Comprehensive assessment of occupational exposure to microbial contamination in waste sorting facilities from Norway

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research was funded by FCT-Fundação para a Ciência e a Tecnologia, I.P. (Portugal) for funding the EEA Grants Project-EXPOGreen FBR38 and by Polish Minister of Science and Higher Education, under the program "Regional Initiative of Excellence" in 2019-2022 (Grant No. 008/RID/2018/19). H&TRC authors gratefully acknowledge the FCT/MCTES national support through the UIDB/05608/2020 and UIDP/05608/2020 and the PhD Grant UI/BD/151431/2021. This work was supported by national funds through FCT/MCTES/FSE/UE, UI/BD/153746/2022 and CE3C unit UIDB/00329/2020 within the scope of a PhD Grant.Introduction: It is of utmost importance to contribute to filling the knowledge gap concerning the characterization of occupational exposure to microbial agents in the waste sorting setting (automated and manual sorting). Methods: This study intends to apply a comprehensive field sampling and laboratory protocol (culture-based methods and molecular tools), assess fungal azole resistance, as well as to elucidate potential exposure-related health effects (cytotoxicity analyses). Skin-biota samples (swabs) were performed on workers and controls to identify other exposure routes. Results: In personal filter samples the guidelines in one automated industry surpassed the guidelines for fungi. Seasonal influence on viable microbial contamination including fungi with reduced susceptibility to the tested azoles was observed, besides the observed reduced susceptibility of pathogens of critical priority (Mucorales and Fusarium sp.). Aspergillus sections with potential toxigenic effects and clinical relevance were also detected in all the sampling methods. Discussion: The results regarding skin biota in both controls´ and workers´ hands claim attention for the possible exposure due to hand-to-face/mouth contact. This study allowed the conclusion that working in automated and manual waste sorting plants implies high exposure to microbial agents.info:eu-repo/semantics/publishedVersio

Comprehensive assessment of occupational exposure to microbial contamination in waste sorting facilities from Norway

IntroductionIt is of upmost importance to contribute to fill the knowledge gap concerning the characterization of the occupational exposure to microbial agents in the waste sorting setting (automated and manual sorting).MethodsThis study intends to apply a comprehensive field sampling and laboratory protocol (culture based-methods and molecular tools), assess fungal azole resistance, as well as to elucidate on potential exposure related health effects (cytotoxicity analyses). Skin-biota samples (eSwabs) were performed on workers and controls to identify other exposure routes.ResultsIn personal filter samples the guidelines in one automated industry surpassed the guidelines for fungi. Seasonal influence on viable microbial contamination including fungi with reduced susceptibility to the tested azoles was observed, besides the observed reduced susceptibility of pathogens of critical priority (Mucorales and Fusarium sp.). Aspergillus sections with potential toxigenic effect and with clinical relevance were also detected in all the sampling methods.DiscussionThe results regarding skin-biota in both controls´ and workers´ hands claim attention for the possible exposure due to hand to face/mouth contact. This study allowed concluding that working in automated and manual waste sorting plants imply high exposure to microbial agents

Luftbårne soppartikler : karakterisering og immunodetektering av soppfragmenter

Indoor environments with high moisture problems often reveal colonization of indoor materials by fungi with release of airborne fungal particles. Exposure to airborne fungal particles has been associated with various negative health effects particulary in the respiratory tract. However, epidemiological and exposure studies based on spore particles could not confirm such an association. Exposure to fungal fragments including submicronic fragments, in addition to spores has been therefore suggested to play an important role in the observed adverse health effects. But, detection and enumeration of these fragments in air samples have not been possible. We aimed in the present thesis to characterize the composition, the morphology and the origin of fungal aerosols and further to develop an appropriate method for detection and enumeration of fragments in air samples using field emission scanning electron microscopy (FESEM).Innemiljøer med fuktproblemer utvikler ofte soppvekst på byggmaterialer som kan føre til frigjøring av luftbårne soppartikler som kan bære allergener, antigener og mykotoksiner. Eksponering for soppartikler har vært assosiert med ulike helseproblemer knyttet til luftveiene, særlig allergi og astma. Epidemiologiske studier basert på eksponeringskarakterisering av sporepartikler kunne ikke bekrefte en slik assosiasjon. Eksperimentell forekomst av soppfragmenter i størrelsen <1μm, i tillegg til sporene, ble derfor foreslått å spille en viktig rolle i de observerte helseproblemene ved eksponering. Hittil, fantes ikke en metode som muliggjør deteksjon og telling av disse fragmentene i luftprøver. Vi satte derfor som mål å karakterisere sammensetningen, morfologien og opprinnelsen til de forskjellige typer soppartiklene som kunne bli luftbårne og utvikle en metode for påvisning og telling av fragmenter i luftprøver ved hjelp av skanning elektronmikroskopi

