Undergraduate occupational medicine education in European Medical Schools: better training to meet today's challenges.

BACKGROUND: Occupational medicine (OM) faces considerable challenges today, one of them related to the university training of future physicians considered suboptimal at a global level as it has been pointed out in many studies. The aim of this study is to update the state of OM medical education in European universities. METHODS: Between March and August 2022, an e-mail survey regarding OM training to undergraduate medical students was conducted among OM professors at European universities in 28 countries (n = 347). RESULTS: Of the 347 universities, 53 medical schools from 19 countries responded (response rate = 15.3%). In 89% of cases, OM was taught. The average number of hours per academic year was 24.3, with significant variation within the same country. Lectures were the most popular teaching technique (98%), with a considerable use of modern approaches such as problem-based learning (61%), and e-learning (57%). While occupational diseases and principles of prevention were covered, other subjects such as the environmental impact or collaboration with an OM physician were poorly represented in the educational program. CONCLUSION: According to data, several European medical schools may provide insufficient OM education and training to their students. The education of undergraduate occupational medicine students in European medical schools should be designed to equip them with the knowledge and skills required to meet today's challenges. It is critical that undergraduate OM education in European medical schools be enhanced, harmonized, and standardized.

Burnout and predictive factors among medical students: a cross-sectional survey.

BACKGROUND: Burnout is a growing problem in medical education, and is usually characterised by three dimensions: emotional exhaustion, cynicism, and reduced professional efficacy. Currently, the majority of burnout studies have been conducted in western high-income countries, overshadowing findings from low- and middle-income countries. Our objective is to investigate burnout and its associated predictive factors in Morocco, aiming to guide intervention strategies, while also assessing differences between the preclinical and clinical years. METHODS: A cross-sectional, self-administered online survey assessing burnout dimensions and its main determinants was distributed among medical students at Université Mohammed VI des Sciences et de la Santé (UM6SS, Casablanca, Morocco). Descriptive analyses involved computing mean scores, standard deviations and Pearson correlations. Further, t-tests were performed to check for significant differences in burnout dimensions across the preclinical and clinical learning phase, and stepwise linear regression analyses were conducted using a backward elimination method to estimate the effects of the selected variables on the three burnout dimensions. RESULTS: A t-test assessing the difference in cynicism found a significant difference between students at the preclinical phase and the clinical phase, t(90) = -2.5, p = 0.01. For emotional exhaustion and reduced professional efficacy no significant difference was observed. A linear regression analysis showed that emotional exhaustion was significantly predicted by workload, work-home conflict, social support from peers and neuroticism. Cynicism was predicted by the learning phase, workload, meaningfulness and neuroticism; and reduced professional efficacy by neuroticism only. CONCLUSIONS: Our findings suggest a potential gradual increase in cynicism during medical education in Morocco. Conducting this study in a low- and middle income country has enhanced the scientific understanding of burnout in these regions. Given the identified predictive factors for burnout, such as workload, work-home conflict, support from peers, neuroticism, and meaningfulness, it is necessary to focus on these elements when developing burnout interventions.

Retaining Healing Hands: A Transnational Study on Job Retention Interventions for the Healthcare Workforce.

Healthcare organizations worldwide face challenges in retaining their healthcare workforce, with individual and organizational factors influencing their intentions to leave. This study conducted eight online co-creation workshops and four Delphi sessions to gain qualitative and in-depth insights into job retention interventions, involving healthcare workers, hospital managers, and policymakers. A thematic analysis was conducted, resulting in multiple interventions that were clustered in four pre-defined themes: professional and personal support, education, financial incentives, and regulatory measures. Professional and personal support interventions included regular interprofessional team meetings, leadership training programs, self-scheduling and sabbaticals, support for administrative and non-clinical work, and the provision of psychological counselling. Educational interventions encompassed facilitating development opportunities, periodic evaluations, onboarding, mentorship programs, and peer support groups. Financial incentives included the provision of competitive salaries, adequate infrastructure, extra benefits, transport possibilities, and permanent employment contracts. Regulatory measures addressed the need for complementary legislation across various levels, fixed healthcare worker-to-patient ratio, and instruments to monitor workload. To optimize retention strategies, healthcare organizations should tailor these interventions to address the unique factors influencing their workforce's intentions to leave within their specific context. The study concludes that combining personal and professional support, educational opportunities, financial incentives, and regulatory measures is necessary because there is no one-size-fits-all solution.

