Secular and Faith-based Organisations as Reliable Information Sources for Residents of Environmentally Stressed Neighbourhoods

A sample of 873 residents of Accra, Ghana, and 504 residents of the state of New Jersey, USA, stratified by type of neighbourhood was gathered in order to determine the sources of information residents rely on for accurate information about their neighbourhoods. In both countries residents relied most heavily on personal contacts, television and radio, and much less on community organisations. Residents who rely on many sources for reliable information tend to have lived in their neighbourhood for a long time and to be more engaged in neighbourhood activities than those who reach out to fewer sources. Those who rely on secular community organisations tend to mistrust science, experts and local officials. Those who rely on faith-based organisations are much more trusting of local officials but are even less trusting of science and experts than their counterparts. The implications of these results for building and sustaining community organisations are discussed.     

Bedding and seasonal effects on chemical and bacterial properties of feedlot cattle manure

Nutrients, soluble salts, and pathogenic bacteria in feedlot-pen manure have the potential to cause pollution of the environment. A three-year study (1998-2000) was conducted at a beef cattle (Bos taurus) feedlot in southern Alberta, Canada to determine the effect of bedding material [barley (Hordeum vulgare L.) straw versus wood chips] and season on the chemical and bacterial properties of pen-floor manure. Manure was sampled for chemical content (N, P, soluble salts, electrical conductivity, and pH) and populations of four groups of bacteria (Escherichia coli, total coliforms, and total aerobic heterotrophs at 27 and 39 degrees C). More chemical parameters of manure were significantly (P < or = 0.05) affected by season (SO4, Na, Mg, K, Ca, sodium adsorption ratio [SAR], total C, NO3-N, NH4-N, total P, and available P) than by bedding (K, pH, total C, C to N ratio, NH4-N, and available P). Bedding had no significant (P > 0.05) effect on the four bacterial groups whereas season affected all four groups. Numbers of E. coli and total coliforms (TC) were significantly higher by 1.72 to 2.02 log10 units in the summer than the other three seasons, which was consistent with a strong positive correlation of E. coli and TC with air temperature. The low ratio of bedding to manure in the pens was probably the major cause of the lack of significant bedding effects. Bedding material and seasonal timing of cleaning feedlot pens and land application of manure may be a potential tool to manage nutrients, soluble salts, and pathogens in manure.     

Environmental hazards,neighbourhood quality,and neighbourhood environmental activism

summary This article presents a study of the association of perceived neighbourhood hazards, neighbourhood quality, and resident behavioural responses in two New Jersey, USA, communities that contain multiple technological hazards and populations that are relatively poor and racially homogeneous. The number of neighbourhood problems was highest among residents who engaged in activities to protect their neighbourhood and perceived that their neighbourhood was of poor or fair quality. These respondents perceived three to five times as many hazards as their counterparts who were passive and perceived that their neighbourhood was of excellent or good quality. Respondents' age, education, gender, type of residential unit occupied, and length of residence in the neighbourhood, were not associated with their evaluation of neighbourhood hazards. The authors argue that multiple-hazard neighbourhoods are excellent environments to learn about perception of hazards.Professor Michael Greenberg is Head of the Department of Urban Studies and Community Health where Professor Dona Schneider and Jim Parry are associates.     

The “data-rich but information-poor” syndrome in water quality monitoring

Water quality monitoring conducted routinely over time at fixed sites has been a part of most water quality management efforts for many years. It has been assumed that such monitoring plays a major role in management. However, the lack of routine data analysis, and reporting of information derived from such analysis, points up the fact that the exact nature of the role of routine, fixed-station monitoring is poorly defined.There is a need to very clearly define this role in the design of such systems if routine monitoring is to efficiently and effectively meet the information expectations placed on it. Design of routine monitoring systems will therefore have to consider not only the where, what, and when of sampling, but also why. A framework for including the why of monitoring in the design process is proposed and experience with using the framework in New Zealand is discussed.     

