Retention and translocation of foliar applied 239,240Pu and 241Am, as compared to 137Cs and 85Sr, into bean plants (Phaseolus vulgaris)

Foliar transfer of 241Am, 239,240Pu, 137Cs and 85Sr was evaluated after contamination of bean plants (Phaseolus vulgaris) at the flowering development stage, by soaking their first two trifoliate leaves into contaminated solutions. Initial retentions of 241Am (27%) and 239,240Pu (37%) were higher than those of 137Cs and 85Sr (10-15%). Mean fraction of retained activity redistributed among bean organs was higher for 137Cs (20.3%) than for 239,240Pu (2.2%), 241Am (1%) or 85Sr (0.1%). Mean leaf-to-pod translocation factors (Bq kg(-1) dry weight pod/Bq kg(-1) dry weight contaminated leaves) were 5.0 x 10(-4) for 241Am, 2.7 x 10(-6) for 239,240Pu, 5.4 x 10(-2) for 137Cs and 3.6 x 10(-4) for 85Sr. Caesium was mainly recovered in pods (12.8%). Americium and strontium were uniformly redistributed among leaves, stems and pods. Plutonium showed preferential redistribution in oldest bean organs, leaves and stems, and very little redistribution in forming pods. Results for americium and plutonium were compared to those of strontium and caesium to evaluate the consistency of the attribution of behaviour of strontium to transuranium elements towards foliar transfer, based on translocation factors, as stated in two radioecological models, ECOSYS-87 and ASTRAL.     

Photosynthesis and growth responses of giant reed (Arundo donax L.) to the heavy metals Cd and Ni

Giant reed (Arundo donax L.) was grown on surface soil and irrigated with mixed heavy metal solutions of Cd(II) and Ni(II) to study the impact of these heavy metals on its growth and photosynthesis. The tested concentrations were 5, 50, and 100 ppm for each heavy metal against the control and resulted in high cadmium and nickel (DTPA extractable) concentrations in the top zone of the pot soil. The examined parameters, namely, stem height and diameter, number of nodes, fresh and dry weight of leaves, and net photosynthesis (Pn) were not affected, indicating that plants tolerate the high concentrations of Cd and Ni. As giant reed plants are very promising energy plants, they can be cultivated in contaminated soils to provide biomass for energy production purposes.     

Toxicities and tolerances of Cd, Cu, Pb and Zn in a primary producer (Isochrysis galbana) and in a primary consumer (Perna viridis)

Studies on toxicities and tolerances of cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) in the brown alga Isochrysis galbana and in the green-lipped mussel Perna viridis were conducted by short-term bioassays using endpoints growth production and mortality, respectively. The 5-day EC(50) and 24-h LC(50) of these heavy metals were determined in the brown alga and mussel, respectively. The EC(50) values calculated for the alga were 0.74 mg/l for Cd, 0.91 mg/l for Cu, 1.40 mg/l for Pb and 0.60 mg/l for Zn. The LC(50) values for the mussels were 1.53 mg/l for Cd, 0.25 mg/l for Cu, 4.12 mg/l for Pb and 3.20 mg/l for Zn. These LC(50) values were within the concentration ranges as reported by other authors who used P. viridis as the test organism. Based on these EC(50) and LC(50) values, the alga was most sensitive to Zn, followed by Cd, Cu and Pb while the mussel was most sensitive to Cu, followed by Cd, Zn and Pb. Differences in the trophic levels, metal handling strategies, biology and ecology of the primary producer (brown alga) and the primary consumer (mussel) are believed to be the plausible causes for the different toxicities and tolerances of the metals studied.     

The effects of FeCl3 on the distribution of the heavy metals Cd, Cu, Cr, and Zn in a simulated multimetal incineration system

Recognizing that waste-derived chlorine can enhance heavy metal emissions by forming volatile metallic chlorides during municipal solid waste (MSW) combustion, and that in Taiwan, FeCl3-containing sewage sludge may either be landfilled or coincinerated with other MSW, this study thus investigated the effects of FeCl3 on the speciation and partitioning of heavy metals in a multimetal incineration system by using a tubular furnace and FeCl3-spiked simulated wastes. The molar ratio of chlorine content to heavy metal content (referred to as the Cl/ M ratio), ranging from 3 to 200, was used as a parameter to evaluate the effects of chlorine on the movement of heavy metals between the incinerator discharges. Results indicate that speciation and partitioning were related to the affinity between the chlorine and the heavy metals and between chlorine and hydrogen in the combustion system. The effectiveness of increasing the Cl/M ratio to the formation potential of metallic chlorides and on the shift of heavy metals from the bottom ash to the fly ash and/or the flue gases was found to have in increasing order as follows: Zn>Cu>Cr, a phenomenon basically reflecting the volatility of the heavy metals and their chlorides formed during combustion.     

