

[Open access] We describe an outbreak of sudden health problems in workers at a Danish grass seed plant after exposure to a particularly dusty lot of grass seeds. The seeds are called problematic seeds. The association between development of organic dust toxic syndrome (ODTS) and the handling of grass seeds causing exposure was assessed in a four-step model: (i) identification of exposure source, (ii) characterization of the emission of bioaerosols from the problematic and reference seeds, (iii) personal and stationary exposure measurement at the plant and (iv) repeated health examinations. The grass seeds were identified as the exposure source; the emissions of some bioaerosol components were up to 107 times higher from the problematic seeds than from reference seeds. Cleaning of the seeds was not enough to sufficiently reduce the high emission from the problematic seeds. Emission in terms of dust was 3.4 times as high from the problematic cleaned seeds as from cleaned reference seeds. The personal exposure reached 3 × 105 endotoxin units m-3, 1 × 106 colony-forming units (cfu) of thermophilic actinomycetes m-3, 8 × 105 cfu of Aspergillus fumigatus m-3 and 9 × 106 hyphal fragments m-3. Several workers working with the problematic seeds had symptoms consistent with ODTS. The most severe symptoms were found for the workers performing the tasks causing highest exposure. Respiratory airway protection proved efficient to avoid development of ODTS. Work with reference seeds did not cause workers to develop ODTS. Exposure was during work with the problematic seeds higher than suggested occupational exposure limits but lower than in studies where researchers for some minutes have repeated a single task expected to cause ODTS. In this study, many different bioaerosol components were measured during a whole working day. We cannot know, whether it is the combination of different bioaerosol components or a single component which is responsible for the development of ODTS. In c

Paid care work and depression: A longitudinal study of antidepressant treatment in female eldercare workers before and after entering their profession [Epub ahead of print]

Tue, 08 May 2012 00:00:00 +0200

Background: Previous studies have reported that employees in paid care work (e.g., child, health, and elderly care) have increased rates of hospitalization with depression and treatment with antidepressants. It is unclear, however, whether these findings reflect a causal effect of the work on employee mental health or a selection into these professions.Methods: We examined prevalences of antidepressant purchases during 1995-2008 in a cohort of female eldercare workers who entered their profession in 2004 (n = 1,946). These yearly prevalences were compared to those of a representative sample of the female Danish working population (n = 4,201). Trends in antidepressants prevalences were examined using generalized estimation equations. Further, to account for bias by treatment seeking, we compared self-reported depressive symptoms in 2005 measured by the mental health scale from the SF-36.Results: Female eldercare workers had consistently higher prevalence of antidepressant treatment than the general female working population. The eldercare workers were also more likely to suffer from depressive symptoms in 2005 (standardized prevalence ratio = 1.28, 95% CI = 1.09-1.49). Prevalences of antidepressant treatment increased during follow up for both cohorts, with similar estimated odds ratios of about 1.15 per year. The trend in the antidepressant prevalences for the eldercare workers was unchanged by entering eldercare work.Conclusions: These findings indicate that female eldercare workers are at increased risk of depression. Further, as the trend in the antidepressant prevalences among the eldercare workers was similar before and after entering their profession, the results suggest that this increased risk is due to selection into the profession.

Transitions between sickness absence, work, unemployment, and disability in Denmark 2004-2008 [Epub ahead of print]

Tue, 08 May 2012 00:00:00 +0200

Objectives: Studies of labor market outcomes like sickness absence are usually restricted to a single outcome. This paper investigates the use of multi-state models for studying multiple transitions between sick-listing, work, unemployment, and disability pension by analyzing longitudinal register data. Every person sick-listed in Denmark during 2004 was followed until the spring of 2008.Methods: A multi-state model was used to analyze transitions between four states: work, sickness absence, unemployment, and disability pension. The first three are possible recurrent states. The predictor variables include age group, gender, geographical region, chronic disease, temporary disease, self-employment sickness absence insurance, and pregnancy. The relative effects of previous transitions were also studied.Results: Risk of transition from sickness absence to disability pension differs with age and geographical region. Those aged 20-29 years have an increased risk of transitioning from work to sickness absence and from sickness absence to unemployment. The self-employed have increased risk of transitioning from work to sickness absence. Those with chronic disease have increased risk of sickness absence, but also a greater probability of returning to work. Previous sickness absence increases the risk of transitioning from work to sickness absence, from sickness absence to unemployment, from work to unemployment, and from work to disability pension. Conclusions: The multi-state model is an effective way of analyzing register data and the transitions between sickness absence, work, unemployment, and disability pension. These methods can be used to develop better predictive models of sickness absence, return to work, unemployment, and disability.