Level of BPA contamination in resin composites determines BPA release.

OBJECTIVES: Resin composites may release bisphenol A (BPA) due to impurities present in the monomers. However, there is a lack of knowledge regarding the leaching characteristics of BPA from resin composites. Therefore, experimental resin composites were prepared with known amounts of BPA. The objective of this study was (1) to determine which amount of BPA initially present in the material leaches out in the short term and, (2) how this release is influenced by the resin composition. METHODS: BPA (0, 0.001, 0.01, or 0.1 wt%) was added to experimental resin composites containing 60 mol% BisGMA, BisEMA(3), or UDMA, respectively, as base monomer and 40 mol% TEGDMA as diluent monomer. Polymerized samples (n = 5) were immersed at 37 °C for 7 days in 1 mL of water, which was collected and refreshed daily. BPA release was quantified with UPLC-MS/MS after derivatization with pyridine-3-sulfonyl chloride. RESULTS: Between 0.47 to 0.67 mol% of the originally added BPA eluted from the resin composites after 7 days. Similar elution trends were observed irrespective of the base monomer. Two-way ANOVA showed a significant effect of the base monomer on BPA release, but the differences were small and not consistent. SIGNIFICANCE: The released amount of BPA was directly proportional to the quantity of BPA present in the resin composite as an impurity. BPA release was mainly diffusion-based, while polymer composition seemed to play a minor role. Our results underscore the importance for manufacturers only to use monomers of the highest purity in dental resin composites to avoid unnecessary BPA exposure in patients.

The Relationship Between Work-Related Stress and Depression: A Scoping Review.

Objectives: Work-related stress is highly prevalent. Recent systematic reviews concluded on a significant association between common work-related stress measures and depression. Our scoping review aims to explore whether work-related psychosocial stress is generally associated with depression or depressiveness, the extent and methodology of the primary research undertaken on this topic and to elucidate inconsistencies or gaps in knowledge. Methods: We searched for literature in Pubmed, PsycInfo and Web of Science including full reports in seven languages published between 1999 and 2022 and applied the PRISMA statement for scoping reviews criteria. Results: Of 463 primarily identified articles, 125 were retained after abstract and full-text screening. The majority report significant associations between work-related stress and depression. Cross-sectional studies are most prevalent. Sufficient evidence exists only for job strain and effort-reward imbalance. Most studies are from Asia, North America and Europe. The health sector is the most studied. Several research gaps such as the lack of interventional studies were identified. Conclusion: The consistency of most studies on the significant association between work-related stress and depression is remarkable. More studies are needed to improve evidence and to close research gaps.

SurLym trial: study protocol for a multicentre pragmatic randomised controlled trial on the added value of reconstructive lymphatic surgery to decongestive lymphatic therapy for the treatment of lymphoedema.

