American Journal of Industrial MedicineCase-control study of pleural mesothelioma in workers with social security in MexicoGuadalupe Aguilar-Madrid, Eduardo Robles-Pérez, Cuauhtémoc Arturo Juárez-Pérez, Isabel Alvarado-Cabrero, Flavio Gerardo Rico-Méndez, Kelly-García Javier Wed, 16 Dec 2009 15:36:00 -0000
Environmental and occupational exposure to asbestos in Mexico in the past has been a cause of deaths and health damages. Its magnitude is unknown to date. Our objective was to identify the proportion of cases of malignant pleural mesothelioma (MPM) that can be attributed to and occupational exposure to asbestos.We carried out a case-control study of MPM in 472 workers insured by the Mexican Institute of Social Security, all Valley of Mexico residents, with 119 incident cases and 353 controls. Cases were histologically confirmed. Participants were questioned concerning their occupational history and sociodemographic data. Assignment to one of the four exposures was performed qualitatively by an expert hygienist. Odds ratios (ORs) and attributable risks (ARs) were calculated using a non-conditional logistic regression model.A total of 80.6% of cases and 31.5% of controls had occupational exposure to asbestos. ORs were adjusted for age and gender and by exposure category, and exhibited an increase with probability of exposure as follows: 3.7(95% CI 1.3-10.4) for the likely category and 14.3(95% CI 8-26) for the certain category; AR in the group occupationally exposed to asbestos was 83.2%, and the population AR was 44%.Our results show that the relationship between industrial uses of all forms of asbestos is generating an increase in mesothelioma-related diseases and deaths among Mexican workers. As a public health policy, Mexico should prohibit the use of asbestos in all production processes with the aim of controlling the epidemic and preventing the occurrence of new cases of MPM. Am. J. Ind. Med. © 2009 Wiley-Liss, Inc.
Follow-up of neck and shoulder pain among sewing machine operators: The Los Angeles garment studyPin-Chieh Wang, Robert J. Harrison, Fei Yu, David M. Rempel, Beate R. Ritz Wed, 16 Dec 2009 15:36:00 -0000
The aim of the present study is to explore factors affecting or modifying self-reported neck/shoulder pain in sewing machine operators.We investigated self-report neck/shoulder pain in 247 workers who participated in a 4-month prospective intervention study for musculoskeletal disorders. All participants were immigrants. We examine the influence of individual and work-related factors on changes in neck/shoulder pain during follow-up employing linear mixed models with time-spline functions.We observed a dramatic decline (72%) in self-reported pain intensity in the first month of follow-up, followed by a small increase from the first to fourth month (4% per month). Workers who perceived and reported their physical workload as high or worked overtime experienced less overall pain reduction. Higher baseline pain intensity, being of Hispanic ethnicity (vs. Asian), and taking cumulative daily rest time during work of 35 min or more allowing for muscles to rest were associated with a larger pain reduction in the first month, but not thereafter.Our findings indicate that some work-related factors may be of clinical relevance for reducing neck/shoulder pain. Having lower physical workloads and less overtime work should be considered when treating patients or planning workplace interventions for managing work-related musculoskeletal disorders in this underserved immigrant population. Am. J. Ind. Med. 2009. © 2009 Wiley-Liss, Inc.
Hearing problems among a cohort of nationally certified EMS professionalsAntonio R. Fernandez, J. Mac Crawford, Jonathan R. Studnek, J.R. Wilkins III Wed, 16 Dec 2009 15:36:00 -0000
The objectives of this study were to estimate the prevalence of hearing problems among a national cohort of emergency medical service (EMS) professionals, determine factors associated with hearing problems, and estimate the percentage of EMS professionals who utilize hearing protection.Utilizing results from a questionnaire, individuals who reported hearing problems were compared to individuals who had not. Multivariable logistic regression was performed to identify variables associated with hearing problems. Finally, items regarding use of hearing protection were assessed to estimate the percentage of usage among EMS professionals.In total, 1,058 (57%) participants responded to the questionnaire. Of those, 1,024 (97%) who completed the hearing problems question were utilized for analysis. There were 153 (14.9%) cases of self-reported hearing problems. The final logistic regression model included lifetime occupational noise exposure 0.99 (95% CI = 0.9997-1.0002), report of previous back problems (odds ratio (OR) = 2.74, 95% CI = 1.8340-4.1042), large community size (OR = 1.67, 95% CI = 1.1211-2.4843), and minority status (OR = 0.61, 95% CI = 0.3719-0.9867). Finally, 213 (20.8%) individuals reported utilizing some form of hearing protection at their main EMS job.The results from this analysis are the first national estimates of the prevalence of self reported hearing problems among EMS professionals. This study was also the first to estimate the percentage of EMS professionals who self reported the utilization of hearing protection. Am. J. Ind. Med. © 2009 Wiley-Liss, Inc.