Time trend analysis of return to work after stroke in Denmark 1996-2006

Tue, 08 May 2012 00:00:00 +0200

Background: In the period 1997-2005, the Danish government initiated a series of legislative changes aimed at facilitating RTW (return to work) in the Danish population. In the present study, we investigated the odds of being gainfully occupied ca. two years after stroke as a function of onset calendar year, 1996-2006. Methods: All previously employed 20-57 year-old stroke patients in Denmark 1996-2006 (N = 19985) were followed prospectively through national registers. The analysis was controlled for the type of stroke and a series of demographic, structural and occupational variables. Results: The odds for RTW increased significantly during the study period (P < 0.0001). The odds at the end of the period were more than twice as high as they were at the beginning, even after post hoc control for improved survival and decreased unemployment rates. The most conspicuous increase coincided with a change in the sickness benefit act that took place in 2005. Conclusion: The study provides quite strong circumstantial evidence that the legislative changes had an effect on the odds of return to work after stroke. More direct evidence is desirable, but such can only be obtained through a randomized controlled study.

Problems of the "outer eyes" in office environment: An ergophthalmologic approach

Tue, 08 May 2012 00:00:00 +0200

Objective: To assist health professionals dealing with the complex clinical picture of "outer" eye symptoms-among top-two in office environments--by an ergophthalmologic approach.Method: The terms "precorneal tear film" (PTF) and eye/ocular discomfort and irritation symptoms were searched together with a number of environmental and personal factors in databases such as PubMed.Results: The microclimate (humidity and temperature), environmental pollution, working conditions and habits, contact lenses, certain medication, nutrition, and personal care products alter the PTF. Ocular allergies also contribute to the overall incidence of ocular symptoms and diseases.Conclusions: These mechanisms alter the structure and chemical composition of the PTF leading to desiccation and hyperosmolarity. A third mechanism causes trigeminal stimulation by air pollutants; in indoor environments by concerted action of the two former mechanisms. Hygienic habits prevent alteration of the PTF.

A functional polymorphism in the promoter region of the IL1B gene is associated with risk of multiple myeloma [Epub ahead of print]

Tue, 08 May 2012 00:00:00 +0200

The cytokine interleukin-1ß (IL1B) is important for anti-tumour immune response. Genetic variation may modify the expression of IL1B and thereby influence the risk of disease. We investigated genetic variations with functional importance in the IL1B and NFKB1 genes in 348 population-based samples of multiple myeloma (MM) and a random sample of 1700 individuals. Carriers of the variant T-allele IL1BC-3737T and carriers of the TGT haplotype were at lower risk of MM [relative risk (RR) 0·58 (95% confidence interval (CI) = 0·41-0·84) and RR 0·59 (95%CI 0·40-0·85), respectively]. No association with risk of MM was found for the NFKB1- 94 ins/del polymorphism.

Sperm DNA integrity in relation to exposure to environmental perfluoroalkyl substances - A study of spouses of pregnant women in three geographical regions [Epub ahead of print]

Tue, 01 May 2012 00:00:00 +0200

Perfluoroalkyl substances (PFASs) can interfere with male reproductive function, but evidence in humans is limited. Six hundred four fertile men (199 from Greenland, 197 from Poland and 208 from Ukraine) were enrolled in the study. We measured four PFASs in serum (PFOS, PFOA, PFNA and PFHxS) and concurrent DNA damage in spermatozoa by sperm chromatin structure assay (SCSA) and in situ terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay, apoptotic markers in semen (Fas-receptor and Bcl-xL), and reproductive hormones in serum. No association between PFASs and SCSA, apoptotic markers or reproductive hormones emerged. We observed a slight increase in SHBG and TUNEL-positivity with increased PFOA exposure in men from Greenland. Thus, consistent evidence that PFAS exposure interferes with sperm DNA fragmentation, apoptosis or reproductive hormones was not found.

