Residual effects of compost and plowing on phosphorus and sediment in runoff

Manure application can lead to excessive soil test P levels in surface soil, which can contribute to increased P concentration in runoff. However, manure application often results in reduced runoff and sediment loss. Research was conducted to determine the residual effects of previously applied compost, plowing of soil with excessive soil test P, and application of additional compost after plowing on volume of runoff and loss of sediment and P in runoff. The research was conducted in 2004 and 2005 under natural rainfall events with plots of 11-m length where low-P and high-P compost had been applied during April 1998 to January 2001. During this initial application period, Bray-P1 in the surface 5-cm of depth was increased from 14 to 553 mg kg(-1) for the high-P compost. Inversion plowing in the spring of 2004 greatly decreased P levels in the surface soil and over the following year reduced runoff by 35% and total P losses by 51% compared with the unplowed compost treatments. Sediment loss was increased with plowing compared with the unplowed compost applied treatments but less than with the no-compost treatment. The application of additional compost after plowing increased surface soil P and dissolved reactive P (DRP) in runoff but did not increase particulate P in runoff. Unplowed compost-amended soil continued to reduce sediment loss but exhibited increased DRP loss even 5 yr after the last application. Plowing to invert excessively high-P surface soil was effective in reducing runoff and DRP loss.     

Environmental technological education in a developing country—Libya

Summary The environmental education needs of a currently wealthy developing country, Libya, are outlined. Because of specific local requirements, the data presented clearly shows how such educational requirements differ in many respects from the various Western-style environmental sciences curricula. The aim is to produce graduates capable of comprehending environmental problems as they arise in the different regions of Libya. This involves not only dealing with the effects of new developments but also with peoples who must adapt to new life-styles.Since most of what has to be learned is communicated originally in English to Arabic-speaking students via lectures, visits and books, special emphasis is laid upon the added importance oflocally produced bilingual audio-visual teaching aids supported by spoken commentaries, printed texts and glossaries of technical terms used in both languages. A technique for producing such aids has been evolved at the Higher Institute of Technology, Brack, Libya.     

Environmental monitoring of carbaryl applied in urban areas to control the glassy-winged sharpshooter in California

Carbaryl insecticide was applied by ground spray to plants in urban areas to control a serious insect pest the glassy-winged sharpshooter, Homalodisca coagulata (Say), newly introduced inCalifornia. To assure there are no adverse impacts to human health and the environment from the carbaryl applications, carbaryl was monitored in tank mixtures, air, surface water, foliage and backyard fruits and vegetables.Results from the five urban areas – Porterville, Fresno, Rancho Cordova, Brentwood and Chico – showed there were no significanthuman exposures or impacts on the environment. Spray tank concentrations ranged from 0.1–0.32%. Carbaryl concentrationsin air ranged from none detected to 1.12 g m^-3, well below the interim health screening level in air of 51.7 g m^-3. There were three detections of carbaryl in surface water nearapplication sites: 0.125 ppb (parts per billion) from a water treatment basin; 6.94 ppb from a gold fish pond; and 1737 ppbin a rain runoff sample collected from a drain adjacent to a sprayed site. The foliar dislodgeable residues ranged from 1.54–7.12 g cm^-2, comparable to levels reported forsafe reentry of 2.4 to 5.6 g cm^-2 for citrus. Carbarylconcentrations in fruits and vegetables ranged from no detectableamounts to 7.56 ppm, which were below the U.S.EPA tolerance, allowable residue of 10 ppm.     

河岸蜘蛛——多样水生生态系统中PCB污染的指示生物

栖息在河岸的蜘蛛越来越多地被用来追踪水生生态系统中存在和流出污染物的空间格局。然而,我们对蜘蛛在何种情况下可有效标志水生污染的认识有限。本研究力证在具有高生境异质性的水生生态系统中,能够有效地利用河岸蜘蛛来追踪沉积物中多氯联苯(PCBs)污染的空间格局。2011年到2013年,在五大湖共同关注区(AOC)的Manistique河流域,对2类常见科属的河岸蜘蛛进行采样,结果表明生物体内的ΣPCB浓度的空间格局能够普遍地追踪采样点范围内沉积物中ΣPCBs的空间变化。该研究区域位于密歇根北部半岛南岸(Manistique,MI,US),是一个河口生态系统,包括港口、河流、回水和湖泊等栖息地。沉积物ΣPCB浓度用总有机碳浓度进行归一,解释了11个采样点中41%的以脂类归一的蜘蛛ΣPCB浓度变异。此外,2类常见河岸蜘蛛类群(园蛛科Araneidae和长脚蛛科Tetragnathidae)的ΣPCB浓度高度相关(r² > 0.78),并且按全年计算其平均ΣPCB浓度两者相似。结果表明,在异质性的水生生态系统中,例如在河流入海口,会因为栖息地和污染物变化在水生生物分类中的差别不明显,河岸蜘蛛就可能成为水生和河岸食物网中PCB有效性的标记物。此外,对于为不同种群大型结网蜘蛛提供生存条件的海岸线开发和沿岸植被的生境异质性,目前的方法具有很强的适用性。
精选自Kraus, J. M., Gibson, P. P., Walters, D. M. and Mills, M. A. (2017), Riparian spiders as sentinels of polychlorinated biphenyl contamination across heterogeneous aquatic ecosystems. Environmental Toxicology and Chemistry, 36: 1278–1286. doi: 10.1002/etc.3658
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3658/full
     

