Development of controlled release formulations of carbofuran and imidacloprid and their bioefficacy evaluation against aphid, Aphis gossypii and leafhopper, Amrasca biguttula biguttula Ishida on potato crop

Controlled release (CR) formulations of carbofuran and imidacloprid were prepared employing polyvinyl chloride and carboxymethyl cellulose (CMC) and their bioefficacy was evaluated against the aphid, Aphis gossypii and leafhopper, Amrasca biguttula biguttula Ishida on potato crop. The CR formulations of carbofuran and imidacloprid provided better or equal control of the pests than commercial formulations. CMC-based formulation provided a superior control of both the pests. The Imida-CMC, which showed the lowest population of leaf hopper (10.50 leafhopper/100 cl), provided significantly superior control among all treatments after 35 days after germination (DAG). The residue of carbofuran and imidacloprid in potato tuber and soils were not detectable at the time of harvesting in any one of the formulations.     

The effect of atmospheric thermal conditions and urban thermal pollution on all-cause and cardiovascular mortality in Bangladesh

This study assessed the effect of temperature and thermal atmospheric conditions on all-cause and cardiovascular mortality in Bangladesh. In particular, differences in the response to elevated temperatures between urban and rural areas were investigated. Generalized additive models (GAMs) for daily death counts, adjusted for trend, season, day of the month and age were separately fitted for urban and rural areas. Breakpoint models were applied for determining the increase in mortality above and below a threshold (equivalent) temperature. Generally, a 'V'-shaped (equivalent) temperature-mortality curve with increasing mortality at low and high temperatures was observed. Particularly, urban areas suffered from heat-related mortality with a steep increase above a specific threshold. This adverse heat effect may well increase with ongoing urbanization and the intensification of the urban heat island due to the densification of building structures. Moreover, rising temperatures due to climate change could aggravate thermal stress.     

Refined sewer epidemiology mass balances and their application to heroin, cocaine and ecstasy

The detection of illicit drugs in environmental matrices may be a cause for concern, both from the perspective of their potential environmental impacts and the fact that their presence in detectable concentrations would be an indicator of significant drug use. The primary goal behind recent studies on this subject has been to use measured influent concentrations of selected illicit drugs or their in vivo metabolites in the environment as a means of estimating the abuse level of these drugs and patterns of consumption. Thus-far, such calculations have hinged on the use of solitary excretion estimates from single studies of limited scope and/or studies of limited applicability. Therefore, the need exists to conduct a comprehensive meta-analysis of metabolic disposition studies to construct excretions profiles for the various illicit drugs and their in vivo metabolites. The constructed excretory profiles should not only provide mean excretion values but also indicate the expected variations in excreted fractions that arise due to differences not only in the metabolic capacity of users but also in the efficiencies of various routes of administration for a given illicit drug. Therefore, the primary goal of the research presented here was to refine sewer epidemiology extrapolation mass balances for various illicit drugs of interest by constructing their excretory profiles segregated by route-of-administration. After conducting such a study with a multi-national scope on illicit drugs including cocaine, heroin and ecstasy, the results obtained clearly indicate that extrapolation factors currently being used in literature for these drugs to enumerate prevalence of abuse required significant refinement to increase their reliability.     

An on-farm survey of spatial and temporal stratifications of 17β-estradiol concentrations

17β-estradiol (E2) is a natural estrogenic hormone found in animal manure and urine, which may cause endocrine disruption in sensitive organisms. 17β-Estradiol has been widely detected in the environment, and animal agriculture may be an important source. The objectives of this study were to investigate the potential sources and/or spatial and temporal characteristics contributing to detections of E2 at the farm-scale. Soil cores, segmented into 0.15 m increments, were taken down to the water table from four locations (three potential E2 sources and one control) at or around a swine (Sus scrofa domesticus) farm on five different dates between 2006 and 2007. Estradiol was quantified in the soil-water extracts using liquid chromatography-with tandem mass spectrometry (LC/MS/MS) analysis. Estradiol detections were widespread and found in 128 out of 345 extractions (37%). Concentrations ranged from 0 to 1910 ng L⁻¹ (porewater equivalents). A location that received field application of manure had significantly lower E2 concentrations compared to other locations. Also, the spring 2007 E2 concentrations were significantly higher than all other sample dates, perhaps related to climatic and hydrological events. Results suggested E2 was not directly related to manure sources, but was widespread in this environment. Where E2 was detected, highest concentrations favored the upper profile, while the greatest frequency of detections was in the lower profile and near the water table. Detections of E2 were associated with high organic mater contents in the upper profile and high sand contents in the lower profile. The study suggests that E2 is widespread in some soil environments, raising questions as to the source and mechanisms that facilitate its transport and mobility.     