Implementation of physical coordination training and cognitive behavioral training interventions at cleaning workplaces - secondary analyses of a randomised controlled trial [Epub ahead of print]

Tue, 01 May 2012 00:00:00 +0200

This study evaluates the implementation of physical coordination training (PCT) and cognitive behavioural training (CBTr) interventions in a randomised controlled trial at nine cleaners' workplaces. Female cleaners (n = 294) were randomised into a PCT, a CBTr or a reference (REF) group. Both 12-week interventions were performed in groups guided by an instructor. Records were kept on intervention dose (adherence) unanticipated events at the work place (context) and quality of intervention delivery (fidelity). Participant adherence was 37% in the PCT and 49% in the CBTr interventions. Optimal implementation was reached by only 6% in PCT and 42% in the CBTr. Analysis of the barriers to successful implementation indicated that the intervention process is sensitive to unanticipated events. In order to succeed in improving the health of high-risk populations such as cleaners and to correctly interpret intervention effects, more research on implementation is needed

The association between health and sickness absence among Danish and non-Western immigrant cleaners in Denmark [Epub ahead of print]

Thu, 26 Apr 2012 00:00:00 +0200

Purpose: The aim of the study is to investigate the association between health and sickness absence among Danish and non-Western immigrant cleaners in Denmark. Methods: This study is based on a cross-sectional analysis of baseline data from 2007 to 2008. The study population includes 276 cleaners, 144 Danish and 132 non-Western immigrant cleaners. Cumulative sickness absences during a 6-month period from administrative records were subdivided into no sickness absence (0 days), low occurrence of sickness absence (1-10 days) and high occurrence of sickness absence (over 10 days). Measures of health consisted of self-report and objective assessments. The relationship between sickness absence and health was analyzed through multinomial logistic regression, stratified by immigrant status. Results: For both Danish and non-Western immigrant cleaners, poor self-reported health was significantly related to high occurrence of sickness absence. Among Danish cleaners, high blood pressure was related to high occurrence of sickness absence. Among non-Western immigrant cleaners, total body pain and having one or more diagnosed chronic disease were related to high occurrence of sickness absence. No association between health and low occurrence of sickness absence was found. Conclusions: The findings confirm the importance of health for high occurrence of sickness absence, in both ethnic groups. Moreover, low occurrence of sickness absence was not related to the health conditions investigated.

A risk model for lung cancer incidence [Epub ahead of print]

Thu, 19 Apr 2012 00:00:00 +0200

Risk models for lung cancer incidence would be useful for prioritising individuals for screening and participation in clinical trials of chemoprevention. We present a risk model for lung cancer built using prospective cohort data from a general population which predicts individual incidence in a given time period. We build separate risk models for current and former smokers utilising 169,035 ever smokers from the multicentre European Prospective Investigation into Cancer and Nutrition (EPIC) and considered a model for never smokers. The data set was split into independent training and test sets. Lung cancer incidence was modelled using survival analysis, stratifying by age started smoking, and for former smokers, also smoking duration. Other risk factors considered were smoking intensity, ten occupational/environmental exposures previously implicated with lung cancer, and SNPs at two loci identified by genome-wide association studies of lung cancer. Individual risk in the test set was measured by the predicted probability of lung cancer incidence in the year preceding last follow-up time, predictive accuracy was measured by the area under the receiver operator characteristic curve (AUC). Utilising smoking information alone gave good predictive accuracy: the AUC and 95% confidence interval in ever smokers was 0.843 (0.810, 0.875), the Bach model applied to the same data gave an AUC of 0.775 (0.737, 0.813). Other risk factors had negligible effect on the AUC, including never smokers for whom prediction was poor. Our model is generalisable and straightforward to implement. Its accuracy can be attributed to its modelling of lifetime exposure to smoking.