Effects of self-reported health conditions and pesticide exposures on probability of follow-up in a prospective cohort studyMartha P. Montgomery, Freya Kamel, Jane A. Hoppin, Laura E. Beane Freeman, Michael C.R. Alavanja, Dale P. Sandler Wed, 16 Dec 2009 15:37:00 -0000
We investigated the potential for selection bias due to non-participation in the follow-up of a large prospective cohort study.Licensed pesticide applicators (52,395 private; 4,916 commercial) in the Agricultural Health Study provided demographic, health, and pesticide exposure information at enrollment (1993-1997) and in a 5-year follow-up telephone interview. Factors associated with non-participation in the follow-up were identified using multiple logistic regression. Potential for selection bias was evaluated by comparing exposure-disease associations between the entire cohort and the follow-up subset.Sixty-six percent of private and 60% of commercial applicators completed the follow-up interview. Private and commercial applicators who did not complete the follow-up reported at enrollment younger age, less education, lower body mass index, poorer health behaviors but fewer health conditions, and lower pesticide use. Estimates of exposure-disease associations calculated with and without non-participants did not indicate strong selection bias.Differences between non-participants and participants in the follow-up interview were generally small, and we did not find significant evidence of selection bias. However, the extent of bias may depend on the specific exposure and outcome under study. Am. J. Ind. Med. © 2009 Wiley-Liss, Inc.
South Africa's export trade in asbestos: Demise of an industryJohn S. Harington, Neil D. McGlashan, Elzbieta Z. Chelkowska Thu, 26 Nov 2009 08:49:00 -0000
South Africa's export of each of its three types of asbestos, crocidolite, amosite, and chrysotile, and the total amounts to 84 countries in metric tonnes is examined over a 24-year period, 1980-2003.For convenience, the countries are divided into nine world regional groups, Europe, Eastern Europe, North America with the Caribbean, South America, Africa, Middle East, Far East, South Asia, and Oceania.The three greatest importing countries of total asbestos in metric tonnes were all in the Far East region, ranging from Japan, South Korea to Thailand, and followed by USA and Italy. All exports to all countries diminished steadily as the South African trade came virtually to an end by 2003, due to ever increasing international pressure.The export trade has changed significantly since 1960 from being dominantly to European countries to being directed in recent years to the Far East, with serious implications for asbestos-related ill-health in those countries. Am. J. Ind. Med. © 2009 Wiley-Liss, Inc.
Costs by industry and diagnosis among musculoskeletal claims in a state workers compensation system: 1999-2004Kari K. Dunning, Kermit G. Davis, Chad Cook, Susan E. Kotowski, Chris Hamrick, Gregory Jewell, James Lockey Tue, 24 Nov 2009 10:18:00 -0000
Musculoskeletal disorders (MSDs) are a tremendous burden on industry in the United States. However, there is limited understanding of the unique issues relating to specific industry sectors, specifically the frequency and costs of different MSDs.Claim data from 1999 to 2004 from the Ohio Bureau of Workers' Compensation were analyzed as a function of industry sector (NAICS industry-sector categories) and anatomical region (ICD-9 codes).Almost 50% of the claims were lumbar spine (26.9%) or hand/wrist (21.7%). The majority of claims were from manufacturing (25.1%) and service (32.8%) industries. The industries with the highest average costs per claim were transportation, warehouse, and utilities and construction. Across industries, the highest costs per claim were consistently for the lumbar spine, shoulder, and cervical spine body regions.This study provides insight into the severity (i.e., medical and indemnity costs) of MSDs across multiple industries, providing data for prioritizing of resources for research and interventions. Am. J. Ind. Med. © 2009 Wiley-Liss, Inc.
