Characterization of particle exposure during tunnel excavation by tunnel boring machines.

Tunnel boring machines (TBMs) are used to excavate tunnels in a manner where the rock is constantly penetrated with rotating cutter heads. Fine particles of the rock minerals are thereby generated. Workers on and in the vicinity of the TBM are exposed to particulate matter (PM) consisting of bedrock minerals including α-quartz. Exposure to respirable α-quartz remains a concern because of the respiratory diseases associated with this exposure. The particle size distribution of PM and α-quartz is of special importance because of its influence on adverse health effects, monitoring and control strategies as well as accurate quantification of α-quartz concentrations. The major aim of our study was therefore to investigate the particle size distribution of airborne PM and α-quartz generated during tunnel excavation using TBMs in an area dominated by gneiss, a metamorphic type of rock. Sioutas cascade impactors were used to collect personal samples on 3 separate days. The impactor fractionates the dust in 5 size fractions, from 10 µm down to below 0.25 µm. The filters were weighted, and the α-quartz concentrations were quantified using X-ray diffraction (XRD) analysis and the NIOSH 7500 method on the 5 size fractions. Other minerals were determined using Rietveld refinement XRD analysis. The size and elemental composition of individual particles were investigated by scanning electron microscopy. The majority of PM mass was collected on the first 3 stages (aerodynamic diameter = 10 to 0.5 µm) of the Sioutas cascade impactor. No observable differences were found for the size distribution of the collected PM and α-quartz for the 3 sampling days nor the various work tasks. However, the α-quartz proportion varied for the 3 sampling days demonstrating a dependence on geology. The collected α-quartz consisted of more particles with sizes below 1 µm than the calibration material, which most likely affected the accuracy of the measured respirable α-quartz concentrations. This potential systematic error is important to keep in mind when analyzing α-quartz from occupational samples. Knowledge of the particle size distribution is also important for control measures, which should target particle sizes that efficiently capture the respirable α-quartz concentration.

Profiles of health literacy and digital health literacy in clusters of hospitalised patients: a single-centre, cross-sectional study.

OBJECTIVE: To investigate health literacy (HL) and digital health literacy (eHL) among patients hospitalised in surgical and medical wards using a cluster analysis approach. DESIGN: Cross-sectional study using Ward's hierarchical clustering method to measure cluster adequacy by evaluating distances between cluster centroids (a measure of cohesion). Different distances produced different cluster solutions. SETTING AND PARTICIPANTS: The study was conducted at a Norwegian university hospital. A total of 260 hospitalised patients were enrolled between 24 May and 6 June 2021. DATA COLLECTION: All data were collected by self-reported questionnaires. Data on HL and eHL were collected by the Health Literacy Questionnaire (HLQ) and the eHealth Literacy Questionnaire (eHLQ). We also collected data on background characteristics, health status and patient diagnosis. RESULTS: We found six HLQ clusters to be the best solution of the sample, identifying substantial diversity in HL strengths and challenges. Two clusters, representing 21% of the total sample, reported the lowest HLQ scores in eight of nine HLQ domains. Compared with the other clusters, these two contained the highest number of women, as well as the patients with the highest mean age, a low level of education and the lowest proportion of being employed. One of these clusters also represented patients with the lowest health status score. We identified six eHL clusters, two of which represented 31% of the total sample with the lowest eHLQ scores in five of seven eHLQ domains, with background characteristics comparable to patients in the low-scoring HLQ clusters. CONCLUSIONS: This study provides new, nuanced knowledge about HL and eHL profiles in different clusters of patients hospitalised in surgical and medical wards. With such data, healthcare professionals can take into account vulnerable patients' HL needs and tailor information and communication accordingly.

Effectiveness of a health communication intervention on health literacy in the first year following kidney transplantation - A randomized controlled study.

OBJECTIVE: This study aimed to evaluate the effect of a new health communication intervention focusing on knowledge management skills on health literacy and medication adherence during the first year following kidney transplantation. METHODS: We randomized 195 patients during 2020-2021, to either intervention- or control group. Questionnaires were completed at baseline and at 12 months post-transplantation with a 12-month response rate of 84%. Health literacy was measured by the multidimensional Health Literacy Questionnaire (HLQ) instrument. Medication adherence was measured by the self-reported questionnaire (BAASIS©). RESULTS: Results showed that the intervention group had a significant increase in 2 HLQ domains compared to the control group capturing the "ability to appraise health information" Domain 5, (p-value = 0.002) and the "ability to navigate the healthcare system" Domain 7, (p-value <0.04). The effect sizes of SRM were 0.49 (Domain 5) and 0.33 (Domain 7). Medication adherence was comparable in the groups at any measure points. CONCLUSIONS: This study contributes to important knowledge about how a health communication intervention focusing on knowledge translation using motivational interviewing techniques positively strengthens health literacy in kidney transplant recipients. PRACTICAL IMPLICATIONS: Current patient education practice may benefit from focusing on knowledge translation in combination with motivational interview technique.

