Anirban Chaudhuri

Bio: Anirban Chaudhuri is an academic researcher from Jadavpur University. The author has contributed to research in topics: Tropical climate & Population. The author has an hindex of 2, co-authored 3 publications receiving 4 citations.

Developement of health risk rating scale for indoor airborne fungal exposure.

Abstract: This paper aims to quantify airborne fungal load in air-conditioned rooms and develop a health risk rating scale for different indoor environments. Five sampling locations in Kolkata frequented by a heterogeneous human population, containing various types of fungal growth-promoting substances (FGPS) like old documents, food items, waste hair, etc. were chosen as sampling locations where an Andersen Two-Stage Cascade Impactor was ran using Rose Bengal agar and Potato Dextrose agar media plates. Total spore load (CFU/m3), species diversity, species dominance, human exposure time, susceptible age and FGPS were considered the risk factors for this study. A risk rating scale was developed after evaluating the relative importance of these different factors in relation to human health. The most dominant genera were Aspergillus, followed by Penicillium. Maximum CFU was observed at library, followed by computer room.

In vitro deterioration study of concrete and marble by Aspergillus tamarii

Abstract: Fungal deterioration is a major concern of conserving building materials. The objective of this paper was to investigate the effect of fungal deterioration of concrete and marble under conditions favourable for the development of microorganisms. Towards this aim, concrete (10 cm × 10 cm x 10 cm) and marble cubes (5 cm × 5 cm x 5 cm) were inoculated with pure cultures of Aspergillus tamarii isolated from Tagore house. Physical, chemical and aesthetic qualities were measured over 180 days. The results showed that reductions of weight for concrete and marble cubes were 1.20% and 1.90% respectively whereas compressive strength loss for both cubes were 24.32% and 19.15% respectively. The Scanning Electron Microscope (SEM) images distinctly exhibit the fungal growth in form of calcium oxalate crystal, increase in porosity and extension of fungal hyphae into interior of both cubes responsible in crack formation. The elemental composition analysis as conducted by micro Energy Dispersive X-ray Fluorescence (EDXRF) exhibited reduction of mass fraction of calcium for concrete (25.93%) and marble (10.19%) as compared to the control powder samples. The infrared (IR) spectral analysis of both samples showed absence of several spectral bands after 180 days which confirmed the fungal invasion for elimination of functional groups and also confirmed deterioration potentiality of the selected fungal species.

Assessment of Potential Damage Factor: A Case Study of St. Paul’s Cathedral, Kolkata:

Abstract: Damaging factors such as airborne microorganisms, relative humidity, ventilation, temperature and air pollutants are the major concerns of the tropical climate of Kolkata, India where our study sit...

Overview of Indoor Air Pollution: A Human Health Perspective

Abstract: In the modern world, humans spend more than 80 percent of their routine lives in indoors rather than outdoors. In recent decades, the improved living standards in indoor environments like houses, commercial offices, and similar places with decorations, refurbishment activities, remodeling, and new furniture emits toxic gases. Indoor Air Pollutants (IAP) comprises carbon monoxide and dioxide, nitrogen oxides, particulate matters, volatile organic compounds (formaldehyde, benzene, ethylene, etc.), and polycyclic aromatic hydrocarbons (biphenyl, benzo[a]pyrene, benzo[ghi]perylene, benzo[c]fluorine, etc.). Inhalation of these pollutants are likely to cause mortalities and morbidities illness attributed to respiratory diseases, cardiovascular diseases, pulmonary, and lung cancer diseases in human. According to World Health Organization, around 3.8 million populations die in a year prematurely from illness attributable to indoor pollution, i.e., pneumonia (27%), ischemic heart disease (27%), chronic obstructive pulmonary disease (20%), stroke (18%) and lung cancer (8%). Under these circumstances, mitigation measures are essential to seal off pollutants from the indoor environment for the protection of occupants from exposure accounting for advanced airflow distribution, photocatalytic oxidation techniques, and green system within indoor includes phytoremediation and biofiltration techniques. Hence, this chapter aimed to provide a comprehensive overview of current information regarding the characterization of indoor air pollutants, its concentration levels, health risk assessment, mitigation strategies, and sustainable remediation intended to reduce the impact of indoor air pollution on human health.

Surface Microbial Contamination and Air Quality before and after Regular Cleaning Procedures

Abstract: Studies on indoor air quality (IAQ) have linked exposure to microorganisms in indoor air to a variety of illnesses. The association between indoor air quality, surface contamination, and IAQ under heterogeneous cleaning procedures are all crucial factors that were investigated in this study. The ATP bioluminescence test demonstrated a significant correlation (r = 0.89; p 0.05) with bacterial count obtained from swab specimens and a moderate correlation (r = 0.57; p 0.001) with viable settling bacterial count. For the entire sample (pre- and post-cleaning), the ATP values were heterogeneous, averaging 230 RLU/100 cm2, 140 RLU/100 cm2, 120 RLU/100 cm2, 135 RLU/100 cm2, 99 RLU/100 cm2, and 80 RLU/100 cm2, in offices, classrooms, toilet doorknobs, reception desks, main lobbies, and exit doorknobs, respectively. An insignificant association between indoor and outdoor PM2.5 (r = 0.21; p 0.05), an I/O ratio of PM2.5 with an average value of 1.2, and an I/O ratio of CO2 exceeding 1 suggest a minor impact of outdoor air. After cleaning, the bacterial and fungal counts on indoor surfaces showed significant reduction, suggesting that the cleaning procedures were effective. The concentrations of VOC but not HCHO in indoor air were significantly affected by cleaning, but not by temperature or relative humidity (RH). We propose ATP bioluminescence as a surrogate for detecting bacterial contamination rather than fungal contamination, which requires additional validation. We suggest that the results of active microbial sampling (in CFU/m3) and settling plates (in CFU/m2/h) be interpreted independently to avoid confusion.

Optimization and application of UVC irradiation for prevention of fungal biodeterioration of vegetable tanned and chrome tanned leather

Abstract: Abstract UV-C irradiation critically effects the growth of micro-fungi and also deteriorate leather materials. In the present study vegetable tanned and chrome tanned leather were infected with pure cultures of Aspergillus niger and Aspergillus flavu s, which were isolated from stored leather materials. UV-C light (λ = 254 nm) was applied on infected leather for 15 and 60 min. The changes in leather qualities were examined through weight, tensile strength, scanning electron microscope, energy dispersive X-ray and Fourier transform infrared spectroscopy study after 15 and 30 days of fungal inoculation. Vegetable tanned leather was more vulnerable in case of fungal attack than chrome tanned leather while A. flavus showed more influence on leather deterioration than A. niger. The results showed that weight loss after 30 days for 15 and 60 min irradiation exposure was 1.3% compared to A. flavus infected leather (3.93%). The tensile strength of vegetable and chrome tanned UV irradiated leather was increased by 44% and 7% respectively. The scanning electron microscopic images exhibit the limited presence of conidiophores in UV-C exposed leather which confirmed the potentiality of irradiation for controlling fungal growth. The infrared spectral analysis of UV-C exposed infected leather samples showed neither shifting of wavenumber nor displacement of any functional groups. Altogether the efficacy of UV-C irradiation against biodeterioration of leather was concluded to be effective. This method can be used to control fungal growth without compromising the leather quality. Graphical Abstract