Trace elemental characterization of fly ash

The purpose of this study was to determine heavy metal concentrations in ash samples taken from the filter of the gas cleaning system of biomass incinerators in Austria. Knowing the concentrations of heavy metals is important for the decision of further treatment or utilization of the ashes. The heavy metals contained in the ashes remain in the bottom ash of the incinerator or leave the incinerator with the off-gas and are collected in the off-gas filter. The amount of the metals in the collected fly ash depends on the composition of the input material. The aim of this study was to examine this influence and compare the results with literature data. For measurement, the fly ash samples were at first dissolved in a microwave digestion unit using nitric acid and hydrochloric acid. Afterwards, 20 metals were analyzed by inductively coupled plasma optical emission spectrometry. Al, Fe, Mg, Mn, and Zn were found in higher concentrations in the fly ash samples. The enrichment factor between the concentrations in the fly ash and the concentrations in the input material was on average in the range of 18.     

Genetic diversity and relatedness of the mangrove Rhizophora mangle L. (Rhizophoraceae) using amplified fragment polymorphism (AFLP) among locations in Florida, USA and the Caribbean

Rhizophora mangle L. is a widespread mangrove species in the Western Hemisphere. Mangrove habitat loss and their importance to coastal and reef ecosystems make greater understanding of their genetic structure useful for conservation and management. An amplified fragment polymorphism (AFLP) analysis was performed on samples from Florida and the Caribbean to discover the genetic structure present. R. mangle had variable genetic diversity not related to latitude; P ranged 7 %–92 %. Some other factor, perhaps human impact, has caused low genetic diversity in some populations. Across Florida R. mangle populations varied in genetic diversity with less diversity (G_st?=?0.195) and greater gene flow on the Atlantic coast (Nm =2.07) than on the Gulf coast (G_st?=?0.717, Nm?=?0.197). Gene flow between Caribbean islands was low (Nm?=?0.386) compared to continental populations (Nm?=?1.40), indicating that long distance dispersal is not common between islands. Analysis of molecular variance (AMOVA) analysis showed significant deviations from Hardy-Weinberg expectations at the level of region among subpopulations and overall genetic difference among subpopulations for R. mangle. One implication for management is that small continental populations and island populations may be genetically isolated and distinct from each other.     

ALTERNATIVES FOR GROUND WATER LAW CHANGE IN ARIZONA1

ABSTRACT: Western state water resources are drawing increasing attention because of prolonged drought, pound-water overdraft and an ever-increasing awareness of insufficient Colorado River water to supply a growing population and meet industrial demand. Arizona is no exception, and the alarming decline in ground-water levels has prompted the Arizona State Legislature to adopt legislation establishing the Ground-Water Management Study Commission to recommend legislative action by 1979. This paper summarizes Arizona's ground water legislative history and discusses possible alternatives for change. The authors address specific issues facing the State and offer a set of possible Commission recommendations.     

Environmental risk: Management strategies in the developing world

This paper describes a heuristic model which helps to relate a developing nation's environmental risk to the level of sophistication appropriate in adjusting management strategy to dealing with environmental hazards. The model takes into account three factors: the degree of risk, the stage of economic growth, and the sophistication of adjustment. The interrelationship of these factors is examined, and the role of international cooperation in establishing strategies is outlined.     

Trends in Water Chemistry in a Maple Forest on a Steep Slope

Year-to-year variation in SO₄ ^2-,NO₃ ^-, Ca²⁺, K⁺, and Mg²⁺concentrations in forest floor and mineral soil percolatefrom a forested, podzolic soil at the Turkey Lakes Watershedon the Precambrian Shield was assessed for monotonic trendsbetween 1986 and 1995. Our objective was to examine howrapidly ion concentrations in soil percolate equilibratedafter stabilization of SO₄ ^2- concentrations inprecipitation. Significant negative trends were detected inmonthly Ca²⁺, and Mg²⁺ concentrations in forestfloor and SO₄ ^2-, Ca²⁺, and Mg²⁺ inmineral soil percolate during the 10-year-period. Thedecline in Ca²⁺ and Mg²⁺ was greater than annualdecreases in SO₄ ^2- and NO₃ ^- in forestfloor percolate and proportional to the reduction inSO₄ ^2- in mineral soil percolate. Response ofmineral soil percolate to a 15 mol_c L^-1SO₄ ^2- decrease in wet-only precipitation between1985 and 1986 was a gradual decline in SO₄ ^2-concentration through 1995. The five-year meanSO₄ ^2- concentration in bulk precipitation, forestfloor percolate, and mineral soil percolate decreased 8, 9and 18 mol_c L^-1 from 1986–90 to 1991–95.Microbial (mineralization of organic S) and sorption(release from and/or retention in the pool of insolubleSO₄ ^2-) processes in the soil were logicalexplanations for the observed changes in SO₄ ^2- inmineral soil percolate.     

Air Quality Management in UK Local Authorities: Public Understanding and Participation

Science and technology are an integral part of informing public policy on air pollution and transport management. Expectations of science and technology by society and their use by air quality policy makers has led to increasing reliance upon this evidence to promote health and well-being. This can be seen, for example, in the setting of the UK national objectives for air pollutants based on exposure and health effects. This paper addresses three questions. It assesses, through the use of focus groups, the public perceptions of air pollution and the atmospheric dispersion model output from the Atmospheric Dispersion Modelling System-Urban. Then it assesses their understanding of this information and its current presentation to the layperson. Finally, it assesses how their perceptions and understanding influence their solutions to local air quality management in the London Borough of Camden. The results show that participants in the study struggled with the concept of air pollution outside their sphere of experience, and they did not understand the scientific basis or modelling used to inform local policy. This is partly a result of the way this information is presented. They did not relate the technological evidence to their opinions of acceptable solutions or they expressed reluctance to suggest specific options. It is proposed that a well-informed public would make comprehensive decisions on air quality based upon a broader range of factors, incorporating the scientific reasoning and technological information as well as emotive and socio-economic factors. A balance between science and technological understanding with the validity of local expertise will improve air quality policy making to the greater satisfaction of all stakeholders.     

Cardiovascular risk under electromagnetic exposure in physiotherapy

The aim of the study was to assess the long-term effects of electromagnetic radiation (EMR) on cardiovascular system of medical staff in physiotherapy. A number of 52 exposed subjects (4 male and 48 female; aged 47.3 ± 8.7 years), and a control group of 52 subjects, matched by sex and age, with similar job characteristics without EMR exposure were studied. The EMR exposure from devices emitting at 50 Hz, 150 kHz, 27.12 MHz, 2.45 GHz, and optical radiation was assessed. The relative values of EMR for the whole frequency range in each physiotherapy were calculated and the obtained quota was much larger than 1. The workload and psychosocial factors were evaluated, too. The cardiovascular risk factors arterial pressure, lipid profile, body mass index, waist/hip ratio, smoking, alcohol consumption, nutrition, family history of cardiovascular disease were studied. The incidence of hypertension was moderate with the studied physiotherapists (26.9% v.s. 23.8% control group). The total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly higher in the exposed group. The odds ratios indicate higher possibility of becoming dyslipidemic for the exposed to EMR subjects [for TC OR (95% CI) = 1.570 (1.048–2.351) and for LDL-C OR (95% CI) = 1.840 (1.158–2.924)]. In conclusion, our data show that the EMR exposure of the medical staff in physiotherapy could be associated with the adverse effects on cardiovascular system.