Regulated flushing in a gravel-bed river for channel habitat maintenance: A Trinity River fisheries case study

The operation of Trinity and Lewiston Dams on the Trinity River in northern California in the United States, combined with severe watershed erosion, has jeopardized the existence of prime salmonid fisheries. Extreme streamflow depletion and stream sedimentation below Lewiston have resulted in heavy accumulation of coarse sediment on riffle gravel and filling of streambed pools, causing the destruction of spawning, nursery, and overwintering habitat for prized chinook salmon (Salmo gairdnerii) and steelhead trout (Oncorhynchus tschawytscha). Proposals to restore and maintain the degraded habitat include controlled one-time remedial peak flows or annual maintenance peak flows designed to flush the spawning gravel and scour the banks, deltas, and pools. The criteria for effective channel restoration or maintenance by streambed flushing and scouring are examined here, as well as the mechanics involved.The liabilities of releasing mammoth scouring-flushing flows approximating the magnitude that preceded reservoir construction make this option unviable. The resulting damage to fish habitat established under the postproject streamflow regime, as well as damage to human settlements in the floodplain, would be unacceptable, as would the opportunity costs to hydroelectric and irrigation water users. The technical feasibility of annual maintenance flushing flows depends upon associated mechanical and structural measures, particularly instream maintenance dredging of deep pools and construction of a sediment control dam on a tributary where watershed erosion is extreme. The cost effectiveness of a sediment dam with a limited useful economic life, combined with perpetual maintenance dredging, is questionable.     

Non-South African ferrochrome prospects

In 1990, South Africa accounted for 43% of the 2 405 000t of ferrochrome produced worldwide. Even though world production has been very close to that level for more than five years, there is still approximately 1 million tlyear of excess capacity in the world today. Despite that huge overhang, when capacity closures are deducted from capacity additions, there was a net increase in capacity of approximately 450 000 t/year during the period 1989–91. Some of this additional capacity is intended to serve a domestic market and some to take advantage of very low production costs. Nevertheless, with so much excess capacity, the price of ferrochrome will remain under pressure for some time to come.     

Urban photochemical pollution in the Iberian Peninsula: Lisbon and Barcelona airsheds

Numerical simulations with photochemical transport models were independently performed for two domains situated in the Iberian Peninsula covering the Lisbon and Barcelona airsheds. Although the days chosen for simulation of the two cities are not the same, the synoptic situations in both cases, known as typical summertime situations, were similar, which allowed the development of typical mesoscale circulations, such as sea breezes and mountain and valley winds dominated by the Azores anticyclone. Emission inventories for the two areas were developed. The O3 concentrations recorded in both cities have a similar level. Nevertheless, O(x) values in Barcelona are higher than in Lisbon, which may, at a first glance, indicate an apparently more oxidant atmosphere in Barcelona. Photochemical modeling for the two cities has shown that the behavior of the circulatory patterns in both urban areas is rather different, which mainly has to do with the different strengths of the sea breeze and the topography, inducing an important offshore vertical layered dimension of pollutant transport in Barcelona versus an important inland horizontal transport in Lisbon.     

Description of sorbing tracers transport in fractured media using the lattice model approach

The transport of contaminants in fractured media is a complex phenomenon with a great environmental impact. It has been described with several models, most of them based on complex partial differential equations, that are difficult to apply when equilibrium and nonequilibrium dynamics are considered in complex boundaries. With the aim of overcoming this limitation, a combination of two lattice Bathnagar, Gross and Krook (BGK) models, derived from the lattice Boltzmann model, is proposed in this paper. The fractured medium is assumed to be a single fissure in a porous rock matrix. The proposed approach permits us to deal with two processes with different length scales: advection-dispersion in the fissure and diffusion within the rock matrix. In addition to the mentioned phenomena, sorption reactions are also considered. The combined model has been tested using the experimental breakthrough curves obtained by Garnier et al. (Garnier, J.M., Crampon, N., Préaux, C., Porel, G., Vreulx, M., 1985. Tra?age par 13C, 2H, I- et uranine dans la nappe de la craie sénonienne en écoulement radial convergent (Béthune, France). J. Hidrol. 78, 379-392.) giving acceptable results. A study on the influence of the lattice BGK models parameters controlling sorption and matrix diffusion on the breakthrough curves shape is included.