Yogesh Kumar Vishwakarma’s research while affiliated with Indian Institute of Technology (Banaras Hindu University) Varanasi and other places

Scientific research on the concentration and size distribution of bioaerosols in diverse environmental conditions is recently being prioritized. Exposure to bioaerosols, especially through inhalation, is linked to many severe health complications. The inhalation of the bioaerosols is directly linked with the size as well as the nature of the bioaerosols. However, information related to the prevalence of bioaerosols is limited in India, constituting the basis for investigating variations in bacterial and fungal bioaerosol concentrations at various indoor sites. Several observational campaigns were initiated within diverse indoor sites, including cowshed, poultry, canteen, library, auditorium, laboratory, and hospital, using a six-stage viable impactor. Bacterial bioaerosols were more prevalent for size > 7.0 μm and between 1.1 and 2.1 μm. In contrast, fungal concentration peaked in the size range of 1.1 to 3.3 μm. At all the sites, the concentration of bacterial bioaerosols exceeded fungal bioaerosols (2 to 12 times), while such variation was exceptionally high in the poultry firm (70 times higher). No significant correlation was noted between bacterial and fungal bioaerosol concentration and environmental factors. The diversity of bacteria and fungi bioaerosols was found to be different as it varied from site to site. However, species like Acinetobacter and Bacillus sp. in bacteria and Penicillium, Aspergillus, and Cladosporium in fungi were most prevalent. Some of the bioaerosols found in these sites are pathogenic in nature and may cause severe health issues (if found in significant amount). The predominance of bioaerosols is mostly within the breathable range (< 3.3 μm) in diverse microenvironments.

Fog is a common atmospheric event in northern India. Frequently, dense and prolonged fog envelops the entire Indo-Gangetic Plain (IGP), especially in the winter season. During winter, conducive atmospheric conditions also facilitate the accumulation of airborne particulates near the earth surface, significantly reducing atmospheric visibility in the presence of water vapour and gases. Besides, fog formation can also change the characteristics of the biological component of the air (bioaerosols). The Anderson six-stage bioaerosol cascade impactor was therefore used to collect bioaerosols during winter-specific foggy and non-foggy days to assess how fog formation affects the loading and characteristic of bioaerosols. It has been found that the concentration of bioaerosols increases during foggy days (2223 ± 553 CFU m⁻³) compared to non-foggy days (days including both before and after fog; 1478 ± 490 CFU m⁻³). Nearly, a 50% rise in the total culturable microbe concentration was noted during foggy days as compared to non-foggy days in an urban habitat over the central IGP. Approximately 46% and 55% increase in bacterial and fungal bioaerosol concentration, respectively, was found to be associated with foggy days. The size of bioaerosols also varied with the change in atmospheric conditions. During foggy days, bacterial and fungal concentration increased in the coarse size fraction (4.7–7.0 μm) compared to fine (0.65–7.0 μm) particles. The presence of bacteria such as Bacillus; Enterobacter; Cocci and fungi such as Aspergillus, Cladosporium and Penicillium were found during foggy days. The measured concentration of bioaerosols did not exhibit strong association with meteorological variables and other atmospheric co-pollutants. Health risk assessment of the exposure to bioaerosols revealed strong possibility to cause adverse human health effects in the exposed population.

The winter period is most ideal for studying near-surface aerosols in the Indo-Gangetic plains (IGP) of India, since this period is inundated with significantly higher concentrations of aerosols across the unique geographical domain because of shallow atmospheric boundary layer. This study focuses on analysing the concentration of the biotic component of aerosols (bioaerosols) in a central location of the IGP and estimating their dominance in ambient particulate matter (PM) from 2021 to 2023. Observations showed that bioaerosol concentrations also increased significantly with the increasing concentrations of PM 2.5 and PM 10 , suggesting that bioaerosols are a dominant component of the total aerosol load in the atmosphere. The total microbe's concentration (collectively fungi and bacteria) was found to be 94 to 226 cfu m −3 in PM 2.5 and 167 to 375 cfu m −3 in PM 10 where bacteria contributed 81.12 and 79.99%, respectively. The contribution of fungal spores in PM 2.5 and PM 10 remained as 18.88 and 20.01%, respectively, in the total microbes in the respective particulate matter. In the bioaerosols, fungi, namely Aspergillus, Cladosporium, and Penicillium, were dominant, and bacteria, namely E. coli, Mammaliicoccus and Enterobacter, were prevalent in both the PM size regimes. The most prominent microbial presence was observed when the temperature ranged between 16 and 20°C and relative humidity between 80 and 85%. The outcomes of the present study will be useful for further research on the health effect of the bioaerosols in the IGP.

Bioaerosols are present everywhere around us, either on surfaces or in the air. Depending on their nature, these bioaerosols have positive or negative impacts on our bodies. Our immune system always creates a balance in our health system in response to these bioaerosols. If our body’s immune system is compromised for a while, it could have many severe health complications. A good example is in patients who recovered from COVID-19 during the COVID-19 pandemic. During treatment, many drugs like dexamethasone, tocilizumob, itolizumab, and steroids were extensively used that suppressed the immune system, resulting in many fungal infections. In this review, we summarise the various studies carried out throughout the globe regarding fungal infection, including Mucormycetes (black fungus), Candida spp., Aspergillus fumigatus, and pneumocystis jirovecii. The patient disease history and treatment details were also examined so as to develop the risk of mortality. Populations with other pre-existing diseases such as diabetes and asthma are more vulnerable to infection. These infections spread at a very high rate and have a high risk of mortality in patients who have recovered from COVID-19. Earnest attention is needed regarding the treatment procedure of COVID-19 patients and for the follow-up of recovered patients. Here, we suggest some treatment methods that will help prevent infection in patients who have recovered from COVID-19 or in immunosuppressed bodies.

Arsenic, even in trace concentration presents several adverse impacts on human health and are classified among carcinogenic species. The subsequent health concerns owing to consumption of arsenic contaminated water has been widely reported, however, the presence and effects of arsenic through air still remains to be explored thoroughly, due to the availability of limited research and literature; the reason being difficulty in estimation of arsenic compounds in gaseous or particulate associated form. The objective of the current review is to present a detailed picture of sources, estimation techniques and control strategies available currently and propose futuristic approaches for abatement of the problem. A summary of the studies conducted globally has been included in the review with an objective to figure out the occurrence and exposure to arsenic in different parts of the world, exposure assessment and control strategies followed to overcome the problem. Studies on dispersion of As in gaseous or particulate form has also been discussed, on the basis of ground observation as well as predicted models.