INTRODUCTION: Lymphoedema is a chronic condition caused by lymphatic insufficiency. It leads to swelling of the limb/midline region and an increased risk of infection. Lymphoedema is often associated with mental and physical problems limiting quality of life. The first choice of treatment is a conservative treatment, consisting of exercises, skin care, lymph drainage and compression. Reconstructive lymphatic surgery is also often performed, that is, lymphovenous anastomoses, lymph node transfer or a combination. However, robust evidence on the effectiveness of reconstructive lymphatic surgery is missing. Therefore, the objective of this trial is to investigate the added value of reconstructive lymphatic surgery to the conservative treatment in patients with lymphoedema. METHODS AND ANALYSIS: A multicentre randomised controlled and pragmatic trial was started in March 2022 in three Belgian university hospitals. 90 patients with arm lymphoedema and 90 patients with leg lymphoedema will be included. All patients are randomised between conservative treatment alone (control group) or conservative treatment with reconstructive lymphatic surgery (intervention group). Assessments are performed at baseline and at 1, 3, 6, 12, 18, 24 and 36 months. The primary outcome is lymphoedema-specific quality of life at 18 months. Key secondary outcomes are limb volume and duration of wearing the compression garment at 18 months. The approach of reconstructive lymphatic surgery is based on presurgical investigations including clinical examination, lymphofluoroscopy, lymphoscintigraphy, lymph MRI or CT angiography (if needed). All patients receive conservative treatment during 36 months, which is applied by the patient's own physical therapist and by the patient self. From months 7 to 12, the hours a day of wearing the compression garment are gradually decreased. ETHICS AND DISSEMINATION: The study has been approved by the ethical committees of University Hospitals Leuven, Ghent University Hospital and CHU UCL Namur. Results will be disseminated via peer-reviewed journals and presentations. TRIAL REGISTRATION NUMBER: NCT05064176.

Narrative review of occupational exposures and noncommunicable diseases.

OBJECTIVE: Within the scope of the Exposome Project for Health and Occupational Research on applying the exposome concept to working life health, we aimed to provide a broad overview of the status of knowledge on occupational exposures and associated health effects across multiple noncommunicable diseases (NCDs) to help inform research priorities. METHODS: We conducted a narrative review of occupational risk factors that can be considered to have "consistent evidence for an association," or where there is "limited/inadequate evidence for an association" for 6 NCD groups: nonmalignant respiratory diseases; neurodegenerative diseases; cardiovascular/metabolic diseases; mental disorders; musculoskeletal diseases; and cancer. The assessment was done in expert sessions, primarily based on systematic reviews, supplemented with narrative reviews, reports, and original studies. Subsequently, knowledge gaps were identified, e.g. based on missing information on exposure-response relationships, gender differences, critical time-windows, interactions, and inadequate study quality. RESULTS: We identified over 200 occupational exposures with consistent or limited/inadequate evidence for associations with one or more of 60+ NCDs. Various exposures were identified as possible risk factors for multiple outcomes. Examples are diesel engine exhaust and cadmium, with consistent evidence for lung cancer, but limited/inadequate evidence for other cancer sites, respiratory, neurodegenerative, and cardiovascular diseases. Other examples are physically heavy work, shift work, and decision latitude/job control. For associations with limited/inadequate evidence, new studies are needed to confirm the association. For risk factors with consistent evidence, improvements in study design, exposure assessment, and case definition could lead to a better understanding of the association and help inform health-based threshold levels. CONCLUSIONS: By providing an overview of knowledge gaps in the associations between occupational exposures and their health effects, our narrative review will help setting priorities in occupational health research. Future epidemiological studies should prioritize to include large sample sizes, assess exposures prior to disease onset, and quantify exposures. Potential sources of biases and confounding need to be identified and accounted for in both original studies and systematic reviews.

Success rate and predictors of return to work after implementation of a formal return-to-work trajectory: A retrospective cohort study.

BACKGROUND: Long term sick leave (SL) is increasing in Europe, several countries have legislative initiatives to reduce long-term absenteeism. OBJECTIVE: We evaluated the impact of a legally defined return-to-work (RTW) trajectory on the RTW of employees on sick leave in Belgium. METHODS: This was a retrospective register-based cohort study of employees (n = 1416) who followed an RTW trajectory in 2017. We linked workers' data from a prevention service with social security data. By multinomial logistic regression, we analysed which characteristics predicted the RTW with the same or another employer. RESULTS: One year after their RTW trajectory, 69.2% of the 1416 employees did not RTW; 10.7% returned to work with the same employer and 20.1% with a new employer. Duration of SL was an important predictor for the RTW with both the same employer and another employer. The odds of RTW were lower when the SL duration was >  6 months compared to <  6 months. Marital status, organization-size, and the occupational physician decision had a significant impact on the RTW with the same employer. Age and who initiated the RTW-trajectory were important predictors on the RTW with another employer. CONCLUSIONS: Overall, 30.8% of employees returned to work after their RTW trajectory. A one-size-fits-all approach is not recommended. A stepped approach with an early, informal start of the RTW process is advised. When employees or employers fail to initiate the RTW on their own, a legally defined RTW trajectory could be useful. In particular, RTW with another employer seemed a positive effect of the RTW-trajectory.

