Organochlorine residues in the avifauna of Tamil Nadu (Southeast coast of India)

Pollution due to persistent pesticides is not a regional but a global problem. Organochlorine pesticides are persistent chemicals, stored and accumulated in the tissues of a wide variety of invertebrates and vertebrates including marine species. In the present study the organochlorine residues HCHs, DDTs and PCBs were measured in different trophic groups of birds (scavengers, inland piscivores, coastal piscivores, insectivores, granivores and omnivores) collected from Tamil Nadu Coast, India. The residue accumulation as a function of sex did not depict distinct variation. However, females had lower residue levels than males in terms of their mean weight and feeding habits. A continuous monitoring programme is recommended to establish the studied organisms as indicator species.     

Effect of temperature and dissolved oxygen on the growth kinetics of Pseudomonas putida F1 growing on benzene and toluene

Batch experiments were conducted to determine the effect of temperature and dissolved oxygen concentration on the rates of growth and substrate (benzene and toluene) degradation by the toluene degrading strain, Pseudomonas putida F1. Over a range of temperature from 15 to 35 degrees C the maximum specific growth rate followed the Topiwala-Sinclair relationship when either benzene or toluene served as the sole carbon and energy source. Oxygen limited growth followed Monod saturation kinetics with the specific growth rate given as a function of the dissolved oxygen concentration. The oxygen half-saturation coefficient was found to be approximately 1 mg/l regardless of whether benzene or toluene was the substrate. Similar experiments with Burkholderia (Ralstonia) pickettii PKO1 for grown on toluene revealed an oxygen half-saturation coefficient of 0.7 mg/l.     

Accumulation features of persistent organochlorines in resident and migratory birds from Asia

Concentrations of organochlorine contaminants including polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) were determined in the resident and migratory birds, which were collected from India, Japan, Philippines, Russia (Lake Baikal) and Vietnam. Accumulation patterns of organochlorine concentrations in resident birds suggested that the predominant contaminants of each country were as follows: Japan--PCBs Philippines--PCBs and CHLs, India--HCHs and DDTs, Vietnam--DDTs, and Lake Baikal--PCBs and DDTs. The migratory birds from Philippines and Vietnam retained mostly the highest concentrations of DDTs among the organochlorines analyzed, indicating the presence of stopover and breeding grounds of those birds in China and Russia. On the other hand, migratory birds from India and Lake Baikal showed different patterns of organochlorine residues, reflecting that each species has inherent migratory routes and thus has exposure to different contaminants. Species which have breeding grounds around the Red Sea and Persian Gulf showed high levels of PCBs, indicating the presence of areas heavily polluted by PCBs in the Middle East.     

Loss of crop yields in India due to surface ozone: an estimation based on a network of observations

Surface ozone is mainly produced by photochemical reactions involving various anthropogenic pollutants, whose emissions are increasing rapidly in India due to fast-growing anthropogenic activities. This study estimates the losses of wheat and rice crop yields using surface ozone observations from a group of 17 sites, for the first time, covering different parts of India. We used the mean ozone for 7 h during the day (M7) and accumulated ozone over a threshold of 40 ppbv (AOT40) metrics for the calculation of crop losses for the northern, eastern, western and southern regions of India. Our estimates show the highest annual loss of wheat (about 9 million ton) in the northern India, one of the most polluted regions in India, and that of rice (about 2.6 million ton) in the eastern region. The total all India annual loss of 4.0–14.2 million ton (4.2–15.0%) for wheat and 0.3–6.7 million ton (0.3–6.3%) for rice are estimated. The results show lower crop loss for rice than that of wheat mainly due to lower surface ozone levels during the cropping season after the Indian summer monsoon. These estimates based on a network of observation sites show lower losses than earlier estimates based on limited observations and much lower losses compared to global model estimates. However, these losses are slightly higher compared to a regional model estimate. Further, the results show large differences in the loss rates of both the two crops using the M7 and AOT40 metrics. This study also confirms that AOT40 cannot be fit with a linear relation over the Indian region and suggests for the need of new metrics that are based on factors suitable for this region.     