Chemical Composition of Thoracic Dust at Workplaces During Cement Production.

OBJECTIVES: Cement belongs to the most used building materials. Clinker is the major constituent of cement, and it is believed that the strong increase of pH after hydration of clinker minerals is responsible for the observed decline in lung function of cement production workers. Information on clinker exposure at workplaces in the cement production industry is scarse. The aims of this study are to determine the chemical composition of thoracic dust and to quantify workplace exposure to clinker in cement production. METHODS: The elemental composition of 1250 personal thoracic samples collected at workplaces in 15 plants located in 8 different countries (Estonia, Greece, Italy, Norway, Sweden, Switzerland, Spain, Turkey) was determined by inductively coupled plasma optical emission spectrometry (ICP-OES), separately for water- and acid-soluble fraction. Positive matrix factorization (PMF) was used to determine the contribution of different sources to the dust composition and to quantify the clinker content in 1227 of the thoracic samples. In addition, 107 material samples were analysed to facilitate interpretation of the factors obtained by PMF. RESULTS: The median thoracic mass concentrations varied for individual plants between 0.28 and 3.5 mg/m3. PMF with 8 water-soluble and 10 insoluble (i.e., acid-soluble) element concentrations yielded a five-factor solution: Ca, K, Na sulfates; silicates; insoluble clinker; soluble clinker-rich; and soluble Ca-rich. The clinker content of the samples was calculated as sum of the insoluble clinker and soluble clinker-rich factors. The median clinker fraction of all samples was 45% (range 0-95%), and varied between 20% and 70% for individual plants. DISCUSSION: The 5-factor solution of PMF was selected on the basis of several mathematical parameters recommended in the literature as well as the mineralogical interpretability of the factors. In addition, interpretation of the factors was supported by the measured apparent solubility of Al, K, Si, Fe, and to a lesser extent Ca in material samples. The total clinker content obtained in the present study is considerably lower than estimates based on the Ca concentrations in a sample, and somewhat lower than estimates based on Si concentrations after selective leaching with a methanol/maleic acid mixture. The clinker abundance in workplace dust of one plant investigated in the present contribution was also estimated in a recent study by electron microscopy, and the good agreement between both studies gives confidence in the results of PMF. CONCLUSIONS: The clinker fraction in personal thoracic samples could be quantified from the chemical composition by positive matrix factorization. Our results allow for further epidemiological analyses of health effects in the cement production industry. As these estimates are more accurate for clinker exposure than aerosol mass, stronger associations with respiratory effects are expected if clinker is the main cause of these effects.

Exposure to Particulate Matter and Respirable Crystalline Silica in Tunnel Construction Workers Using Tunnel Boring Machines.

OBJECTIVES: This study aimed to assess the exposure to a selection of aerosols and gases in the work environment for workers performing tunnel construction using tunnel boring machines (TBMs), to identify determinants of exposure based on the information available and to calculate robust estimates of exposure using a statistical model. The focus was particulate matter (PM) and respirable crystalline silica (RCS). In addition, concentrations of nitrogen dioxide (NO2), elemental carbon (EC), and oil mist were assessed. METHODS: Personal sampling was conducted from February 2017 to February 2019. PM in the thoracic and the respirable aerosol fractions was collected, and RCS was determined in the respirable aerosol fraction. Context information was collected on questionnaires. Because the workers could participate in the sampling more than once and multiple measurements were performed on the same date a mixed model was used in the analysis. Concentrations of PM and RCS are presented as estimated and measured geometric means (GMest and GMmea) and estimated arithmetic mean (AMest) in addition to the median. Measured concentrations of NO2, EC, and oil mist are presented as geometric means. RESULTS: A total of 290 and 289 personal samples of PM in the thoracic and respirable aerosol fractions were available for analysis, respectively. Work title/work location, type of work (production, maintenance, or a combination of the two), and date of sampling were identified as determinants of exposure. Workers in the front of the TBMs had the highest exposure to PM and RCS. The GMest of RCS exposure varied from 35 to 413 µg m-3 depending on the work title. The geometric standard deviations for measured RCS concentrations by work title ranged from 1.6 to 3.5. A total of 16 samples of NO2 and EC and 12 samples of oil mist were collected. Maximum values of NO2 and EC were 54 µg m-3 and 23 µg m-3, respectively. The maximum measured value of oil mist was 0.08 mg m-3. CONCLUSIONS: All TBM workers were exposed to PM and RCS. Exposure to RCS may be substantial, and workers in front of the TBM were exposed to the highest concentrations of both PM and RCS. A day-to-day variation was found, probably caused by differences in drilling activities. Preventive measures are warranted to keep the exposure to PM and consequently the exposure to RCS as low as possible to protect the health of workers in tunnel construction.

