A perusal on the correlation of pesticide application on tobacco growing in the districts of NWFP-Pakistan and cancers incidence

Tobacco is an important cash crop in Pakistan. It is a sensitive plant prone to many bacterial, fungal, and viral diseases. It is also attacked by several species of worms, beetles and moths. Therefore high levels of pesticides are used to grow tobacco. The obvious benefits from the use of the pesticides are so spectacular that some of the problems associated with their use are not recognized. However, many of these pesticides are highly toxic and have impacts on tobacco workers, especially occupational exposures, which are the direct victims of pesticides poisoning. The victims include many children, pregnant women and elders who all participate in tobacco production. Pesticides either cause or exacerbate a number of illnesses in farmers and farm workers when they are exposed to them. So, occupational exposure is probably one of the most important impacts on tobacco farmers, since they and their families are exposed constantly to a large amount of pesticides. This exposure can lead to many serious problems. No study has been done to identify the effects of tobacco pesticides on human health especially on farmers health in Pakistan. The objective of this paper is to establish a correlation of pesticides application on tobacco crop with cancer incidence in the tobacco growing districts of NWFP- Pakistan.     

Permeable homes: A historical political ecology of insects and pesticides in US public housing

This paper traces changes in the political ecology of insects and chemicals in US public housing since Congress founded public housing in 1937. Drawing upon the literature of critical geographies of home, urban political ecology, and medical history, it argues that the constitution of “public” and “private” space within public housing was deeply entangled with pest control practices there. Prior to 1945, reformers treated the housing as a commons, in part compelled by the mobility of bedbugs and the pesticide used to combat them, both of which were seen as serious health threats. Managers were also motivated by social welfare ideologies, while residents eagerly assisted with communal control policies in order to achieve freedom from the health insults of bedbugs. Following 1945, however, new synthetic pesticides like DDT seemed to stay safely within one apartment unit, encouraging housing managers to abandon community-oriented pest control practices. Meanwhile, curtailed budgets, particularly after the Housing Act of 1949, left the infrastructure of public housing to decay, rendering units more physically permeable even as managers neglected the communities there. The new pesticides nearly eradicated bedbugs, but tenacious populations of German cockroaches blossomed thanks to the permeable buildings and synthetic pesticides. Residents grew increasingly resistant to pesticide use as they observed that cockroach populations went unabated. The paper serves as a case for applying political ecology frameworks to domestic spaces, and also argues that housing quality and domestic pesticide use are not merely private responsibilities but should be regarded as environmental justice issues.     

Pesticide behaviour in Quaternary sediments

Pesticides are very often spread in agricultural and forest areas covering important groundwater bodies in Quaternary sand and gravel deposits. They are mostly synthetic organic chemicals used for plant protection against predators and competing herbs. According to their radius of action they can be separated into herbicides, insecticides, nematicides, acaricides, molluscicides, rodenticides, fungicides, and bactericides. With respect to the risks of groundwater contamination by pesticides, only the first three groups are of interest. For a risks assessment of groundwater contamination, detailed knowledge of the geochemical behaviour of the pesticides and of the physico-chemical processes controlling their persistence and transport in the sediments is necessary. These processes can be summarized as dissolution/precipitation, adsorption/ desorption, degradation and transport processes in the soil in the unsaturated and saturated zones. Furthermore, the type of plant production being established in the area has to be considered. In the case of crop rotation the applied pesticides are changed every year and the risk of groundwater contamination is normally low because of retardation and degradation. In soils used for special-purpose crops, an accumulation of pesticide residues is possible, because the same substances are applied every year. Especially on sandy soils the leaching of residues can lead to severe groundwater contamination.     

全国地下水调查中12种半挥发性必检组分的测定

经过优化组合建立了适用于全国地下水调查中六六六、滴滴涕、苯并[a]芘等12种必检组分测定的分析流程。方法利用正己烷液-液萃取,以气相色谱法(电子捕获检测器)检测11种有机氯组分,高效液相色谱法(紫外、荧光检测器)检测苯并[a]芘。建立了分析过程的质量控制流程程序与质量管理指标范围,确保检测数据达到允许的范围之内。所建分析方法检测限低、精密度好,方法简便、准确,适用于批量样品分析。方法报出限在1.00~1.50 ng/L,8次测定相对标准偏差为2.52%~6.07%,加标回收率为85.3%~106.0%,满足了全国地下水调查评价规范的要求。     

