Long-term environmental problems of radioactively contaminated land

This paper examines the various sources of radiological land contamination; its extent; its impacts on man, agriculture, and the environment; countermeasures for mitigating exposures; radiological standards; alternatives for achieving land decontamination and cleanup; and possible alternatives for utilizing the land. The major potential sources of extensive long-term land contamination with radionuclides, in order of decreasing extent, are nuclear war, detonation of a single nuclear weapon (e.g. terrorist act), serious reactor accidents, and nonfission nuclear weapons accidents that disperse the nuclear fuels (termed) “broken arrows”). Over the long term, external radiation doses are dominated primarily by ¹³⁷Cs and internal radiation doses primarily by ⁹⁰Sr. Plutonium and the transuranic elements are also important, primarily because of their long half-lives and relatively high inhalation doses. Costs for cleanup of contaminated land are very high. For example, cleanup of the broken arrow in Palomares, Spain, was approximately $33,600 per hectare. If cleanup of agricultural land is impractical, alternative land uses might include production of fiber crops, seed-stock crops, or plant biomass for alcohol fuels, or diversion of the land from crop production. Conversion of cropland to pasture or rangeland takes benefit from the generally lower accumulation of radionuclides into animals products compared with plant products. Another alternative is to fence off the land and use it for production of timber. This alternative would allow for 25–100 y or more of radiological decay before recovery of the timber.     

Evaluation and ranking of restoration strategies for radioactively contaminated sites.

An international project, whose aim was the development of a transparent and robust method for evaluating and ranking restoration strategies for radioactively contaminated sites (RESTRAT), was carried out under the Fourth Framework of the Nuclear Fission Safety Programme of the EU. The evaluation and ranking procedure used was based on the principles of justification and optimisation for radiation protection. A multi-attribute utility analysis was applied to allow for the inclusion of radiological health effects, economic costs and social factors. Values of these attributes were converted into utility values by applying linear utility functions and weighting factors, derived from scaling constants and expert judgement. The uncertainties and variabilities associated with these utility functions and weighting factors were dealt with by a probabilistic approach which utilised a Latin Hypercube Sampling technique. Potentially relevant restoration techniques were identified and their characteristics determined through a literature review. The methodology developed by this project has been illustrated by application to representative examples of different categories of contaminated sites; a waste disposal site, a uranium tailing site and a contaminated freshwater river.     

Mapping large areas of radioactively contaminated land with a self adapted, handheld, GPS coupled, scintillation detector

In Belgium, during several decennia, a phosphate plant discharged radium chloride containing waste water into two small rivers. One of those is part of a hydrographically very complex ecosystem with lots of small tributaries and hundreds of hectares of flooding zones. Hence, the river banks and large parts of these flooding zones have become contaminated with radium, heavy metals and chlorides. During a foot campaign, using a home made portable data logging system, consisting of a commercial 2.5 kg NaI detector, a computer mouse sized GPS, and a small pocket PC, the radioactive contamination of about 600 ha of sometimes very rough terrain was measured and mapped. The resulting very detailed radium contamination maps shed a whole new light on the water flow patterns of the ecosystem. The apparatus can also be used for efficiently guiding sampling campaigns for investigating other types of contamination. The ground maps are also compared to existing maps from helicopter measurements, evaluating strengths and weaknesses from both methods.     

Short rotation coppice for revaluation of contaminated land.

When dealing with large-scale environmental contamination, as following the Chernobyl accident, changed land use such that the products of the land are radiologically acceptable and sustain an economic return from the land is a potentially sustainable remediation option. In this paper, willow short rotation coppice (SRC) is evaluated on radiological, technical and economic grounds for W. European and Belarus site conditions. Radiocaesium uptake was studied in a newly established and existing SRC. Only for light-texture soils with low soil potassium should cultivation be restricted to soils with contamination levels below 100-370 kBq m-2 given the TFs on these soils (5 x 10(-4) and 2 x 10(-3) m2 kg-1) and considering the Belarus exemption limit for firewood (740 Bq kg-1). In the case of high wood contamination levels (> 1000 Bq kg-1), power plant personnel working in the vicinity of ash conveyers should be subjected to radiation protection measures. For appropriate soil conditions, potential SRC yields are high. In Belarus, most soils are sandy with a low water retention, for which yield estimates are too low to make production profitable without irrigation. The economic viability should be thoroughly calculated for the prevailing conditions. In W. Europe, SRC production or conversion is not profitable without price incentives. For Belarus, the profitability of SRC on the production side largely depends on crop yield and price of the delivered bio-fuel. Large-scale heat conversion systems seem the most profitable and revenue may be considerable. Electricity routes are usually unprofitable. It could be concluded that energy production from SRC is potentially a radiologically and economically sustainable land use option for contaminated agricultural land.     