Distribution of Cd,Cu, Fe,Mn, Pb and Zn in selected tissues of juvenile whales stranded in the SE Gulf of California (Mexico)

With the aim of knowing the concentration and distribution of essential and nonessential metals in selected tissues of whales, analysis of Cd, Cu, Fe, Mn, Pb and Zn were carried out in kidney, liver and muscle of the gray whale Eschrichtius robustus and the sperm whale Physeter catodon. Whales were found stranded in the southeast Gulf of California. Individuals were in a juvenile stage; mean length of whales was 9.3 m for E. robustus and 7 m for P. catodon. Sequence of metal concentrations was Fe>Zn>Cu>Mn>Cd>Pb in E. robustus, and Fe>Zn>Cu>Cd>Mn>Pb in P. catodon. In E. robustus, highest concentrations of Cu, Mn, Pb and Zn (17.2, 19.6, 0.9 and 388 microg g(-1), respectively) were measured in liver, Cd (5.7 microg g(-1)) in kidney and Fe (1009 microg g(-1)) in muscle. In P. catodon, the highest levels of Cu, Fe and Pb (48.6, 5200 and 4.2 microg g(-1), respectively) were found in liver, Cd and Zn (94 and 183 microg g(-1)) in kidney and Mn (8 microg g(-1)) in muscle. Metal concentrations reported here were not considered to contribute to the stranding of specimens.     

Germination and growth effects of hexavalent chromium in Orocol TL (a corrosion inhibitor) on Phaseolus vulgaris

This research was designed to address the potential for germination and growth effects in bush beans (Phaseolus vulgaris L. var. Bush Blue Lake) from hexavalent chromium in Orocol TL, a proprietary chromated, zinc-phosphate compound added to DOE cooling water systems for corrosion inhibition. Studies were conducted at low and high Orocol TL concentrations in the soil by adjusting soil pH and the percent of organic matter. Germination effects were determined for seeds germinated in soils adjusted to differing pH ranges (4–4.5, 5–5.5, and 6.5–7), levels of organic matter (1.8%, 3%, and 5%), and Orocol TL amendments (control of 0, 10, and 500 μg/g chromium). Growth responses (effects) were determined from plants cultured in the same soil treatment combinations as described for the germination study. High levels (500 μg/g) of hexavalent chromium in soil (as Orocol TL) affected germination and growth, while a high level of organic matter significantly reduced chromium toxicity on germination. At lower chromium concentrations there was significant uptake by all plant parts, with a corresponding reduction in biomass of leaves. Consequently, adjustments of soil pH from 4.0 to 7.0 appear to have no significant effect on chromium uptake in plants. Increasing the organic matter level to 5%, while decreasing the toxicity of high chromium levels to germinating seed, did not affect chromium uptake.     

Comparison of transfer and effects of Cd on rats exposed in a short experimental snail-rat food chain or to CdCl2 dosed food

Transfer and toxic effects of two cadmium (Cd) forms, inorganic (CdCl2 dosed rat food) or organic (contaminated snail-based rat food) were studied in Wistar rat. Cd concentrations in rat food were 0 and 2.5 microg Cd g(-1) for both inorganic and organic forms and a high concentration of 100 microg Cd g(-1) was also tested for the inorganic form. Rats were exposed for four weeks to contaminated food. Both forms of Cd were bioavailable to rats, with a percentage of transfer from food to rats of around 1% for all contaminated groups. Cd concentrations in rat tissues increased with increasing Cd concentrations in the food. Rats fed with organic form of Cd accumulated significantly more Cd in the main organ for Cd toxicity, the kidney, than those eating the inorganic form. Survival was not affected for any rat group but a decrease in growth and food consumption was observed for the inorganic form. As a defence system against Cd toxicity, rats increased their metallothionein (MT) synthesis at the highest Cd concentration in the target organs (kidney, liver and small intestine) and even did the same at low Cd concentrations (2.5 microg Cd g(-1)) in the kidney. At this low Cd concentration, MT induction was lower in the small intestine of rats ingesting organic Cd than those ingesting inorganic Cd. Bioavailability of organic and inorganic forms of Cd was similar, but subsequent Cd distribution within organs was different. This quantification of the trophic transfer of both inorganic and organic forms of a toxicant is a basis for a better assessment of the fate and effects of chemicals in food webs.     