植物修复技术在污染治理中的应用现状

植物修复技术是利用活的植物对污染土、污染地下水等介质进行修复。植物对金属元素的净化机理是植物积累、根系过滤、植物根系对土的稳定作用;植物对有机物的净化机理是植物降解、生物刺激和植物的蒸发作用;此外植物的水力控制也是控制污染的主要途径。目前国外在利用植物修复卤代烃、农药、汽油、柴油、重金属、放射性物质、废旧炸药、处理污染填土淋滤液、利用植物分解处理空气中的污染物质或将氧化氮转化为氮气等多方面的研究已取得很多重要成果,而其中最为显著的是利用杂交植物对卤代烃污染地下水进行修复和研究利用转基因植物吸收土壤中的甲基汞。我国在植物修复技术方面的研究也取得重大成果,如利用凤眼莲修复污水中的某些农药、利用蜈蚣草叶片富集砷,利用印度芥菜对土壤中难溶态镉的吸收等。     

Modeling contaminant transport in soil column and ground water pollution control

A mathematical and computer model for the transport and transformation of solute contaminants through a soil column from the surface to the groundwater is presented. The model simulates selenium species such as selenate, selenite, and selenomethionine as well as pesticides and nitrogen. This model is based on the mass balance equation including convective transport, dispersive transport, surface adsorption, oxidation and reduction, volatilization, chemical and biological transformation. The governing equations are solved numerically by the method of implicit finite difference. The simulation results are in good agreement with measured values. The major finding in the present study indicates that as the time of simulation increases, the concentration of different selenium species approaches the measured values.     

Spatial pattern of variation in populations of Acacia nilotica in semi-arid environment

Variability among populations was analyzed in five provenances of Acacia nilotica from spatially variable habitats. Populations of A. nilotica developed in response to their habitat conditions. The level of variability was significantly high among the populations. Phenotypic variability was extremely high for leaf and stipular spine characteristics. The nature of morphological variability for vegetative traits appeared environmentally controlled. The differentiation of leaf and stipular spine expression seems to have an adaptive significance for the species in terms of water economy. Although, seed and pod characteristics are genetically controlled showing a lower proportion of variability but these traits supported r and k-selection that may allow the species to survive under a wide array of contrasting habitats. The study suggested that populations of A. nilotica are differentiated in relation to the heterogeneity of environment. These populations became adapted to their habitat through the variability of morphological expressions. The morphologically differentiated populations of the species had allowed them to maintain themselves in a wide array of environmental situations enabling A. nilotica to occupy ample ecological ranges.     

轮藻居群的种内变异与生物地层对比

传统轮藻化石研究对中国白垩系-古近系地层界线划分起到了重要的作用,但是轮藻属种的洲际对比却难以实现,究其原因,主要是中国与国际分类学方法未统一,属种名称不一致所导致。前人通过对现生轮藻藏卵器形态发育的观察发现,一个轮藻种的藏卵器钙化程度的不同,会导致其螺旋细胞呈现由凹到凸的变化。文章介绍了以居群为单位的轮藻化石研究思路,居群内不同的藏卵器个体在形态上存在一定的差异, 但这些差异之间存在连续过渡的关系,并未出现明显的分异,我们将这些形态变化称为种内变异;种内形态分析可以对已建立的属种进行有效厘定,有助于中国与国际的轮藻化石居群进行对比。此外,轮藻生物地层学研究还需结合古生态学和古地理学分析,优先选择生态域广和地理分布范围广的分子进行生物带命名,有利于进行洲际地层对比。     

Wastes from the olive oil production in sustainable bioremediation systems to prevent pesticides water contamination

