Polycyclic aromatic hydrocarbons in some grounded coffee brands

Potentially toxic 16 priority polycyclic aromatic hydrocarbons (PAHs) were determined in four brands of grounded coffee. Four to 13 PAHs were detected. Concentrations of total PAHs in different brands of coffee samples were in the range of 831.7–1,589.7 μg/kg. Benzo[a]pyrene (2A: probable human carcinogen) was found in Nescafe Premium whereas naphthalene (2B: possible human carcinogen) was found in all the samples of coffee.     

Development of an analytical method for analysis of flubendiamide, des-iodo flubendiamide and study of their residue persistence in tomato and soil

Flubendiamide is a new insecticide that has been found to give excellent control of lepidopterous pests of tomato. This study has been undertaken to develop an improved method for analysis of flubendiamide and its metabolite des-iodo flubendiamide and determine residue retention in tomato and soil. The analytical method developed involved extraction of flubendiamide and its metabolite des-iodo flubendiamide with acetonitrile, liquid-liquid partitioning into hexane-ethyl acetate mixture (6:4, v v?1) and cleanup with activated neutral alumina. Finally the residues were dissolved in gradient high pressure liquid chromatography (HPLC) grade acetonitrile for analysis by HPLC. The mobile phase, acetonitrile-water at 60:40 (v v?1) proportion and the wavelength of 235 nm gave maximum peak resolution. Using the above method and HPLC parameters described, nearly 100 % recovery of both insecticides were obtained. There was no matrix interference and the limit of quantification (LOQ) of the method was 0.01 mg kg?1. Initial residue deposits of flubendiamide on field-treated tomato from treatments @ 48 and 96 g active ingredient hectare?1 were 0.83 and 1.68 mg kg?1, respectively. The residues of flubendiamide dissipated at the half-life of 3.9 and 4.4 days from treatments @ 48 and 96 g a.i. ha?1, respectively and persisted for 15 days from both the treatments. Des-iodo flubendiamide was not detected in tomato fruits at any time during the study period. Residues of flubendiamide and des-iodo flubendiamide in soil from treatment @ 48 and 96 g a.i. ha?1 were below detectable level (BDL, < 0.01 mg kg?1) after 20 days. Flubendiamide completely dissipated from tomato within 20 days when the 480 SC formulation was applied at doses recommended for protection against lepidopterous pests.     

Removal of sulfadimethoxine in soil mediated by extracellular oxidoreductases

Sulfadimethoxine (SDM) is an antibiotic commonly used in concentrated animal feeding operations and released into the environment via manure application on agricultural lands. Transformation of antibiotics in soil impacts the likelihood of their entry to water bodies, uptake by plants, and thus their effect on terrestrial and aquatic organisms. We conducted experiments to incubate SDM in a sandy loam soil in the presence of humification enzymes commonly found in natural soil, laccase, horseradish peroxidase, and lignin peroxidase. Incubation with the enzymes led to significant reduction in the fraction of SDM extractable from soil, indicating the formation of bound residues. Such transformation was enhanced when the organic matter content in soil is increased or when certain chemical mediators were used along with laccase. The study provided a basis for understanding the environmental fate of sulfonamides and help with the development of remediation methods to mitigate the release of sulfonamides from soil to water.     

Quantitative determination of gibberellins by high performance liquid chromatography from various gibberellins producing Fusarium strains

High performance liquid chromatographic (HPLC) method was developed for analysis of seven gibberellins, i.e., GA₃, GA₄, GA₇, GA₃ methyl ester, GA₇ methyl ester 3,13 diacetate, GA₇ methyl ester, and fusaric acid, using an isocratic system. Method was used for estimation of gibberellins from different Fusarium strains. Gibberellins were extracted from 28 strains of Fusarium, out of which six strains of Fusarium were isolated from soil of different parts of India and 22 strains were procured from the Indian Type Culture Collection, Indian Agricultural Research Institute, New Delhi. Extracts were analyzed for qualitative and quantitative estimation of gibberellins by thin layer chromatography and HPLC, respectively. On the basis of quantitative analysis of produced gibberellins by HPLC, they were categorized as low, moderate, and high gibberellin producing strain. For the first time, Fusarium solani was also reported as high GA₃ producing strain.     