Internationally educated nurses and resilience: A systematic literature review.

AIM: To synthesize knowledge extracted from the literature about protecting factors and challenges to resilience, among migrant nurses, and specifically how knowledge synthesized through the process of the literature review is relevant to nursing and health policy. BACKGROUND: How nurses, in general, face challenges is well documented and is often linked to the concept of resilience; however, there seems to be a lack of systematic knowledge synthesis focusing on the resilience of internationally educated nurses following migration. METHOD: The review was guided by the PRISMA guidelines, and a systematic search of peer-reviewed qualitative and mixed-method articles reporting empirical research was performed in the MEDLINE, CINAHL, PsycINFO and Academic Search Ultimate databases. Methodological rigour was assessed by the Joanna Briggs' checklist, and a structured theme-based ecological framework, inspired by Ungar's model of resilience, was chosen. RESULTS: Following critical appraisal, 37 studies were included that identified both challenges and individual, contextual and structural protective factors in host countries and are linked to resilience. DISCUSSION: Resilience of internationally educated nurses depends on a combination of individual and contextual protective factors, with the major emphasis being placed on individual protective factors. It is crucial to consider resilience in ensuring that internationally educated nurses' experience is appreciated, as this is necessary if nurses are to deliver the best possible health service while integrating into their host country. IMPLICATION FOR NURSING AND HEALTH POLICY: Authorities, managers in clinical practice and education, trade unions and nurses in general should be aware of the coping strategies, the strengths and supportive factors that can promote resilience and be aware of the challenges that undermine resilience and negatively impact internationally educated nurses' practice and social interactions.

"A bit of everything": Health literacy interventions in chronic conditions - a systematic review.

OBJECTIVE: To systematically evaluate health literacy (HL) interventions in chronic conditions by exploring theoretical perspectives, intervention content and effectiveness. METHOD: We searched MEDLINE, Cochrane, CINAHL, EMBASE, ERIC, Web of Science and PsycINFO. Standardised systematic review methods were used, and sequences informing our research question were extracted and analysed. The study includes a descriptive summary of the included papers. RESULTS: We included 39 unique interventions, with diabetes and heart disease as the most targeted chronic conditions. Fifty-four percent of papers included a definition of HL, but the studies showed significant heterogeneity of theoretical underpinnings, modes, measures and content. We identified 23 HL measures, mostly assessing functional HL. The HL interventions were often more complex than the measures indicated. A significant change in HL was found in 28 studies. Study quality was generally poor. CONCLUSIONS: Interventions optimizing HL appear important to improve health outcomes in chronic conditions. To ensure cumulative knowledge development of this field we need theory-based interventions, consistency in methods and more tailored and comprehensive measures to capture the interventions' complexity. PRACTICE IMPLICATIONS: A more valid understanding of HL interventions and measurements is needed to reach an agreed understanding of their components and intentions.

Dental hygienists' biopsychosocial beliefs and giving autonomy support in treatment of patients: A self-determination theory perspective.

OBJECTIVES: Self-determination theory posits that managers' autonomy-supportive behaviour and employees' autonomy causality orientation are motivation constructs to explain internalization of values, functioning and wellness at work. Hypothesis 1 tested whether profiles comprising perceived dental clinic managers' autonomy-supportive, as opposed to their controlling interpersonal style, and dental hygienists' autonomy, as opposed to their control and impersonal, causality orientations at baseline, would be positively related to dental hygienists' biopsychosocial (BPS) beliefs and giving autonomy support in treatment of patients after 18 months. Hypothesis 2 tested whether dental hygienists' BPS beliefs in treatment of patients will be positively associated with their autonomy-supportive behaviour given to patients after 18 months. MATERIAL AND METHODS: A prospective cohort design with 299 (Mage  = 42.71; SDage  = 12.62) dental hygienists completed an online survey at baseline and after 18 months. RESULTS: Latent profile and correlational analyses supported the hypotheses. Effect sizes were moderate to large. CONCLUSIONS: Both perceived managerial styles and dental hygienists' causality orientations are important for dental hygienists' BPS beliefs and autonomy-supportive behaviours when working with dental patients.

