Assessing particle count in electron microscopy measurements of nanomaterials to support regulatory guidance

In the European Union, nanomaterials are regulated through different pieces of sectoral legislation.This legislation often requires risk assessments and thus reliable characterization data, for whichregulatory guidance generally recommend electron microscopy. The guidance provides best practicesfor measurements but lacks requirements on how many particles to measure. Using transmissionelectron microscopy data of nanomaterials, a strategy based on repeated subsampling is proposedto establish, for different particle size and shape measurands, mathematical relationships betweenparticle count and precision, and subsequently to determine the minimum particle count. Our resultsconfirm that the minimum particle count generally depends on the width of the size and shapedistributions and that the median of the distribution can be determined with the highest precisioncompared to other percentiles. Upon combining the precision uncertainty related to particle numberwith uncertainties from other sources, such as sample preparation, calibration and trueness, wereach an optimal particle count above which additional particle measurements only yield negligibleimprovements to the combined measurement uncertainty. Our findings offer an experimentalapproach for determining the minimum particle count to measure particle size and shape by electronmicroscopy. It enables efficient analyses and facilitates compliance with legislation addressingnanomaterials across various application&nbsp;domains.</p

EBoD-FL. Guidelines for mapping the environmental burden of disease in Flanders, 2024

The environment poses a diverse range of health risks. Environmental burden of disease (EBD) studies try to estimate the impact of environmental stressors in terms of mortality or morbidity on a population level. Although environmental risks have been studied in Flanders, an effort to routinely quantify the environmental disease burden completely and coherently has thus far not been established. For this reason, Sciensano and Departement Zorg are partnering up in a project to map the Environmental Burden of Disease in Flanders (EBoD-FL). The aim of the research is to inventory the burden of disease attributable to all relevant environmental stressors according to a coherent framework. To tackle this objective, the disease burden attributable to environmental stressors is estimated using comparative risk assessment (CRA). As this method determines the attributable burden proportionally, figures for the total disease burden are required as a baseline to obtain absolute estimates. In EBoD-FL, the EBD is quantified as disability-adjusted life years (DALYs), a summary measure that combines both mortality and&nbsp;morbidity. In EBoD-FL, a novel approach is developed where the EBD is calculated locally at the level of the statistical sector. This approach adds geographic detail to the EBD estimates, and allows to mutually compare small areas and local populations. Additionally, the local results can be aggregated to wider areas and larger populations, which allows to extract estimates for any part of the Flemish Region in a flexible manner. As collecting the necessary data on this fine-scale level poses a challenge, a parallel track of calculations was set up, where the EBD is determined ‘globally’ on the level of &nbsp;Flanders. Data on this aggregated level (Flanders) are relatively easy to obtain, which allows to complete the steps in the analysis more&nbsp;swiftly. Given the extensive list of potential risk factor-health outcome pairs, a set of priorities was defined in terms of environmental stressors and health outcomes. The risk factors that were prioritised are those related to air quality, environmental noise and extreme temperature. In terms of outcomes, priority was given to all-cause mortality, respiratory diseases and cardiovascular diseases. This report outlines the CRA methodology in general, and the application on the risk-outcome pairs that have been given priority. The basic steps of CRA&nbsp;are: Selection of risk factors: Which risk factors are included in the study and how is exposure quantified as a&nbsp;metric? Exposure assessment: how to measure or model exposure to the risk factors in the&nbsp;population? Identification of risk-outcome pairs: which health outcomes are caused by the risk&nbsp;factors? Quantification of the risk-outcome relation: what is the risk of developing the outcome in function of&nbsp;exposure? Calculation of the population attributable fraction: what is the proportion of the disease burden attributed to one or multiple risk&nbsp;factors? The purpose of this report is to outline the general methodology used to tackle the objective of EBoD-FL and to apply the CRA methodology to the stressors that are prioritized. Additionally, possibilities for the application of the results for evidence-based policy are explored, as well as some challenges and&nbsp;limitations.</p

Impact of substance type and patient characteristics on the choice of treatment setting for substance use disorder in Belgium

Background:&nbsp;Specialised addiction treatment centers (SAC) and general mental health centers (GMHC) both offer care to people with substance use disorders (SUD) in Belgium, but these sectors often operate in parallel, with little collaboration. This fragmented system may lead to inefficiencies, particularly in the treatment of individuals with dual diagnoses. Despite the recognized challenges, there is limited understanding of the factors that influence whether patients with SUD are treated in SAC or GMHC. Objectives:&nbsp;This observational study has two main objectives: METHODS: The study used routinely collected data from treatment centers in Belgium from 2019 (Belgian Treatment Demand Indicator). Logistic regression evaluated the weight of drug use and sociodemographic variables for people entering treatment for SUD for the first time (n = 8322). A random forest algorithm was used to study all patients’ orientation toward both sectors, across all treatment episodes (n =&nbsp;29,658). Results:&nbsp;The study found that the primary substance significantly influences sector choice. Patients using illicit substances like cannabis, opiates, cocaine, and stimulants are 6-12 times more likely to be treated in an SAC than those using alcohol. Factors such as income source and referral source (e.g. self-referral, general practitioner, etc) also significantly impact patient&nbsp;orientation. Conclusion:&nbsp;These findings highlight the need for better integration between SAC and GMHC to adequately address the complex needs of people with SUD, especially with dual&nbsp;diagnosis.</p

Surveillance épidémiologique de l&#039;hépatite A en Belgique, 2023-2024

Messages&nbsp;clés • Le nombre de cas d’hépatite A enregistrés était de 175 en 2023 et 254 en 2024 (données de la déclaration obligatoire et du Centre National de Référence). • Après une baisse du nombre de cas d&#8217;hépatite A pendant la pandémie de COVID-19 (surtout en 2020 et 2021), le nombre de cas d&#8217;hépatite A est revenu aux niveaux antérieurs à la pandémie de COVID-19 en 2024. • En 2024, il y avait légèrement plus d&#8217;hommes que de femmes atteints d&#8217;hépatite A (en 2023, il n&#8217;y avait aucune différence). Les incidences les plus élevées ont été enregistrées dans les groupes d&#8217;âge inférieurs à 10 ans. • L&#8217;hépatite A présente une évolution saisonnière en Belgique, avec un nombre plus élevé de cas après l&#8217;été, lié aux voyageurs revenant de pays où la maladie est&nbsp;endémique.</p

20240109_RAG_RespiRadar

20250109_RAG_RespiRadar</p