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Co-composting of fresh tobacco leaves and soil: an exploration on the utilization of fresh tobacco waste in farmland
2022
Di, Huihui | Wang, Rui | Ren, Xiaohong | Deng, Jianqiang | Deng, Xiaohua | Bu, Guijun
A large amount of fresh tobacco waste with high water content are produced in farmland, and it may cause environmental pollution if it is not properly treated. The fresh tobacco waste is not easily collected and transported, resulting in its centralized treatment is expensive. This study is to clarify whether it is feasible to treat fresh tobacco wastes by co-composting of them and soil in farmland and applied the obtained compost product into the soil instead of a part of tobacco-specific fertilizer. The results showed that, compared with that in original soil, the relative abundance of Pseudomonas, Azotobacter, and Coprinus of the co-composted products increased by roughly 244%, 323%, and 675%, respectively, and effective nitrogen and available potassium increased by roughly 157% and 132%, respectively. In addition, the nicotine content in co-composted products decreased dramatically compared with the discarded tobacco leaves. The application of the co-composted products and 20% fertilizer amount (15 g/plant) (YD5) exhibited the highest relative abundance of beneficial microbial communities in the soil and the best growth of tobacco plants. The co-composting of fresh tobacco waste and soil in farmland is an effective measure to treat the fresh tobacco waste, and its products increased beneficial microorganisms and stimulate the growth of tobacco plants by replacing an amount of the fertilizer.
Show more [+] Less [-]Fungal populations in the bedroom dust of children in Havana, Cuba, and its relationship with environmental conditions
2021
Sánchez Espinosa, Kenia C. | Rojas Flores, Teresa I. | Davydenko, Sonia Rodríguez | Venero Fernández, Silvia J. | Almaguer, Michel
The study of the fungal community composition in house dust is useful to assess the accumulative exposure to fungi in indoor environments. The objective of this research was to characterize the fungal diversity of house dust and its association with the environmental conditions of bedrooms. For this, the dust was collected from 41 bedrooms of children between the ages of 8 and 9 with a family history of asthma, residents of Havana, Cuba. The fungal content of each sample was determined by two methods: plate culture with malt extract agar and by direct microscopy. An ecological analysis was carried out from the fungal diversity detected. To describe the factors associated with the fungi detected, bivariate logistic regression was used. Through direct microscopy, between 10 and 2311 fragments of hyphae and spores corresponding mainly to Cladosporium, Coprinus, Curvularia, Aspergillus/Penicillium, Xylariaceae, and Periconia were identified. Through the culture, 0–208 CFU were quantified, where Aspergillus, Cladosporium, and Penicillium predominated. The culturability evidenced the differences between the quantification determined by both methods. A positive relationship was found between the type of cleaning of the furniture, the presence of trees in front of the bedroom, indoor relative humidity, indoor temperature, the presence of air conditioning, and natural ventilation with specific spore types and genera. The use of two different identification methods allowed to detect a greater fungal diversity in the residences evaluated. Monitoring the exposure to these fungal allergens in childhood can help to prevent sensitization in the allergic child, the development of asthma, and other respiratory diseases.
Show more [+] Less [-]Intradiurnal variation of predominant airborne fungal spore biopollutants in the Central European urban environment
2019
Ščevková, Jana | Hrabovský, Michal | Kováč, Jozef | Rosa, Samuel
Fungal spores are an important cause of allergic respiratory diseases worldwide. However, little is known about the intradiurnal pattern of spore concentrations of different fungal spore types in the air of the urban area. In this study, we evaluated bihourly variation in spore concentration of eight predominant fungal spore types in the atmosphere of Bratislava city (Agrocybe, Alternaria, Cladosporium, Coprinus, Exosporium, Epicoccum, Ganoderma, Leptosphaeria) with the aim to understand the relationships between the spore concentrations against associated environmental variables. Spore samples were collected using a Hirst-type volumetric aerospore trap from January to December 2016. Alternaria, Cladosporium, Epicoccum and Exosporium peaked during the daytime period between 10:00 and 16:00, while for Agrocybe, Ganoderma, Coprinus and Leptosphaeria, the nighttime peaks (20:00 and 04:00) were observed. Effect of a complex of environmental variables on bihourly concentrations of selected airborne fungal spore taxa was evaluated through multiple regression analysis. Air temperature, wind speed, sunshine duration and precipitation were positively associated with daytime spore types, while the association with nighttime spores was negative. In contrast, relative air humidity influenced negatively Exosporium daytime spore type but positively the Leptosphaeria nighttime spore type. Moreover, a circadian cycle of light and darkness was considered as an important predictor of nighttime spore levels. Among the atmospheric pollutants, PM₁₀ was positively associated with all analysed daytime spores, while except for Leptosphaeria, O₃ was negatively associated with nighttime spore types. NO₂ and PM₁₀ had mixed effects on nighttime spore levels. In general, air temperature, PM₁₀ and wind speed were environmental parameters with great influence on airborne fungal spore concentration, being present in eight, seven and four regression models, respectively. Constructed regression models which the best explained variation in fungal spore concentrations were those for Ganoderma (R² = 0.38) and Alternaria (R² = 0.31).
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