Infection and immunization trials of Asian seabass (Lates calcarifer) against fish pathogen Vibrio anguillarum

Vibriosis is one of the most prevalent fish diseases caused by bacteria belonging to the genus Vibrio sp. Fish disease will be controlled by proper vaccination trials and maintenance of fish form. Pathogenicity for Asian seabass (Lates calcarifer) against V anguillarum results in necrosis and haemorrhagic areas near the base of fins, exopthalmia and ulcers on the skin surface. Around 50, 100, 200 microl of formalin killed bacterial cells were injected (Intraperitoneal) to three different size (5-10, 20-30, 35-50 g) of seabass fishes respectively and control sere as saline were maintained separately. The Relative Percentage Survival (RPS) for vaccinated fishes was 60, 75, and 62.5 respectively and the vaccinations for 20-30 g fishes stay alive. These results stated that the vaccination for fishes with 20-30 g size may fabricate good immune response.     

Synthesis and application of titanium dioxide photocatalysis for energy,decontamination and viral disinfection: a review

Environmental Chemistry Letters - Global pollution is calling for advanced methods to remove contaminants from water and wastewater, such as TiO2-assisted photocatalysis.  The...     

Organochlorine residues in the avifauna of Tamil Nadu (Southeast coast of India)

Pollution due to persistent pesticides is not a regional but a global problem. Organochlorine pesticides are persistent chemicals, stored and accumulated in the tissues of a wide variety of invertebrates and vertebrates including marine species. In the present study the organochlorine residues HCHs, DDTs and PCBs were measured in different trophic groups of birds (scavengers, inland piscivores, coastal piscivores, insectivores, granivores and omnivores) collected from Tamil Nadu Coast, India. The residue accumulation as a function of sex did not depict distinct variation. However, females had lower residue levels than males in terms of their mean weight and feeding habits. A continuous monitoring programme is recommended to establish the studied organisms as indicator species.     

Perchlorate contamination of groundwater from fireworks manufacturing area in South India

Perchlorate contamination was investigated in groundwater and surface water from Sivakasi and Madurai in the Tamil Nadu State of South India. Sensitive determination of perchlorate (LOQ?=?0.005 μg/L) was achieved by large-volume (500 μL) injection ion chromatography coupled with tandem mass spectrometry. Concentrations of perchlorate were <0.005–7,690 μg/L in groundwater (n?=?60), <0.005–30.2 μg/L in surface water (n?=?11), and 0.063–0.393 μg/L in tap water (n?=?3). Levels in groundwater were significantly higher in the fireworks factory area than in the other locations, indicating that the fireworks and safety match industries are principal sources of perchlorate pollution. This is the first study that reports the contamination status of perchlorate in this area and reveals firework manufacture to be the pollution source. Since perchlorate levels in 17 out of 57 groundwater samples from Sivakasi, and none from Madurai, exceeded the drinking water guideline level proposed by USEPA (15 μg/L), further investigation on human health is warranted.     

SARS-CoV-2 phase I transmission and mutability linked to the interplay of climatic variables: a global observation on the pandemic spread

The study aims to determine the impact of global meteorological parameters on SARS-COV-2, including population density and initiation of lockdown in twelve different countries. The daily trend of these parameters and COVID-19 variables from February 15th to April 25th, 2020, were considered. Asian countries show an increasing trend between infection rate and population density. A direct relationship between the time-lapse of the first infected case and the period of suspension of movement controls the transmissivity of COVID-19 in Asian countries. The increase in temperature has led to an increase in COVID-19 spread, while the decrease in humidity is consistent with the trend in daily deaths during the peak of the pandemic in European countries. Countries with 65°F temperature and 5 mm rainfall have a negative impact on COVID-19 spread. Lower oxygen availability in the atmosphere, fine droplets of submicron size together with infectious aerosols, and low wind speed have contributed to the increase in total cases and mortality in Germany and France. The onset of the D614G mutation and subsequent changes to D614 before March, later G614 in mid-March, and S943P, A831V, D839/Y/N/E in April were observed in Asian and European countries. The results of the correlation and factor analysis show that the COVID-19 cases and the climatic factors are significantly correlated with each other. The optimum meteorological conditions for the prevalence of G614 were identified. It was observed that the complex interaction of global meteorological factors and changes in the mutational form of CoV-2 phase I influenced the daily mortality rate along with other comorbid factors. The results of this study could help the public and policymakers to create awareness of the COVID-19 pandemic.