Growing ambient air pollution in Lucknow is a menace to the monuments, urban dwellers, and the ecosystem. In view of the above, air pollution tolerance potential of dominant plants against air pollutants was assessed supported by indices and statistics. The study was conducted at three sampling sites in Lucknow city: commercial, industrial, and rural in the years 2021-22. PM2.5 concentrations were 163.4 ± 25.3, 155.1 ± 14.6 and 113.2 ± 30.8 µg/m3 at commercial, industrial, and rural locations, respectively, breaching national ambient air quality standards (60 µg/m3) by 172.3, 158.5 and 88.7

Clean air is the foremost essentiality to ensure a good life on our planet. Nonetheless, escalating air pollution levels in urban spaces have caused an increase in morbidity and mortality. The air pollution predicament requires a comprehensive understanding of the local scale. In this perspective, the present study was carried out to assess the load of PM10, PM2.5, SO2, NO2, O3 and associated chemical profiles, including trace elements and ionic species of the commercial, industrial and rural areas over Lucknow city during winter months of 2022–23. The average 24-hour PM2.5 concentrations (Avg ± SD) in the commercial, industrial, and rural areas were recorded to be 189.1 ± 57.6, 177.7 ± 36.5, and 141.6 ± 23.0 μg/m3, respectively, with a percentage exceedance over national ambient air quality standards (NAAQS) of 224 to 215, 196, and 136%. Similarly, the concentrations of PM10 were 337.9 ± 109.2, 285.6 ± 53.1, and 234.9 ± 43.0 μg/m3, with 238, 186, and 135% exceedance, respectively. SO2 level ranged from 8.7 to 23.9 μg/m3, whereas NO2 level ranged from 16.8 to 45.7 μg/m3 for the study period. Based on the air quality index (AQI) values, commercial (353), industrial (344), and rural (317) areas fell in the “very poor” category of AQI. 12 studied elemental species in descending order were Al>Fe>Mg>Zn>Pb>Mn>Cr>Cu>Ni>Co>Cd>Mo while the sequence of 8-ionic species was SO4 2->Cl- >K+>NH4 +>NO3 ->Ca2+>Na+>F–. Residents of Lucknow city have been found to be frequently exposed to particulate pollution and related chemical elements, particularly during haze and inversion occurrences in the winter. It is, therefore, imperative to assess and develop pollution abatement strategies to combat urban air pollution.

Chlorinated compounds are typically used in farmlands, industries and health centres to avert damage to crops and human health. On the other hand, they are noxious agro-industrial chemicals that are a huge menace to living beings and the environment. Municipal sewage, agricultural fields, surface runoff and industries are prime sources of chlorinated contaminants in water bodies. The persistent and lipophilic nature of organochlorines leads to resistance to biodegradation and imparts the potential to reach the circulatory system and get accumulated in adipose tissues. Exposure to organochlorines brings mutagenic, cytotoxic, endocrine-disrupting, carcinogenic effects and causes susceptibility to diseases. Owing to their toxicological and environmental perspectives; it is a prime concern to understand their mitigation and degradation approaches. In this context, it is imperative to highlight the application of bio-catalytic enzymes (peroxidase, laccase) and bio- and phytoremediation approaches for the remediation of organochlorines. This review aims to deliberate comprehensive knowledge of classification, application, disposal, toxicity, hazardous influences, remediation (in-situ and ex-situ), and enzyme-based bio-degradation of organochlorines with relevant examples. Predictive mitigation and degradation of organochlorines can be deemed as a feasible and suitable option which could be used to protect the environment from potentially hazardous pollutants.

Clean air is imperative to the survival of all life forms on the planet. However, recent times have witnessed enormous escalation in urban pollution levels. It is therefore, incumbent upon us to decipher measures to deal with it. In perspective, the present study was carried out to assess PM10 and PM2.5 loading, metallic constituents, gaseous pollutants, source contributions, health impact and noise level of nine-locations, grouped as residential, commercial, and industrial in Lucknow city for 2019–21. Mean concentrations during pre-monsoon for PM10, PM2.5, SO2 and NO2 were: 138.2 ± 35.2, 69.1 ± 13.6, 8.5 ± 3.3 and 32.3 ± 7.4 µg/m3, respectively, whereas post-monsoon concentrations were 143.0 ± 33.3, 74.6 ± 14.5, 12.5 ± 2.1, and 35.5 ± 6.3 µg/m3, respectively. Exceedance percentage of pre-monsoon PM10 over National Ambient Air Quality Standards (NAAQS) was 38.2

Sustainable river ecosystem is the fundamental backbone of all civilizations of the world. Water contamination through heavy metals and metalloids causes wide environmental and public discontent which makes it a global concern. With this view, 20 km stretch of Gomti River encompassing 5-locations was selected for determination of 16-physicochemical parameters and 11-heavy metals in water and bed-sediment samples during two consecutive years 2019–2020 covering three seasons supplemented by indices and statistics. Bed-sediment characterization was done through scanning electron microscope–energy dispersive X-rays and attenuated total reflection-Fourier transform infrared analysis. River is significantly contaminated with Fe, Mg, Mn, Zn, Pb, Cu, Ni, Cr, Co, Cd, Hg having corresponding mean values 10.1 ± 1.8, 31.7 ± 6.2, 1.4 ± 0.5, 0.42 ± 0.07, 0.09 ± 0.03, 0.03 ± 0.02, 0.17 ± 0.02, 0.41 ± 0.14,0.19 ± 0.01, 0.18 ± 0.01, 0.002 ± 0.001 mg/l in water and 3418.7 ± 529.9, 1839.9 ± 417.6, 194.3 ± 49.1, 112.2 ± 37.5, 42.5 ± 15.7, 36.1 ± 10.6, 23.4 ± 8, 16.7 ± 5.9, 8.4 ± 3.2, 8.2 ± 3.3, 0.002 ± 0.001 µg/g in bed-sediment, respectively. Corresponding order of heavy metals concentration was Mg > Fe > Mn > Zn > Cr > Co > Cd > Ni > Pb > Cu > Hg and Fe > Mg > Mn > Zn > Pb > Cu > Ni > Cr > Co > Cd > Hg, respectively. Higher values of indices for risk quantification; geo-accumulation index (5.0), contamination factor (1191.8), enrichment factor (46.5) and potential ecological risk index (393.8) were found for Cd in bed-sediment samples. Principal component analysis (λ > 1) scored 3-factors having 65