International Archives of Occupational and Environmental HealthHeart rate variability assessment in Japanese workers recovered from depressive disorders resulting from job stress: measurements in the workplace Sat, 12 Dec 2009 14:16:42 -0000
Abstract
Purpose The purpose of this study is to clarify workers’ autonomic nerve balance after long-term sick leave due to depressive disorders
resulting from job stress compared with healthy workers.
Methods The participants were 28 Japanese male workers recovered from depressive disorders and 75 healthy male workers. For each participant,
the lifestyle and the fatigue within 1 month were assessed by a checklist. Heart rate variability (HRV) was measured at the
workplace by acceleration plethysmography (APG). HRV was assessed by the coefficient of variation of rate intervals (CV),
the spectral components in the high- and low-frequency areas represented by the normalized HF and LF (nHF and nLF), and the
ratio of LF to HF components (LF/HF).
Results There was no significant difference in individual lifestyle and fatigue symptoms between the recovered and the healthy workers.
The former workers showed significantly lower CV, higher nLF and log10LF/HF, and lower nHF that represent the predominance of sympathetic activity in comparison with the healthy workers. Moreover,
the recovered workers who discontinued medications indicated significantly higher nLF and log10LF/HF, and lower nHF compared to the recovered workers who continued their medications.
Conclusions Recovered workers in the workplace tended to show the depressive HRV feature that is the dominant sympathetic activity compared
with the healthy workers. They might still be showing job stress that was not detected by the checklist. HRV analyses by APG
in addition to questionnaire has the potential to become an effective approach for assessing workers’ job stress to prevent
repeated absences.
Content Type Journal ArticleCategory Original ArticleDOI 10.1007/s00420-009-0499-1Authors
Mikio Takada, Nagoya City University Graduate School of Medical Sciences Department of Occupational and Environmental Health 1 Kawasumi, Mizuho-cho, Mizuho-ku Nagoya Aichi 467-8601 JapanTakeshi Ebara, Nagoya City University Graduate School of Medical Sciences Department of Occupational and Environmental Health 1 Kawasumi, Mizuho-cho, Mizuho-ku Nagoya Aichi 467-8601 JapanMichihiro Kamijima, Nagoya City University Graduate School of Medical Sciences Department of Occupational and Environmental Health 1 Kawasumi, Mizuho-cho, Mizuho-ku Nagoya Aichi 467-8601 Japan
Journal International Archives of Occupational and Environmental HealthOnline ISSN 1432-1246Print ISSN 0340-0131
Correlates shift work with increased risk of gastrointestinal complaints or frequency of gastritis or peptic ulcer in H. pylori-infected shift workers? Fri, 11 Dec 2009 06:52:24 -0000
Abstract
Aim There is an ongoing discussion whether work under shift work conditions enhances the ulcerogenic potential of Helicobacter pylori infections. This may be induced by a disruption of the circadian rhythm. The present study assessed whether there is an association
between H. pylori infection and an increased risk of gastrointestinal complaints or frequency of gastritis or peptic ulcer in H. pylori-infected shift workers.
Methods We analyzed 615 workers divided in shift and daytime. Upper gastrointestinal diseases, medication or operation, unspecific
gastrointestinal complaints, smoking habits, subjective job strain and private stress factors were monitored. The H. pylori status was analyzed using IgA and IgG antibody concentration in blood and qualitative ELISA for feces.
Results It was observed that 27.6% of all workers, 34.6% of the shift workers and 16% of daytime workers were Hp positive (P = 0.004). Shift workers reported reflux or pyrosis less frequently than daytime workers. No increased lifetime prevalence
for gastritis, ulcus or eradication therapy was found for shift workers. Analysis revealed a weak regression between age and
Hp-positive gastritis or upper gastrointestinal complaints, smoking habits were a major confounding factor for ulcus disease.
Clinical manifestation of gastritis or ulcus disease did not correlate with shift work or especially shift work including
night work.
Conclusions As a result of the present study, it cannot be confirmed that there is a causal connection between shift work and upper or
unspecific gastrointestinal complaints or gastritis or peptic ulcer in dependency of a H. pylori colonization.