Installation of biobed biopurification systems at farm level, traditionally composed of soil, peat and straw, to reduce point source contamination is difficult in some countries where peat is not environmentally or economically feasible. This study evaluates the use of local organic wastes from olive oil production such as wet olive cake and its vermicompost as substitutes of peat and olive tree pruning as substitute of straw to perform robust biobeds capable of removing mixtures of pesticides at high concentrations. Adsorption capacity of the novel biomixtures was comparable to or higher than traditional one. The biomixture with soil and olive tree pruning showed the highest pesticides adsorption, except for imidacloprid. The biomixture with soil, vermicompost and olive tree pruning showed dissipation efficiency of dimethoate, imidacloprid and oxyfluorfen (>73%) higher than traditional biobed. Meanwhile, the biomixture with soil and vermicompost was the alternative biomixture with the highest dissipation of diuron (54%) and tebuconazole (35%) but it was lower than traditional biomixture (59 and 47% for diuron and tebuconazole, respectively). The low dissipation of these compounds (<60%) is probably due to competitive and/or inhibitory phenomena between the pesticides in the mixture. Labile organic compounds from biomixture components such as water-soluble carbon constitute a more available carbon source for microorganisms that may counteracted the negative impact of high pesticide load on biomixture microbial populations, but they may have limited the pesticides dissipation. Novel biomixtures composed of olive oil mill waste may be a sustainable and less expensive alternative to traditional biomixture.     

A review of materials used as carrier agents in pesticide formulations

Development of environmentally-friendly pesticides for sustainable agriculture is a key focus in the agrochemical industry. Identifying novel active ingredients and improving the delivery system of a pesticide are the main challenges in developing new pesticides. Strategies for the control of delivery systems for slow and sustained release of agrochemicals are of great interest to environmental scientists. In this context, the selection of materials to be used as carrier agents in pesticide formulations is crucial. In recent years, the efficacy of several materials for agrochemical formulations has been evaluated by researchers. These materials have unique properties, such as being biodegradable and biocompatible, and having low toxicity and involving a simple preparation process. This review summarises recent applications of various materials in pesticide formulations. The application of the materials can effectively encapsulate or bind the pesticide’s active ingredients in the material’s matrix with a sustained release profile and slow mobility in soil. This review also discusses some issues and concerns that are faced in formulating pesticide products.     

Chemical effect of pesticide application on soils: evidence from rare earth elements

The main objective of this study is to investigate the distribution of rare earth elements (REEs) in Lolium perenne L. plant species which has been grown on vineyard soils treated with pesticide commonly used in the study area. These plants have been grown on two types of soils: (1) brown calcareous soils developed on loess and (2) brown to calcic brown soils developed on conglomerates. The significant correlation observed between the concentrations of phosphorus and the total amount of REEs, in addition to the enrichment in middle REEs (MREEs), suggests the complexation of REEs with phosphates and organic matter. The soils were enriched in REEs due to pesticide application but the plants were depleted. The ratio of REEs in plant over REEs in soil before application of pesticides is higher than that after application of pesticides. Application of pesticides to crops did not affect the fractionation of REEs neither in leaves nor in roots. No selectivity in uptake of REEs occurred because of pesticides except for Ce and Eu which show a negative anomaly relative to the other REEs.     

Species richness in patchy environments

The logical structure of species richness determinations is outlined in order to explain how their accuracy is affected by nonrandomly distributed populations. The transformation of a species-area curve to a species-range curve is discussed in general terms and conditions required for accurate species richness determinations are given. Applications of the approach to scleractinid coral and pine-tree communities illustrate the method.     

微波萃取-气相色谱/气相色谱-质谱法测定土壤中18种有机氯农药

采用微波萃取-Florisil固相萃取柱净化分离、气相色谱和气相色谱-质谱相结合的方法测定土壤中的痕量半挥发性有机氯农药。优化了微波萃取和固相萃取柱净化条件,在最优条件下18种有机氯农药(α-HCH、β-HCH、γ-HCH、δ-HCH、七氯、艾氏剂、环氧七氯、硫丹Ⅰ、p,p′-DDE、狄氏剂、异狄氏剂、硫丹Ⅱ、p,p′-DDD、o,p′-DDT、异狄氏剂醛、硫丹硫酸酯、p,p′-DDT、甲氧滴滴涕)的回收率在89.56%~114.22%。对气相色谱和气相色谱-质谱法的仪器检出限、回收率、精密度和方法检出限进行对比,确定了采用气相色谱-质谱定性和气相色谱定量相结合的方法,测定实际土壤样品中的有机氯农药,使得定性和定量的准确度都得到提高。     

Carnivorous caterpillars: the behavior,biogeography and conservation of Eupithecia (Lepidoptera: Geometridae) in the Hawaiian Islands