The influence of benzo(a)pyrene on the growth of wheat and corn

Corn seeds responded to soaking in aqueous solutions of benzo(a)pyrene with increased root growth. Growth stimulation decreased from 14% to 0 with increasing concentrations (0.0005–0.02 ppm), and with increasing soaking times (6 and 12 hr). Shoot growth and dry weights of shoots were not affected. Wheat did not respond as distinctly as corn to similar treatments. A decrease in the growth of shoots and roots with increasing BaP concentrations was not statistically significant.     

Heavy metals in fish (Solea vulgaris, Anguilla anguilla and Liza aurata) from salt marshes on the southern Atlantic coast of Spain

Comparisons were made of metal concentrations in water and sediment with those in the muscle and livers of three species of fish caught in four seawater reservoirs (two in the Odiel estuary and two in the Bay of Cádiz). The concentrations of a large number of metals in the water, sediment and fish were higher in the Odiel reservoirs than in those in Cádiz. We found high metal-enrichment factors in the livers as compared to muscle (over 100 for Fe and Cu and around 5 for Zn, Ni, Cd and Pb). The three fish species showed differences in metal content. For example, eels accumulated more metals in muscle and grey mullet in the liver. The metal levels found in muscle in the three species were below the legal limits for human consumption, although Cu in the liver was above the limit in the three species taken from the Odiel reservoirs, and Zn levels in liver were over the maximum in eels from one of the Odiel marshes. Significant correlations (p<0.05) were obtained for the levels of numerous metals in water, sediment and fish.     

Influence of alumina coating on characteristics and effects of SiO2 nanoparticles in algal growth inhibition assays at various pH and organic matter contents

Silica nanoparticles (NPs) belong to the industrially most important NP types. In a previous study it was shown that amorphous SiO(2) NPs of 12.5 and 27.0 nm are stable in algal growth inhibition assays and that their ecotoxic effects are related to NP surface area. Here, it was hypothesized and demonstrated that an alumina coating completely alters the particle-particle, particle-test medium and particle-algae interactions of SiO(2) NPs. Therefore, stability and surface characteristics, dissolution, nutrient adsorption and effects on algal growth rate of both alumina coated SiO(2) NPs and bare SiO(2) NPs in OECD algal test medium as a function of pH (6.0-8.6) and natural organic matter (NOM) contents (0-12 mg C/l) were investigated. Alumina coated SiO(2) NPs aggregated in all media and adsorbed phosphate depending on pH and NOM concentration. On the other hand, no aggregation or nutrient adsorption was observed for the bare SiO(2) NPs. Due to their positive surface charge, alumina coated SiO(2) NPs agglomerated with Pseudokirchneriella subcapitata. Consequently, algal cell density measurements based on cell counts were unreliable and hence fluorescent detection of extracted chlorophyll was the preferred method. Alumina coated SiO(2) NPs showed lower toxicity than bare SiO(2) NPs at concentrations ≥46 mg/l, except at pH 6.0. At low concentrations, no clear pH effect was observed for alumina coated SiO(2) NPs, while at higher concentrations phosphate deficiency could have contributed to the higher toxicity of those particles at pH 6.0-6.8 compared to higher pH values. Bare SiO(2) NPs were not toxic at pH 6.0 up to 220 mg/l. Addition of NOM decreased toxicity of both particles. For SiO(2) NPs the 48 h 20% effect concentration of 21.8 mg/l increased 2.6-21 fold and a linear relationship was observed between NOM concentration and effective concentrations. No effect was observed for alumina coated SiO(2) NPs in presence of NOM up to 1000 mg/l. All experiments point out that the alumina coating completely altered NP interactions. Due to the difference in surface composition the SiO(2) NPs, which had the smallest surface area, were more toxic to the alga than the alumina coated SiO(2) NPs. Hence, surface modification can dominate the effect of surface area on toxicity.     