Content Type Journal ArticleCategory Original ArticleDOI 10.1007/s00420-009-0495-5Authors
Anke van Mark, University of Lübeck Institute of Occupational Medicine Ratzeburger Allee 160 23538 Lübeck GermanyMichael Spallek, European Research Society for Environment and Health in Transportation (EUGT) e. V. 14195 Berlin GermanyDavid A. Groneberg, Free University and Humboldt-University Institute of Occupational Medicine, Charité—Universitätsmedizin Berlin 14195 Berlin GermanyRichard Kessel, University of Lübeck Institute of Occupational Medicine Ratzeburger Allee 160 23538 Lübeck GermanyStephan W. Weiler, AUDI AG 85045 Ingolstadt Germany
Journal International Archives of Occupational and Environmental HealthOnline ISSN 1432-1246Print ISSN 0340-0131
A population-based study of blood lead levels in relation to depression in the United States Sun, 06 Dec 2009 00:50:34 -0000
Abstract
Purpose Lead is a known neurotoxicant. Several studies have suggested that occupational exposure to lead may lead to depression, anxiety
and other psychiatric illness, but few studies have examined environmental lead exposure and depression. We evaluated the
relationship between blood lead levels (BLL) and depression in a sample representative of the US population.
Methods We analyzed data from 4,159 adults ages ≥20 who participated in the 2005–2006 cycle of the National Health and Nutrition Examination
Survey (NHANES). Depression was assessed by the Patient Health Questionnaire-9 (PHQ-9). Relative risks were calculated using
Poisson regression, and odds ratios were calculated with ordinal logistic regression using SUDAAN, controlling for pertinent
covariates.
Results The risk of depression was only slightly elevated with increasing blood lead levels when lead was modeled as a categorical
variable, with adjusted relative risks of 1.16 (95% confidence interval (CI) = 0.99–1.36), 1.20 (CI = 1.07–1.36) and 1.16
(CI = 0.87–1.54) for 0.89–1.40 μg/dL, 1.41–2.17 μg/dL and >2.17 μg/dL, respectively, when compared to 0–0.88 μg/dL using Poisson
regression. Similar results were obtained with ordinal logistic regression. Analyses using BLL as a continuous variable did
not show a significant relationship with depression.
Conclusions This cross-sectional study did not provide consistent evidence for an association between environmental lead exposure and
depression within the investigated blood lead levels.
Content Type Journal ArticleCategory Original ArticleDOI 10.1007/s00420-009-0497-3Authors
Natalia I. Golub, University of Rochester School of Medicine and Dentistry Department of Community and Preventive Medicine 601 Elmwood Avenue Box 644 Rochester NY 14642 USAPaul C. Winters, University of Rochester School of Medicine and Dentistry Department of Family Medicine 1381 South Avenue Rochester NY 14620 USAEdwin van Wijngaarden, University of Rochester School of Medicine and Dentistry Department of Community and Preventive Medicine 601 Elmwood Avenue Box 644 Rochester NY 14642 USA
Journal International Archives of Occupational and Environmental HealthOnline ISSN 1432-1246Print ISSN 0340-0131
Factors impacting on the excess arseniasis prevalence due to indoor combustion of high arsenic coal in a hyperendemic village Fri, 04 Dec 2009 21:14:55 -0000
Abstract
Background A few villages in Southwest Guizhou, China represented a unique case of arseniasis due to indoor combustion of high arsenic-content
coal. The present study is aimed to analyze the contribution of possible factors or of their combination to excess prevalence
of arseniasis in the exposed population.
Methods An epidemiological investigation was conducted in all the members of three large ethnic, patrilineal clans in one of the hyperendemic
villages (702 residents in 178 families, including 408 Han and 294 Hmong) where farmers of different ethnic origin have been
living together in the same village for generations. A multilevel model logistic regression analysis was performed.
Results The arseniasis prevalence was found to associate with the duration of As indoor exposure (years of high As coal burning and
of poorly ventilated traditional stove using) and is largely dependent on the subject’s ethnicity and clan consanguinity,
too. The prevalence of arseniasis in ethnic Han residents was significantly higher than that in their Hmong neighbors (35.0
vs 4.8% OR = 15.18, 95% CI = 3.45–67.35). Notable variances of arseniasis prevalence were observed not only between the ethnic
Han clans (G1, G3, and B) and Hmong clan P, but also between different lineages (G1 and G2) inside the ethnic Han clan. Smokers
suffered more frequently from arseniasis than non-smokers (47.3 vs 15.7% OR = 5.42, 95% CI = 2.25–12.93).