Characterization and pro‐inflammatory potential of indoor mold particles

A number of epidemiological studies find an association between indoor air dampness and respiratory health effects. This is often suggested to be linked to enhanced mold growth. However, the role of mold are obviously difficult to disentangle from other dampness related exposure including microbes as well as non‐biological particles and chemical pollutants. The association may partly be due to visible mycelial growth and a characteristic musty smell of mold. Thus, the potential role of mold exposure should be further explored by evaluating information from experimental studies elucidating possible mechanistic links. Such studies show that exposure to spores and hyphal fragments may act as allergens and pro‐inflammatory mediators, and that they may damage airways by the production of toxins, enzymes and volatile organic compounds. In the present review, we hypothesizes that continuous exposure to mold particles may result in chronic low‐grade pro‐inflammatory responses contributing to respiratory diseases. We summarize some of the main methods for detection and characterization of fungal aerosols and highlight in vitro research elucidating how molds may induce toxicity and pro‐inflammatory reactions in human cell models relevant for airway exposure. Data suggest that the fraction of fungal hyphal fragments in indoor air is much higher than that of airborne spores, and the hyphal fragments often have a higher pro‐inflammatory potential. Thus, hyphal fragments of prevalent mold species with strong pro‐inflammatory potential may be particularly relevant candidates for respiratory diseases associated with damp/mold‐contaminated indoor air. Future studies linking of indoor air dampness with health effects should assess the toxicity and pro‐inflammatory potential of indoor air particulate matter, and combined this information with a better characterization of biological components including hyphal fragments from both pathogenic and non‐pathogenic mold species. Such studies may increase our understanding of the potential role of mold exposure

Characterization and pro‐inflammatory potential of indoor mold particles

A number of epidemiological studies find an association between indoor air dampness and respiratory health effects. This is often suggested to be linked to enhanced mold growth. However, the role of mold are obviously difficult to disentangle from other dampness related exposure including microbes as well as non‐biological particles and chemical pollutants. The association may partly be due to visible mycelial growth and a characteristic musty smell of mold. Thus, the potential role of mold exposure should be further explored by evaluating information from experimental studies elucidating possible mechanistic links. Such studies show that exposure to spores and hyphal fragments may act as allergens and pro‐inflammatory mediators, and that they may damage airways by the production of toxins, enzymes and volatile organic compounds. In the present review, we hypothesizes that continuous exposure to mold particles may result in chronic low‐grade pro‐inflammatory responses contributing to respiratory diseases. We summarize some of the main methods for detection and characterization of fungal aerosols and highlight in vitro research elucidating how molds may induce toxicity and pro‐inflammatory reactions in human cell models relevant for airway exposure. Data suggest that the fraction of fungal hyphal fragments in indoor air is much higher than that of airborne spores, and the hyphal fragments often have a higher pro‐inflammatory potential. Thus, hyphal fragments of prevalent mold species with strong pro‐inflammatory potential may be particularly relevant candidates for respiratory diseases associated with damp/mold‐contaminated indoor air. Future studies linking of indoor air dampness with health effects should assess the toxicity and pro‐inflammatory potential of indoor air particulate matter, and combined this information with a better characterization of biological components including hyphal fragments from both pathogenic and non‐pathogenic mold species. Such studies may increase our understanding of the potential role of mold exposure

Pro-Inflammatory Responses in Human Bronchial Epithelial Cells Induced by Spores and Hyphal Fragments of Common Damp Indoor Molds