ABCC2 transporter gene polymorphisms, diet and risk of colorectal cancer: a Danish prospective cohort study

Tue, 17 Apr 2012 00:00:00 +0200

A specific diplotype defined by PPP1R13L rs1970764, CD3AP rs967591 and ERCC1 rs11615 and lung cancer risk in a Chinese population

Tue, 17 Apr 2012 00:00:00 +0200

Haplotypes defined by multiple loci may be more precise and useful than genotypes in providing risk esti-mates for particular cancers. Diplotype is defined as a specific combination of two haplotypes. A Chinese case-control analysis comprising 370 cases and 388 controls was conducted to evaluate the effects of the high-risk diplotype predefined as PPP1R13L rs1970764AA-CD3EAP rs967591GG-ERCC1 rs11615AA among Caucasians and three SNPs alone or other haplotypes combined for lung cancer risk. Both the variant G-allele of PPP1R13L rs1970764 and the variant A-allele of CD3EAP rs967591 were significantly over-represented among cases (P = 0.03 and P = 0.002, respectively). The variant GG-homozygotes of PPP1R13L rs1970764 had increased risk [GG versus AA: adjusted OR (95% CI) = 1.30 (1.04-1.62), P = 0.02]. The carri-ers of variant A-allele of CD3EAP rs967591 also presented increased risk [AA versus GG: adjusted OR (95% CI) = 1.40 (1.12-1.75), P = 0.004; AG versus GG: adjusted OR (95% CI) = 1.47 (1.05-2.07), P = 0.03 and AG + AA versus GG: adjusted OR (95% CI) = 1.26 (1.07-1.48), P = 0.005]. Interaction between CD3EAP rs967591 and smoking duration was observed (P = 0.003). Only haplotype 1 (the common haplotype) defined as PPP1R13L rs1970764G-CD3EAP rs967591A-ERCC1 rs11615G showed marginally increased risk [OR (95% CI) = 1.38 (1.09-1.75), P = 0.009] after Bonferroni correction. The frequency of the high-risk diplotype predefined among Caucasians was 1% in controls and no significant evidence of the diplotype distribution between cases and controls was detected in present study. In conclusion, we found that vari-ant alleles of PPP1R13L rs1970764 and CD3EAP rs967591 may contribute to risk factors of lung cancer, but the high-risk diplotype predefined among Caucasians was rare and the diplotype is unlikely to confer lung cancer risk in a Chinese population.

The relationship between low back pain and leisure time physical activity in a working population pf cleaners - a study with weekly follow-ups for 1 year

Thu, 12 Apr 2012 00:00:00 +0200

[Open access] Background: Low back pain (LBP) and leisure time physical activity (LTPA) are considered to be closely related, and clinical guidelines for the treatment of acute LBP recommend patients stay physically active. However, the documentation for this recommendation is sparse and based on studies involving patient populations. The purpose of the study was (1) to investigate the correlation between LBP and LTPA on a weekly basis over the course of a year in a high-risk group of cleaners; and (2) to investigate if maintaining LTPA during an episode of acute LBP has a positive effect on LBP intensity in the subsequent 4 weeks. Methods: 188 cleaners consented to participate in a 52-week text message survey about hours of LTPA and intensity of LBP (from 0 to 9) over the previous 7 days. The correlation between LBP and LTPA was calculated by Pearson correlation coefficient. During an episode of acute LBP, a mixed effect logistic regression model was used to investigate whether cleaners who maintain LTPA have a lower pain intensity and higher probability of returning to initial pain intensity within the following four weeks compared with cleaners who decrease LTPA during acute LBP. Results: The correlation between weekly LTPA and LBP data was negative, but numerically low (r = -0.069) and statistically insignificant (p = 0.08). Among the 82 cleaners experiencing at least one episode of acute LBP, those maintaining LTPA during an episode of acute LBP did not have a lower pain intensity (average LBP intensity difference between groups of 0.06; 95% confidence interval (95% CI) of -0.417 to 0.539) or higher probability of returning to initial pain level (Odds ratio 1,02; 95% CI of 0.50 to 2.09) in the following four weeks compared with cleaners decreasing LTPA during acute LBP. Conclusions: Hours of LTPA and intensity of LBP measured on a weekly basis throughout a year showed no close correlation. Maintaining LTPA during an episode of acute LBP did not result in a posi