A completely new feeding pattern has been found among caterpillars native to Hawaii: certain geometrid larvae (commonly called “inchworms”) consume no leaves or other plant matter. Instead, they perch inconspicuously along leaf edges and stems to seize insects that touch their posterior body section. By bending the front of their body backwards in a very rapid strike, the caterpillars opportunistically capture their prey with elongated, spiny legs and 900 larvae and eggs of these moths have been collected from native forests of all the main islands and reared in the laboratory. All are species of Eupithecia, a worldwide group of over 1000 members that had been reported to feed only on plant matter such as flowers, leaves or seeds. At least 6 of Hawaii's described Eupithecia species are raptorially carnivorous, only 2 are known to feed predominantly on plant material, especially Metrosideros flowers. A diet including protein-rich flower pollen and a defensive behavior of snapping may have preadapted Hawaii's ancestral Eupithecia for a shift to predation. Severe barriers to dispersal of mantids and other continental insect predators into Hawaii resulted in an environment favoring behavioral and consequent morphological adaptations that produced these singular insects, which can be commonly called the “grappling inchworms”. Most damage to native biota and habitat is due to imported species or “biological pollution”, and has caused a serious need for protective management.     

Environmental monitoring of economically important invertebrate pests in Bramley apple orchards in Northern Ireland

Apple orchards are host to many species of both pest and beneficial invertebrates. Many of the pest species can cause severe economic damage if populations are left unchecked. Within Northern Irish Bramley apple orchards only four species are deemed to be of economic importance; Panonychus ulmi, Aculus schlechtendali,Rhopalosiphum insertum and Archips podana. Little information exists on the current population status and economic damage potential of these four pests. The population levels of these species and their potential to cause economic damage on the Bramley fruit is therefore discussed in regard to current economic spray thresholds.     

液-液萃取-气相色谱法测定水中9种有机氯农药

采用正己烷液-液萃取法提取,气相色谱法-电子捕获检测器测定水中9种有机氯农药。优化了实验条件:添加两种替代物作为分析过程的质量监控;使用浓硫酸磺化法净化去除杂质;采用Rtx-5MS和Rtx-1701柱双柱定性,保证数据准确可靠。9种有机氯农药的方法检出限为0.0017～0.0079μg/L,回收率为74.7%～105.1%,相对标准偏差(RSD,n=7)为4.2%～9.3%,9种农药在0.5～100μg/L内与峰面积呈良好的线性关系。方法检出限低,准确度和精密度高,简便,适用于批量样品的分析。     

圆盘固相萃取富集-气相色谱法测定地表水中有机氯和有机磷农药

采用环境友好的圆盘固相萃取新技术富集水体中有机氯农药和有机磷农药,分别用微池电子捕获检测器(μECD)和火焰光度检测器(FPD)气相色谱法检测,实现了水中有机氯和有机磷农药残留物的测定。结果表明,16种有机氯农药的平均回收率为64.7%~102%,精密度(RSD,n=6)为2.9%~15%;13种有机磷农药的平均回收率为65.9%~104%,精密度(RSD,n=6)为1.7%~17%。方法快速、灵敏、低污染,可用于水体中多种有机氯农药和有机磷农药的残留分析。     

Regional differences in plant-soil mercury relations in Equisetum, Plantago and Taraxacum

The mercury contents of Equisetum, Plantago and Taraxacum growing in the Prince George area of British Columbia varied with soil mercury level. In contrast, mercury in the same plant species growing around Mount St. Helens was soil-concentration independent. Both regions are mercury-rich, but the former is relatively thermally inactive at present. It is suggested that both populations limit their tissue mercury levels to about 100–500 ppb but that those around Mount St. Helens, where soil levels remain moderate, equilibrate tissues with atmospheric mercury from the volcano, whereas those in British Columbia depend more upon biovolatilization as a partial control process.     

福建兴化湾水体有机氯农药污染状况

利用气相色谱-电子检测器对福建兴化湾河水和海水中的19种有机氯农药(HCHs、DDTs等)进行的分析结果表明,几种有机氯农药尽管已停止生产多年,但在河水及海水中仍有残留.二者的有机氯农药的质量浓度分别为10.96～56.31,5.78～161.64 ng/L ,同国内外其他港口海区及河流相比,其污染程度相对较低.丰水期河水中DDT的降解产物主要为DDE,而海水中DDT的降解产物主要为DDD.同时,对有机氯农药现状的分析表明,近年来仍有有机氯农药污染的输入,其农药的使用主要集中在六六六和滴滴涕上.