This study estimates the radiative forcing by biomass burning and dust aerosols over the Indian subcontinent, with emphasis on the Indo-Gangetic Plains (IGP) during the period from January 2021 to April 2021, based on multiple satellite and reanalysis datasets. In this respect, we used retrievals from the Moderate Resolution Spectroradiometer (MODIS) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) system, as well as reanalysis data from the Goddard Earth Observing System, version 5 (GEOS-5), the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2), the Copernicus Atmosphere Monitoring Service (CAMS), and ERA-Interim. According to the MERRA-2 and the CAMS, the highest black carbon (BC) concentrations in January 2021 were 7–8 µg m⁻³, which were significantly lower than measurements performed in main cities along the IGP, such as Patiala, Delhi, and Kanpur. The meteorological data analysis accompanied by the CALIPSO lidar measurements showed that the vertical distribution of total attenuated backscatter (TAB) could reach altitudes of up to ~4–5 km and could be transported over the central Himalayan region. The spatial-averaged daily aerosol radiative forcing (ARF) values over the Indian subcontinent from January 2021 to April 2021 were found to range from −51.40 to −6.08 W m⁻² (mean of −22.02 ± 9.19 W m⁻²), while on a monthly basis, the ARF values varied widely, from −146.24 to −1.63 W m⁻² (mean of −45.56 ± 22.85 W m⁻²) over different parts of the study region. Furthermore, the spatial-averaged daily BC radiative forcing ranged from −2.23 to −0.35 (−1.01 ± 0.40 W m⁻²), while it varied from −15.29 to −0.31 W m⁻² (−2.46 ± 2.32 W m⁻²) over different regions of southern Asia, indicating a rather small contribution to the total aerosol radiative effect and a large presence of highly scattering aerosols. Our findings highlight the importance of growing biomass burning, in light of recent climate change and the rapid decline in air quality over North India and the Indian Ocean.

The present study, for the first time, evaluated the seasonal variation of PM₁₀-associated bacterial and fungal concentrations at four locations (CARS premises, Doyel Chattar, Postogola, and Chittagong Road) in Dhaka, Bangladesh. In this study, PM₁₀ samples were collected four times on 20.3 × 25.4 cm irradiated glass fibre filter from November 2018 to August 2019. The concentrations of total airborne bacteria (14,073 ± 8,897 CFU/m³) were found to be significantly higher (one-way ANOVA; p < 0.05) in Chittagong Road, which is known for traffic congestion, than that of the other locations. The total airborne bacterial concentrations occurred in the following descending order: winter>spring>summer>rainy. Bacillus spp. and Staphylococcus spp. were found to be the dominant species present in PM₁₀ particles. Based on Pearson correlation analysis and stepwise multiple-regression analysis, relative humidity was found to be the most important variable controlling the concentrations of total airborne bacteria. Common fungi such as Aspergillus, Penicillium, Cladosporium and Fusarium genera were identified in the PM₁₀ samples. The highest fungal concentration (1,974 ± 1,173 CFU/m³) was found at Chittagong Road. The total fungal spore concentrations occurred in the following descending order: summer>spring>winter>rainy. From correlation analysis and stepwise regression analysis, the temperature was found to be the most important variable influencing the concentrations of fungi in PM₁₀ samples. A dose-rate estimation study revealed that the children were more vulnerable compared to adults with respect to exposure to bacterial and fungal dose rates. The present study has enormous implications considering the health hazards the bacterial and fungal communities pose to humans.

Air Pollution Tolerance Index (APTI) was used to assess four plant species, namely Mangifera indica, Artocarpus heterophyllus, Psidium guajava and Sweitenia mahagoni for their response toward air pollution in Dhaka city. Leaf samples of the plant species were analyzed for their physicochemical and biochemical attributes, including relative water content, leaf extract pH, ascorbic acid content and chlorophyll content. APTI values of all the plant species were found to be sensitive with respect to air pollution. Our results indicate that the studied plant species are not suitable for mitigating air pollution and should not be considered for urban roadside plantation. Supplemental data for this article can be accessed at https://doi.org/10.1080/10406026.2020.1858606.

Antibiotics are released into the environment either directly in an unchanged form or in a partially metabolized form. The discharge is usually through untreated waste or industrial treatment effluents. The potential concern is the uptake of these antibiotics by crops irrigated by treated wastewater. This study collected wastewater from eight points at the Pagla, Kadamtali, Dhaka treatment plant. Here we consider three crucial antibiotics, Doxycycline, Ciprofloxacin, and Tetracycline, used mainly during the last two years of the pandemic. A PDA detector was used in high-performance liquid chromatography (HPLC) analysis to determine the raw and processed effluent antibiotics. The most frequently seen antibiotics in natural wastewater were Doxycycline and Ciprofloxacin, with the highest concentration of 0.23µgL-1and 0.20 µgL-1(raw water), respectively. Tetracycline was not detected in natural water. Contrarily, Doxycycline was discovered in the Pagla plant's completed water and had the highest concentration (0.12 gL-1), whereas Ciprofloxacin and Tetracycline were not found in the dead water. The findings of this study showed that Doxycycline was still present in both the raw and processed effluent. Both natural and finished wastewater was subjected to a microbial-resistant test in the presence of all three antibiotics. The results revealed that the samples detected both heterotrophic bacteria and total coliform. The viable aerobic heterotrophic bacteria ranged between 5.421 and 4.754 log cfu/ml. Total bacteria load gradually decreased in the finished wastewater.