Organochlorine pollutants in human blood and their relation with age, gender and habitat from North-east India

Organochlorine pesticides (OCPs) have been beneficial to man and environment but their inadvertent use has caused considerable harm to human health. Despite the proliferation of different types of pesticides, organochlorines such as HCH and DDT still account for two third of the total consumption in India because of their low cost and versatility in action again various pests. Since, Assam, a state in North-eastern part of India is an endemic area with perennial transmission where mosquito borne diseases are serious health problems; these pesticides are still being used in huge quantities in vector control as well as in agriculture. A total of 331 human blood samples were collected from district Nagaon and Dibrugarh of Assam to determine the residue levels of DDT and HCH in human blood. The concentrations of selected persistent organochlorine pollutants were measured with gas chromatography-electron capture detector. The results demonstrated that the mean levels of total DDT and HCH were 743 μg L(-1) and 627 μg L(-1) for district Nagaon while 417 μg L(-1) and 348 μg L(-1) for district Dibrugarh. The difference of total HCH and total DDT between these two districts was found to be highly significant (P<0.0001). Among DDT metabolites, the same trend was observed for both the districts as p,p-DDT was the principal component contributed 41% for Nagaon and 58% for Dibrugarh. In case of HCH residues, for Nagaon, β-HCH was the predominant contaminant comprised more than 34% while for Dibrugarh, it was α-HCH that was contributing 43% of total HCH concentration.     

Sources,distribution, and acidity of sulfate–ammonium aerosol in the Arctic in winter–spring

We use GEOS-Chem chemical transport model simulations of sulfate–ammonium aerosol data from the NASA ARCTAS and NOAA ARCPAC aircraft campaigns in the North American Arctic in April 2008, together with longer-term data from surface sites, to better understand aerosol sources in the Arctic in winter–spring and the implications for aerosol acidity. Arctic pollution is dominated by transport from mid-latitudes, and we test the relevant ammonia and sulfur dioxide emission inventories in the model by comparison with wet deposition flux data over the source continents. We find that a complicated mix of natural and anthropogenic sources with different vertical signatures is responsible for sulfate concentrations in the Arctic. East Asian pollution influence is weak in winter but becomes important in spring through transport in the free troposphere. European influence is important at all altitudes but never dominant. West Asia (non-Arctic Russia and Kazakhstan) is the largest contributor to Arctic sulfate in surface air in winter, reflecting a southward extension of the Arctic front over that region. Ammonium in Arctic spring mostly originates from anthropogenic sources in East Asia and Europe, with added contribution from boreal fires, resulting in a more neutralized aerosol in the free troposphere than at the surface. The ARCTAS and ARCPAC data indicate a median aerosol neutralization fraction [NH₄⁺]/(2[SO₄^2?] + [NO₃^?]) of 0.5 mol mol^?1 below 2 km and 0.7 mol mol^?1 above. We find that East Asian and European aerosol transported to the Arctic is mostly neutralized, whereas West Asian and North American aerosol is highly acidic. Growth of sulfur emissions in West Asia may be responsible for the observed increase in aerosol acidity at Barrow over the past decade. As global sulfur emissions decline over the next decades, increasing aerosol neutralization in the Arctic is expected, potentially accelerating Arctic warming through indirect radiative forcing and feedbacks.     

Evaluation of the Potential of Laser-Induced Breakdown Spectroscopy for Detection of Trace Element in Liquid

Abstract

The analytical figure of merit of the potential of laser-induced breakdown spectroscopy (LIBS) has been evaluated for detection of trace element in liquid. LIBS data of Mg, Cr, Mn, and Re were studied. Various optical geometries, which produce the laser spark in and at the liquid sample, were tested. The calibration curves for Mg, Cr, Mn, and Re were obtained at the optimized experimental conditions with bulk liquid and in liquid jet. It was found that measurements using a liquid jet provide better detection limits than bulk liquid measurements. The limits of detection (LOD) of Mg, Cr, Mn, and Re in the present liquid jet measurement are found to be 0.1, 0.4, 0.7, and 8 ppm, respectively. The LOD of Mg using Mg 279.55 nm was compared with the values found in other liquid work.     

Use of activated dry flowers (ADF) of Alstonia Scholaris for chromium (Vl) removal: equilibrium, kinetics and thermodynamics studies

In this study, a natural adsorbent (activated dry flowers (ADF)) was prepared from plant-derived waste biomass by chemical activation and employed for chromium (VI) removal from aqueous medium using experimental batch technique. Experiments were carried out as function of adsorbent dosage, pH, and contact time. The maximum chromium (Vl) removal was observed at initial pH 3 (~94 % removal). The equilibrium data was fitted well to Langmuir isotherm. The adsorption capacity of ADF was found to be 4.40 (mg chromium (Vl)/g) which was comparable to the adsorption capacity of some other adsorbents documented. Among various kinetic models applied, pseudo second-order model was found to explain the kinetics of chromium (VI) adsorption most effectively (R ² >0.99). Thermodynamic parameters such as ΔG, ΔS, and ΔH shows that adsorption process was spontaneous and endothermic at all the concentration ranges studied. Desorption of chromium (Vl) with 2 N NaOH was effective (~71 %) and, hence, there exists the possibility of recycling the ADF. The major advantages of using ADF as an adsorbent are due to its effectiveness in reducing the concentration of chromium (Vl) to very low levels. It requires little processing and is reversible as well as eco-friendly in contrast to traditional methods.     

