Radioactive contamination of wood and its products

This paper presents research on radioactive contamination of the three most common kinds of wood in Croatia--beech, oak and fir as well as acorn. Gamma-spectrometric measurements carried out on the samples of bark and wood of beech, oak, fir and acorn have shown radioactivity contents ranging from 1.6 +/- 0.1 to 37.3 +/- 0.5 Bq/kg from deposited 137Cs, whose concentrations in the soil of Croatia have increased after the Chernobyl accident. Measurements have also shown the radioactivity originating from 40K and 214Bi, which are part of the natural composition of the soil. The distribution of the radionuclides in wood has been discussed, as well as the impact of radioactive contamination of wood by the artificial radionuclide 137Cs upon the forest ecosystem. According to the corresponding model, it has been calculated that a 10 h daily stay in a typical family house increases the annual radiation dose of the population, due to the deposited 137Cs in the structure or furniture, by 343 microSv.     

Impacts of climate change and climate variability on the competitiveness of wheat and beef cattle production in Emerald, north-east Australia.

Emerald, north-east Queensland, is at the northern margin of the wheat cropping region of Australia. The Emerald region was previously used predominantly for grazing beef cattle; however, cropping has developed in importance over the past 30 years. We use historical climate records (1890-1998) to simulate and compare wheat yields, grass production and live-weight gain (LWG) over time. The cropping expansion from the 1970s to the early 1990s has occurred in a unique period in the 108-year record with the highest average wheat yields, lowest wheat yield variability and the greatest relative productivity of wheat production against grass production. If this window of opportunity is a result of long-term climate variability, then cropping is likely to decline in the region as conditions return to those experienced earlier in the record. If this increase is related to climate change, then cropping is likely to persist in the region with productivity maintained at current levels particularly through the yield-enhancing effects of increased atmospheric CO2 concentrations. However, this persistence will be influenced by the frequencies of El Ni?o conditions that may increase with global warming. The high relative productivities experienced over the past few decades have probably biased producers' expectations, and applications for drought support need to take into account the longer-term perspective provided by this analysis. Nevertheless, the last 6 years have the lowest simulated mean LWG production on the record. The identification of poor production periods depended on the production element being addressed and the timescale involved.     

Integrated measures for preservation, restoration and improvement of the environmental conditions of the Lagoon Olho d'Água basin

The Lagoon Olho d'Água in Pernambuco State, Northeast Brazil has received increasing environmental concern due to significant stress from pollution in the catchment. The existing environmental problems are the result of great pressure from a broad range of human activities, especially in the last 10 years. Serious pollution exists mainly from some industrial and urban activities, which increased intensively after the eighties. There is a strong social and economical pressure for housing and construction near the lagoon, due to the available land nearby beaches and estuarine zone, and recently by growing tourism activities. Uncontrolled land use by low-income communities and the pressure for construction by developers have led to landfilling and to deterioration of water quality in the lagoon catchment. Improvement of the environmental conditions in the catchment needs integrated measures. Guidelines and some specific actions involving several institutions have been established and refer to sanitation and urban infrastructure as the main priorities. A main target is the construction of low-cost sewage system with smaller and decentralised treatment plants.     

The Use of Natural Taraxacum officinale Wigg. Populations for Assessing the State of Technogenically Disturbed Areas

Russian Journal of Ecology -     

Formation of Two Xylem Frost Injuries in One Annual Ring in Siberian Spruce under Conditions of Western Siberian Forest-Tundra

The phenomenon of the formation of two damaged xylem layers in one frost ring is described in Siberian spruce grown in western Siberian forest-tundra. Temperature conditions providing for the formation of pathological cell and tissue structures are determined. The relationship between the formation of double frost injuries and cold periods is demonstrated.     

Morphogenesis of the Procumbent Life Form in Siberian Stone Pine at the Timberline in the Western Sayan Mountains

The morphology and development are described for Siberian stone pine (Pinus sibiricaDu Tour) growing at the timberline in the Western Sayan Mountains. Throughout ontogeny, these plants have a short stem trailing in an approximately horizontal direction. Maximal longevity and viability are characteristic of basal branches, which are able to root and produce vegetative generations. This allows these plants to be classified with the procumbent tree life form, in which the clones of most adaptive genotypes not only survive under extreme environmental conditions, but can also reproduce vegetatively.     

