Radioactivity in Future Phosphogypsum: New predictions based on estimates of 'Peak P' and rock phosphate resources.

Global food supplies currently depend on producing inorganic P fertilisers from a finite reserve of rock phosphate (RP). P fertilisers are themselves significant pollutants but their production from RP also leaves a phosphogypsum (PG) by-product that is sufficiently radioactive that its reuse is restricted. PG is mostly accumulated in open 'stacks' that make up a significant proportion of all Technologically Enhanced Naturally-Occurring Radioactive Material (TENORM) waste.

Developmental, Morphological and Physiological Traits in Plants Exposed for Five Generations to Chronic Low-Level Ionising Radiation.

The effects of ionising radiation (IR) on plants are important for environmental protection but also in agriculture, horticulture, space science, and plant stress biology. Much current understanding of the effects of IR on plants derives from acute high-dose studies but exposure to IR in the environment frequently occurs at chronic low dose rates. Chronic low dose-rate studies have primarily been field based and examined genetic or cytogenetic endpoints.

Predicting the Effects of Low Dose-Rate Ionizing Radiation on Redox Potential in Plant Cells.

During exposure of cells to acute high dose-rate ionizing radiation (IR), oxidants from the radiolysis of water can overwhelm antioxidant systems. Protecting flora from the effects of IR released from a nuclear industry of increasing global significance and managing the growth of plants during space flight both necessitate estimating the effects of chronic low dose-rate exposure to IR. In contrast to effects at acute high-dose rates, under chronic low dose-rate exposure it is subtle, progressive, long-term effects on antioxidant systems that it is important to estimate.

Ionizing Radiation, Higher Plants, and Radioprotection: From Acute High Doses to Chronic Low Doses.

Understanding the effects of ionizing radiation (IR) on plants is important for environmental protection, for agriculture and horticulture, and for space science but plants have significant biological differences to the animals from which much relevant knowledge is derived. The effects of IR on plants are understood best at acute high doses because there have been; (a) controlled experiments in the field using point sources, (b) field studies in the immediate aftermath of nuclear accidents, and (c) controlled laboratory experiments. A compilation of studies of the effects of IR on plants reveals that although there are numerous field studies of the effects of chronic low doses on plants, there are few controlled experiments that used chronic low doses.

Making the most of what we have: application of extrapolation approaches in radioecological wildlife transfer models.

We will never have data to populate all of the potential radioecological modelling parameters required for wildlife assessments. Therefore, we need robust extrapolation approaches which allow us to make best use of our available knowledge. This paper reviews and, in some cases, develops, tests and validates some of the suggested extrapolation approaches.

Thai visitors' expectations and experiences of explainer interaction within a science museum context.

In Western literature, there is evidence that museum explainers offer significant potential for enhancing visitors' learning through influencing their knowledge, content, action, behaviour and attitudes. However, little research has focused on the role of explainers in other cultural contexts. This study explored interactions between visitors and museum explainers within the setting of Thailand.

Soil to plant transfer of radionuclides: predicting the fate of multiple radioisotopes in plants.

Predicting soil-to-plant transfer of radionuclides is restricted by the range of species for which concentration ratios (CRs) have been measured. Here the radioecological utility of meta-analyses of phylogenetic effects on alkali earth metals will be explored for applications such as 'gap-filling' of CRs, the identification of sentinel biomonitor plants and the selection of taxa for phytoremediation of radionuclide contaminated soils. REML modelling of extensive CR/concentration datasets shows that the concentrations in plants of Ca, Mg and Sr are significantly influenced by phylogeny.

Phylogeny can be used to make useful predictions of soil-to-plant transfer factors for radionuclides.

Soil-to-plant transfer of radionuclides can be related to plant evolutionary history (phylogeny). For some species and radionuclides the effect is significant enough to be useful in predicting Transfer Factors (TFs). Here a Residual Maximum Likelihood (REML)-based mixed model and a recent plant phylogeny are used to compile data on soil-to-plant transfer of radionuclides and to show how the phylogeny can be used to fill gaps in TFs.

Phylogenetic variation in the tolerance and uptake of organic contaminants.

An investigation into the phylogenetic variation of plant tolerance and the root and shoot uptake of organic contaminants was undertaken. The aim was to determine if particular families or genera were tolerant of or accumulated organic pollutants. Data were collected from sixty-nine studies.

Species selection for phytoremediation of 36Cl/35Cl using angiosperm phylogeny and inter-taxa differences in uptake.

High concentrations of 35Cl and the radioisotope 36Cl (produced naturally by cosmic radiation and anthropogenically by U fission and the use of neutron sources) can be problematic in soil, but are potentially amenable to phytoremediation if appropriate plants can be found. Here, results are reported that might aid the selection of plants with unusually high or low uptake of 36Cl A residual maximum likelihood analysis was used to estimate, from 13 experiments, relative 36Cl uptake by 106 species across the angiosperm phylogeny. Nested analysis of variance, coded using a recent angiosperm phylogeny, showed that there were significant inter-species differences in 36Cl uptake and that species behavior was not independent; but linked through theirphylogeny.

Predicting inter-taxa differences in plant uptake of cesium-134/137.

For (134/137)Cs, and many other soil contaminants, research into transfer to plants has focused on particular crops and phytoremediation candidates, producing uptake data for a small proportion of all plant taxa. Despite the significance of differences in uptake between plant taxa, the capacity of soil-to-plant transfer models to predict them is currently confined to those taxa for which data exist, there being no method to predict uptake by other taxa. We used residual maximum likelihood (REML) analysis on data from experiments (including 89 plant taxa from China plus 32 phytoremediation candidates) together with data from the literature, to construct a database of relative (134/137)Cs concentrations in 273 plant taxa.

Topology: a novel method to describe branching patterns in Peronospora viciae colonies.

Topology provides a novel means to describe branching patterns and has not been applied to fungal colonies previously. For any branched structure, various topologies are possible, and these lie between two extremes, a herringbone pattern (main axis with primary laterals) and a dichotomous pattern (highly branched system). We applied topological methods to colonies of Peronospora viciae 48 h after inoculation of Pisum sativum leaves.

Soil availability, plant uptake and soil to plant transfer of 99Tc--a review.

The fission yield of 99Tc from 239Pu and 235U is similar to that of 137Cs or 90Sr and it is therefore an important component of nuclear weapons fall-out, nuclear waste and releases from nuclear facilities. There is particular current interest in 99Tc transfer from soil to plants for: (a) environmental impact assessments for terrestrial nuclear waste repositories, and (b) assessments of the potential for phytoextraction of radionuclides from contaminated effluent and soil. Vascular plants have a high 99Tc uptake capacity, a strong tendency to transport it to shoot material and accumulate it in vegetative rather than reproductive structures.

Phylogenetic variation in heavy metal accumulation in angiosperms.

•  The influence of phylogeny on shoot heavy metal content in plants was investigated and the hypothesis tested that traits impacting on the accumulation of cadmium, chromium, copper, nickel, lead and zinc in plant shoots are associated. •  Data suitable for comparative analyses were generated from a literature survey, using a residual maximum likelihood (REML) procedure. Both pair-wise regressions and principal components analyses (PCA) were performed on independent contrasts of shoot metal content.