Wastewater reuse from wastewater treatment plants (WWTPs) is promoted in agriculture as a sustainable strategy to address water scarcity. However, current regulatory frameworks primarily require the control of conventional bacterial indicators, while fungal communities remain largely overlooked. This study provides an integrated assessment of fungal hazards and mycotoxin risks in treated wastewaters intended for agricultural reuse. A literature review covering the period 2000–2025 was conducted to investigate the occurrence and reported effects of filamentous fungi in WWTPs. The analysis revealed that Aspergillus and Fusarium are the most frequently detected genera in wastewater systems and include species associated with pathogenicity and mycotoxin production. Conversely, Trichoderma, widely recognized for its antagonistic activity against plant pathogens, suggests complex ecological interactions that may influence pathogen dynamics and, potentially, offer opportunities for biological control strategies within the reuse irrigation system. On the basis of these findings, a full-scale monitoring campaign was conducted in two WWTPs before and after the final disinfection step. Culture-based analyses identified Aspergillus, Fusarium and Trichoderma in most samples, both pre- and post-disinfection. These findings were incorporated into a structured and gap-aware risk assessment framework to evaluate potential human and environmental exposure pathways associated with fungi and mycotoxins due to wastewater reuse. A Quantitative Chemical Risk Assessment (QCRA) was performed for deoxynivalenol (DON), selected among the most frequently reported mycotoxins in WWTP. In parallel, a Quantitative Microbial Risk Assessment (QMRA) was developed to assess the risk associated with the fungal load found in the effluents. Although most of the modelled risk indicators remained below the threshold of concern under the adopted assumptions, the persistent occurrence of fungal genera and mycotoxins highlights an underexplored dimension of wastewater reuse safety. By integrating full-scale monitoring evidence with a transparent risk framework, this study supports the need to expand regulatory approaches beyond conventional bacterial parameters and opens perspectives for further research on fungal ecological interactions and their engineering implications, including the exploration of biocontrol-oriented strategies within sustainable wastewater reuse systems.
Il riutilizzo delle acque reflue provenienti dagli impianti di trattamento delle acque reflue (WWTPs) è promosso in agricoltura come strategia sostenibile per contrastare la scarsità idrica. Tuttavia, gli attuali quadri normativi richiedono principalmente il controllo dei tradizionali indicatori batterici, mentre le comunità fungine rimangono trascurate. Il presente studio fornisce una valutazione integrata dei rischi legati alla presenza di funghi e micotossine nelle acque reflue trattate destinate al riuso. È stata effettuata una revisione della letteratura (2000–2025) per indagare la presenza e gli effetti dei funghi filamentosi nei WWTPs. Dall’analisi è emerso che Aspergillus e Fusarium sono i generi più frequentemente rilevati nei WWTPs con specie associate a patogenicità e produzione di micotossine. Al contrario, Trichoderma, ampiamente riconosciuto per la sua attività antagonista nei confronti dei funghi patogeni, suggerisce la presenza di complesse interazioni ecologiche che possono influenzare la dinamica dei patogeni e, potenzialmente, offrire opportunità per strategie di controllo biologico all’interno dei sistemi di irrigazione con acque riutilizzate. Sulla base di tali risultati, è stata condotta una campagna di monitoraggio in due WWTPs prima e dopo la fase di disinfezione. Le analisi, effettuate con metodi di coltura su piastra, hanno identificato Aspergillus, Fusarium e Trichoderma nella maggior parte dei campioni. Questi risultati sono stati integrati in un framework strutturato e consapevole delle limitazioni connesse per la valutazione del rischio, al fine di analizzare le potenziali vie di esposizione umana e ambientale associati a funghi e micotossine derivanti dal riutilizzo delle acque reflue. È stata condotta una Quantitative Chemical Risk Assessment (QCRA) per il deossinivalenolo (DON), selezionato tra le micotossine più frequentemente riportate negli effluenti dei WWTP. In parallelo, è stata sviluppata una Quantitative Microbial Risk Assessment (QMRA) per valutare il rischio associato alla carica fungina rilevata. Sebbene la maggior parte degli indicatori siano risultati inferiori alla soglia di rischio, la persistente presenza di funghi e micotossine evidenzia una dimensione poco studiata della sicurezza del riuso delle acque reflue. I risultati supportano la necessità di ampliare gli attuali approcci regolatori oltre i parametri batterici convenzionali e aprono prospettive per ulteriori ricerche sulle interazioni ecologiche fungine e sulle loro possibili implicazioni ingegneristiche, incluse strategie orientate al biocontrollo in sistemi sostenibili di riutilizzo delle acque reflue.
Beyond conventional indicators: fungal occurrence in reclaimed wastewater and implications for agricultural reuse
De Pirro, Gaia
2025/2026
Abstract
Wastewater reuse from wastewater treatment plants (WWTPs) is promoted in agriculture as a sustainable strategy to address water scarcity. However, current regulatory frameworks primarily require the control of conventional bacterial indicators, while fungal communities remain largely overlooked. This study provides an integrated assessment of fungal hazards and mycotoxin risks in treated wastewaters intended for agricultural reuse. A literature review covering the period 2000–2025 was conducted to investigate the occurrence and reported effects of filamentous fungi in WWTPs. The analysis revealed that Aspergillus and Fusarium are the most frequently detected genera in wastewater systems and include species associated with pathogenicity and mycotoxin production. Conversely, Trichoderma, widely recognized for its antagonistic activity against plant pathogens, suggests complex ecological interactions that may influence pathogen dynamics and, potentially, offer opportunities for biological control strategies within the reuse irrigation system. On the basis of these findings, a full-scale monitoring campaign was conducted in two WWTPs before and after the final disinfection step. Culture-based analyses identified Aspergillus, Fusarium and Trichoderma in most samples, both pre- and post-disinfection. These findings were incorporated into a structured and gap-aware risk assessment framework to evaluate potential human and environmental exposure pathways associated with fungi and mycotoxins due to wastewater reuse. A Quantitative Chemical Risk Assessment (QCRA) was performed for deoxynivalenol (DON), selected among the most frequently reported mycotoxins in WWTP. In parallel, a Quantitative Microbial Risk Assessment (QMRA) was developed to assess the risk associated with the fungal load found in the effluents. Although most of the modelled risk indicators remained below the threshold of concern under the adopted assumptions, the persistent occurrence of fungal genera and mycotoxins highlights an underexplored dimension of wastewater reuse safety. By integrating full-scale monitoring evidence with a transparent risk framework, this study supports the need to expand regulatory approaches beyond conventional bacterial parameters and opens perspectives for further research on fungal ecological interactions and their engineering implications, including the exploration of biocontrol-oriented strategies within sustainable wastewater reuse systems.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/253483