Conclusions Arseniasis prevalence in this unique exposure case was impacted by an array of multiple factors. Besides a long-term indoor
exposure to As, the ethnicity or the clan consanguinity of exposed subjects may play an important role, too.
Content Type Journal ArticleCategory Original ArticleDOI 10.1007/s00420-009-0494-6Authors
Guo-Fang Lin, Chinese Academy of Sciences Shanghai Institutes for Biological Sciences, Institute of Plant Physiology and Ecology 200032 Shanghai ChinaHong Meng, Second Military Medical University Department of Health Statistics 200433 Shanghai ChinaHui Du, Prefecture Center for Disease Prevention and Control of Southwest Guizhou Buyi and Miao Ethnic Autonomous Prefecture 562400 Xingyi Guizhou ChinaHong-Chao Lu, Prefecture Center for Disease Prevention and Control of Southwest Guizhou Buyi and Miao Ethnic Autonomous Prefecture 562400 Xingyi Guizhou ChinaYun-Shu Zhou, Prefecture Center for Disease Prevention and Control of Southwest Guizhou Buyi and Miao Ethnic Autonomous Prefecture 562400 Xingyi Guizhou ChinaJi-Gang Chen, Chinese Academy of Sciences Shanghai Institutes for Biological Sciences, Institute of Plant Physiology and Ecology 200032 Shanghai ChinaKlaus Golka, Leibniz Research Centre for Working Environment and Human Factors (IfADo) 44139 Dortmund GermanyJia-Chun Lu, Guangzhou Medical College Department of Epidemiology, State Key Lab of Respiratory Disease 510182 Guangzhou Guangdong ChinaJian-Hua Shen, Chinese Academy of Sciences Shanghai Institutes for Biological Sciences, Institute of Plant Physiology and Ecology 200032 Shanghai China
Journal International Archives of Occupational and Environmental HealthOnline ISSN 1432-1246Print ISSN 0340-0131
Can we explain the exposure variability found in hand-arm vibrations when using angle grinders? A round robin laboratory study Fri, 04 Dec 2009 21:14:53 -0000
Abstract
Objectives To quantify variance components of hand-arm vibration exposure from data collected in a laboratory study of four different
angle grinders.
Methods Four different angle grinders were sent to seven laboratories for grinding tests by three operators at each laboratory. Vibration
in both the throttle and support handles was measured. For one grinder, the experimental set-up was repeated and two measurements
were collected for that specific grinder.
Results At least one-third of the estimated variability is attributable to the wheel and less than one-third to the operator. In repeated
experiments, between-occasion, operator and wheel factors explained 4, 29 and 17% of the total variability, respectively.
Conclusions Since measured vibrations in the support and throttle handles are significantly differed, measurements should be taken at
both locations. Factors influencing vibration variability include the presence/absence of an auto balance unit, wheel and
operator, but other factors remain to be elucidated.
Content Type Journal ArticleCategory Original ArticleDOI 10.1007/s00420-009-0498-2Authors
I. Liljelind, Umeå University Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine 901 87 Umeå SwedenJ. Wahlström, Umeå University Hospital Occupational and Environmental Medicine 901 85 Umeå SwedenL. Nilsson, Umeå University Department of Mathematics and Mathematical Statistics 901 87 Umeå SwedenM. Persson, Atlas Copco Tools AB Sweden 105 23 Stockholm SwedenT. Nilsson, Umeå University Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine 901 87 Umeå Sweden
Journal International Archives of Occupational and Environmental HealthOnline ISSN 1432-1246Print ISSN 0340-0131
Need for recovery from work in relation to age: a prospective cohort study Thu, 03 Dec 2009 18:20:52 -0000
Abstract
Purpose To investigate the impact of increasing age on the need for recovery (NFR) over time among day workers
Methods The study is based on data from the first 2 years of follow-up of the Maastricht Cohort Study (n = 7,734). To investigate whether age predicted the onset of elevated NFR, multivariate survival analyses were conducted
Results The highest levels of NFR were observed in the age group of 46–55 years. The relative risk for developing elevated NFR was
highest in the age groups 36–45 years (RR 1.30; 1.07–1.58) and 46–55 years (RR 1.25; 1.03–1.52) in men and 46–55 years (RR
1.36; 1.04–1.77) in women when compared to the reference group
Conclusions While NFR increased with age until the age of 55, this was followed by decreased levels of NFR among older employees. Explanations
for the decreasing levels of NFR in the highest age group can be found in several domains such as the work environment, private
situation and compensation strategies.