Lucknow is one of the most polluted metro-city in India with increasing vehicular density and fuel consumption in the last three decades. The study was conducted during years 2019–2021 for measurement of fine particulate matter (PM 2.5 ), nitrogen dioxide (NO 2 ), sulphur dioxide (SO 2 ), respirable particulate matter (PM 10 ), and noise levels at nine selected sites; 4 residential, 4 commercial, and 1 industrial, encompassing prior-to-lockdown, during-lockdown, and after-lockdown periods. Values of PM 10 for prior-to-lockdown, during-lockdown, and after-lockdown period ranged from 133.2 to 197.4, 77.0 to 135.0, and 91.4 to 148.0 µg/m 3 , respectively while values of PM 2.5 were 66.5 to 93.6, 41.9 to 67.5 and 49.5 to 98.6 µg/m 3 , respectively. Corresponding values of SO 2 ranged from 8.7 to 12.8, 5.5 to 7.6, and 11.4 to 17.6 µg/m 3 , respectively while values of NO 2 were 24.6 to 57.0, 20.5 to 32.8, and 26.1 to 43.8 µg/m 3 , respectively. Order of the trace metals associated with PM 2.5 is Co < Cd < As < Cr < Ni < Cu < Pb < Mn < K < Zn, Co < Cd < As < Cr < Cu < Ni < Pb < Mn < Zn < K and Cd < Co < As < Cr < Cu < Ni < Pb < Mn < K < Zn in the same periods. Statistical data evidenced that the air quality of the city witnessed drastic improvement during the COVID-19 pandemic. WHO AIRQ + was utilized to calculate attributable health risk and post-neonatal disease burden; showing 1447 ± 768 estimated number of cases attributable to ambient PM 10 per lakh of population. Regulatory authorities need to establish new benchmarks for the prevention and management of public health risks for urban resilience and environmental management for episodic events in the near future.

Sustainable ecosystem is of essence to the river for its survival and maintenance of ecological balance. Gomti river, a groundwater-fed tributary of the Holy Ganges, is the lifeline of the middle Indo-Gangetic Plains. Screening of river pollutants for river cleanup is a challenging task. To this end, 20 km Lucknow stretch of Gomti was sampled at 5 locations for physicochemical–bacteriological analysis. Collected samples were analyzed for pH, TA, turbidity, DO, BOD, TH, COD, TDS, fecal coliform, and E. coli. Analytical instruments AAS and GC-ECD were used for heavy metal and organochlorine pesticide analysis. DO was 3.2 ± 0.3 to 7.4 ± 0.4 (avg 5 ± 1.8) mg/l, BOD was 10.6 ± 0.5 to 41 ± 1.7 (avg 22.9 ± 13.3) mg/l, while COD was 26.6 ± 4.6 to 93.5 ± 4.6 (avg 56 ± 31.3) mg/l. WQI values gradually increased from S1 (56.7) to S5 (181.8) which denotes a significant deterioration of water quality downstream of the river. Cd, Mn, Fe, Pb, and Cr had increment of 64, 18, 12, 6, and 2 fold, respectively, as compared to individual BIS:10500 standards. Among the OCPs, concentrations were in the order: aldrin > pp-DDT > β-HCH > γ-HCH > α-endosulfan > pp-DDE > α-HCH. Statistically strong positive correlation (r > 0.95 at 0.01) was observed among physicochemical parameters. Furthermore, bacterial species Aeromonas salmonicida subsp. Achromogenes, Aeromonas salmonicida strain A527, Aeromonas encheleia strain NCTC12917, and Aeromonas salmonicida strain ATCC33658 were identified by 16S rRNA gene amplification and molecular phylogenetic analysis. The study indicated heavy contamination of the river with organic and inorganic pollutants owing to mixing of untreated sewage, industrial effluents, and associated toxicants along with pathogenic bacteria which are a barrier to the harmony of aquatic life.

Urban air pollution is a growing menace leading to human discomfort, increased hospitalizations, morbidity, and mortality. This study deals with deteriorated air quality due to firecracker bursting during Diwali in Lucknow. Inhalable particulates and gaseous pollutants were monitored during Diwali 2020 using air samplers. Elements, ions, and surface morphology of particles were analyzed using ICP-MS, ion chromatograph, and SEM-EDX, respectively. PM10, PM2.5, SO2, and NO2 were 558, 352, 44, and 86 μg/m3 during Diwali night and 233, 101, 17, and 40 μg/m3 on pre-Diwali night while 241, 122, 24, and 43 μg/m3 on Diwali day. Concentrations surged for PM10: 139