Damp indoor environments contaminated with different mold species may contribute to the development and exacerbation of respiratory illnesses. Human bronchial epithelial BEAS-2B cells were exposed to X-ray treated spores and hyphal fragments from pure cultures of Aspergillus fumigatus, Penicillum chrysogenum, Aspergillus versicolor and Stachybotrys chartarum. Hyphal fragments of A. fumigatus and P. chrysogenum induced expression and release of the pro-inflammatory cytokine interleukin (IL)-6 and the chemokine IL-8, while none of the other hyphal preparations had effects. Hyphal fragments from A. fumigatus and P. chrysogenum also increased the expression of IL-1α, IL-1β and tumor necrosis factor (TNF)-α, but these cytokines were not released. X-ray treated spores had little or no inflammatory potential. Attenuating Toll-like receptor (TLR)-2 by blocking antibodies strongly reduced the A. fumigatus and P. chrysogenum hyphae-induced IL-6 and IL-8 release, whereas TLR4 antagonist treatment was without effects. Untreated A. fumigatus spores formed hyphae and triggered expression of pro-inflammatory genes with similarities to the effects of hyphal fragments. In conclusion, while X-ray treated spores induced no pro-inflammatory responses, hyphal fragments of A. fumigatus and P. chrysogenum enhanced a TLR2-dependent expression and release of IL-6 and IL-8

Pro-Inflammatory Responses in Human Bronchial Epithelial Cells Induced by Spores and Hyphal Fragments of Common Damp Indoor Molds

Damp indoor environments contaminated with different mold species may contribute to the development and exacerbation of respiratory illnesses. Human bronchial epithelial BEAS-2B cells were exposed to X-ray treated spores and hyphal fragments from pure cultures of Aspergillus fumigatus, Penicillum chrysogenum, Aspergillus versicolor and Stachybotrys chartarum. Hyphal fragments of A. fumigatus and P. chrysogenum induced expression and release of the pro-inflammatory cytokine interleukin (IL)-6 and the chemokine IL-8, while none of the other hyphal preparations had effects. Hyphal fragments from A. fumigatus and P. chrysogenum also increased the expression of IL-1α, IL-1β and tumor necrosis factor (TNF)-α, but these cytokines were not released. X-ray treated spores had little or no inflammatory potential. Attenuating Toll-like receptor (TLR)-2 by blocking antibodies strongly reduced the A. fumigatus and P. chrysogenum hyphae-induced IL-6 and IL-8 release, whereas TLR4 antagonist treatment was without effects. Untreated A. fumigatus spores formed hyphae and triggered expression of pro-inflammatory genes with similarities to the effects of hyphal fragments. In conclusion, while X-ray treated spores induced no pro-inflammatory responses, hyphal fragments of A. fumigatus and P. chrysogenum enhanced a TLR2-dependent expression and release of IL-6 and IL-8

Profile and Morphology of Fungal Aerosols Characterized by Field Emission Scanning Electron Microscopy (FESEM)

<div><p>Fungal aerosols consist of spores and fragments with diverse array of morphologies; however, the size, shape, and origin of the constituents require further characterization. In this study, we characterize the profile of aerosols generated from <i>Aspergillus fumigatus</i>, <i>A. versicolor,</i> and <i>Penicillium chrysogenum</i> grown for 8 weeks on gypsum boards. Fungal particles were aerosolized at 12 and 20 L min⁻¹ using the Fungal Spore Source Strength Tester (FSSST) and the Stami particle generator (SPG). Collected particles were analyzed with field emission scanning electron microscopy (FESEM). We observed spore particle fraction consisting of single spores and spore aggregates in four size categories, and a fragment fraction that contained submicronic fragments and three size categories of larger fragments. Single spores dominated the aerosols from <i>A. fumigatus</i> (median: 53%), while the submicronic fragment fraction was the highest in the aerosols collected from <i>A. versicolor</i> (median: 34%) and <i>P. chrysogenum</i> (median: 31%). Morphological characteristics showed near spherical particles that were only single spores, oblong particles that comprise some spore aggregates and fragments (<3.5 μm), and fiber-like particles that regroup chained spore aggregates and fragments (>3.5 μm). Further, the near spherical particles dominated the aerosols from <i>A. fumigatus</i> (median: 53%), while oblong particles were dominant in the aerosols from <i>A. versicolor</i> (68%) and <i>P. chrysogenum</i> (55%). Fiber-like particles represented 21% and 24% of the aerosols from <i>A. versicolor</i> and <i>P. chrysogenum,</i> respectively. This study shows that fungal particles of various size, shape, and origin are aerosolized, and supports the need to include a broader range of particle types in fungal exposure assessment.</p></div