Filtration efficiency of medical and community face masks using viral and bacterial bioaerosols.

Face masks are often recommended in community settings to prevent the airborne transmission of respiratory viruses or bacteria. Our first objective was to develop an experimental bench to assess the viral filtration efficiency (VFE) of a mask with a methodology similar to the normative measurement of bacterial filtration efficiency (BFE) used to determine the filtration performance of medical masks. Then, using three categories of masks of increasing filtration quality (two types of community masks and one type of medical mask), filtration performances measured ranged from 61.

Impact of washing parameters on bacterial filtration efficiency and breathability of community and medical facemasks.

Can medical face masks be replaced by reusable community face masks with similar performance? The influence of the number of wash cycles, the wash temperature and the use of detergent was evaluated on the performance of one medical face masks (MFM) and ten community face masks (CFM). The performance of the new and washed masks was characterized from the bacterial filtration efficiency (BFE) and the differential pressure (DP). The tests on the new masks showed that the MFM had always better BFE than CFMs.

Comparison of bacterial filtration efficiency vs. particle filtration efficiency to assess the performance of non-medical face masks.

As a result of the current COVID-19 pandemic, the use of facemasks has become commonplace. The performance of medical facemasks is assessed using Bacterial Filtration Efficiency (BFE) tests. However, as BFE tests, require specific expertise and equipment and are time-consuming, the performance of non-medical facemasks is assessed with non-biological Particle Filtration Efficiency (PFE) tests which are comparatively easier to implement.

Elemental fingerprint of human amniotic fluids and relationship with potential sources of maternal exposure.

Background: The impact of nanoparticles we are increasingly exposed to remains largely unknown. Of particular concern is the exposure of pregnant women and potential impact on fetal development. Indeed, many in vitro and in vivo animal studies have shown that nanoparticles are able to cross the placental barrier and induce toxic effects to the fetus.

Metal load assessment in patient pulmonary lavages: towards a comprehensive mineralogical analysis including the nano-sized fraction.

Mineralogical analyses of clinical samples have been proved useful to identify causal relationship between exposure to airborne particles and pulmonary diseases. The most striking example is asbestosis where the assessment of asbestos bodies in patient lung samples has allowed defining values specific of pathologies. However, this type of analyses only considers the micro-sized fraction of the particles, neglecting the specific impact of nano-sized particles which have been otherwise shown to be reactive and able to induce biological effects.

Impact of cerium oxide nanoparticles shape on their in vitro cellular toxicity.

Cerium oxides (CeO) nanoparticles, also referred to as nanoceria, are extensively used with a wide range of applications. However, their impact on human health and on the environment is not fully elucidated. The aim of this study was to investigate the influence of the CeO nanoparticles morphology on their in vitro toxicity.

Impact of the chemical composition of poly-substituted hydroxyapatite particles on the in vitro pro-inflammatory response of macrophages.

To improve the biological properties of calcium phosphate (CaP) bone substitute, new chemical compositions are under development. In vivo such materials are subject to degradation that could lead to particles release and inflammatory reactions detrimental to the bone healing process. This study aimed at investigating the interactions between a murine macrophage cell line (RAW 264.

Metals distribution in colorectal biopsies: New insight on the elemental fingerprint of tumour tissue.

Background: Some studies have linked colorectal cancer to metal exposure.

Aims: Our objective was to evaluate the element distribution in colorectal adenocarcinoma biopsies, adjacent non-tumour tissues, and healthy controls.

Methods: The study is a case-control study which compared the element distribution in colon biopsies from two groups of patients: with colorectal cancer (2 types of samples: colorectal cancer biopsies and adjacent non-tumour tissues) and healthy controls.