Changes in Health Literacy during the first year following a kidney transplantation: Using the Health Literacy Questionnaire.

OBJECTIVES: The study aimed to identify changes in health literacy (HL) and associated variables during the first year following a kidney transplantation. METHODS: A total of 196 transplant recipients were included in a prospective follow-up study. The patients answered the Health Literacy Questionnaire (HLQ) at 5 days, 8 weeks, 6 and 12 months following the kidney transplantation. Mixed linear models were used to analyze changes in HL and backward elimination was used to identify variables associated with HL. RESULTS: Two main patterns of change were identified: a) HL increased during the first 8 weeks of close follow-up and b) in several domains, the positive increase from 5 days to 8 weeks flattened out from 5 days to 6 and 12 months. Self-efficacy, transplant-related knowledge, and general health were core variables associated with HL. CONCLUSIONS: Overall, HL increased during the 8 weeks of close follow-up following the kidney transplantation, while 6 months seem to be a more vulnerable phase. Furthermore, low self-efficacy, less knowledge, and low self-perceived health may represent vulnerable characteristics in patients. PRACTICAL IMPLICATIONS: Future kidney transplant care should take into account patients' access to and appraisal of health information and social support, and draw attention to potentially vulnerable groups.

Identifying Core Variables Associated With Health Literacy in Kidney Transplant Recipients.

BACKGROUND: A kidney transplantation requires complex self-care skills and adequate follow-up from health-care providers. Identifying strengths and limitations in different aspects of health literacy (HL) and associated variables are central to being able to improve health care. The objective of this study was to identify core variables associated with independent domains of HL 8 weeks following a kidney transplantation. METHODS: A single-center cross-sectional study was conducted, wherein 159 kidney transplant recipients answered the Health Literacy Questionnaire (HLQ). Multivariable linear regression with backward elimination was used to investigate variables possibly associated with the 9 domains of HL. RESULTS: The transplant recipients had the lowest scores in "appraisal of health information" and "navigating the healthcare system." The highest scores were found in "feeling understood and supported by health-care providers" and "ability to actively engage with health-care provider." General perceived self-efficacy, transplant-specific knowledge, and general health were the driving variables in several of the HL domains. CONCLUSIONS: The HLQ provides a more complex picture of strengths and limitations related to HL, as well as important knowledge about vulnerable groups following a kidney transplantation. The study offers an important supplement to the field of HL in kidney transplant care.

A courageous journey: Experiences of migrant Philippine nurses in Norway.

AIMS AND OBJECTIVES: To explore how Philippine-educated nurses explain their choice of Norway as their migration destination and their experience with the credential assessment process in Norway. BACKGROUND: Norway has an increasing need for nurses, and nurses educated in non-EU countries are an important resource for the Norwegian health service. Philippine nurses compose the largest group of internationally educated nurses from outside the EU, but their Philippine nursing education is only credited as equivalent to 2 years in Norway. Migration is known to engender stressful experiences amongst migrant nurses, which may affect their health. However, studies on Philippine nurses' experiences of migrating to and working in Norway are lacking. DESIGN AND METHODS: The study used a hermeneutic design, conducting qualitative research interviews with ten Philippine nurses. All of them had a certification as auxiliary nurses, but not as registered nurses. The Consolidated Criteria for Reporting Qualitative Research is used. RESULTS: The nurses' choice of a migration country appeared to be both random and based on the opportunity to find well-paid work, as well as having acquaintances who had already migrated to Norway. The migrated Philippine nurses seemed experienced and competent. In Norway, they were disappointed as they felt undervalued. The nurses struggled to learn Norwegian, while striving for survival when acquiring jobs or accommodations. They were excluded from acting as legal nurses in the Norwegian healthcare system; they fulfilled the governmental requirements, but they were repeatedly rejected. The informants saw this as harsh, but still hoped to be successful. CONCLUSIONS: There is a need to facilitate effective language training and a well-founded, predictable system of credentialing. RELEVANCE TO CLINICAL PRACTICE: Attention should be paid to the integration of immigrants and safeguarding and strengthening the professional competence the nurses bring with them.