Elution from direct composites for provisional restorations.

Purpose To assess elution from direct composite materials for provisional restorations and compare them with elution from direct restorative composites for permanent restorations.Methods Two dual-cure (Integrity Multi-Cure and Tempsmart DC) and two self-curing composites (Protemp 4 and Structur 3) were used, with Essentia serving as a reference. Cylindrical specimens (n=20) were cured according to the manufacturer's instructions; the dual-cure materials were prepared in both self- and dual-curing modes. Elution experiments were performed using water and absolute ethanol. The samples were incubated at 37 °C for either 24 h or four weeks; the extraction solvents were refreshed weekly. The eluted BisEMA (-3 / -6 / -10), BisGMA, CQ, UDMA, and TEGDMA were quantified using UHPLC-MS/MS.Results Monomer elution was detected in all provisional composites at 24 h and four weeks, but the amounts released did not exceed those released by the reference composite. When prepared in self-curing mode, Integrity Multi-Cure exhibited significantly higher elution of BisEMA-3, -6, and -10 in ethanol both after 24 h and cumulatively after four weeks. Self-cured Tempsmart DC released significantly more CQ, TEGDMA, and UDMA in both water and ethanol after immersion for 24 h and four weeks, along with significantly more BisGMA in ethanol both after 24 h and four weeks comparison to dual-cured Tempsmart DC (two-way ANOVA, post-hoc Tukey, P < 0.05).Conclusions Provisional composite materials did not elute higher amounts of monomers than a restorative composite. Dual-cured materials, prepared in the self-curing mode, show a trend towards higher monomer elution.

Evaluating offspring Genomic and Epigenomic alterations after prenatal exposure to Cancer treatment In Pregnancy (GE-CIP): a multicentric observational study.

INTRODUCTION: Around 1 in 1000-2000 pregnancies are affected by a cancer diagnosis. Previous studies have shown that chemotherapy during pregnancy has reassuring cognitive and cardiac neonatal outcomes, and hence has been proposed as standard of care. However, although these children perform within normal ranges for their age, subtle differences have been identified. Given that chemotherapeutic compounds can cross the placenta, the possibility that prenatal chemotherapy exposure mutates the offspring's genome and/or epigenome, with potential deleterious effects later in life, urges to be investigated. METHODS AND ANALYSES: This multicentric observational study aims to collect cord blood, meconium and neonatal buccal cells at birth, as well as peripheral blood, buccal cells and urine from infants when 6, 18 and/or 36 months of age. Using bulk and single-cell approaches, we will compare samples from chemotherapy-treated pregnant patients with cancer, pregnant patients with cancer not treated with chemotherapy and healthy pregnant women. Potential chemotherapy-related newborn genomic and/or epigenomic alterations, such as single nucleotide variants, copy number variants and DNA-methylation alterations, will be identified in mononuclear and epithelial cells, isolated from blood, buccal swabs and urine. DNA from maternal peripheral blood and paternal buccal cells will be used to determine de novo somatic mutations in the neonatal blood and epithelial cells. Additionally, the accumulated exposure of the fetus, and biological effective dose of alkylating agents, will be assessed in meconium and cord blood via mass spectrometry approaches. ETHICS AND DISSEMINATION: The Ethics Committee Research of UZ/KU Leuven (EC Research) and the Medical Ethical Review Committee of University Medical Center Amsterdam have approved the study. Results of this study will be disseminated via presentations at (inter)national conferences, through peer-reviewed, open-access publications, via social media platforms aimed to inform patients and healthcare workers, and through the website of the International Network on Cancer, Infertility and Pregnancy (www.cancerinpregnancy.org).

Hazardous Effects of Pesticides on Human Health.

Pesticides, a major group of biocides, are designed to control harmful and/or unwanted organisms [...].