Representing large-scale land acquisitions in land use change scenarios for the Lao PDR

Regional Environmental Change - Agricultural large-scale land acquisition (LSLA) is a process that is currently not captured by land change models. We present a novel land change modeling approach...     

Towards a roadmap for sustainable land use in Europe

Regional Environmental Change -     

Climate change, drought risk and land capability for agriculture: implications for land use in Scotland

Land capability classification systems define and communicate biophysical limitations on land use, including climate, soils and topography. They can therefore provide an accessible format for both scientists and decision-makers to share knowledge on climate change impacts and adaptation. Underlying such classifications are complex interactions that require dynamic spatial analysis, particularly between soil and climate. These relationships are investigated using a case study on drought risk for agriculture in Scotland, which is currently considered less significant than wetness-related issues. The impact of drought risk is assessed using an established empirical system for land capability linking indicator crops with water availability. This procedure is facilitated by spatial interpolation of climate and soil profile data to provide soil moisture deficits and plant available water on a regular 1-km grid. To evaluate potential impacts of future climate change, land capability classes are estimated using both large-scale ensemble (multi-simulation) data from the HadRM3 regional climate model and local-scale weather generator data (UKCP09) derived from multiple climate models. Results for the case study suggest that drought risk is likely to have a much more significant influence on land use in the future. This could potentially act to restrict the range of crops grown and hence reduce land capability in some areas unless strategic-level adaptation measures are developed that also integrate land use systems and water resources with the wider environment.     

Sea-to-land transfer of technetium-99 through the use of contaminated seaweed as an agricultural soil conditioner

The use of seaweed as an agricultural soil conditioner gives rise to a potential pathway for the transfer of Technetium-99 ((99)Tc) from marine to terrestrial ecosystems and thence to man. However, to date there is little information on the extent of the release of (99)Tc from seaweed into soil and the mechanisms involved. This pot experiment has shown that (99)Tc is released fairly rapidly from Fucus vesiculosus into a sandy coastal soil. Despite low temperature conditions, 60% of the (99)Tc added with the seaweed had accumulated in the soil 15 weeks after addition. Concurrent CO(2) monitoring (used as a measure of microbial decomposition or catabolism) suggested that the initial (99)Tc release (up to 40% in the first 8 weeks) was due to leaching from the seaweed and that microbial decomposition was responsible for the release of the remaining (99)Tc in the latter phase (12-15 weeks).     

Current practices and challenges for modelling past and future land use and land cover changes in mountainous regions

Regional Environmental Change -     

A review of regulatory decisions for environmental protection: part II - the case-study of contaminated land management in Portugal

This paper provides a case-study analysis of the challenges in the implementation of national soil policies, which was developed by the authors in Part I of the review of regulatory decisions for environmental protection [Rodrigues SM, Pereira ME, Ferreira da Silva E, Hursthouse A, Duarte AC. A review of regulatory decisions for environmental management: Part I-challenges in the implementation of national soil policies. Environ Int 2009. doi:10.1016/j.envint.2008.08.007]. The Portuguese case was selected as a case-study since specific regulatory decisions for contaminated land management are still in the early stages of development. Given the gap between the situation at the EU level and the state of Portuguese soil policy development, it is of merit to consider national contaminated land policy regimes already in place within the EU and to see if these provide a suitable basis to define the main challenges and research needs for the implementation of a Portuguese contaminated land management strategy. A framework combining the D-P-S-I-R (drivers-pressures-sources-impacts-responses) structure of policy evaluation with the Source-Pathway-Receptor approach to health risk assessment is proposed to derive an effective regulatory framework for managing contaminated land in Portugal, using available information and only to develop new data and research where knowledge gaps exist. Funding site clean-up and assigning liability were identified as relevant factors currently hampering site remediation. Most relevant research needs for the development of contaminated land management practices in Portugal are those associated to the definition of a risk assessment framework and setting guidelines for the evaluation of risks posed to both humans and ecosystems. Other relevant and innovative features are the integration of soil function analysis into site investigations and the definition of a framework that combines risk assessment with soil function analysis. The analysis of the Portuguese case also provides insight into the discussions needed for the effective development of regulatory decisions for contaminated land management in countries with no history of implementing specific soil policies.     

