Assessment of Fungal Concentrations Associated with Relative Humidity and Temperature Variations in the Indoor Environment

Background: Indoor environmental factors and human activities influence the presence and concentration of fungal propagules which may lead to the risk of developing respiratory infections and allergic reactions. Aim/Objectives: This study aimed to identify the factors that influence indoor fungal composition and determine its association with the development of respiratory and allergic reactions. Methodology: A total of 549 air samples and 226 nasal swabs of occupants were examined using health base questionnaire, malt extract agar and A6 single stage microbial air sampler. House dampness, mould growth on indoor materials, temperature, relative humidity, type of ventilation, type of human activity, and location of building were found to affect the prevalence and diversity of indoor fungi. Results: A total of 55, 46 and 50 species of fungi were isolated from homes, offices and hospitals respectively. High fungal count, were recorded in homes with moisture problems, low temperature and high relative humidity and homes located in high density areas. High cases of respiratory health problems were reported by occupants of these homes. Conclusion: Improvement in housing and establishment of awareness programmes can be used to lower fungal load and health problems associated with dampness in homes.It is necessary to maintain and prevent the housekeeping activities that can predispose fungal concentration in indoor environment.

A novel nano-sulphur and essential oil-based room freshener

Introduction: Alternaria spp. and Candida spp. are the main fungal pathogen of indoor environment like house, office, classroom, etc. These may cause various diseases and infections like systemic infections, or chronic asthma in immunocompromised individuals through secretion of various toxic substances. Chemical-based commercially available room fresheners used to control the fungal load of indoor environment are not beneficial to human health. Objective: was to provide viable alternative in the form of nanoparticle-based approach for the management of air-borne fungi. Methodology: The present study primarily focuses on the isolation, microscopic and biochemical identification of indoor fungi; Azadirachta indica-mediated sulphur nanoparticles (SNPs) synthesis, their detection and characterization; and in vitro assessment of SNPs against isolated fungi present in indoor environment. Result: The isolated fungi were identified as Alternaria spp and Candida spp. The SNPs showed absorbance maxima at 291 nm. NTA analysis showed average size of 188.4 nm, and zeta potential of -4.94 mV which represented synthesis of stable SNPs. XRD pattern confirmed the face centered cubic, crystalline nature of SNPs. FTIR spectrum depicted the presence of polyhydroxyl, nitrile, keto, aromatic and carboxylic compounds which stabilized the SNPs. The antifungal assays demonstrated the significant activity of the formulated SNPs and eucalyptus oil infused air freshener. Conclusion: It can be concluded that A. indica-mediated SNPs can be applied in the formulation and manufacture of an ecofriendly air freshener for the management of indoor fungal pathogens like Alternaria spp. and Candida spp.

Contribution of Visible Surface Mold to Airborne Fungal Concentration as Assessed by Digital Image Quantification

The rapid monitoring of total fungi, including air and surface fungal profiling, is an important issue. Here, we applied air and surface sampling, combined with digital image quantification of surface mold spots, to evaluate the contribution of surface fungi to airborne fungal concentrations. Cladosporium, Penicillium, Aspergillus, and yeast often appeared in the air or on wall surfaces during sampling. The indoor/outdoor concentration ratios (I/O ratios) demonstrated that the airborne concentrations of commonly found fungal genera outdoors were higher than those indoors (median I/O ratio = 0.65–0.91), excluding those of Penicillium and yeast. Additionally, the surface density (fungal concentration/area) of individual fungi showed no significant correlation with the airborne concentration, excluding that of Geotrichum. However, if a higher surface ratio (>0.00031) of mold spots appeared in the total area of an indoor environment, then the concentrations of Aspergillus and Geotrichum in the air increased significantly. Our results demonstrated that the airborne concentration of indoor fungi is significantly correlated with the outdoor concentration. A higher density of surface fungi does not necessarily contribute to a high fungal concentration in the air. In contrast to fungal density, quantification of the surface fungal area is recommended to assess the risk of surface fungi propelling into the air.

Profiles of Environmental Mold: Indoor and Outdoor Air Sampling in a Hematology Hospital in Seoul, South Korea

Inhalation of fungal spores can cause various spectrums of fungal diseases in immunocompromised hosts. The aim of this study was to evaluate the concentrations and profiles of fungal species in air collected at different locations in hematology wards and outside of the hospital in Seoul St. Mary’s Hospital over the course of a year. Air sampling was performed at four locations—outside the hospital (O), in the general ward (GW), in the lounge in the cleanroom (CRL), and in the patients’ room in the cleanroom (CRR)—by using Andersen single-stage air sampler at every two weeks between May 2017 and May 2018. The results showed higher mean fungal density in summer, and the concentrations of fungi decreased as follows: O (954.8 colony-forming units, CFU/m3) > GW (4.2 CFU/m3) > CRL (0.7 CFU/m3) > CRR (0 CFU/m3). Aspergillus was most prevalent both inside (47%) and outside (62%) of the hospital. However, the outdoor fungal profile was more diverse than the indoor profile. Within the hospital, Penicillium was the second most dominant species. In conclusion, the outdoor fungal profile is diverse even in Seoul, a highly urbanized area in Korea. The distribution of indoor air fungi is significantly different from outdoor due to air quality systems. Heating, ventilation, and air conditioning (HVAC), as well as high-efficiency particulate air (HEPA)-filtered systems should be established to effectively reduce levels of indoor fungi.

Indoor Fungal Growth on Variable Antifungal at Different Wall Finishing on Plasterboard

Various health complaints often been attributed to pollution and the poor quality of the indoor air. If there is good practice in building design, construction, and maintenance, the structures should remain dry. However, when there is moisture damage, the materials may be in contact with water for prolonged times, which inevitably leads to microbial growth or even total deterioration of the building material. Antimicrobial coating is designed to generate a surface that is easy to clean and can also incorporate active agents, commonly called antifungal, that prevent microbial colonization, the subsequent growth and bio-deterioration of the substrate. This paper presents the sustainable treatment for indoor environment quality in buildings by examining the application of potassium sorbate, zinc salicylate, and calcium benzoate that used as food industry preservatives as indoor antimicrobial agents. Four types of wall finishing used on plasterboard substrate: acrylic paint, glycerol based-paint, thin wallpaper, and thick wallpaper. The result indicated that potassium sorbate is the best bio compound to react as antifungal agent to prohibit the growth of indoor fungi. All the antifungal shows difference level of their effectiveness from each other. Only 40% of fungi were able to grow on thin wallpaper by using potassium sorbate as antifungal agent.