HBM4EU E-waste study: Assessing persistent organic pollutants in blood, silicone wristbands, and settled dust among E-waste recycling workers in Europe.

E-waste recycling is an increasingly important activity that contributes to reducing the burden of end-of-life electronic and electrical apparatus and allows for the EU's transition to a circular economy. This study investigated the exposure levels of selected persistent organic pollutants (POPs) in workers from e-waste recycling facilities across Europe. The concentrations of seven polychlorinated biphenyls (PCBs) and eight polybrominated diphenyl ethers (PBDEs) congeners were measured by GC-MS. Workers were categorized into five groups based on the type of e-waste handled and two control groups. Generalized linear models were used to assess the determinants of exposure levels among workers. POPs levels were also assessed in dust and silicone wristbands (SWB) and compared with serum. Four PCB congeners (CB 118, 138, 153, and 180) were frequently detected in serum regardless of worker's category. With the exception of CB 118, all tested PCBs were significantly higher in workers compared to the control group. Controls working in the same company as occupationally exposed (Within control group), also displayed higher levels of serum CB 180 than non-industrial controls with no known exposures to these chemicals (Outwith controls) (p < 0.05). BDE 209 was the most prevalent POP in settled dust (16 µg/g) and SWB (220 ng/WB). Spearman correlation revealed moderate to strong positive correlations between SWB and dust. Increased age and the number of years smoked cigarettes were key determinants for workers exposure. Estimated daily intake through dust ingestion revealed that ΣPCB was higher for both the 50th (0.03 ng/kg bw/day) and 95th (0.09 ng/kg bw/day) percentile exposure scenarios compared to values reported for the general population. This study is one of the first to address the occupational exposure to PCBs and PBDEs in Europe among e-waste workers through biomonitoring combined with analysis of settled dust and SWB. Our findings suggest that e-waste workers may face elevated PCB exposure and that appropriate exposure assessments are needed to establish effective mitigation strategies.

Towards a more effective REACH legislation in protecting human health.

There is growing evidence indicating the substantial contribution of man-made products to an increase in the risk of diseases of civilization. In this article, the Belgian Scientific Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) Committee gives a critical view on the working of REACH. The current regulatory framework needs to further evolve taking into account data generated using modern science and technology. There is a need for improved assessment process not only before but also after entering the market. Objectivity, transparency, and the follow-up after market access can be optimized. Additionally, no guidance documents exist for regulation of mixture effects. Further, the lengthiness before regulatory action is a big concern. Decision-making often takes several years leading to uncertainties for both producers and end users. A first proposed improvement is the implementation of independent toxicity testing, to assure objectivity, transparency, and check and improve compliance. A "no data, no market" principle could prevent access of hazardous chemicals to the market. Additionally, the introduction of novel testing could improve information on endpoints such as endocrine disrupting abilities, neurotoxicity, and immunotoxicity. An adapted regulatory framework that integrates data from different sources and comparing the outputs with estimates of exposure is required. Fast toxicology battery testing and toxicokinetic testing could improve speed of decision-making. Hereby, several improvements have been proposed that could improve the current REACH legislation.

Effects of exposure to environmental factors on obesity-related growth parameters and leptin (LEP) methylation in children.

The prevalence of childhood obesity is rapidly increasing. Therefore, gaining more information on the role of environmental parameters is key. With overexpression of leptin (encoded by LEP) in obesity, LEP methylation might be altered by environmental exposures. This study aims to assess effects of ambient air pollution and nearby greenness on obesity-related growth and LEP methylation in early childhood. We monitored 120 mother-child pairs from conception until the age of five. Buccal swabs and anthropometric measurements of the children were taken at six months, one year, and five years old. Buccal DNA was extracted to determine LEP methylation levels. Estimates of air pollution and nearby greenness were calculated using high-resolution models. Effects of air pollution and nearby greenness on growth or LEP methylation were investigated using linear mixed effects models. Positive associations were shown for air pollution between conception and age one on impedance in six-month-olds and one-year-olds in the crude model. PM with aerodynamic diameter ≤10 (PM10) and ≤2.5 µm (PM2.5) positively associated with waist-hip-ratio and waist circumference at age five in the fully adjusted model. In early childhood, closest distance to forest negatively, and urban green and forest positively associated with weight-for-length, body mass index, and fat percentage in five-year-olds in the fully adjusted model. No significant associations for noise, and walkability on growth were seen. Negative associations were shown for smaller green clusters and positive associations for greater green clusters on LEP methylation in one-year-olds. For forest distance, walkability, noise, or all green on LEP methylation, no significant associations were found. Evidence is provided that ambient air pollution might have a significant effect on impedance and waist-hip-ratio, suggesting an increased risk of childhood obesity. Based on LEP methylation, greater green clusters might associate with a decreased risk of childhood obesity, while smaller green clusters showed the opposite.