Protein futures for Western Europe: potential land use and climate impacts in 2050

Multiple production and demand side measures are needed to improve food system sustainability. This study quantified the theoretical minimum agricultural land requirements to supply Western Europe with food in 2050 from its own land base, together with GHG emissions arising. Assuming that crop yield gaps in agriculture are closed, livestock production efficiencies increased and waste at all stages reduced, a range of food consumption scenarios were modelled each based on different ‘protein futures’. The scenarios were as follows: intensive and efficient livestock production using today’s species mix; intensive efficient poultry–dairy production; intensive efficient aquaculture–dairy; artificial meat and dairy; livestock on ‘ecological leftovers’ (livestock reared only on land unsuited to cropping, agricultural residues and food waste, with consumption capped at that level of availability); and a ‘plant-based eating’ scenario. For each scenario, ‘projected diet’ and ‘healthy diet’ variants were modelled. Finally, we quantified the theoretical maximum carbon sequestration potential from afforestation of spared agricultural land. Results indicate that land use could be cut by 14–86 % and GHG emissions reduced by up to approximately 90 %. The yearly carbon storage potential arising from spared agricultural land ranged from 90 to 700 Mt CO₂ in 2050. The artificial meat and plant-based scenarios achieved the greatest land use and GHG reductions and the greatest carbon sequestration potential. The ‘ecological leftover’ scenario required the least cropland as compared with the other meat-containing scenarios, but all available pasture was used, and GHG emissions were higher if meat consumption was not capped at healthy levels.     

Marginal land use and value characterizations in Lagos: untangling the drivers and implications for sustainability

Lagos, the leading African megacity, is a coastal city located in creeks and riparian environment. In all parts of the city, transactions in marginal lands—riparian or water-logged areas—are increasingly becoming more noticeable. However, while previous studies have focused upon normal land transactions, the dynamics of land uses in marginal regions remain largely unexplained. Information on the dynamics of informal land transactions in the marginal regions of Lagos city is important for urban sustainability. This study therefore interrogates the attributes, uses, values and drivers of marginal land in Lagos using generalized linear model (GLM). Findings show that the predominant land use in marginal areas of Lagos is residential, majority of the lands are less than full plot size, close to river channels and less accessible, and the mean price ranges from NGN 3,156,908 to NGN 4,052,158. The GLM estimations show that distance to river channels/lagoon and buyer’s status have more significant influence on marginal land uses and values in Lagos. These findings have significant policy and practical implications for the city’s land use and sustainability. For urban and environmental sustainability, there is need to stem transactions in coastal marginal environments of Lagos for their obvious implications for climate change, flooding, erosion, sea incursion, building collapse, natural parks and public spaces, river channels and urban greening.     

Global-scale quantitative assessment for biodiversity on forest land use: applying the Global No Net Loss approach

Here we propose a method to quantitatively assess and examine Global No Net Loss (GNNL) of forest biodiversity on a global scale. The method produces a GNNL index of existing forest and enables future predictions of forest loss under different assumptions. The method tests the feasibility of the GNNL index and enables discussion of policy for future global scale sustainable forest management up to 2050. The GNNL index was estimated from an equation including forest areas per country per forest type (primary forest, secondary forest and plantation forest), diversity of forest ecosystem, and species density. Estimates derived from historical data revealed an approximate 7% reduction in GNNL index between 1990 and 2005. Predictions of the GNNL index until 2050 emphasize the importance of regenerating large portions of forests felled for agricultural land (or other uses) with secondary forests.     

