A pilot survey of blood lead levels in various types of workers in the United Arab Emirates.

The aim of the present study is to determine the effect of blood lead on the health of industrial workers in United Arab Emirates (UAE). This is a cross-sectional pilot survey of blood lead levels (BLL) of 100 industrial workers (exposed) and 100 non-industrial workers (nonexposed), matched for age, sex and nationality selected from Al-Ain, Abu-Dhabi Emirate. Industrial workers had significantly higher mean of BLL (77.5+/-42.8 microg/dl and median 80.9 microg/dl) than non-industrial workers (19.8+/-12.3 microg/dl and median 11.0 microg/dl). In the present study, reported symptoms among industrial workers were strongly associated with BLL nausea/vomiting, muscular symptoms, dizziness, fatigue, irritability, memory disturbances, insomnia and allergic conjuctivitis, rhinitis and dermatitis. Furthermore, the present study revealed that industrial workers had higher prevalence of respiratory symptoms for phlegm, shortness of breath and diagnosed asthma. In conclusion, this study determined that occurrence of certain symptoms might be associated with lead exposure among industrial workers.     

Determination of causes of death in animal survival experiments

Life-span studies, using the laboratory mouse, are an efficient means for determining potential chronic toxicity of various materials. However, difficulties that affect the analysis of the data include (1) incomplete and missing observations due to canabilism or autolysis, (b) possible differences in overall mortality rate between treated and control populations that preclude assessments based upon observed final incidence, and (c) potential interaction between specific pathological states. Being aware of these difficulties does not eliminate their consequence, but careful attention to ascertaining the presence or absence of a disease state coupled with an assessment of its significance for each individual can allow greater confidence to be placed in data obtained from survival studies. The question of possible interaction between disease states is better approached experimentally by judicious use of serial killing to define age-specific disease prevalence.Many diseases are difficult to identify in animals as small as the mouse. At the other extreme, too much importance may be attributed to some disease states, not because of their lethality, but because of their ease of detection. One way to minimize the uncertainties introduced by conscious and unconscious observational bias is to adhere to a highly systematic tissue examination of every animal, regardless of condition of apparent cause of death. Through application of well-defined and stable diagnostic criteria a better appreciation can be obtained of the full spectrum of lethal and incidental pathologies observed in animals dying throughout the survival study.     

Effects of past sewage sludge additions on heavy metal availability in light textured soils: implications for crop yields and metal uptakes

The effect of heavy metal additions in past sewage sludge applications on soil metal availability and the growth and yield of crops was evaluated at two sites in the UK. At Gleadthorpe, sewage sludges enriched with salts of zinc (Zn), copper (Cu) and nickel (Ni) had been applied to a loamy sand in 1982 and additionally naturally contaminated Zn and Cu sludge cakes in 1986. At Rosemaund, sewage sludges naturally contaminated with Zn, Cu, Ni and chromium (Cr) had been applied in 1968-1971 to a sandy loam. From 1994 to 1997, the yields of both cereals and legumes at Gleadthorpe were up to 3 t/ha lower than the no-sludge control where total topsoil Zn and Cu concentrations exceeded 200 and 120 mg/kg, respectively, but only when topsoil ammonium nitrate extractable metal levels also exceeded 40 mg/kg Zn and 0.9 mg/kg Cu. At Rosemaund, yields were only decreased where total topsoil Cu concentrations exceeded 220 mg/kg or 0.7 mg/kg ammonium nitrate extractable Cu. These results demonstrate the importance of measuring extractable as well as total heavy metal concentrations in topsoils when assessing likely effects on plant yields and metal uptakes, and setting soil quality criteria.     

Effect of dissolved organic matter and bacteria on contaminant transport in riverbank filtration

A mathematical model for the transport of hydrophobic organic contaminants in an aquifer under simplistic riverbank filtration conditions is developed. The model considers a situation where contaminants are present together with dissolved organic matter (DOM) and bacteria. The aquifer is conceptualized as a four-phase system: two mobile colloidal phases, an aqueous phase, and a stationary solid phase. An equilibrium approach is used to describe the interactions of contaminants with DOM, bacteria, and solid matrix. The model is composed of bacterial transport equation and contaminant transport equation. Numerical simulations are performed to examine the contaminant transport behavior in the presence of DOM and bacteria. The simulation results illustrate that contaminant transport is enhanced markedly in the presence of DOM and bacteria, and the impact of DOM on contaminant mobility is greater than that of bacteria under examined conditions. Sensitivity analysis demonstrates that the model is sensitive to changes of three lumped parameters: K+1 (total affinity of stationary solid phase to contaminants), K+2 (total affinity of DOM to contaminants), and K+3 (total affinity of bacteria to contaminants). In a situation where contaminants exist simultaneously with DOM and bacteria, contaminant transport is mainly affected by a ratio of K+1/K+2/K+3, which can vary with changes of equilibrium distribution coefficient of contaminants and/or colloidal concentrations. In riverbank filtration, the influence of DOM and bacteria on the transport behavior of contaminants should be accounted to accurately predict the contaminant mobility.     