A small subsurface ion mobility spectrometer sensor for detecting environmental soil-gas contaminants

A small subsurface ion mobility spectrometer (SS-IMS) was constructed and tested with several environmental contaminants to determine its potential for monitoring gaseous volatile organic compounds in the vadose zone. Trichloroethylene (TCE) and tetrachloroethylene (PCE) were detected and separated in IMS for the first time. Detection limits as low as 1 part per billion volume-to-volume (ppb(v)) were observed. Reduced mobility (K(0)) values were reported for 11 environmental contaminants. These data demonstrated the potential of ion mobility spectrometry as a viable technology for detecting and separating environmental soil-gas contaminants in the field, which may lead to a practical and simple approach for long-term monitoring of contaminated soils.     

Worker representation and psycho-social risks: A problematic relationship?

This paper explores the relationship between worker representation and the prevention and control of psycho-social risks at work. It argues that to understand this relationship it is helpful to position it within the labour relations context in which it occurs and which helps explain the strengths and limitations of interventions involving worker representation.The paper opens with some important questions of definition with regard to psycho-social risks and worker representation and consultation on health and safety. It goes on to review the evidence for the success or otherwise of worker representation in health and safety generally and discusses this evidence in relation to the control of psycho-social risks specifically. It discusses the problems that the restructuring of work pose for the sustainability of the preconditions for the effectiveness of the statutory model on which worker representation on psycho-social risk is predicated. In so doing the paper notes that many of the features of current restructuring of work that present problems for traditional model of worker representation are the same ones that lead to the increased prevalence of psycho-social risks at the workplace.The paper identifies both barriers and opportunities presented by the changing world of work for achieving an improved preventive scenario for psycho-social risks and discusses the implications of these for current and future strategies of trade unions. It concludes that in the present political and economic climate the state cannot be relied upon for effective regulatory strategies on the psycho-social risks of work. In the absence, or much reduced presence, of this support, some joined up thinking on the part of organised labour is required. Interventions by health and safety representatives on psycho-social risks at the workplace level need to be fully integrated in such thinking if they are to be effective.     

Prevalence, patterns, and effects of shell damage on Geukensia demissa in South Carolina estuarine habitats

Shelled molluscs frequently exhibit a record of damage on exterior surfaces that can evidence past predation attempts and may affect survival and growth. In South Carolina populations of the ribbed marsh mussel, Geukensia demissa, >90% of the individuals and up to 60% of the total shell area are damaged. A trend toward greater amounts of damage occurred on mid-marsh compared to oyster reef mussels from the barrier beach side of inlets. Shell damage effects on survivorship and shell and tissue growth were assessed seasonally during multi- and single-season field experiments. Mussels from a common mid-marsh site were divided into size classes (~50 or 70 mm), treated to create two damage levels (undamaged and damaged), and replaced within mid-marsh exclusion cages to minimize additional shell damage. In both multi- and single-season experiments increased shell damage resulted in significantly greater mortality. Linear shell growth was unaffected by increased damage, but 50 mm mussels grew twice as fast. Shell mass increased 16–50% in the multi-season and single-season winter period, but decreased 7–12% during the single-season summer period. Tissue mass significantly decreased 31–43% in 50 mm damaged mussels, but increased by 33% for 70 mm mussels in both multi-season and the single-season winter period experiments. Shell damage did reduce tissue mass 43% in 70 mm single-season summer mussels. Experimental results indicate shell damage from a simulated increase in predation can affect negatively both survival and growth of marsh mussels. Seasonal timing of shell damage and initial mussel size also influenced the effects of sublethal predation on shell and tissue growth. The previously unrecognized importance of sublethal predation and the resultant significant negative effects of shell damage on survival and growth will affect the distribution and population dynamics of G. demissa in coastal marshes and will influence the overall contribution of ribbed mussels to estuarine ecosystems.