Multidimensional factors of burnout in general practice: a cross sectional survey.

BACKGROUND: GPs are particularly vulnerable to job burnout. Tailored prevention and intervention strategies are needed. AIM: To investigate organisational, interpersonal, and individual factors contributing to exhaustion and disengagement at work among GPs. DESIGN & SETTING: We conducted a cross-sectional study in a sample of Belgian GPs. METHOD: A total of 358 doctors (73% females, 301 with complete data) completed an online anonymous questionnaire assessing job burnout, psychosocial characteristics of the work environment, perceived social support in the private domain, emotional competence, and self-compassion. RESULTS: GPs reported moderate levels of exhaustion and disengagement. Regression models showed that included factors jointly explained 69% of the variance in exhaustion and 63% in disengagement. Exhaustion was significantly predicted by female sex (ß effect size = -0.1), high perceived emotional demands (ß = 0.19), as well as low self-compassion (ß = -0.14) and low emotional competence (ß = 0.09). Disengagement was significantly predicted by low seniority (ß = -0.12) and limited opportunities for development (ß = -0.16). Both exhaustion and disengagement were predicted by low perceived quality of work (ß = -0.19 and -0.14, respectively), meaning of work (ß = -0.17 and -0.31, respectively), and role clarity (ß = 0.09 and 0.12, respectively), as well as high perceived work-life conflict (ß = 0.46 and 0.21, respectively). Moreover, GPs working in a multidisciplinary group reported lower levels of exhaustion and disengagement than those working in a monodisciplinary group or a solo practice, and this difference was associated with factors such as work-life conflict. CONCLUSION: Organisational, interpersonal, and intrapersonal factors interact to predict a substantial part of burnout in general practice. The most significant risk factors were perceived work-life conflict and poor meaning of work. Policymakers should work to support more sustainable practices based on the specific needs and constraints reported by GPs.

Biopsychosocial rehabilitation in the working population with chronic low back pain: a concept analysis.

OBJECTIVE: To identify the essential attributes of biopsychosocial rehabilitation for chronic low back pain in the working population. DESIGN: A concept analysis was conducted according to the 8-step method of Walker and Avant. This framework provides a clear concept and theoretical and operational definitions. METHODS: Five databases were searched, followed by a systematic screening. Subsequently, attributes, illustrative cases, antecedents, consequences and empirical referents were formulated. RESULTS: Of the 3793 studies identified, 42 unique references were included. Eleven attributes were identified: therapeutic exercise, psychological support, education, personalization, self-management, participation, follow-up, practice standard, goal-setting, social support, and dietary advice. Subsequently, illustrative cases were described. Antecedents, such as motivation, preparedness and a multidisciplinary team, were found, together with consequences such as decreased pain, less sick-leave and increased function and work status. Finally, examples of empirical referents were given. CONCLUSION: This study identified the attributes that are necessary to develop biopsychosocial rehabilitation intervention programmes for chronic low back pain. The defined concept of biopsychosocial rehabilitation for chronic low back pain may serve as a solid base to further develop and apply interventions. Future research should focus on the objectification of biopsychosocial rehabilitation and conceptualization regarding how personalization is done.

Exposure of children to brominated flame retardants and heavy metals in Morocco: Urine and blood levels in association with global cytosine and adenine methylation.