Species-specific effects of P-solubilizing and N<Subscript>2</Subscript>-fixing bacteria on seedling growth of three salt-tolerant trees

Coastal afforestation suffers from low survival and slow growth due to harsh conditions and lack of robust seedlings. Inoculation of P-solubilizing bacteria (PSB) or N₂-fixing bacteria (NFB) are effective in promoting plant growth and thus potentially helpful for coastal afforestation. However, it remains unclear about the generality and specificity of these plant-growth-promoting-bacteria (PGPB) on the growth of salttolerant trees. We inoculated seedlings of two mangrove trees and one terrestrial salt-tolerant tree with pure cultures of PSB or mixed cultures of PSB and NFB. Plant biomass, height, base diameter and N and P concentrations were determined six months after bacterial inoculation. We found that inoculation of PGPB had an overall promoting effect on the seedling growth of three tree species, but the effects differed greatly (3–280% increase) among plant species and bacterial isolates or bacterial combinations. Only in the terrestrial tree, co-inoculations of PSB and NFB showed greater promoting effects than monocultures of PSB. Root: shoot ratios of seedlings were not changed by bacterial inoculation. Inoculation treatments moderately elevated N concentrations in shoots and roots and P concentrations only in roots of seedlings. Our results suggest that PGPB might have a general promoting effect on the seedling growth of salt-tolerant trees. Nevertheless, the magnitude of promoting effects and the comparative advantage of dual inoculation over single inoculation are species-specific. The generality and specificity of the plant-PGPB relationship are similar to the plantmycorrhizal symbiosis. In addition, tissue nutrient improvement might not be the main mechanism of the promoting effects by PGPB.     

Impacts of climate change and urban growth on the streamflow of the Milwaukee River (Wisconsin,USA)

Regional Environmental Change - Hydrological impact studies of climate change increasingly take land use changes into account. However, the Midwestern USA is still understudied in this context....     

Structure and dynamics of marginal Gymnadenia conopsea (L.) R. Br. (Orchidaceae) populations on limestones in the northeast of European Russia

Data are presented on the abundance, structure, and dynamics of hemipopulations of G. conopsea protocorms and autotrophic individuals at the northern boundary of the species range. The dynamics of ontogenetic structure of G. conopsea cenopopulations have a fluctuating pattern. Their response to adverse weather conditions is manifested in short-term reduction of density and increase in cenopopulation ageness in subsequent years. Deterioration of growing conditions in a series of ecotopes is accompanied by an increase in the proportion of young individuals, which allows the species to level off the impact of adverse weather factors on population size.     

Biomorphology and ontogeny of Gymnadenia conopsea (L.) R. Br. (Orchidaceae) in marginal populations on limestones in the northeast of European Russia

The life form of G. conopsea (short-lived perennial with annual vegetative renewal) makes it possible to combine the long-term, complete ontogeny and polycarpy of the genet with the short life span and monocarpy of individual daughter ramets. Annual changes in the structural organization of daughter individuals allow the plants to adapt to changing environmental conditions and retain the territory they have occupied. Organismal mechanisms providing for the sustainable development of G. conopsea plants in marginal populations are considered in the context of the concept of multivariant plant ontogeny.     

Impacts of elevated atmospheric CO(2) on forest trees and forest ecosystems: knowledge gaps

Atmospheric CO(2) is rising rapidly, and options for slowing the CO(2) rise are politically charged as they largely require reductions in industrial CO(2) emissions for most developed countries. As forests cover some 43% of the Earth's surface, account for some 70% of terrestrial net primary production (NPP), and are being bartered for carbon mitigation, it is critically important that we continue to reduce the uncertainties about the impacts of elevated atmospheric CO(2) on forest tree growth, productivity, and forest ecosystem function. In this paper, I review knowledge gaps and research needs on the effects of elevated atmospheric CO(2) on forest above- and below-ground growth and productivity, carbon sequestration, nutrient cycling, water relations, wood quality, phenology, community dynamics and biodiversity, antioxidants and stress tolerance, interactions with air pollutants, heterotrophic interactions, and ecosystem functioning. Finally, I discuss research needs regarding modeling of the impacts of elevated atmospheric CO(2) on forests.Even though there has been a tremendous amount of research done with elevated CO(2) and forest trees, it remains difficult to predict future forest growth and productivity under elevated atmospheric CO(2). Likewise, it is not easy to predict how forest ecosystem processes will respond to enriched CO(2). The more we study the impacts of increasing CO(2), the more we realize that tree and forest responses are yet largely uncertain due to differences in responsiveness by species, genotype, and functional group, and the complex interactions of elevated atmospheric CO(2) with soil fertility, drought, pests, and co-occurring atmospheric pollutants such as nitrogen deposition and O(3). Furthermore, it is impossible to predict ecosystem-level responses based on short-term studies of young trees grown without interacting stresses and in small spaces without the element of competition. Long-term studies using free-air CO(2) enrichment (FACE) technologies or forest stands around natural CO(2) vents are needed to increase the knowledge base on forest ecosystem responses to elevated atmospheric CO(2). In addition, new experimental protocols need to continue to be developed that will allow for mature trees to be examined in natural ecosystems. These studies should be closely linked to modeling efforts so that the inference capacity from these expensive and long-term studies can be maximized.     