Content Type Journal ArticleCategory Original ArticleDOI 10.1007/s00420-009-0491-9Authors
D. C. L. Mohren, Maastricht University CAPHRI School for Public Health and Primary Care, Department of Epidemiology P.O. Box 616 6200 MD Maastricht The NetherlandsN. W. H. Jansen, Maastricht University CAPHRI School for Public Health and Primary Care, Department of Epidemiology P.O. Box 616 6200 MD Maastricht The NetherlandsIJ. Kant, Maastricht University CAPHRI School for Public Health and Primary Care, Department of Epidemiology P.O. Box 616 6200 MD Maastricht The Netherlands
Journal International Archives of Occupational and Environmental HealthOnline ISSN 1432-1246Print ISSN 0340-0131
Occupational Therapy InternationalPost-stroke fatigue: qualitative study of three focus groupsNancy A. Flinn, Jan E. Stube Mon, 28 Sep 2009 05:18:00 -0000
Fatigue affects many persons after cerebrovascular accident, particularly those with mild stroke. A qualitative methodology using focus groups with 19 community-living post-stroke survivors was utilized to explore the occupational impact of fatigue as communicated by the participants. Although self-report of a small sample of the United States' post-stroke population will have limitations in generalizability, this study identifies specific health-related quality of life issues that can occur with post-stroke fatigue. The participants felt unprepared for the fatigue phenomenon and struggled to adapt, with fatigue having a debilitating influence upon daily occupational performance and roles, including social participation, return to work, driving, reading and sleeping. The participants indicated that exercise (such as walking and water aerobics) and use of assistive technology were helpful strategies in reducing fatigue. The occupational performance and role impact identified by participants in this study can inform the design of effective occupational therapy interventions and further quantitative study of persons with post-stroke fatigue. Copyright © 2009 John Wiley & Sons, Ltd.
Occupational therapy students' attitudes towards inclusion education in Australia, United Kingdom, United States and TaiwanKeli Mu, Ted Brown, Claudia G. Peyton, Sylvia Rodger, Yan-Hua Huang, Chin-Yu Wu, Callie Watson, Karen Stagnitti, Eve Hutton, Jackie Casey, Chia Swee Hong Fri, 21 Aug 2009 06:45:00 -0000
This international, cross-cultural study investigated the attitudes of occupational therapy students from Australia, United Kingdom, United States and Taiwan towards inclusive education for students with disabilities. The possible impact of professional education on students' attitudes was also explored. A total of 485 students from 11 entry-level occupational therapy education programmes from Australia, the United Kingdom, the United Sates and Taiwan participated in the study. Among them, 264 were freshmen (first-year students) and 221 were seniors (final-year students). Data collected from a custom-designed questionnaire were analysed both quantitatively and qualitatively.In general, the occupational therapy students reported having positive attitudes towards inclusion. Considerable differences, however, existed among the student groups from the four countries. Professional education appeared to have a significant impact on students' attitudes towards inclusion from first year to senior year. Although students were in favour of inclusion, they also cautioned that their support for inclusive practices depended on various factors such as adequate preparation, support and assistance to students with disabilities.Limitations of the study included the small, convenience sample and different degree structures of the participating programmes. Future research studies need to compare occupational therapy students' attitudes with students from other health care professions. A longitudinal study on the impact of the professional education programme on students' attitudes towards inclusive education is warranted. Copyright © 2009 John Wiley & Sons, Ltd.
Identifying indicators of well-being for caregivers of children with disabilitiesElizabeth Larson Mon, 17 Aug 2009 08:39:00 -0000
This study identified key indicators of well-being for caregivers of children with disabilities, Thirty-nine caregivers completed life satisfaction and psychological well-being (WB) measures, and qualitative interviews. Data analysis included descriptive statistics of WB measures and categorical analysis of qualitative data. Data triangulation was achieved by importing theoretically derived codes for initial qualitative coding and quantitizing qualitative categories. Core indicators focused on positive family functioning and a reasonable family lifestyle, caregiver's personal growth and capacity to manage life demands, and the importance of daily balance. Study limitations included no standardized assessments of the child with disabilities' functioning, and the inclusion of caregivers with a range of years of experience. Findings suggest therapists need to attend to how interventions foster or impede positive family functioning and assist caregivers in balancing daily occupations to support capacity to caregiving. Future research should examine how well-being varies over time as caregivers adapt from initial and later caregiving. Copyright © 2009 John Wiley & Sons, Ltd.