A quantification of occupational skin exposures and the use of protective gloves among hairdressers in Denmark [Epub ahead of print]

Thu, 12 Apr 2012 00:00:00 +0200

Background: Occupational hand eczema is common in hairdressers, owing to excessive exposure to wet work and hairdressing chemicals.Objectives: To quantify occupational skin exposure and the use of protective gloves among hairdressers in Denmark.Methods. A register-based study was conducted comprising all graduates from hairdressing vocational schools from 1985 to 2007 (n = 7840). The participants received a self-administered postal questionnaire in May 2009, including questions on hairdressing tasks performed in the past week at work and the extent of glove use. A response rate of 67.9% (n = 5324) was obtained.Results: Of the respondents, 55.7% still worked as hairdressers, and they formed the basis of this study. Daily wet work was excessive; 86.6% had wet hands for =2 hr, and 54% for = 4 hr. Glove use was fairly frequent for full head hair colouring and bleaching procedures (93-97.7%), but less frequent for highlighting/lowlighting procedures (49.7-60.5%) and permanent waving (28.3%). Gloves were rarely worn during hair washing (10%), although this was more frequently the case after hair colouring procedures (48.9%).Conclusions: Occupational skin exposure was excessive among hairdressers; the extent of wet work and chemical treatments was high, and glove use was inconsistent, especially for certain hair colouring procedures and wet work tasks.

Jobs encompassing prolonged sitting in cramped positions and risk of venous thromboembolism: cohort study

Thu, 29 Mar 2012 00:00:00 +0200

[Open access] Objectives:There is mounting evidence that prolonged cramped sitting in connection with long-lasting air travel increases the risk of deep vein thrombosis of the legs and pulmonary embolism, i.e. venous thromboembolism (VTE). Prolonged cramped sitting may occur even in various jobs unrelated to air travel, and, theoretically, be associated with an increased risk of VTE. The issue is unsettled. Design: A dynamic cohort study (open for both entry and departure) in Danish national registers 1997-2006. Participants: 20-59-year-old manual workers. The cohort consisted of an exposed group with job functions basically characterised as sedentary (n = 105,564) and a control group with more dynamic work (n = 283,966). Setting: Denmark. Main outcome measures: Deaths and hospital contacts due to pulmonary embolism and deep vein thrombosis. Results: Compared with occupations characterized by dynamic physical activity, the group encompassing those who would potentially be exposed to prolonged sitting in ergonomically adverse positions, had a significantly higher risk of pulmonary embolism (n = 77, relative risk 1.28; 95% CI 0.97-1.67, P = 0.04 in one-sided test). With respect to deep vein thrombosis they had a slightly but not significantly higher risk (n = 256, relative risk 1.09; 95% CI 0.94-1.26, P = 0.12). Conclusion: Despite the crude method used allowing for no control of individual risk factors, occupations encompassing longer and shorter periods of sitting in potentially adverse ergonomic positions, i.e. cramped sitting, had a higher risk of VTE, than a socioeconomically comparable group with more dynamic physical work demands.

The effect of stength training, recreational soccer and running exercise on stretch-shortening cycle muscle performance during countermovement jumping [Epub ahead of print]

Thu, 29 Mar 2012 00:00:00 +0200

The purpose of the present study was to evaluate the effect of contrasting training modalities on mechanical muscle performance and neuromuscular activity during maximal SSC (stretch-shortening cycle) countermovement jumps (CMJ). Bilateral countermovement jumping, surface electromyography (EMG) and muscle fiber size (CSA) were studied in untrained individuals (n = 49, 21-45 yrs) pre and post 12 weeks of progressive heavy-resistance strength training (ST, n = 8), recreational soccer training (SOC, n = 15), high-intensity interval running (INT, n = 7), continuous running (RUN, n = 9) or continuation of an inactive life-style (CON, n = 10). ST displayed shortened CMJ take-off time (p < .05) and increased (p < .05) maximal CMJ jump height, peak down- and upward velocity of center of mass (COM), rate of vertical force development (RFD: ?FZ/?t), peak power production, rate of power development (RPD), mean plantar flexor EMG and peak hamstring rate of EMG rise (RER). Peak quadriceps EMG rate of rise increased in SOC (p < .05). Moreover, ST and SOC demonstrated increased quadriceps muscle fiber CSA and lean leg mass. Positive relationships (r > .70) were observed following ST between training-induced changes in CMJ SSC muscle performance, neuromuscular activity and muscle fiber CSA, respectively. ST induced a more rapid CMJ take-off phase and elevated muscle power production, indicating a more explosive-type SSC muscle performance. No effects were detected in CMJ performance after continuous running, high-intensity interval running and recreational soccer, despite an increased muscle fiber CSA and quadriceps muscle activity in SOC. Enhanced neuromuscular activity in the hip extensors (hamstrings) and plantar flexors, and increased myofiber fiber size were responsible for the enhanced CMJ SSC muscle performance with ST.