Institutional capacity for long-term climate change adaptation: evidence from land use planning in Albay,Philippines

Mainstreaming climate change adaptation (CCA) into plans and programs is still a new approach in adaptation and thus there is limited information on how to operationalize it on-ground. This paper addresses this gap by investigating the challenges in mainstreaming CCA into the local land use plans in the province of Albay, Philippines. Specifically, this paper developed 20 quantitative “mainstreaming indicators” to assess the state-of-play and the challenges for local mainstreaming. These indicators were classified under three groupings, namely, the information, institutional, and resource capacities of systems. Qualitative analysis of the indicator scores suggested that developing the institutional capacities of local governments is crucial in the local mainstreaming process. Likewise, the results highlighted the “institutional issues” indicator as the primary barrier in operationalizing the approach. These institutional issues are: fragmented laws and regulations; overlapping policy requirements; and the lack of guidelines for mainstreaming CCA into the local land use plans. Meanwhile, the “leadership” indicator, as signified by a climate change champion in Albay, was evaluated as an opportunity for local mainstreaming. The champion effectively led the CCA efforts because the existing institutional mechanisms supported the champion’s capacity to influence the behavior of people and produce collective action towards CCA.     

Integrated simulation of land use,transportation and air quality: Policy tests for the San Francisco region

This paper describes a series of tests carried out with a comprehensive transportation, land use and air quality simulation system, which has been designed for planning application at the metropolitan or regional scale, within the framework of the U.S. Government's Clean Air legislation. The urban location portion of the system was developed at the University of Pennsylvania under the direction of S. H. Putman. The air quality sections incorporate models formulated in earlier studies. The system was tested with data from the San Francisco Bay area, for the period 1975–1980. The test policies included changes in regional transportation costs and population totals; local interventions in the transportation network; and controls on pollutant emissions from mobile and stationary sources. To assess net impacts, the outcomes predicted for each policy were compared with the outcomes predicted in a “benchmark”, or base run of the system. The tests showed that the system is sensitive to a broad range of air quality policies, and that it is capable of predicting important air quality consequences of transportation and land use policies. Some further development will be needed before the system can be used in practical planning situations, but there is little doubt as to the soundness of its central theoretical constructs and logical structure.     

Spatially differentiated management-revised discharge scenarios for an integrated analysis of multi-realisation climate and land use scenarios for the Elbe River basin

A spatially differentiated, management-revised projection of natural water availability up to 2053 was requested for a basin-wide scenario study about the impact of global change in the Elbe River basin. Detailed discharge and weather information of the recent years 1951–2003 were available for model calibration and validation. However, the straightforward “classic” approach of calibrating a hydrological model on observed data and running it with a climate scenario could not be taken, because most observed river runoffs in Central Europe are modified by human management. This paper reports how the problem was addressed and how a major projection bias could be avoided. The eco-hydrological model SWIM was set up to simulate the discharge dynamics on a daily time step. The simulation area of 134,890?km2 was divided into 2,278 sub-basins that were subdivided into more than 47,500 homogeneous landscape units (hydrotopes). For each hydrotope, plant growth and water fluxes were simulated while river routing calculation was based on the sub-basin structure. The groundwater module of SWIM had to be extended for accurate modelling of low flow periods. After basin-scale model calibration and revisions for known effects of lignite mining and water management, evapotranspiration and groundwater dynamics were adjusted individually for more than 100 sub-areas largely covering the entire area. A quasi-natural hydrograph was finally derived for each sub-area taking into account management data for the years 2002 (extremely wet) and 2003 (extremely dry). The validated model was used to access the effect of two climate change scenarios consisting of 100 realisations each and resembling temperature increases of 2 and 3?K, respectively. Additionally, four different land use scenarios were considered. In all scenario projections, discharge decreases strongly: The observed average discharge rate in the reference period 1961–1990 is 171?mm/a, and the scenario projections for the middle of the twenty-first century give 91–110?mm/a, mainly depending on the climate scenario. The area-averaged evapotranspiration increases only marginally within the scenario period, e.g., from about 570 to about 580?mm/a for the temperature increase of 2?K, while potential evapotranspiration increases considerably from about 780 to more than 900?mm/a. Both discharge and evapotranspiration changes vary strongly within the basin, correlating with elevation. The runoff coefficient that globally decreases from 0.244 to 0.160 in the 2?K scenario is locally governed primarily by land use; 68% of the variance of the decreases can be attributed to this factor.     