Monitoring of Daily Integrated Exposure of Outdoor Workers to Respirable Particulate Matter in an Urban Region of India

It is more and more recognised that an estimation of the exposure of the population to air pollutants is more relevant than the ambient air quality, since it gives a better indication of health risk. Outdoor workers in an urban region are generally of low income status and are exposed to higher levels of both indoor and outdoor air pollution. Hence respondents from this population subgroup have been selected for this study. Outdoor workers are divided into two categories, viz. traffic constables and casual outdoor workers like watchmen, roadside shopkeepers etc. Most of the respondents are from the lower income group. Each respondent is monitored for a continuous 48-hour period. The sampling frequency is once a week.The study region is situated in the north-west part of the Greater Mumbai Municipal Corporation. It can be classified as industrial cum residential area. The daily integrated exposure of the outdoor workers consists of two major micro-environments, viz. occupational and indoor residential.A personal air sampler was used along with a cyclone to measure levels of Respirable Particulate Matter (RPM). The cyclone has a 50% removal efficiency for particle diameter of 5 m. Paired samples of PM10 (ambient) and RPM (personal) were collected to establish the correlation between them. The average 24-hour integrated exposure to RPM was 322 g/m3 and exceeded the corresponding PM10 level observed at the nearest Ambient Air Quality Monitoring Station by a factor of 2.25. The 90% confidence interval for this exposure is 283–368 g/m3. This study clearly demonstrates that the daily integrated exposure and therefore the health risk of outdoor workers in an urban area is significantly more serious than that indicated by ambient air quality data.     

Evaluation of uptake rate of heavy metals by Eichhornia crassipes and Hydrilla verticillata

Lakes, ponds, and streams are the sources of surface water, which anchorage the survival of aquatic life flora and fauna and maintain ecological balance. Due to urbanization, population explosion, and industrialization, these natural sources are getting polluted. Present paper is an attempt to evaluate the uptake rate of heavy metals namely lead (Pb), zinc (Zn), iron (Fe), and chromium (Cr) by the macrophytes. The two macrophytes taken for the study are Eichhornia crassipes and Hydrilla verticillata. Both macrophytes have the capacity to absorb heavy metals from contaminated water. The present experimental study was conducted to compare and identify their potential to improve the water quality by removing the heavy metals. The paper critically evaluates the water-purifying capacity of submerged macrophyte (H. verticillata) and free-floating macrophyte (E. crassipes). It also evaluates the extent up to which heavy metal can be removed by macrophyte in a given period of time.     

The geoenvironmental cycle of cadmium: a case study

Amidst the hue and cry about anthropogenic sources of pollution, there are regions in the world facing silent metal discharges purely due to geochemical factors. The present investigation relates to such a situation and deals with the non-anthropogenic discharge of cadmium into the local environment. The phosphorite rocks of the Roorkee area of India contain cadmium and, particularly as these are used in the manufacture of superphosphate, the rocks could lead to the large-scale disbursement of cadmium into the open environment. The area under study has soil rich in cadmium-containing minerals, as a result of which water is likely to leach out mobile cadmium and the ground water and crops could become contaminated. This is evident from the high values of cadmium in the tap water and food samples in the area. The Ganga and the Yamuna, the two major rivers traversing the area that originate in the central crystalline rocks of the Himalayas, show high cadmium values at Rishikesh and Dakpathar. Moreover, the sediments of these rivers have cadmium in easily bioavailable form. Food samples and milk analysed from the area show, in some cases, cadmium levels above the safety limits. This high exposure to cadmium is probably causing ailments so far unreported.     

Multivariate ordination approach for identification of sub-regional homogeneities in Gujarat, western India

Identification of homogeneous invariant geographical units assumes considerable importance in the context of current attempts at developing environmental indices to monitor changes. Data on the edaphic and climatic parameters for the state of Gujarat--a predominantly arid to semi-arid province in western India--has been used to elaborate an approach that employs principal component analysis (PCA) as the basis for unbiased clustering of similar geographic units at sub-regional scales. PCA identified different sets of edaphic and climatic variables responsible for separating one unit from another. With the exception of a few cases, soil variables exhibited greater influence on the separation of units than climate. Response of some agro-ecological variables (total cultivable area, forestland and normalized difference vegetation index) to both original and ordinated variables in each of the identified edaphic-climatic units (ECU) has been evaluated using step-wise multiple regressions. The edaphic-climatic parameters were good predictors of these variables, although ordination did not necessarily enhance the predictive power of the independent variables. Instead, in many cases original variables showed better correlations. The response of these variables, chosen on the basis of varying levels of dynamism (slow to seasonal fluctuations), showed that independent of the degree of dynamism, the dependence of these variables was distinct in each ECU. This provided a reality check on the agro-ecological and bio-climatic differentiation among the ECUs.