Subacute oral toxicity investigation of nanoparticulate and ionic silver in rats

Fri, 23 Mar 2012 00:00:00 +0100

Subacute toxicity of 14 nm nanoparticulate silver (Ag-NP) stabilised with polyvinylpyrrolidone and ionic silver in the form of silver acetate (Ag-acetate) was investigated in four-week-old Wistar rats. Animals received orally by gavage the following: vehicle control (10 ?, 6 ?); Ag-NP at doses: 2.25 (8 ?), 4.5 (8 ?) or 9 mg/kg bw/day (10 ?, 6 ?); or Ag-acetate 9 mg silver/kg bw/day (8 ?) for 28 days. Clinical, haematolological and biochemical parameters, organ weights, macro- and microscopic pathological changes were investigated. Caecal bacterial phyla and their silver resistance genes were quantified. For the Ag-NP groups, no toxicological effects were recorded. For Ag-acetate, lower body weight gain (day 4-7, 11-14, 14-16, P < 0.05; overall, day 1-28, P < 0.01), increased plasma alkaline phosphatase (P < 0.05), decreased plasma urea (P < 0.05) and lower absolute (P < 0.01) and relative (P < 0.05) thymus weight were recorded. In conclusion, these findings indicate toxicity of 9 mg/kg bw/day ionic silver but not of an equimolar Ag-NP dose. This is in accordance with previously reported data showing that oral Ag-acetate, in comparison with an equimolar dose of Ag-NP, resulted in higher silver plasma and organ concentrations.

Increasing work-time influence: consequences for flexibility, variability, regularity and predictability

Thu, 22 Mar 2012 00:00:00 +0100

This quasi-experimental study investigated how an intervention aiming at increasing eldercare workers' influence on their working hours affected the flexibility, variability, regularity and predictability of the working hours. We used baseline (n = 296) and follow-up (n = 274) questionnaire data and interviews with intervention-group participants (n = 32). The work units in the intervention group designed their own intervention comprising either implementation of computerised self-scheduling (subgroup A), collection of information about the employees' work-time preferences by questionnaires (subgroup B), or discussion of working hours (subgroup C). Only computerised self-scheduling changed the working hours and the way they were planned. These changes implied more flexible but less regular working hours and an experience of less predictability and less continuity in the care of clients and in the co-operation with colleagues. In subgroup B and C, the participants ended up discussing the potential consequences of more work-time influence without actually implementing any changes.

Airway effects of inhaled quaternary ammonium compounds in mice [Epub ahead of print]

Thu, 15 Mar 2012 00:00:00 +0100

Quaternary ammonium compounds (QAC) constitute a family of widely used chemical substances. The QAC benzalkonium chloride (BAC) has caused bronchoconstriction in human beings by poorly understood mechanisms and lung damage at high concentration as shown in a single rat study. This study evaluates acute airway effects in mice after inhalation of aerosols of the QACs, BAC, hexadecyl trimethyl ammonium bromide (HTA), cetyl pyridinium chloride (CPC) and dimethyl dioctadecyl ammonium bromide (DDA). The QACs gave rise to concentration-dependent decreases in the tidal volume (VT) and a concomitant increase in respiratory rate indicating pulmonary irritation. The potencies of the QAC to induce these effects were in the order: BAC > HTA = CPC > DDA. Furthermore, inhalation of BAC and CPC aerosols gave rise to pulmonary inflammation as apparent from bronchoalveolar lavage. Stimulation of nasal trigeminal nerve endings by QAC, which may serve as a warning signal, was absent.

