Aggregates in England—Economic contribution and environmental cost of indigenous supply

Aggregates represent one of the largest material flows in the UK economy; however, the importance of these minerals in underpinning economic activity is frequently not recognised. Features such as the spatial imbalance between resources and demand centres, exacerbated by changes in demographics and public perception, are placing increased pressure on the planning system to maintain supply. This paper sets out the direct and indirect economic contributions made by the indigenous aggregates industry to the English economy through Gross Value Added and employment sustained. It describes the key role of aggregates in construction activities, assesses the links between infrastructure development and economic growth. In 2005, aggregates extraction directly contributed £810 million of Gross Value Added to the English economy. Primary aggregates are, however, extracted at a cost to the environment and this cost, based on amenity value reduction, is estimated by updating previously published contingent valuation data. Estimates for the costs associated with carbon dioxide emissions are derived from values published by the European Union and, separately, by the UK Government. These two elements combined result in an environmental cost of indigenous extraction of £445 million in 2005. Additionally, an examination of the potential for a significant increase in the level of aggregate imports into England is made and the consequences assessed. This includes an evaluation of shipping costs and port capacity, and concludes that there are significant barriers to any substantial increase in the level of aggregate imports into England. As a consequence, indigenous supply is likely to predominate into the foreseeable future.     

An assessment of benthic condition in several small watersheds of the Chesapeake Bay, USA

We examined benthic condition in three small watersheds in the Chesapeake Bay. Characterization of benthic condition was based on the combined measurements of benthic fauna, sediment toxicity, and sediment contaminant loads. Significant differences between watersheds were detected for sediment contaminant concentrations and water quality. The intensity of benthic impairment was greatest in the river surrounded by the most developed watershed. Spatial patterns of benthic condition were detected within all three watersheds. In contrast to current, intense focus on nutrient pollution in the Chesapeake Bay, qualitative comparison of our findings to land-use patterns supports findings of other studies that suggest benthic condition in tributaries of the Chesapeake Bay may more closely relate to urbanization than agricultural land uses.     

Transport and survival of viruses in the subsurface—processes,experiments, and simulation models

The remediation of groundwater contaminated with waterborne pathogens, in particular with viruses, is based on their probable or actual ability to be transported from the source of origin to a point of withdrawal while maintaining the capacity to cause infections. The transport is often associated with both the unsaturated and saturated subsurface composed of varying geological settings with commensurate hydrogeological variability. Included among the most important hydrogeological factors that can be used to evaluate viral transport are the flux of moisture in the unsaturated zone, the media through which the particles travel, the length of the flow path, and the time of travel. With respect to the movement and inactivation of viruses in the subsurface, the vadose zone can provide an effective barrier for movement into groundwater and for the protection of downgradient points of withdrawal and use. Models developed to predicate viral transport in soil and groundwater are introduced, including screening models and more sophisticated predictive numerical models. As evidenced by the exponential growth of virus transport research in the literature, as well as a continuing interest in human health, the subject will continue to be one of critical importance to professionals active in the development, treatment, and conveyance of groundwater in the future. © 2005 Wiley Periodicals, Inc.     

The 1984 Hazardous and Solid Waste Amendments: A Bold Experiment in Hazardous Waste Management

The 1984 amendments by Congress to the Resource Conservation and Recovery Act (RCRA) resulted primarily from a sense of frustration with EPA's apparent lack of progress in addressing the myriad problems associated with hazardous waste management. The amendments were also a manifestation of Congress’ clear sense of purpose in wanting to steer a radically different course at much greater speed. Whether this bold experiment works remains to be seen. EPA appears to be committed to carrying out both the letter and spirit of the Hazardous and Solid Waste Amendments of 1984, but no one should underestimate the magnitude of the task.     

Two new species of Xyala (Nematoda,Monhysteroidea) from sublittoral sediments in Liverpool Bay

Two new species of Xyala (Nematoda, Monhysteroidea) are described from sublittoral sediments in Liverpool Bay, England. Xyala barbata n. sp. is distinguished mainly by the dorsally directed gubernacular apophyses and X. longicaudata n. sp. is distinguished by the long tail, the large amphids and the high, narrow labial rugae.     

Maternal serum human chorionic gonadotrophin and pregnancy-associated plasma protein a,markers for fetal down syndrome at 8–14 weeks

Maternal serum levels of human chorionic gonadotrophin and its subunits (intact, α, and free βhCG) and pregnancy-associated plasma protein A (PAPP-A) were measured in 279 women between 8 and 14 weeks' gestation. This group included 23 pregnancies in which the fetus had Down syndrome (DS), diagnosed either at birth or during the second trimester (n=17) or from chorionic villus sampling (CVS) (n=6). Normal medians were determined from the 258 apparently normal pregnancies. The median levels of intact hCG (1·4 MOM) and free βhCG (2·1 MOM) were significantly raised, whereas the median level of PAPP-A (0·39 MOM) was significantly lower in the DS pregnancies when compared with the control group. Levels of αhCG were similar in both the control and the DS pregnancies. Analysis of samples taken prior to 14 weeks' gestation demonstrated that only PAPP-A (0·34 MOM) was significantly altered in DS pregnancies. However, after the exclusion of DS cases diagnosed at CVS, the median intact hCG (1·56 MOM), free βhCG (2·27 MOM), and αhCG (1·8 MOM) were all raised in DS pregnancies. This emphasizes the problem of the interpretation of biochemical markers when DS cases are diagnosed at CVS.