Occupational Medicine - current issueIn this issue of Occupational MedicineHobson, J.
The importance of thinking in occupational medicineShanahan, E. M., Sladek, R. M.
Ben Shahn Death of a Miner (1949)McKiernan, M.
pubmed: 0355-3140Annals of Occupational Hygiene - current issueProposed British-Dutch Guidance on Measuring Compliance with Occupational Exposure LimitsOgden, T. L.
Oxygen Depletion and Formation of Toxic Gases following Sea Transportation of Logs and Wood ChipsSvedberg, U., Petrini, C., Johanson, G.
Several recent accidents with fatal outcomes occurring during discharge of logs and wood chips from ships in Swedish ports indicate the need to better understand the atmospheric conditions in holds and connecting stairways. The principal aim of the present study was to assess the air levels of oxygen and toxic gases in confined spaces following sea transportation of logs and wood chips. The focus of the study was the conditions in the stairways, as this was the location of the reported accidents. Forty-one shipments of logs (pulpwood) and wood chips carried by 10 different ships were investigated before discharge in ports in northern Sweden. A full year was covered to accommodate variations due to seasonal temperature changes. The time from completion of loading to discharge was estimated to be 37–66 h (mean 46 h). Air samples were collected in the undisturbed air of altogether 76 stairways before the hatch covers were removed. The oxygen level was measured on-site by handheld direct-reading multi-gas monitors. On 16 of the shipments, air samples were additionally collected in Tedlar® bags for later analysis for carbon dioxide, carbon monoxide, and hydrocarbons by fourier transform infrared spectroscopy. The mean oxygen level was 10% (n = 76) but in 17% of the samples the oxygen level was 0%. The oxygen depletion was less pronounced during the cold season. The mean CO2 and CO levels were 7.5% (n = 26) and 46 p.p.m. (n = 28), respectively. More than 90% of the hydrocarbons were explained by monoterpenes, mainly -pinene (mean 41 p.p.m., (n = 26). In conclusion, the measurements show that transport of logs and wood chips in confined spaces may result in rapid and severe oxygen depletion and CO2 formation. Thus, apparently harmless cargoes may create potentially life-threatening conditions. The oxygen depletion and CO2 formation are seemingly primarily caused by microbiological activity, in contrast to the oxidative processes with higher CO formation that predominate in cargoes of wood pellets. Improved technical and organizational measures are considered necessary to prevent future accidents. Recommendations given regarding safe entry procedures and technical preventive methods may also apply to other oxygen-depleting products.
Rate and Peak Concentrations of Off-Gas Emissions in Stored Wood Pellets--Sensitivities to Temperature, Relative Humidity, and Headspace VolumeKuang, X., Shankar, T. J., Bi, X. T., Lim, C. J., Sokhansanj, S., Melin, S.
Wood pellets emit CO, CO2, CH4, and other volatiles during storage. Increased concentration of these gases in a sealed storage causes depletion of concentration of oxygen. The storage environment becomes toxic to those who operate in and around these storages. The objective of this study was to investigate the effects of temperature, moisture, and the relative size of storage headspace on emissions from wood pellets in an enclosed space. Twelve 10-l plastic containers were used to study the effects of headspace ratio (25, 50, and 75% of container volume) and temperatures (10–50°C). Another eight containers were set in uncontrolled storage relative humidity (RH) and temperature. Concentrations of CO2, CO, and CH4 were measured by gas chromatography (GC). The results showed that emissions of CO2, CO, and CH4 from stored wood pellets are more sensitive to storage temperature than to RH and the relative volume of headspace. Higher peak emission factors are associated with higher temperatures. Increased headspace volume ratio increases peak off-gas emissions because of the availability of oxygen associated with pellet decomposition. Increased RH in the enclosed container increases the rate of off-gas emissions of CO2, CO, and CH4 and oxygen depletion.
Emission of Volatile Aldehydes and Ketones from Wood Pellets under Controlled ConditionsArshadi, M., Geladi, P., Gref, R., Fjallstrom, P.