Persistent pollutants, namely brominated flame retardants (BFRs) and heavy metals, are compounds that are added to a wide range of products and materials for preventing ignition, increasing the functionality of materials or improving their performance, e.g. electric conductivity. The exposure of children might consequently be inferred, through indoor dust and hand-to-mouth or toy-chewing behaviors. The current study is aimed at assessing the exposure of Moroccan children to BFRs and heavy metal elements, and evaluating their associations with global DNA methylation. First, parents responded to a questionnaire pertaining to children's lifestyle, then blood and urine samples were collected from (n = 93) children aged between 5 and 11 years for biomonitoring and DNA methylation analysis. BFRs were detected in 54.84% of samples with a median concentration of 0.01 nmol/mL (range: 0.004-0.051 nmol/mL) while metal elements were detected in more than 90% of samples. BFRs showed no variations with global DNA methylation, unlike metal elements, which revealed significant associations with global DNA methylation markers, namely 5-mC, 5-hmC and N6-mA levels. Moroccan children may be exposed to flame retardants and heavy metals through several routes. Further research is required to assess the exposure and the health impacts of environmental pollutants and ultimately protect the Moroccan population by the prevention of adverse health effects.

HBM4EU chromates study - PFAS exposure in electroplaters and bystanders.

The study aims to reveal the exposure to perfluoroalkyl substances (PFAS) in workers in different industry sectors with exposures to hexavalent chromium (Cr(VI)). The PFAS exposure of in total 172 individuals from 4 countries was assessed by the determination of 8 perfluoroalkyl carboxylic acids and 4 perfluoroalkyl sulfonic acids in plasma samples. The participants were 52 chrome plating workers, 43 welders, 3 surface treating workers and 74 workers without any occupational Cr exposure as controls. Significant differences between workers with Cr exposure and controls were found for the perfluoroalkyl sulfonic acids, particularly for perfluorooctane sulfonic acid (PFOS). The median and maximum levels were, respectively, 4.83 and 789 µg/l for chrome plating workers, 4.97 and 1513 µg/l for welders, and 3.65 and 13.9 µg/l for controls. The considerably high PFOS exposure in Cr platers and welders can be explained by the former application of PFOS as mist suppressants in electroplating baths, which resulted in an exposure of the directly involved operators, but also of welders performing maintenance and repair service at these workplaces.

Degradation products of resin-based materials detected in saliva in vivo.

OBJECTIVES: Dental composites remain under scrutiny regarding their (long-term) safety. In spite of numerous studies on the release of monomers both in vitro and in vivo, only limited quantitative data exist on the in vivo leaching of degradation products from monomers and additives. The aim of this observational study was for the first time to quantitatively and qualitatively monitor the release of parent compounds and their degradation products in saliva from patients undergoing multiple restorations. MATERIALS AND METHODS: Five patients in need of multiple large composite restorations (minimally 5 up to 28 restorations) due to wear (attrition, abrasion, and erosion) were included in the study, and they received adhesive restorative treatment according to the standard procedures in the university clinic for Restorative Dentistry. Saliva was collected at different time points, starting before the restoration up until 24 h after the treatment with composite restorations. Saliva extracts were analyzed by liquid chromatography-mass spectrometry. RESULTS: Leaching of monomers and degradation products was highest within 30 min after the placement of the restorations. The highest median concentrations of monomers were recorded for UDMA, BisEMA-3, and TEGDMA; yet, besides BisEMA-3 and TEGDMA, no monomers could be detected after 24 h. Mono- and demethacrylated degradation products remained present up to 24 h and concentrations were generally higher than those of monomers. In patients with multiple restorations, degradation products were still present in the sample taken before the next operation, several weeks after the previous operation. CONCLUSIONS: Exposure to residual monomers and degradation products occurs in the first hours after restoration. Monomers are present in saliva shortly after restoration, but degradation products can be detected weeks after the restoration confirming a long-term release. CLINICAL SIGNIFICANCE: Future research should focus more on the release of degradation products from monomers and additives from resin-based materials given their prolonged presence in saliva after restoration.