The trigger-information-response model: Exploring health literacy during the first six months following a kidney transplantation.

The main objective of this study was to explore how kidney transplant recipients find, understand, and use health information, and make decisions about their health-also known as health literacy. Kidney transplant recipients must take an active part in their health following the transplantation, since a new organ requires new medication and focus on lifestyle to prevent side-effects and signs of organ rejection. Consequently, it is of major clinical relevance to explore how kidney transplant recipients understand and relate to health literacy. Ten kidney transplant recipients were interviewed at three weeks and again at six months post-transplantation. Design and analysis were inspired by constructivist grounded theory. The results of the study are presented through a model consisting of three phases: the trigger phase, the information phase, and the response phase. The participants were influenced by context and personal factors as they moved between three phases, as information seekers, recipients, and sharers. This study illustrates health literacy as an active process. It gives new insight into what motivates kidney recipients to find, share, and receive information, and how a hierarchy of resources is built and used.

Perceived oral health and its association with symptoms of psychological distress, oral status and socio-demographic characteristics among elderly in Norway.

BACKGROUND: There is poor knowledge about the extent to which psychological distress influences oral health in older people in Norway. The aim of this study was two-fold: i) to describe the oral health of Norwegian elderly and their levels of psychological distress; and ii) to examine the relationship of psychological distress with self-rated oral health, while controlling for oral status and socio-demographic characteristics, in Norwegian elderly. METHODS: Data were retrieved from a national cross-sectional survey conducted by Statistics Norway in 2012 and included information about self-rated oral health, psychological distress (measured using the Hopkins Symptom Checklist 25; HSCL-25), gender, age, civil status, smoking, self-reported number of teeth present and dental attendance for 949 non-institutionalised adults aged 65 years or older. Logistic regression was used to establish whether psychological distress predicts self-rated oral health, controlling for socio-demographic characteristics and oral status. RESULTS: Around 27% of the elderly reported having poor oral health, and 8 % had a HSCL-25 mean score ≥ 1.75, which indicates higher levels of psychological distress. Among the symptoms listed in the HSCL-25, the most frequently reported problems were lack of energy (1.7 ± 0.8) and difficulties falling and staying asleep (1.6 ± 0.7). The likelihood of reporting poor oral health was independently associated with having a mean HSCL-25 score ≥ 1.75 (OR = 1.89; 95% CI = 1.14-3.15), even when smoking (OR = 1.83; 95% CI = 1.17, 2.87) and having fewer than 20 teeth (OR = 3.49; 95% CI = 2.56, 4.76) were taken into account. CONCLUSION: Most of the Norwegian elderly in our sample perceived themselves to have good oral health and reported relatively low levels of psychological distress. Higher levels of psychological distress can influence the oral health of the elderly independently of other factors such as smoking and having reduced number of teeth. Dental care professionals should consider screening their elderly patients for psychological distress and individualise the information about dental care for this specific population.

Occupational exposure to beryllium in primary aluminium production.

Alumina used in the production of primary aluminium contains Be which partly vaporises from the cryolite bath into the workroom atmosphere. Since Be may be toxic at lower exposure levels than previously thought, the personal exposure to Be among workers in 7 Norwegian primary smelters has been assessed. In total, 480 personal Respicon® virtual impactor full shift air samples have been collected during 2 sampling campaigns and analysed for water soluble Be, Al and Na using inductively coupled plasma optical emission spectrometry. In addition, water soluble F(-) has been measured by ion chromatography. The Be air concentrations in the inhalable, thoracic and respirable aerosol fractions have been calculated. The Be concentrations in the inhalable aerosol fraction vary between the different smelters. The highest GM concentration of Be in the inhalable fraction (122 ng m(-3), n = 30) was measured in the prebake pot room of a smelter using predominantly Jamaican alumina where also the highest individual air concentration of 270 ng m(-3) of Be was identified. The relative distribution of Be in the different aerosol fractions was fairly constant with the mean Be amount for the two sampling campaigns between 44-49% in the thoracic fraction expressed as % of the inhalable amount. Linear regression analysis shows a high correlation between water soluble Be, Al, F and Na describing an average measured chemical bulk composition of the water soluble thoracic fraction as Na(5.7)Al(3.1)F(18). Be is likely to be present as traces in this particulate matter by replacing Al atoms in the condensed fluorides and/or as a major element in a nanoparticle sized fluoride. Thus, the major amount of Be present in the work room atmosphere of Al smelter pot rooms will predominantly be present in combination with substantial amounts of water soluble Al, F and Na.