Different qualities of biofuel pellets were made from pine and spruce sawdust according to an industrial experimental design. The fatty/resin acid compositions were determined by gas chromatography-mass spectrometry for both newly produced pellets and those after 2 and 4 weeks of storage. The aldehydes/ketones compositions were determined by high performance liquid chromatography at 0, 2, and 4 weeks. The designs were analyzed for the response variables: total fatty/resin acids and total aldehydes/ketones. The design showed a strong correlation between the pine fraction in the pellets and the fatty/resin acid content but the influence decreased over storage time. The amount of fatty/resin acids decreased ~40% during 4 weeks. The influence of drying temperature on the aldehyde/ketone emission of fresh pellets was also shown. The amounts of emitted aldehydes/ketones generally decreased by 45% during storage as a consequence of fatty/resin acid oxidation. The matrices of individual concentrations were subjected to multivariate data analysis. This showed clustering of the different experimental runs and demonstrated the important mechanism of fatty/resin acid conversion.
Effects of Headspace and Oxygen Level on Off-gas Emissions from Wood Pellets in StorageKuang, X., Shankar, T. J., Sokhansanj, S., Lim, C. J., Bi, X. T., Melin, S.
Few papers have been published in the open literature on the emissions from biomass fuels, including wood pellets, during the storage and transportation and their potential health impacts. The purpose of this study is to provide data on the concentrations, emission factors, and emission rate factors of CO2, CO, and CH4 from wood pellets stored with different headspace to container volume ratios with different initial oxygen levels, in order to develop methods to reduce the toxic off-gas emissions and accumulation in storage spaces. Metal containers (45 l, 305 mm diameter by 610 mm long) were used to study the effect of headspace and oxygen levels on the off-gas emissions from wood pellets. Concentrations of CO2, CO, and CH4 in the headspace were measured using a gas chromatograph as a function of storage time. The results showed that the ratio of the headspace ratios and initial oxygen levels in the storage space significantly affected the off-gas emissions from wood pellets stored in a sealed container. Higher peak emission factors and higher emission rates are associated with higher headspace ratios. Lower emissions of CO2 and CO were generated at room temperature under lower oxygen levels, whereas CH4 emission is insensitive to the oxygen level. Replacing oxygen with inert gases in the storage space is thus a potentially effective method to reduce the biomass degradation and toxic off-gas emissions. The proper ventilation of the storage space can also be used to maintain a high oxygen level and low concentrations of toxic off-gassing compounds in the storage space, which is especially useful during the loading and unloading operations to control the hazards associated with the storage and transportation of wood pellets.
Evaluation of Five Decontamination Methods for Filtering Facepiece RespiratorsViscusi, D. J., Bergman, M. S., Eimer, B. C., Shaffer, R. E.
Concerns have been raised regarding the availability of National Institute for Occupational Safety and Health (NIOSH)-certified N95 filtering facepiece respirators (FFRs) during an influenza pandemic. One possible strategy to mitigate a respirator shortage is to reuse FFRs following a biological decontamination process to render infectious material on the FFR inactive. However, little data exist on the effects of decontamination methods on respirator integrity and performance. This study evaluated five decontamination methods [ultraviolet germicidal irradiation (UVGI), ethylene oxide, vaporized hydrogen peroxide (VHP), microwave oven irradiation, and bleach] using nine models of NIOSH-certified respirators (three models each of N95 FFRs, surgical N95 respirators, and P100 FFRs) to determine which methods should be considered for future research studies. Following treatment by each decontamination method, the FFRs were evaluated for changes in physical appearance, odor, and laboratory performance (filter aerosol penetration and filter airflow resistance). Additional experiments (dry heat laboratory oven exposures, off-gassing, and FFR hydrophobicity) were subsequently conducted to better understand material properties and possible health risks to the respirator user following decontamination. However, this study did not assess the efficiency of the decontamination methods to inactivate viable microorganisms. Microwave oven irradiation melted samples from two FFR models. The remainder of the FFR samples that had been decontaminated had expected levels of filter aerosol penetration and filter airflow resistance. The scent of bleach remained noticeable following overnight drying and low levels of chlorine gas were found to off-gas from bleach-decontaminated FFRs when rehydrated with deionized water. UVGI, ethylene oxide (EtO), and VHP were found to be the most promising decontamination methods; however, concerns remain about the throughput capabilities for EtO and VHP. Further research is needed before any specific decontamination methods can be recommended.
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