HapMap-based evaluation of ERCC2, PPPIR13L and ERCC1 and lung cancer risk in a Chinese population

Thu, 08 Mar 2012 00:00:00 +0100

A genomic region on chromosome 19q13.3 has been associated with cancer susceptibility. A Chinese case-control study including 339 lung cancer cases and 358 controls was conducted using haplotype-tagging SNP (htSNP) approach and HapMap database to evaluate the role of this locus. Four htSNPs (rs6966, rs2070830, rs4802252, and rs4803817) representing 95% of the common variations in PPP1R13L, as well as fourteen htSNPs encompassing ERCC2, PPP1R13L, and ERCC1 on chromosome 19q13.3 were explored. Three haplotype blocks of strong linkage disequilibrium were identified. Overall, no single htSNP or haplotype associations were found for PPP1R13L. Highly significant differential distributions of haplotypes defined by both nine htSNPs covering ERCC2 and PPP1R13L and fourteen htSNPs covering ERCC2, PPP1R13L, and ERCC1 were found (global test P = 8.12e-005 and P = 4.82e-006, respectively). The results indicate that the biologically relevant genetic variation may be located at or near the subregion spanning from ERCC2 inton19 rs1799787 to PPP1R13L intron8 rs2070830.

Carbon black nanoparticle instillation induces sustained inflammation and genotoxicity in mouse lung and liver

Mon, 05 Mar 2012 00:00:00 +0100

[Open access] Background: Widespread occupational exposure to carbon black nanoparticles (CBNPs) raises concerns over their safety. CBNPs are genotoxic in vitro but less is known about their genotoxicity in various organs in vivo. Methods. We investigated inflammatory and acute phase responses, DNA strand breaks (SB) and oxidatively damaged DNA in C57BL/6 mice 1, 3 and 28 days after a single instillation of 0.018, 0.054 or 0.162 mg Printex 90 CBNPs, alongside sham controls. Bronchoalveolar lavage (BAL) fluid was analyzed for cellular composition. SB in BAL cells, whole lung and liver were assessed using the alkaline comet assay. Formamidopyrimidine DNA glycosylase (FPG) sensitive sites were assessed as an indicator of oxidatively damaged DNA. Pulmonary and hepatic acute phase response was evaluated by Saa3 mRNA real-time quantitative PCR. Results: Inflammation was strongest 1 and 3 days post-exposure, and remained elevated for the two highest doses (i.e., 0.054 and 0.162 mg) 28 days post-exposure (P < 0.001). SB were detected in lung at all doses on post-exposure day 1 (P < 0.001) and remained elevated at the two highest doses until day 28 (P < 0.05). BAL cell DNA SB were elevated relative to controls at least at the highest dose on all post-exposure days (P < 0.05). The level of FPG sensitive sites in lung was increased throughout with significant increases occurring on post-exposure days 1 and 3, in comparison to controls (P < 0.001-0.05). SB in liver were detected on post-exposure days 1 (P < 0.001) and 28 (P < 0.001). Polymorphonuclear (PMN) cell counts in BAL correlated strongly with FPG sensitive sites in lung (r = 0.88, P < 0.001), whereas no such correlation was observed with SB (r = 0.52, P = 0.08). CBNP increased the expression of Saa3 mRNA in lung tissue on day 1 (all doses), 3 (all doses) and 28 (0.054 and 0.162 mg), but not in liver. Conclusions: Deposition of CBNPs in lung induces inflammatory and genotoxic effects in mouse lung that persist considerab

Nanotitanium dioxide toxicity in mouse lung is reduced in sanding dust from paint