Oral health-related quality of life and associated factors in Norwegian adults.

OBJECTIVE. To investigate associations between oral health-related quality of life assessed with the Oral Health Impact Profile (OHIP)-14 and demographic factors, number of teeth present, dental visits, dental health behaviour and self-rated oral health in a representative sample of 20-80-year-old Norwegians. MATERIAL AND METHODS. The study was conducted in a stratified random sample of 3538 individuals. Questionnaires including questions on demographic factors, number of remaining teeth, dental visits, dental health behaviour, self-rated oral health and OHIP-14 were mailed to the sample. Bivariate and multivariate analyses were performed. RESULTS. The response rate was 69%. The mean OHIP-14 score was 4.1 (standard deviation = 6.2). No problem was reported by 35% of the respondents. The most frequently reported problems were: physical pain (56%), psychological discomfort (39%) and psychological disability (30%). When the effect of all independent variables was analysed in multivariate analysis, self-rated oral health, frequency of dental visits, number of teeth, age and sex were significantly (P < 0.05) associated with the prevalence of having problems and frequent problems. Self-rated oral health had the strongest association with having problems [odds ratio (OR) 4.5; 95% confidence interval (CI) 3.4-6.0] and with having frequent problems (OR 4.0; 95% CI 2.7-5.8). Dental health behaviour, use of floss and toothpicks and oral rinsing were not associated with having problems related to oral quality of life in multivariate analyses. CONCLUSION. In this Norwegian adult sample, self-rated oral health, frequency of dental visits, number of teeth, age and sex were associated with having problems as estimated using the OHIP-14.

A future vision: A serious attempt to integrate terminologies in nursing practice, a strategy for 2005-2007.

The Norwegian Nurses Association has developed a strategy for the use and development of terminologies in nursing. The proposal for this strategy is that terminologies are important in developing nursing practice. The goal of the strategy is to contribute to the nursing endeavours in documenting, quality insurance and influencing health policies. One method of achieving this is to stimulate the use and further development of terminologies, through structured and standardized documentation. The purpose is to inform and educate clinical practice, education, professional development and research. It is a goal that the strategy will also influence health authorities in the choice and decisions of terminologies that will be used for nursing. The strategy gives an overview of the terminologies that the Norwegian Nurses Association has decide translate and evaluate. In addition, the strategy exemplifies recommendations for status in 2007 for structured documentation and the use of terminologies and how this status should be achieved. This paper will highlight three areas from the strategy that the Norwegian Nurses Association wishes to focus on: 1. Translations of classifications systems and version control. 2. The need for systematic research and evaluation of terminologies in the context of nursing practice and laws in Norway. 3. The challenge of educating nurses in the use of terminologies.

Air exposure assessment and biological monitoring of manganese and other major welding fume components in welders.

In a cross-sectional study, 96 welders were compared with 96 control subjects. Also 27 former welders, all diagnosed as having manganism, were examined. Exposure to welding fumes was determined in the 96 welders, while the concentration of elements in whole blood and urine was determined in all subjects. The geometric mean (GM) concentrations of manganese (Mn) and iron in the workroom air were 97 microg m(-3) (range 3-4620 microg m(-3); n=188) and 894 microg m(-3) (range 106-20 300 microg m(-3); n=188), respectively. Thus the Mn concentration in the workroom air was on average 10.6% (GM) of that of the Fe concentration. No substantial difference was observed in the air Mn concentrations when welding mild steel as compared to welding stainless steel. The arithmetic mean (AM) concentration of Mn in whole blood (B-Mn) was about 25% higher in the welders compared to the controls (8.6 vs. 6.9 microg l(-1); p < 0.001), while the difference in the urinary Mn concentrations did not attain statistical significance. A Pearson's correlation coefficient of 0.31 (p < 0.01) was calculated between B-Mn and Mn in the workroom air that was collected the day before blood sampling. Although the exposure to welding fumes in the patients had ceased on average 5.8 years prior to the study (range 4 years-7 years), their AM B-Mn concentration was still higher than in referents of similar age (8.7 microg l(-1) vs. 7.0 microg l(-1)). However, their urinary concentrations of cobolt, iron and Mn were all statistically significantly lower.