Forging New Directions in Science and Environmental Politics and Policy: How Can Co-operation, Deliberation and Decision be Brought Together?

Science, politics and environmental policy have for several years been encountering social and institutional as well as scientific challenges, national and international. The normative basis of all sciences is pressurised from three sides: by awareness of the public, who claims more transparency and sensibility from the scientific institutions regarding factual or possible impacts of science-based industrial progress; by the industries, which try to speed up and intensify the industrialisation of knowledge; and by the public policies, which want to see the sciences engaged in ways to mitigate unintended consequences of economic, ecological and social developments. At the same time, environmental policy is undergoing a tremendous sea change both in conceptual and practical matters. Since the Brundtland Report in 1987 and accelerated after UNCED 1992, environmental policy has been struggling to become a groundbreaking new paradigm for the capacity of resolving social and political issues as well. Any successful attempt to alter traditional institutional and mental structures in policy-making toward sustainability presupposes a renewed association of co-operation, deliberation and decision making. Results from theory of democracy, studies in science and technology, and evaluation studies in environmental policy and politics can be utilised for this context.     

Dynamics of Tree and Shrub Vegetation in the Eastern Sayan Mountain Tundra

Russian Journal of Ecology - Climate change entails shifts in the ranges of woody plants along both latitudinal and altitudinal gradients in the boreal forest biome. In this study,...     

Earthquake hazard assessment after Mexico (1985)

The 1985 Mexican earthquake ranks foremost amongst the major earthquake disasters of the twentieth century. One of the few positive aspects of the disaster is that it provided massive quantities of data that would otherwise have been unobtainable. Every opportunity should be taken to incorporate the findings from these data in earthquake hazard assessments. The purpose of this paper is to provide a succinct summary of some of the more important lessons from Mexico. It stems from detailed field investigations, and subsequent analyses, conducted by the author on the behalf of reinsurance companies.     

Emergency centers in Israel: A small community organizes to cope with war related crises*

This paper focuses on community-wide emergencies caused by war-related events in Lebanon at the beginning of June 1982. Mobilization for the "Peace for Galilee" campaign began on Friday, 4th June. Overnight, families were disrupted, husbands and sons were in danger, and within 24 hours there were notifications of casualities and deaths. Families in crisis became a widespread phenomenon. In Herzlia, as in many other communities, a new service - the Emergency Center - emerged under the auspices of the Ministry of Labor and Social Affairs and the Municipality. The authors describe this process of getting organized, the populations served, how the Center was staffed, the role of citizen volunteers, and the types of interventions used to help vulnerable families as well as soldiers home on leave. Stress is placed on the unique type of short-term co-operation achieved between social workers of the local Department of Social Welfare, the staff of the Department of Community Services (especially its Volunteer Bureau), the local liason officer of the Israel Defence Force, the municipal government, and public-spirited volunteers. Mention is made of conditions which made possible the activation of such a service within hours, of the Center's capacity to serve all segments of the population, and of how it was deactivated within a few weeks when the emergency ended. On the basis of lessons learned from this experience, the paper ends with a number of specific recommendations. The authors hope that such innovative forms of crisis-intervention will become part of the helping technology widely available at the community level in future years.     

How Many Species Are There in Brazil?

Abstract:  We produced estimates of the total number of species currently known and the total numbers predicted to occur in Brazil. Lists of species recorded in Brazil were obtained from specialists and the literature. For taxa lacking information on total known species, we produced estimates based on bootstrap resampling from a set of 87 taxa with checklists for Brazil and the world. The estimated proportion of Brazilian species was 9.5% of the world total (95% CI, 8.5 to 11.5%). From this we estimated a known Brazilian biota of 170,000 to 210,000 species. We used a similar procedure to estimate Brazil's total biota—known plus undiscovered. Based on 17 relatively well-known taxa, the average Brazilian share in the world's biota was estimated at 13.1% (CI 10.0 to 17.6%). Accordingly we estimated the country's total biota at 1.8 million species (CI 1.4 to 2.4 million). Given that the Neotropics is the least-studied major region of the world, these figures are still likely to be underestimates and hence may be taken as a lower bound of the actual proportion of the world's species that occur in Brazil. Scientists, policy makers, and citizens will find these numbers useful in appreciating the magnitude of the tasks involved in surveying, describing, and conserving the country's biota. The numbers also bring proposals and priorities into a more realistic perspective.