Atmospheric polycyclic aromatic hydrocarbons and isomer ratios as tracers of biomass burning emissions in Northern India

Emission from large-scale post-harvest agricultural-waste burning (paddy-residue burning during October–November and wheat-residue burning in April–May) is a conspicuous feature in northern India. The poor and open burning of agricultural residue result in massive emission of carbonaceous aerosols and organic pollutants to the atmosphere. In this context, concentrations of atmospheric polycyclic aromatic hydrocarbons (PAHs) and their isomer ratios have been studied for a 2-year period from a source region (Patiala: 30.2°N; 76.3°E) of two distinct biomass burning emissions. The concentrations of 4—6 ring PAHs are considerably higher compared to 2–3 ring PAHs in the ambient particulate matter (PM_2.5). The crossplots of PAH isomer ratios, fluoranthene?/?(fluoranthene?+?pyrene) and indeno[1,2,3-cd]pyrene/(indeno[1,2,3-cd]pyrene?+?benzo[g,h,i]perylene) for two biomass burning emissions, exhibit distinctly different source characteristics compared to those for fossil-fuel combustion sources in south and south-east Asia. The PAH isomer ratios studied from different geographical locations in northern India also exhibit similar characteristics on the crossplot, suggesting their usefulness as diagnostic tracers of biomass burning emissions.     

Mapping species distributions: A comparison of skilled naturalist and lay citizen science recording

To assess the ability of traditional biological recording schemes and lay citizen science approaches to gather data on species distributions and changes therein, we examined bumblebee records from the UK’s national repository (National Biodiversity Network) and from BeeWatch. The two recording approaches revealed similar relative abundances of bumblebee species but different geographical distributions. For the widespread common carder (Bombus pascuorum), traditional recording scheme data were patchy, both spatially and temporally, reflecting active record centre rather than species distribution. Lay citizen science records displayed more extensive geographic coverage, reflecting human population density, thus offering better opportunities to account for recording effort. For the rapidly spreading tree bumblebee (Bombus hypnorum), both recording approaches revealed similar distributions due to a dedicated mapping project which overcame the patchy nature of naturalist records. We recommend, where possible, complementing skilled naturalist recording with lay citizen science programmes to obtain a nation-wide capability, and stress the need for timely uploading of data to the national repository.     

Indoor exposure to respirable particulate matter and particulate-phase PAHs in rural homes in North India

In order to evaluate the exposure of the northern India rural population to polyaromatic hydrocarbon (PAH) inhalation, indoor pollution was assessed by collecting and analyzing the respirable particulate matter PM_2.5 and PM₁₀ in several homes of the village Bhithauli near Lucknow, UP. The home selection was determined by a survey. Given the nature of biomass used for cooking, homes were divided into two groups, one using all kinds of biomass and the second type using plant materials only. Indoor mean concentrations of PM_2.5 and associated PAHs during cooking ranged from 1.19 ± 0.29 to 2.38 ± 0.35 and 6.21 ± 1.54 to 12.43 ± 1.15 μg/m³, respectively. Similarly, PM₁₀ and total PAHs were in the range of 3.95 ± 1.21 to 8.81 ± 0.78 and 7.75 ± 1.42 to 15.77 ± 1.05 μg/m³, respectively. The pollutant levels during cooking were significantly higher compared to the noncooking period. The study confirmed that indoor pollution depends on the kind of biomass fuel used for cooking.     

Impact of different types of polluted irrigation water on soil fertility and wheat grain yield in clayey black soils of central India

This study was carried out in three different cities of western Madhya Pradesh (India) to investigate the effects of long-term irrigation with industrial waste water (IWW), contaminated groundwater (CGW), and untreated municipal sewage water (USW) on soil fertility as well as on wheat crop yield. Irrigation with these three types of polluted water increased organic matter content as well as contents of available P (with IWW and USW only), available K, available S, available Zn, available Cu (IWW only), and available Mn (IWW and CGW only). The magnitude of improvement in soil fertility status was the highest in the case of USW, followed by IWW and finally, by CGW. Concentrations of Na in wheat leaf tissue increased by 198 and 58 % whereas concentrations of Ca decreased significantly by 16 and 13 % due to the use of IWW and CGW, respectively, resulting in poor Ca nutrition to the crop. Although wheat grain yield increased considerably due to USW, the same recorded significant decreases with IWW and CGW. In spite of the enhancement in the available nutrient status, decrease in wheat grain yield with the use of IWW and CGW could be due to the build-up of salts in the soil and an imbalance in the Na/Ca ratio in wheat crops irrigated with IWW and CGW. The adverse effect on wheat productivity was more pronounced with IWW as compared to CGW.     

Composition, seasonal variation, and sources of PM10 from world heritage site Taj Mahal, Agra

Air samples for PM(10) (dp?相似文献   

Persistence of insecticides in ready-mix formulations and their efficacy against Lipaphis erysimi (Kalt) in cauliflower

Persistence of cypermethrin, deltamethrin, profenofos, and triazophos in cauliflower curd was studied, following application of two premix formulations viz: Roket 44EC (profenofos 40 % + cypermethrin 4 %) and Anaconda Plus 36EC (triazophos 35 % + deltamethrin 1 %) at recommended (1.0 L ha^?1) and double doses (2.0 L ha^?1). In the case of Roket 44EC, residues of cypermethrin dissipated with the half-life values of 1.5–2.1 days, whereas residues of profenofos dissipated with the half-life of 2.9–3.3 days on cauliflower curd. In the case of Anaconda, residues of triazophos and deltamethrin dissipated from curd with the half-life values of 2.6–3.0 and 2.2–2.6 days, respectively. Both the combination mix significantly reduced the aphid population up to 14 days after spray and increased the yield by 155–160 % over control. Anaconda (2.0 L ha^?1) treated plots yielded the highest number of marketable curds. Based on risk assessment analysis, safe waiting period of 3 and 5 days has been suggested for Roket 44EC and Anaconda Plus 36EC, respectively, in cauliflower at recommended dose of application.