Changing land use/cover patterns and implications for sustainable environmental management in the Irangi Hills,central Tanzania

This article examines the changes in land-use/cover types in the Irangi Hills, central Tanzania during the last 45 years and how such changes have influenced environmental and agricultural sustainability in the area. The spatial and temporal changes of land-use/cover were analysed through aerial photographs interpretation. Local perceptions and experiences of changes were addressed through household interviews and field observations. Results from this study show that during the last 45 years open and wooded grasslands, and other tree-cover types covered about 40% of the land area, ranging from 29% in 1960 to 43–45% between 1977 and 1992. Also, during the same period both the total area and spatial distribution of cultivated fields varied greatly. The cultivated area increased from 31% in 1977 to 35% in 1992, mainly due to agricultural expansion into areas formerly used for grazing and in sandy watercourses that shrunk by 55% between 1977 and 1992. The spatial distribution of the different land-use/cover types is influenced by variations in the scale of soil erosion and soil-conservation initiatives implemented in the Irangi Hills since the early 1970s. However, with increasing pressure on the land, and the declining capacity of the soil conservation authority, sustaining agricultural production in the area remains a major challenge.     

Invariance of isotope ratios of lithogenic radionuclides: more evidence for their use as sediment source tracers

Activities of radionuclides in the 238U (230Th, 226Ra, 210Pb) and 232Th (232Th, 228Th, 228Ra) decay series were determined in sediments from an east Texas watershed and examined with isotope ratios and compared to particulate organic carbon (POC), % fines (<63 microm) and total concentrations of Al, Fe and Mn. The objective was to elucidate the presence or absence of relationships affecting the effectiveness of these radionuclides in modeling sediment transport. Strong positive correlations were observed between radionuclides and Mn (Th) and % fines (Ra and Th). Isotope ratios effectively reduce these influences, supporting the contention that isotope ratios offset extrinsic variability in terrestrial sediments. Strong associations of 210Pbxs (excess 210Pb) and 226Ra/230Th with POC agree with data from marine and terrestrial settings, indicating that the role of POC in isotope fractionation, transport and sequestration merits further investigation.     

Drying wastes from urban forestry as an option for their recovery and use in furniture and small wooden objects

The management of urban trees generates wood wastes that are commonly destined for use as firewood or compost. However, they can be used for more noble purposes such as making furniture or small wooden objects. This study aimed to investigate the drying and the shrinkage of the wood of seven typical urban afforestation species to determine the possibility of high-valued alternative use(s). Samples of these species (Cenostigma pluviosum (DC.) E. Gagnon & G.P. Lewis.; Delonix regia (Bojer ex Hook.) Raf.; Ficus benjamina L.; Licania tomentosa (Benth.) Fritsch; Nectandra megapotamica (Spreng.) Mez; Terminalia catappa L.; and Tipuana tipu (Benth.) Kuntze) underwent a drastic drying test in a laboratory oven at 103?±?2 °C, followed by weighing on an analytical balance to monitor the weight over a 24-h period, separated into four intervals of 4 h and one of 8 h. The drying rate, shrinkage and anisotropy coefficient of the species were evaluated. Wood wastes of the species C. pluviosum and L. tomentosa showed greater shrinkage during drying, with the lowest drying rates being found among the other species. F. benjamina, D. regia, N. megapotamica, T. catappa and T. tipu showed lower values of shrinkage and regular anisotropy coefficients close to ideal for application to make small wooden objects according to the characteristics of the species already present in the industrial market. The seven species thus have potential for application in the production of small wooden objects and furniture. This use is a potential alternative for environmental and social betterment.