Mon, 05 Mar 2012 00:00:00 +0100

Background: Little is known of how the toxicity of nanoparticles is affected by the incorporation in complex matrices. We compared the toxic effects of the titanium dioxide nanoparticle UV-Titan L181 (NanoTiO2), pure or embedded in a paint matrix. We also compared the effects of the same paint with and without NanoTiO2. Methods: Mice received a single intratracheal instillation of 18, 54 and 162 ug of NanoTiO2 or 54, 162 and 486 ug of the sanding dust from paint with and without NanoTiO2. DNA damage in broncheoalveolar lavage cells and liver, lung inflammation and liver histology were evaluated 1, 3 and 28 days after intratracheal instillation. Printex 90 was included as positive control. Results: There was no additive effect of adding NanoTiO2 to paints: Therefore the toxicity of NanoTiO2 was reduced by inclusion into a paint matrix. NanoTiO2 induced inflammation in mice with severity similar to Printex 90. The inflammatory response of NanoTiO2 and Printex 90 correlated with the instilled surface area. None of the materials, except of Printex 90, induced DNA damage in lung lining fluid cells. The highest dose of NanoTiO2 caused DNA damage in hepatic tissue 1 day after intratracheal instillation. Exposure of mice to the dust from paints with and without TiO2 was not associated with hepatic histopathological changes. Exposure to NanoTiO2 or to Printex 90 caused slight histopathological changes in the liver in some of the mice at different time points. Conclusions: Pulmonary inflammation and DNA damage and hepatic histopathology were not changed in mice instilled with sanding dust from NanoTiO2 paint compared to paint without NanoTiO2. However, pure NanoTiO2 caused greater inflammation than NanoTiO2 embedded in the paint matrix.

Development of a computerized adaptive test to assess health-related quality of life in adults with asthma

Mon, 05 Mar 2012 00:00:00 +0100

Objective. The purpose of this research was to calibrate an item bank for a computerized adaptive test (CAT) of asthma impact on health-related quality of life (HRQOL), test CAT versions of varying lengths, conduct preliminary validity testing, and evaluate item bank readability. Methods. Asthma Impact Survey (AIS) bank items that passed focus group, cognitive testing, and clinical and psychometric reviews were administered to adults with varied levels of asthma control. Adults self-reporting asthma (N = 1106) completed an Internet survey including 88 AIS items, the Asthma Control Test, and other HRQOL outcome measures. Data were analyzed using classical and modern psychometric methods, real-data CAT simulations, and known groups validity testing. Results. A bi-factor model with a general factor (asthma impact) and several group factors (cognitive function, fatigue, mental health, physical function, role function, sexual function, self-consciousness/stigma, sleep, and social function) was tested. Loadings on the general factor were above 0.5 and were substantially larger than group factor loadings, and fit statistics were acceptable. Item functioning for most items and fit to the model was acceptable. CAT simulations demonstrated several options for administration and stopping rules. AIS distinguished between respondents with differing levels of asthma control. Conclusions. The new 50-item AIS item bank demonstrated favorable psychometric characteristics, preliminary evidence of validity, and accessibility at moderate reading levels. Developing item banks for CAT can improve the precise, efficient, and comprehensive monitoring of asthma outcomes and may facilitate patient-centered care.

Comparison of sampling methods for assessment of indoor microbial exposure [Epub ahead of print]

Tue, 28 Feb 2012 00:00:00 +0100

Indoor microbial exposure has been related to allergy and respiratory disorders. However the lack of standardized sampling methodology is problematic when investigating dose-response relationships between exposure and health effects. In this study, different sampling methods were compared regarding their assessment of microbial exposures, including culturable fungi and bacteria, endotoxin, as well as the total inflammatory potential (TIP) of dust samples from Danish homes. The GSP filter sampler and BioSampler were used for sampling of airborne dust, whereas the Dust Fall Collector (DFC), the Electrostatic Dust Fall Collector (EDC) and vacuum cleaner were used for sampling of settled dust. The GSP assessed significantly higher microbial levels than the BioSampler, yet measurements from both samplers correlated significantly. Considerably higher levels of fungi, endotoxin and TIP were found in the EDC compared to the DFC, and regarding fungi, the EDC correlated more strongly and significantly to vacuumed dust than the DFC. Fungi in EDC- and vacuum dust correlated most strongly to airborne dust, and in particular the measurements from the EDC associated well with the GSP. Settled dust from the EDC was most representative of airborne dust and may thus be considered as a surrogate for assessment of indoor airborne microbial exposure.