The marine iodine cycle has significant impacts on air quality and atmospheric chemistry. Specifically, the reaction of iodide with ozone in the top few micrometres of the surface ocean is an important sink for tropospheric ozone (a pollutant gas) and the dominant source of reactive iodine to the atmosphere. Sea surface iodide parameterisations are now being implemented in air quality models, but these are currently a major source of uncertainty. Relatively little observational data is available to estimate the global surface iodide concentrations, and this data has not hitherto been openly available in a collated, digital form. Here we present all available sea surface (<20 m depth) iodide observations. The dataset includes values digitised from published manuscripts, published and unpublished data supplied directly by the originators, and data obtained from repositories. It contains 1342 data points, and spans latitudes from 70°S to 68°N, representing all major basins. The data may be used to model sea surface iodide concentrations or as a reference for future observations.

5The Bay of Bengal (BoB) plays a fundamental role in controlling the weather systems that make up the South Asian summer monsoon system. In particular, the southern BoB has cooler sea surface temperature (SST) that influence ocean-atmosphere interaction and impact on the monsoon. Compared to the southeast, the southwestern BoB is cooler, more saline, receives much less rain, and is influenced by the Summer Monsoon Current (SMC). To examine the impact of these features on the monsoon, the BoB Boundary Layer Experiment (BoBBLE) was jointly undertaken by India and the UK during June

The fugacity of CO2 (fCO2 (water)) and air‐water CO2 flux were compared between a river‐dominated anthropogenically disturbed open estuary, the Hugli, and a comparatively pristine mangrove‐dominated semiclosed marine estuary, the Matla, on the east coast of India. Annual mean salinity of the Hugli Estuary (≈7.1) was much less compared to the Matla Estuary (≈20.0). All the stations of the Hugli Estuary were highly supersaturated with CO2 (annual mean ~ 2200 µatm), whereas the Matla was marginally oversaturated (annual mean ~ 530 µatm). During the postmonsoon season, the outer station of the Matla Estuary was under saturated with respect to CO2 and acted as a sink. The annual mean CO2 emission from the Hugli Estuary (32.4 mol C m−2 yr−1) was 14 times higher than the Matla Estuary (2.3 mol C m−2 yr−1). CO2 efflux rate from the Hugli Estuary has increased drastically in the last decade, which is attributed to increased runoff from the river‐dominated estuary.

In the present study, the toxicity of gold nanoparticles (Au NPs) was evaluated on various trophic organisms. Bacteria, algae, cell line, and mice were used as models representing different trophic levels. Two different sizes (CIT30 and CIT40) and surface-capped (CIT30-polyvinyl pyrrolidone (PVP)-capped) Au NPs were selected. CIT30 Au NP aggregated more rapidly than CIT40 Au NP, while an additional capping of PVP (CIT30-PVP capped Au NP) was found to enhance its stability in sterile lake water medium. Interestingly, all the forms of NPs evaluated were stable in the cell culture medium during the exposure period. Size- and dose-dependent cytotoxicities were observed in both bacteria and algae, with a strong dependence on reactive oxygen species (ROS) generation and lactate dehydrogenase (LDH) release. CIT30-PVP capped Au NP showed a significant decrease in toxicity compared to CIT30 Au NP in bacteria and algae. In the SiHa cell line, dose- and exposure-dependent decline in cell viability were noted for all three types of Au NPs. In mice, the induction of DNA damage was size and dose dependent, and surface functionalization with PVP reduced the toxic effects of CIT30 Au NP. The exposure to CIT30, CIT40, and CIT30-PVP capped Au NPs caused an alteration of the oxidative stress-related endpoints in mice hepatocytes. The toxic effects of the gold nanoparticles were found to vary in diverse test systems, accentuating the importance of size and surface functionalization at different trophic levels.

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The present study aims to assess the physicochemical properties and prevalence of microbial communities in soils samples collected from different locations of Cachar district, Assam, India. Bacterial communities in the soil were screened by morphological, biochemical and 16S rDNA sequence analysis and were identified as Bacillus megaterium, Bacillus cereus, Pseudomonas aeruginosa and Chromobacterium pseudoviolaceum. High concentrations of toxic metals negatively affect bacterial growth, and therefore, the minimum inhibitory concentration of isolated bacteria was determined against Cd, Pb, Fe and Cu by agar dilution technique. Co-resistance of antibiotic was also determined, which demonstrated that most of the metal-tolerant isolates were resistant to Methicillin and Penicillin. However, P. aeruginosa showed resistance to other antibiotics such as Cefdinir, Ampicillin, Kanamycin, Rifampicin and Vancomycin. The development and evolution of antibiotic resistance in soil bacteria occurs very likely naturally as a result of unethical and non-scientific disposal of toxic substances and industrial discharge, which also includes heavy-metal effluents and other clinical by-products. Therefore, pragmatic measures must be taken to limit the spread of antimicrobial resistance across the environment and to reduce the incidence of healthcare-associated infections.

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