Growth responses and metal accumulation capabilities of woody plants during the phytoremediation of tannery sludge

Five woody plants species (i.e. Terminalia arjuna, Prosopis juliflora, Populus alba, Eucalyptus tereticornis and Dendrocalamus strictus) were selected for phytoremediation and grow on tannery sludge dumps of Common Effluent Treatment Plant (CETP), Unnao (Uttar Pradesh), India. Concentration of toxic metals were observed high in the raw tannery sludge i.e. Fe-1667 > Cr-628 > Zn-592 > Pb-427 > Cu-354 > Mn-210 > Cd-125 > Ni-76 mg kg⁻¹ dw, respectively. Besides, physico-chemical properties of the raw sludge represented the toxic nature to human health and may pose numerous risks to local environment. The growth performances of woody plants were assessed in terms of various growth parameters such as height, diameter at breast height (DBH) and canopy area of plants. All the plant species have the capabilities to accumulate substantial amount of toxic metals in their tissues during the remediation. The ratio of accumulated metals in the plants were found in the order Fe > Cr > Mn > Pb > Zn > Cu > Cd > Ni and significant changes in physico-chemical parameters of tannery sludge were observed after treatment. All the woody plants indicated high bioconcentration factor for different metals in the order Fe > Cr > Mn > Ni > Cd > Pb > Zn > Cu. After one year of phytoremediation, the level of toxic metals were removed from tannery sludge up to Cr (70.22)%, Ni (59.21)%, Cd (58.4)%, Fe (49.75)%, Mn (30.95)%, Zn (22.80)%, Cu (20.46)% and Pb (14.05)%, respectively.     

Assessing the genotoxic potentials of arsenic in tilapia (Oreochromis mossambicus) using alkaline comet assay and micronucleus test

This experiment was conducted to study the genotoxic potentials of sodium arsenite (NaAsO₂) in freshwater fish Oreochromis mossambicus by using alkaline comet assay and micronucleus (MN) test. Fish were exposed to three different concentrations (3 ppm, 28 ppm and 56 ppm) of arsenic and gill, liver and blood tissue samples were collected after 48 h, 96 h and 192 h of exposure. Arsenic exposure induced DNA damage in all tissues examined in a concentration dependent manner. A significant (p < 0.05) increase in the comet tail DNA (%) of the exposed fish liver, gill, and blood was observed after 48 h and 96 h of exposure, but a decline in DNA damage was recorded in all the tissues at all the three concentrations studied after 192 h of exposure. Liver tissue exhibited significantly (p < 0.05) higher DNA damage at all the concentrations examined, followed by gill and blood. Higher liver tail DNA (51.38 ± 0.21%) refers that it is more prone to injury to arsenic toxicity than the gill and blood. In blood samples arsenic induced micronucleus formation in a concentration dependent manner and highest (5.8 ± 0.46%) value was recorded in 56 ppm after 96 h of exposure, whereas, it was decreased after 192 h of exposure at all the three concentrations of NaAsO₂ examined which refers to the DNA repairing ability of fish to arsenic toxicity. The results of this study depict the genotoxic potentials of arsenic to fish which in turns provide insight on advanced study in aquatic toxicology.     

Toxic responses in primary rat hepatocytes exposed with occupational dust collected from work environment of bone-based industrial unit

In this in vitro study we investigated the toxic responses in hepatocytes treated with occupational dust to which workers are exposed in bone-based industrial units. The present study investigated the toxicity mechanism of bone-based occupational dust, from a particular industrial unit, on isolated rat hepatocytes. The hepatocytes were isolated by collagenase perfusion method and cell viability was determined by trypan blue exclusion and MTT [3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay treated with occupational dust at 0.1-1.0 mgmL(-1), for 120 min. The cell viability decreased significantly in a concentration-dependent manner. Dust induced significant membrane damage measured by lactate dehydrogenase (LDH) and glutathione (GSH) release in culture media for 30-, 60- and 120 min treatment duration. The toxicity was found to be correlated with the induction of lipid peroxidation (LPO). In addition, nitric oxide (NO), and hydrogen peroxide (H(2)O(2)) generation by occupational dusts were also found to be time- and concentration-dependent. Over all the present study provides initial evidences for the toxic potential of occupational dust generated in bone-based industries and, therefore, the dust exposure to workers in unorganized industrial units should be controlled.     