A multidisciplinary study on the effects of climate change in the northern Adriatic Sea and the Marche region (central Italy)

An integrated analysis of recent climate change (including atmosphere, sea and land), and social reaction and adaptation, was conducted in central Italy and the northern portion of the Adriatic Sea. The collected environmental data included meteorological, oceanographic, and river gauges stations, covering the time period 1961–2009. Social data included 800 questionnaires and interviews carried out on selected samples of residents, decision-makers, and emergency managers. The trend analysis of air temperature data detailed an overall increase in all seasons, whereas rainfall data showed decrease in winter, spring, and summer, and increase in autumn, influencing river flow changes. Marine data showed a warming of the water column after the year 1990, particularly relevant in the cold season. Surface salinity increased in spring and summer and strongly decreased in autumn and also in winter (due to the spreading over the basin of the increased autumnal river runoff). These changes, combined with anthropogenic effects, appear to influence the northern Adriatic marine environment and ecosystems. Impacts in the coastal areas are also evident inland; the analysis of Aridity index, and potential water deficit, suggests negative impacts in terms of soil deterioration and agricultural productivity, particularly in the area near the coastline. At the same time, the analysis of social data revealed awareness among local residents of these impacts and associated risks connected to climate change. Yet, this awareness is not currently translated into preventive and protective actions; among the main reasons for this delay is also ineffective information exchange among citizens, public administrators, and the scientific community.     

Intake of phthalates and di(2-ethylhexyl)adipate: results of the Integrated Exposure Assessment Survey based on duplicate diet samples and biomonitoring data

Phthalates are ubiquitous environmental chemicals with potential detrimental health effects. The purpose of our study was to quantify dietary intake of phthalates and of DEHA (Di-ethylhexyl adipate) using duplicate diet samples and to compare these data with the calculated data based on urinary levels of primary and secondary phthalate metabolites. 27 female and 23 male healthy subjects aged 14-60 years collected daily duplicate diet samples over 7 consecutive days. Overall, 11 phthalates were measured in the duplicates by GC/MS and LC/MS methods. Urinary levels of primary and secondary phthalate metabolites are also available. The median (95th percentile) daily intake via food was 2.4 (4.0) microg/kg b.w. (Di-2-ethylhexyl phthalate, DEHP), 0.3 (1.4) microg/kg b.w. (Di-n-butyl phthalate, DnBP), 0.6 (2.1) microg/kg b.w. (Di-isobutyl phthalate, DiBP) and 0.7 (2.2) microg/kg b.w. for DEHA. MEPH (Mono-2-ethylhexyl phthalate) was detectable only in minor concentrations in the samples, thus conversion of DEHP to MEHP and dietary intake of MEHP were negligible. When comparing back-calculated intake data of the DEHP metabolites with dietary DEHP intake from the day before significant correlations were observed for most of the metabolites. No correlation was found for DnBP and only a weak but significant correlation for DiBP. The median and 95th percentile daily dietary intake of all target analytes did not exceed the recommended tolerable daily intake. Our data indicated that food was the predominant intake source of DEHP, whilst other sources considerably contributed to the daily intake of DnBP and DiBP in an adult population.     

Variation in Morphophysiological Traits of Male and Female <Emphasis Type="Italic">Aporia crataegi</Emphasis> L. (Lepidoptera: Pieridae) Depending on the Timing of Adult Emergence

The correlation between the timing of adult emergence and variation in morphophysiological parameters of males and females has been analyzed in the black-veined white Aporia crataegi L. In 2013 to 2015, black-veined white butterflies were collected from a natural population in the south of Sverdlovsk oblast throughout the emergence period; at the same time, adult insects were reared from pupae in individual cages. Comparison of the field observations in nature and the results of rearing preimaginal stages has shown that the largest adults are the first to emerge, while the smallest are the last to emerge. This pattern holds true both for the parameters varying throughout the adult insect life (body weight and relative abdomen weight) and for the permanent characteristic of the “structural” size (wing area). The influence of protandry and food availability to caterpillars on the variation in the size of adult A. crataegi during the period of generation emergence is discussed.