No abstract

Diatom indices have gained considerable popularity in estimation of the trophic state and degree of pollution in lotic ecosystems. However, their applicability and efficacy have rarely been tested in Indian streams and rivers. In the present study, benthic diatom assemblages were sampled at 27 sites along the Chambal River in Central India. PCA revealed three groups of sites, namely, heavily polluted (HVPL), moderately polluted (MDPL), and least polluted (SANT). A total of 100 diatom taxa belonging to 40 genera were identified. Brachysira vitrea (Grunow) was the most abundant species recorded from the least polluted sites with an average relative abundance of 29.52. Nitzschia amphibia (Grunow) was representative of heavily polluted sites (average relative abundance 31.71) whereas moderately polluted sites displayed a dominance of Achnanthidium minutissimum (Kϋtzing) with an average relative abundance of 26.33. CCA was used to explore the relationship between diatom assemblage composition and environmental variables. Seventeen different diatom indices were calculated using diatom assemblage data. The relationship between measured water quality variables and index scores was also investigated. Most of the diatom indices exhibited strong correlations with water quality variables including BOD, COD, conductivity, and nutrients, particularly phosphate. Best results were obtained for TDI and IPS indices which showed a high level of resolution with respect to discrimination of sites on the basis of pollution gradients. Water quality maps for the Chambal River were hence prepared in accordance with these two indices. However, satisfactory results with respect to water quality evaluation were also obtained by the application of EPI-D and IGD indices. The present study suggests that TDI and IPS are applicable for biomonitoring of rivers of Central India. Diatom indices, which are simpler to use such as IGD, may be considered, at least for a coarser evaluation of water quality.

Graphical abstract The nexus of COVID-19 and environment is conspicuously deep-rooted. The roles of environmental factors in the origin, transmission and spread of COVID-19 and the mutual impact of the pandemic on the global environment have been the two perspectives to view this nexus. The present paper attempts to systematically review the existing literature to understand and explore the linkages of COVID-19 with environment and proposes conceptual frameworks to underline this nexus. Our study indicates a critical role of meteorological factors, ambient air pollutants and wastewater in severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) transmission-spread dynamics. The study also focuses on the direct and indirect impacts of COVID-19 on the regional and global environment. Most of the indirect environmental effects of COVID-19 were attributed to global human confinement that resulted from the implementation of the pandemic containment measures. This worldwide anthropogenic ‘pause’ sent ripples to all environmental compartments and presented a unique test bed to identify anthropogenic impacts on the earth’s natural systems. The review further addresses emerging sustainability challenges in the new normal and their potential solutions. The situation warrants critical attention to the environment-COVID-19 nexus and innovative sustainable practices to address the ramifications of short- and long-term environmental impacts of the COVID-19 pandemic.

The people living in Ghaggar river basin are facing various waterborne diseases due to polluted water of Ghaggar River. The quality of Ghaggar river water was tested and analysed during this study. A health survey was also conducted to strengthen the work. The results undoubtedly verify that the quality of Ghaggar river water is not suitable to withstand the aquatic life and not fit for domestic uses. The low dissolved oxygen level and other checked parameters are clearly indicating it. The observed maximum values of biochemical oxygen demand (BOD5), color, pH, total dissolved solids (TDS), chloride (Cl-),turbidity and chemical oxygen demand (COD) were 36 mg/l, 500 ptcu, 8.6, 1321 mg/l, 161 mg/l, 301 NTU and 265 mg/l respectively. Most probable number count of river was also carried out and it shows very high number and clearly indicating that the river has bad quality of water. To understand the possible relationship between the quality of river water and water-borne diseases amongst the locals, a questionnaire survey was also carried out. The waterborne diseases observed in the study area were Jaundice, Diarrhea, Typhoid, Hepatitis, Malaria etc.

The study aimed to identify the tolerance level of rice and wheat due to air pollutants around the gas-based power plant. Ten sites were selected around 10km radius of gas based power plant. Major air pollutants like NOx, SOx, ozone, and PM10 were monitored in ten sites during the growth of rice and wheat. The Air Quality Index (AQI) of villages falls mostly in the category of moderately polluted sites. Air Pollution Tolerance Index (APTI) is a tool applied for categorizing sensitive or tolerant plants towards air pollution and is calculated by using four biochemical parameters like total chlorophyll content, ascorbic acid, pH, and relative water content of rice and wheat. Results indicated that the pH of cell sap of both the crops was acidic to neutral pH (3.5-6.9) at polluted sites while neutral to slightly alkaline (7.0-7.9) at less polluted sites. Ascorbic acid content was high at polluted sites since ascorbic acid shows a defense mechanism against air pollution. Chlorophyll content (up to 0.61mg/g) and relative water content have shown a significant decrease at most polluted sites. As per APTI values (APTI<11), both the crops were sensitive to air pollution in the selected area. APTI might be beneficial in the selection of crop species in the polluted area which shows that a higher concentration of air pollutants can damage crops severely. APTI was found to be positively correlated with pH, total chlorophyll content, and relative water content and negatively correlated with ascorbic acid.