Chemical Composition of Bottled Water in Saudi Arabia

Fourteen domestic and seven imported bottled water brands were analysed in Saudi Arabia for various physico-chemical water quality parameters. The results of the analysis were compared with the drinking water standards set by Saudi Arabia and World Health Organization. The levels of different physico-chemical parameters like TDS, Ca, Mg, Na, K, NO₃, Cl and SO₄ of all local and imported bottled water brands met the different drinking water standards. Fluoride was found below the Saudi Arabian Standard Organization recommended limits in two of the local brands whereas fluoride levels in all of the imported brands were below the recommended values. In one imported brand, pH was found not conforming to the recommended standards. The concentrations of trace metals in all brands were within the drinking water standards. Comparison of the study results with the reported label values indicated good agreement with stated pH values but considerable variation for Ca, Mg, and Na in the local brands and comparatively low variation in the imported brands. Low F and SO₄ variations were found in the local brands and comparatively high SO₄ variation in the imported brands.     

Determination of elemental carbon in lake sediments using a thermal–optical transmittance (TOT) method

An improved chemical oxidation pretreatment method has been developed for the determination of elemental carbon (EC) [also known as black carbon (BC) or soot] in lake sediments, using a thermal–optical transmittance (TOT) carbon analyzer. The method employs six steps: (1) removal of carbonates by treatment with HCl; (2) removal of silicates by treatment with HF + HCl; (3) removal of any remaining carbonates by treatment with HCl; (4) removal of humic acids by treatment with NaOH; and (5) oxidation of kerogens by K₂Cr₂O₇ + H₂SO₄. A critical step of zinc chloride treatment was added; this apparently changes EC's morphology and enhances retention on quartz fiber filter, resulting in several-fold increased chemical yield. EC was determined using the TOT method with modified combustion timings. Carbon black (acetylene) and four NIST standard reference materials (SRMs) were used for quality control, and to assess the precision of the analysis. The EC recoveries from 18 carbon black samples varied from 90 to 111%, with a mean value of 99 ± 6%. The high EC recoveries confirmed the validity of the method. Char reference materials (i.e. chestnut wood and grass char) were used to determine potential contribution to EC in our measurements. The char references containing about 700 mg total organic carbon (OC) contributed ～1.5% EC. The measured EC values from four NIST standards were 17.0 ± 0.6, 24.2 ± 3.2, 5.6, and 1.9 ± 0.1 mg g_dw^?1 for SRM-1648, SRM-1649a, SRM-1941b and SRM-8704, respectively. These values in SRMs were in agreement (<±4%) with the previously reported values. The method was applied to determine the EC in sediment cores from an urban lake and a remote mountain lake in the Northeastern United States. The EC concentrations in two lakes mimic the model EC emissions from the industrial revolution in United States.     

Methodology for computer aided fuzzy fault tree analysis

Probabilistic risk assessment (PRA) is a comprehensive, structured and logical analysis method aimed at identifying and assessing risks of complex process systems. PRA uses fault tree analysis (FTA) as a tool to identify basic causes leading to an undesired event, to represent logical dependency of these basic causes in leading to the event, and finally to calculate the probability of occurrence of this event.To conduct a quantitative fault tree analysis, one needs a fault tree along with failure data of the basic events (components). Sometimes it is difficult to have an exact estimation of the failure rate of individual components or the probability of occurrence of undesired events due to a lack of sufficient data. Further, due to imprecision in basic failure data, the overall result may be questionable. To avoid such conditions, a fuzzy approach may be used with the FTA technique. This reduces the ambiguity and imprecision arising out of subjectivity of the data.This paper presents a methodology for a fuzzy based computer-aided fault tree analysis tool. The methodology is developed using a systematic approach of fault tree development, minimal cut sets determination and probability analysis. Further, it uses static and dynamic structuring and modeling, fuzzy based probability analysis and sensitivity analysis.This paper also illustrates with a case study the use of a fuzzy weighted index and cutsets importance measure in sensitivity analysis (for system probabilistic risk analysis) and design modification.