Effect of Mountain Relief and Industrial Air Pollution on Biometric Characteristics of Pine Stands

The effect of mountain relief and industrial air pollution on biometric parameters of pine stands was studied. The empirical–statistical models of the dependence of biometric characteristics on the parameters of forest sites were developed using raster modeling and multivariate analysis. The possibility of predicting changes in the biometric parameters at any site on the basis of these models is shown.     

The cost-effectiveness of residential radon remediation programmes: assumptions about benefits stream profiles over time

A recent cost-effectiveness analysis of a residential radon remediation programme considered and highlighted many areas of uncertainty in the parameters chosen for the analysis. One assumption not challenged in the study was the benefits stream profile adopted. There are several different ways of loading the benefits in terms of life years into the cost-effectiveness model and several of these are explored and the results are reported in this study. The benefits profile depends upon the lead-time to cancer manifestation post environmental carcinogen (radon) exposure. The literature reviewed suggests that there are many options for loading benefits to radon-induced lung cancer prevention programmes. In this study, the alternative benefits stream profiles are explored and their implications for the cost-effectiveness ratio are examined. Adopting different benefits stream profiles to the model results in a range of cost-effectiveness ratios from 14912.90 pounds per life year gained to 52416.27 pounds per life year gained. The preferred model is reported where the life years gained are assumed to be equally distributed over the last 15 years of the 40-year time horizon of the analysis (Y25-40) and the corresponding cost-effectiveness ratio is 37,943 pounds per life year gained.     

Arsenic poisoning in groundwater: health risk and geochemical sources in Bangladesh

Of the 2508 water samples analyzed in 10 districts of Bangladesh, 51%, on an average, contained arsenic levels of 0.05 to 2.50 mg/l. 95% of nail, 96% of hair, and 94% of urine samples contained arsenic above the normal level. Approximately 3.58 million people out of a total of 17.92 million who are drinking water containing arsenic levels >0.20 mg/l are potentially exposed to high risk of health hazard. Eight thousand and five hundred arsenic patients are identified; they are suffering from various skin lesions, gangrene in leg, skin, lung, bladder, liver, and renal cancer. A big portion of the total population is highly vulnerable to various internal cancers. Lowest arsenic concentration in drinking water producing dermatological disease is found to be 0.103 mg/l. However, the exposure time to develop arsenicosis varies from case to case reflecting its dependence on arsenic level in drinking water and food, nutritional status, genetic variant of human being, and compounding factors. This study has determined the high intensity of fluorescent humic substances in drinking water containing elevated concentrations of arsenic and very low concentrations of heavy metals. The synergistic/antagonistic effect of fluorescent compounds present in drinking water may aggravate the toxicity of arsenic. Geochemical study suggests that arsenic may be released from both reductive dissolution of Fe and Mn (oxy)hydroxide and microbial oxidation of organic matter.     

Variability in background levels of surface soil radionuclides in the vicinity of the US DOE waste isolation pilot plant

Concentrations of radionuclides were measured in soils from a grid of locations surrounding the US Department of Energy Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico and from a grid on a reference site approximately 20 km southeast of the WIPP site. Each of the two grids has 16 sampling locations (grid nodes) systematically distributed within an area of 16.580 ha. Sampling was conducted prior to the arrival of the first waste shipment at WIPP. Thus, the 137Cs and 23,240Pu in the soil are expected to have been deposited as global fallout, although the Gnome Site, 8.8 km southwest of the WIPP, is also a potential source of 239,240Pu and fission products. The reference grid has significantly higher concentrations of fallout and natural radionuclides than the WIPP grid. Up to 80% of the total variability in radionuclide concentrations across the two grids is attributable to differences between grid nodes. Differences between replicates within a location account for 44-50% of the variability in concentrations of the uranium isotopes, but only 11-17% of the variability in the concentrations of the other radionuclides. Samples having similar abundance of radionuclides were spatially aggregated across the terrain. The activity concentrations of the radionuclides were strongly correlated with the concentrations of Al and Pb, and with the percentages of sand, silt and clay in the soil. Normalizing radionuclide concentrations to the concentration of Al or percent fine particles can help adjust for differences in soil textures among samples and facilitate the detection of gradients or temporal changes in soil concentrations.