Persistence behaviour of imidacloprid and its metabolites in soil under sugarcane

The persistence and metabolism of imidacloprid in soil under sugarcane were studied following application of imidacloprid at 20 and 80 g active ingredient (a.i.) ha^?1. Soil samples were collected at different time intervals (7, 15, 30, 45, 60 and 90 days after application), and the residues of imidacloprid and its metabolites (6-chloronicotinic acid, nitrosimine, imidacloprid-NTG, olefin, urea and 5-hydroxy) were quantified by high-performance liquid chromatography. In soil, the total imidacloprid residues were mainly constituted by the parent compound followed by 6-chloronicotinic acid, nitrosimine and imidacloprid-NTG metabolites. Maximum residues of imidacloprid and its metabolites were 4.29 and 7.81 mg kg^?1 in soil samples collected 7 days after the application of imidacloprid at 20 and 80 g a.i. ha^?1, respectively. At both doses, these residues declined to below the detectable limit in soil after 90 days of application. Olefin, urea and 5-hydroxy metabolites were not detected in soil. Dissipation of total imidacloprid residues did not follow the first-order kinetics with a coefficient of determination value of 0.883 and 0.838 for the recommended dose and four times the recommended dose, respectively. The half-life (T _1/2) value of total imidacloprid was observed to be 10.64 and 10.10 days for the recommended dose and four times the recommended dose, respectively.     

Challenges of small protected areas in urban cities: a case study of Okhla Bird Sanctuary,India

Protected areas have been earmarked throughout the world for the purpose of conserving the biodiversity. The protected areas are facing serious threats due to rapid urban growth, especially in the developing countries like India. The current threats and impacts of urbanization on the Okhla Bird Sanctuary (Delhi, India) have been presented in this paper as a case in point. Uncontrolled urbanization and the lack of policy implementation have been identified as one of the major contributors to incessant biodiversity loss in India and other countries. In addition, a possible management framework for a smaller protected area in an urban setting is presented in brief.     

Organophosphorous compounds and oxidative stress: a review

Organophosphorous compounds (OP) have largely been used as pesticides globally. These chemicals induce oxidative stress as a possible mechanism of action, which has been a focus of toxicological research for the last decade. This review evaluated the presence of oxidative stress, balance between total antioxidant capacity, and oxygen free radicals associated with OP compound exposure. Oxidative stress induced by OP leads to disturbances in function of different organs and tissues. Evidence indicates that stimulation of free radical production, induction of lipid peroxidation, and disturbance of the total antioxidant capacity are mechanisms of toxicity induced by most OP. Thus, use of antioxidants may be beneficial in treatment of OP poisoning, which remains to be elucidated with further clinical trials.     

Groundwater Quality Assessment of Tehsil Kheragarh, Agra (India) with Special Reference to Fluoride

Fluoride concentration and other parameters in groundwater from 261 villages in Tehsil Kheragarh of District Agra were assessed and attempts were made to observe the relationship between fluoride and other water quality parameters. Of 658 groundwater samples (collected from separate sources) analysed for fluoride, 27% were in the range of 0–1.0 mg/L, 25% in 1.0–1.5 mg/L, 32% in1.5–3.0 mg/L and 16% above 3.0 mg/L. The highest fluoride concentration recorded was 12.80 mg/L. Significant correlation of fluoride with pH, alkalinity, Na, SiO₂ and PO₄ were observed. Factor analysis was also attempted in order to identify the contributing sources.     

Effect of electrostatic precipitator on exhaust emissions in biodiesel fuelled CI engine

Environmental Science and Pollution Research - The exhaust emissions from the compression ignition engines are harmful to both human beings and the environment. After-treatment devices placed in...     

Metal ion-induced enhanced oxidation of organic contaminants by ferrate: a review

Environmental Chemistry Letters - The global contamination of water resources by organic contaminants such as pharmaceuticals and pesticides is calling for advanced remediation techniques, yet...     

Overlooked involvement of phosphate radicals in the degradation of the atrazine herbicide by sulfate radical-based advanced oxidation

Environmental Chemistry Letters - The persistence of recalcitrant pollutants in water is a major health issue calling for advanced and green techniques to clean polluted waters. For instance,...     

Nutrient concentrations affect the antimicrobial resistance profiles of cattle manures

Environmental Science and Pollution Research - Antimicrobial resistance (AMR) in cattle is widespread because of the increased use of antibiotics to combat microbial diseases and enhance milk...     

Assessing farm-level agricultural sustainability over a 60-year period in rural eastern India

Agricultural sustainability is a vital parameter to be ascertained locally and globally if food security is to be achieved and maintained. Agricultural sustainability is the combined product of social, economic and ecological sustainability. It is also a function of temporal and spatial variations, a fact which indicates that area-specific sustainability indices need to be designed. We present here an Agricultural Sustainability Index (ASI) for rural eastern India and use it to calculate the ASI for 150 farms for three decades over a 60-year period, viz., 1950–1960, 1980–1990 and 2000–2010 for a representative Indian village of Gangapur (25°83′N, 85°65′E). The ASI was calculated using 30 variables, 10 each of social, economic and ecological sustainability. An extensive questionnaire-based survey was carried out to collect the relevant data. Our study reveals that over a 60-year period, ASI values do not show a statistically significant change. We conclude that the agricultural practices of the region have maintained sustainability so far although the scope for improvement in several broad areas identified by us is immense. Increased ecological literacy and better implementation of government policies, aiming at health, education and better scientist–farmer interactions, must target improved ASI values in coming decades.